ai lecture

fix missing backgrounds when scroll view is actived responsively (fixes #3554 )
rebuild
2024-01-05 14:53:07 +08:00 · 2023-12-22 13:18:06 +01:00 · 2023-12-15 09:03:32 +01:00 · 2023-12-15 08:56:55 +01:00 · 2023-12-15 13:59:27 +08:00 · 2023-12-06 14:26:02 +01:00
131 changed files with 11335 additions and 12539 deletions
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -1,10 +1,9 @@
 ## Contributing
-
-Please keep the [issue tracker](http://github.com/hakimel/reveal.js/issues) limited to **bug reports**, **feature requests** and **pull requests**.
+Please keep the [issue tracker](https://github.com/hakimel/reveal.js/issues) limited to **bug reports**.


-### Personal Support
-If you have personal support or setup questions the best place to ask those are [StackOverflow](http://stackoverflow.com/questions/tagged/reveal.js).
+### General Questions and Support
+If you have questions about how to use reveal.js the best place to ask is in the [Discussions](https://github.com/hakimel/reveal.js/discussions). Anything that isn't a bug report should be posted as a dicussion instead.


 ### Bug Reports
@@ -12,11 +11,10 @@ When reporting a bug make sure to include information about which browser and op


 ### Pull Requests
+- Should be submitted from a feature/topic branch (not your master)
 - Should follow the coding style of the file you work in, most importantly:
  - Tabs to indent
  - Single-quoted strings
- Should be made towards the **dev branch**
- Should be submitted from a feature/topic branch (not your master)


 ### Plugins
--- a/.github/workflows/js.yml
+++ b/.github/workflows/js.yml
@@ -1,24 +1,31 @@
 name: tests

-on: [push]
+on:
+  - push
+
+permissions:
+  contents: read

 jobs:
  build:
-
    runs-on: ubuntu-latest

    strategy:
      matrix:
-        node-version: [10.x, 14.x, 16.x]
+        node-version:
+          - 18
+          - 20

    steps:
-    - uses: actions/checkout@v2
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
-      with:
-        node-version: ${{ matrix.node-version }}
-    - run: npm install
-    - run: npm run build --if-present
-    - run: npm test
-      env:
-        CI: true
+      - uses: actions/checkout@v4
+
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - run: npm install
+      - run: npm run build --if-present
+      - run: npm test
+        env:
+          CI: true
--- a/.gitignore
+++ b/.gitignore
@@ -8,5 +8,4 @@ out/
 log/*.log
 tmp/**
 node_modules/
-.sass-cache
-dist/*.map
+.sass-cache
--- a/.npmignore
+++ b/.npmignore
@@ -1,7 +1,5 @@
 /test
 /examples
 .github
-.gulpfile
 .sass-cache
 gulpfile.js
-CONTRIBUTING.md
--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-Copyright (C) 2020 Hakim El Hattab, http://hakim.se, and reveal.js contributors
+Copyright (C) 2011-2023 Hakim El Hattab, http://hakim.se, and reveal.js contributors

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
--- a/README.md
+++ b/README.md
@@ -1,28 +1,50 @@
 <p align="center">
  <a href="https://revealjs.com">
-  <img src="https://hakim-static.s3.amazonaws.com/reveal-js/logo/v1/reveal-black-text.svg" alt="reveal.js" width="450">
+  <img src="https://hakim-static.s3.amazonaws.com/reveal-js/logo/v1/reveal-black-text-sticker.png" alt="reveal.js" width="500">
  </a>
  <br><br>
  <a href="https://github.com/hakimel/reveal.js/actions"><img src="https://github.com/hakimel/reveal.js/workflows/tests/badge.svg"></a>
  <a href="https://slides.com/"><img src="https://s3.amazonaws.com/static.slid.es/images/slides-github-banner-320x40.png?1" alt="Slides" width="160" height="20"></a>
 </p>

-reveal.js is an open source HTML presentation framework. It enables anyone with a web browser to create fully featured and beautiful presentations for free. [Check out the live demo](https://revealjs.com/).
+reveal.js is an open source HTML presentation framework. It enables anyone with a web browser to create beautiful presentations for free. Check out the live demo at [revealjs.com](https://revealjs.com/).

-The framework comes with a broad range of features including [nested slides](https://revealjs.com/vertical-slides/), [Markdown support](https://revealjs.com/markdown/), [Auto-Animate](https://revealjs.com/auto-animate/), [PDF export](https://revealjs.com/pdf-export/), [speaker notes](https://revealjs.com/speaker-view/), [LaTeX support](https://revealjs.com/math/), [syntax highlighted code](https://revealjs.com/code/) and much more.
+The framework comes with a powerful feature set including [nested slides](https://revealjs.com/vertical-slides/), [Markdown support](https://revealjs.com/markdown/), [Auto-Animate](https://revealjs.com/auto-animate/), [PDF export](https://revealjs.com/pdf-export/), [speaker notes](https://revealjs.com/speaker-view/), [LaTeX typesetting](https://revealjs.com/math/), [syntax highlighted code](https://revealjs.com/code/) and an [extensive API](https://revealjs.com/api/).

-<h1>
-  <a href="https://revealjs.com/installation" style="font-size: 3em;">Get Started</a>
-</h1>
+---

-## Documentation
-The full reveal.js documentation is available at [revealjs.com](https://revealjs.com).
+Want to create reveal.js presentation in a graphical editor? Try <https://slides.com>. It's made by the same people behind reveal.js.

-## Online Editor
-Want to create your presentation using a visual editor? Try the official reveal.js presentation platform for free at [Slides.com](https://slides.com). It's made by the same people behind reveal.js.
+---

-## License
+### Sponsors
+Hakim's open source work is supported by <a href="https://github.com/sponsors/hakimel">GitHub sponsors</a>. Special thanks to:
+<div align="center">
+  <table>
+    <td align="center">
+      <a href="https://workos.com/?utm_campaign=github_repo&utm_medium=referral&utm_content=revealjs&utm_source=github">
+        <div>
+          <img src="https://user-images.githubusercontent.com/629429/151508669-efb4c3b3-8fe3-45eb-8e47-e9510b5f0af1.svg" width="290" alt="WorkOS">
+        </div>
+        <b>Your app, enterprise-ready.</b>
+        <div>
+          <sub>Start selling to enterprise customers with just a few lines of code. Add Single Sign-On (and more) in minutes instead of months.</sup>
+        </div>
+      </a>
+    </td>
+  </table>
+</div>

-MIT licensed
+---

-Copyright (C) 2011-2021 Hakim El Hattab, https://hakim.se
+### Getting started
+- 🚀 [Install reveal.js](https://revealjs.com/installation)
+- 👀 [View the demo presentation](https://revealjs.com/demo)
+- 📖 [Read the documentation](https://revealjs.com/markup/)
+- 🖌 [Try the visual editor for reveal.js at Slides.com](https://slides.com/)
+- 🎬 [Watch the reveal.js video course (paid)](https://revealjs.com/course)
+
+--- 
+<div align="center">
+  MIT licensed | Copyright © 2011-2023 Hakim El Hattab, https://hakim.se
+</div>
--- a/ai_lecture.md
+++ b/ai_lecture.md
@@ -0,0 +1,219 @@
+# 使用 MLP 识别 MNIST 手写数字
+
+主讲人：陈永源 2024-01-05
+
+Note:
+这个课程假设各位是有编程基础的机器学习小白，课程我会用直观的说明方式讲解机器学习原理及相关代码，不会涉及到过多数学上的细节。
+
+---
+
+## 课程简介
+
+在这个课程中，我们将会使用机器学习技术对手写数字图像进行分类，并包括
+
+- 定义 Pytorch MLP 模型
+- 使用数据集工具 DataLoader
+- 从零开始训练模型
+- 使用测试集评估模型
+
+Note:
+
+机器学习和传统程序设计的一个主要区别是
+你无需明确告诉计算机该如何去识别一个数字
+例如说6这个数字有一个竖线还有一个圈
+你不需告诉计算机这些规则
+机器学习能够自动从数据集中学到这些特征
+并且使用这些特征逐步训练它自己的神经网络，
+然后逐步提升它的准确性，
+这和我们人类或者是生物的学习方式是类似的。
+
+---
+
+## 神经网络简介
+
+神经网络这一概念在 1959 年被提出
+
+神经网络的核心概念来源于人脑的神经元网络，它由许多相互连接的节点（或称为"神经元"）组成。这些节点可以接收输入，并根据输入数据的不同对其进行加权处理，产生输出
+
+![nn](./media/nn.png)
+
+
+Demo: <https://playground.tensorflow.org/>
+
+Note:
+
+该术语于1959年由IBM的亚瑟·塞缪尔提出，当时他正在开发能够下跳棋的人工智能程序。半个世纪后，预测模型已经嵌入在我们日常使用的许多产品当中，执行两项基本工作：一是对数据进行分类，例如判断路上是否有其他车辆，或者患者是否患有癌症；二是对未来结果做出预测，如预测股票是否会上涨
+
+而神经网络，是机器学习中一类特别重要的算法模型。神经网络的核心概念来源于人脑的神经元网络，它由许多相互连接的节点（或称为"神经元"）组成。这些节点可以接收输入，并根据输入数据的不同对其进行加权处理，产生输出。特别是在处理像图像或自然语言这样的数据集时，神经网络显示出强大的功能，因为它可以自动提取和创建特征，而无需手动的特征工程。
+
+// 打开 demo
+
+这是一个非常直观的关于神经网络的演示。我们的任务是训练一个神经网络，对对右边的橙色和蓝色的点进行分类。
+用人眼看过去,我们很直观的就能发现
+蓝色的点在中间,外面一圈都是橙色的点
+但是我们要如何让计算机自己去学到这一个规则呢?
+这个时候,我们设计了有两个隐藏层的神经网络
+第一个隐藏层有四个神经元,第二个隐藏层有两个神经元
+同时使用两个线性特征作为输入。
+// 点开始学习，在一百多个迭代之后这个神经网络就能学习到我们期望的特征
+// 将鼠标放在各个神经元上，可以看到每个神经元所学习到的特征已经他们和其他神经元之间的权重。
+除此之外，我们还有一些参数可以调整，例如学习率，可以理解为神经网络学习的步长，太大的值可能会学习不到最优解，太小的值可能会花费更多的时间来学习甚至永远学不到最优解
+那么我们现在就开始手写数字分类的任务
+
+---
+
+## MNIST 手写数字数据集
+
+- 总共7000张图片，包含1000张测试集
+- 10个分类，代表0～9
+
+![mnist handwritting digits](./media/minst.jpg)
+
+Note:
+这个数字节里面包含了大约7000张图片，
+每一张图片都是这种黑白的手写数字，
+分别一共有10种，
+代表0~9
+这7000张图片里面有6000张是训练级,1000张是测试级，我们只会使用训练级的图片来训练神经网络，测试级的图片不会给神经网络看,但会在评估阶段用来测试神经网络的性能，这样就能看一下这个神经网络对于它没见过的图片是否也能做到准确分类，
+
+---
+
+## 神经网络结构
+
+1. 输入层大小: 28*28 = 784
+2. 隐藏层
+3. 输出层大小: 10
+
+![mlp structure](./media/mlp.jpeg)
+
+Note:
+这是我们即将设计的神经网络的结构
+它首先在输入层接受一个维度为28*28,也就是784这样一个大小的输入
+然后它会经过几个隐藏层,最终来到有10个神经元的输出层
+完成手写数字识别的分类任务
+
+---
+
+## 神经网络优化器
+
+优化器的作用是寻找最佳的参数组合以最小化损失函数
+
+![optimizer](./media/optimizer.gif)
+
+---
+
+## 代码讲解
+
+```python [0-6|8-14|16-20|18|19|22-27]
+import torch
+import torchvision
+import torch.nn as nn
+import torch.optim as optim
+from torchvision import datasets, transforms
+from torch.utils.data import DataLoader
+
+# 检查设备
+device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
+print('Using device:', device)
+# 设置超参数
+batch_size = 64
+learning_rate = 0.01
+epochs = 5
+
+# 设置数据集的变换
+transform = transforms.Compose([
+    transforms.ToTensor(),
+    transforms.Normalize((0,), (1,))
+])
+
+#加载数据集
+train_dataset = datasets.MNIST(root='./data_mlp', train=True, transform=transform, download=True)
+test_dataset = datasets.MNIST(root='./data_mlp', train=False, transform=transform, download=True)
+
+train_loader = DataLoader(train_dataset, batch_size=batch_size, shuffle=True)
+test_loader = DataLoader(test_dataset, batch_size=batch_size, shuffle=False)
+```
+
+Note:
+0-6 首先前后行我们载入一些需要用到的库 包括神经网络层,优化器,数据集需要用到的工具
+8-14
+然后初始化一些变量和参数
+这里用了一段代码自动判断CUDA显卡设备是否可用
+如果不可用的话则会选择CPU进行运算
+超参数的这个batch_size指的是每一次迭代中
+这个神经网络会一次性看多少张图片
+我们神经网络训练数据的时候不是一张图一张图的去看
+而是多张图放在一个批次里一起去看
+一般來說,Batch Size會盡可能設置得高,讓顯卡充分發揮它的並行運算能力,但是也要看情況具體分析,太高的話可能導致過擬核,影响模型最终的学习效果
+Learning Rate就是学习率,我们刚才讲过的
+指的是神经网络一次调整
+自身权重的步长
+数值越大,学得越快
+但是太大也可能会导致完全无法学习
+最后一个参数Epoch,代表需要学习整个数据集多少遍
+数字太小的话
+训练过程可能
+还没学到这些数字的特征就结束了 数字太大的话
+他可能会把数据集里面的所有噪音都记住 最终在测试级上表现效果不佳
+16-20
+Transform这一部分是告诉DataLoader
+我们应该在读取数据，在喂给神经网络之前，做哪一些格式变换操作
+18
+首先我们会把这些整数类型的数据转换成Tensor,也就是PyTorch能够进行运算的向量类型数据
+19
+然后我们会调用Normalize把它归一化成均值为0,标准差为1的数据。
+因为在某些数据集中，数值之间的尺度是不匹配的，例如我们分析身高和机票价格之间的关系，身高的单位是米，一个人身高撑死最多2米多，但是机票价格从几千到几万不等。这时候进行normalize就非常有必要。
+这样经过调整之后,输入神经网络的数值就在一个合理的范围之内
+
+---
+
+## 代码讲解
+
+```python [1-14|16-17|19-21|23-32|34-46]
+# 定义MLP模型
+class MLP(nn.Module):
+    def __init__(self):
+        super(MLP, self).__init__()
+        self.fc1 = nn.Linear(28*28, 512)
+        self.fc2 = nn.Linear(512, 256)
+        self.fc3 = nn.Linear(256, 10)
+
+    def forward(self, x):
+        x = x.view(-1, 28*28)
+        x = torch.relu(self.fc1(x))
+        x = torch.relu(self.fc2(x))
+        x = self.fc3(x)
+        return x
+
+# 创建模型实例并将其移到正确的设备上
+model = MLP().to(device)
+
+# 定义损失函数和优化器
+criterion = nn.CrossEntropyLoss()
+optimizer = optim.SGD(model.parameters(), lr=learning_rate)
+
+# 训练模型
+for epoch in range(epochs):
+    model.train()
+    for batch_idx, (data, target) in enumerate(train_loader):
+        data, target = data.to(device), target.to(device)
+        optimizer.zero_grad()
+        output = model(data)
+        loss = criterion(output, target)
+        loss.backward()
+        optimizer.step()
+
+# 测试模型
+model.eval()
+test_loss = 0
+correct = 0
+with torch.no_grad():
+    for data, target in test_loader:
+        data, target = data.to(device), target.to(device)
+        output = model(data)
+        test_loss += criterion(output, target).item()
+        pred = output.argmax(dim=1, keepdim=True)
+        correct += pred.eq(target.view_as(pred)).sum().item()
+
+test_loss /= len(test_loader.dataset)
+```
--- a/css/layout.scss
+++ b/css/layout.scss
@@ -16,7 +16,7 @@
 	box-sizing: border-box;
 }

-// Text that auto-fits it's container
+// Text that auto-fits its container
 .reveal .r-fit-text {
 	display: inline-block; // https://github.com/rikschennink/fitty#performance
 	white-space: nowrap;
--- a/css/print/paper.scss
+++ b/css/print/paper.scss
@@ -1,42 +1,30 @@
-/* Default Print Stylesheet Template
-   by Rob Glazebrook of CSSnewbie.com
-   Last Updated: June 4, 2008
-
-   Feel free (nay, compelled) to edit, append, and
-   manipulate this file as you see fit. */

@media print {
 	html:not(.print-pdf) {
-
-		background: #fff;
+		overflow: visible;
 		width: auto;
 		height: auto;
-		overflow: visible;

 		body {
-			background: #fff;
-			font-size: 20pt;
-			width: auto;
-			height: auto;
-			border: 0;
-			margin: 0 5%;
+			margin: 0;
 			padding: 0;
 			overflow: visible;
-			float: none !important;
 		}
+	}
+
+	html:not(.print-pdf) .reveal {
+		background: #fff;
+		font-size: 20pt;

-		.nestedarrow,
 		.controls,
-		.fork-reveal,
-		.share-reveal,
 		.state-background,
-		.reveal .progress,
-		.reveal .backgrounds,
-		.reveal .slide-number {
+		.progress,
+		.backgrounds,
+		.slide-number {
 			display: none !important;
 		}

-		body, p, td, li {
+		p, td, li {
 			font-size: 20pt!important;
 			color: #000;
 		}
@@ -49,7 +37,6 @@
 			letter-spacing: normal;
 		}

-		/* Need to reduce the size of the fonts for printing */
 		h1 { font-size: 28pt !important; }
 		h2 { font-size: 24pt !important; }
 		h3 { font-size: 22pt !important; }
@@ -74,18 +61,19 @@
 			margin: 0;
 			text-align: left !important;
 		}
-		.reveal pre,
-		.reveal table {
+		pre,
+		table {
 			margin-left: 0;
 			margin-right: 0;
 		}
-		.reveal pre code {
+		pre code {
 			padding: 20px;
 		}
-		.reveal blockquote {
+		blockquote {
 			margin: 20px 0;
 		}
-		.reveal .slides {
+
+		.slides {
 			position: static !important;
 			width: auto !important;
 			height: auto !important;
@@ -106,7 +94,7 @@

 			perspective-origin: 50% 50%;
 		}
-		.reveal .slides section {
+		.slides section {
 			visibility: visible !important;
 			position: static !important;
 			width: auto !important;
@@ -129,19 +117,24 @@
 			transform: none !important;
 			transition: none !important;
 		}
-		.reveal .slides section.stack {
+		.slides section.stack {
 			padding: 0 !important;
 		}
-		.reveal section:last-of-type {
+		.slides section:last-of-type {
 			page-break-after: avoid !important;
 		}
-		.reveal section .fragment {
+		.slides section .fragment {
 			opacity: 1 !important;
 			visibility: visible !important;

 			transform: none !important;
 		}
-		.reveal section img {
+
+		.r-fit-text {
+			white-space: normal !important;
+		}
+
+		section img {
 			display: block;
 			margin: 15px 0px;
 			background: rgba(255,255,255,1);
@@ -149,11 +142,11 @@
 			box-shadow: none;
 		}

-		.reveal section small {
+		section small {
 			font-size: 0.8em;
 		}

-		.reveal .hljs {
+		.hljs {
 			max-height: 100%;
 			white-space: pre-wrap;
 			word-wrap: break-word;
@@ -161,11 +154,11 @@
 			font-size: 15pt;
 		}

-		.reveal .hljs .hljs-ln-numbers {
+		.hljs .hljs-ln-numbers {
 			white-space: nowrap;
 		}

-		.reveal .hljs td {
+		.hljs td {
 			font-size: inherit !important;
 			color: inherit !important;
 		}
--- a/css/print/pdf.scss
+++ b/css/print/pdf.scss
@@ -5,7 +5,7 @@
 * https://revealjs.com/pdf-export/
 */

-html.print-pdf {
+html.reveal-print {
 	* {
 		-webkit-print-color-adjust: exact;
 	}
@@ -36,7 +36,6 @@ html.print-pdf {

 	.reveal pre code {
 		overflow: hidden !important;
-		font-family: Courier, 'Courier New', monospace !important;
 	}

 	.reveal {
@@ -71,6 +70,10 @@ html.print-pdf {
 		page-break-after: always;
 	}

+	.reveal .slides .pdf-page:last-of-type {
+		page-break-after: avoid;
+	}
+
 	.reveal .slides section {
 		visibility: visible !important;
 		display: block !important;
@@ -100,7 +103,6 @@ html.print-pdf {
 		box-shadow: none;
 	}

-
 	/* Slide backgrounds are placed inside of their slide when exporting to PDF */
 	.reveal .backgrounds {
 		display: none;
@@ -147,6 +149,7 @@ html.print-pdf {
 		display: block;
 		position: absolute;
 		font-size: 14px;
+		visibility: visible;
 	}

 	/* This accessibility tool is not useful in PDF and breaks it visually */
--- a/css/reveal.scss
+++ b/css/reveal.scss
@@ -1,3 +1,5 @@
+@use "sass:math";
+
 /**
 * reveal.js
 * http://revealjs.com
@@ -17,6 +19,7 @@ html.reveal-full-page {
 	height: 100%;
 	height: 100vh;
 	height: calc( var(--vh, 1vh) * 100 );
+	height: 100svh;
 	overflow: hidden;
 }

@@ -29,6 +32,18 @@ html.reveal-full-page {

 	background-color: #fff;
 	color: #000;
+
+	--r-controls-spacing: 12px;
+}
+
+// Force the presentation to cover the full viewport when we
+// enter fullscreen mode. Fixes sizing issues in Safari.
+.reveal-viewport:fullscreen {
+	top: 0 !important;
+	left: 0 !important;
+	width: 100% !important;
+	height: 100% !important;
+	transform: none !important;
 }


@@ -36,11 +51,14 @@ html.reveal-full-page {
 * VIEW FRAGMENTS
 *********************************************/

-.reveal .slides section .fragment {
-	opacity: 0;
-	visibility: hidden;
+.reveal .fragment {
 	transition: all .2s ease;
-	will-change: opacity;
+
+	&:not(.custom) {
+		opacity: 0;
+		visibility: hidden;
+		will-change: opacity;
+	}

 	&.visible {
 		opacity: 1;
@@ -52,7 +70,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.grow {
+.reveal .fragment.grow {
 	opacity: 1;
 	visibility: inherit;

@@ -61,7 +79,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.shrink {
+.reveal .fragment.shrink {
 	opacity: 1;
 	visibility: inherit;

@@ -70,7 +88,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.zoom-in {
+.reveal .fragment.zoom-in {
 	transform: scale( 0.1 );

 	&.visible {
@@ -78,7 +96,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.fade-out {
+.reveal .fragment.fade-out {
 	opacity: 1;
 	visibility: inherit;

@@ -88,7 +106,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.semi-fade-out {
+.reveal .fragment.semi-fade-out {
 	opacity: 1;
 	visibility: inherit;

@@ -98,7 +116,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.strike {
+.reveal .fragment.strike {
 	opacity: 1;
 	visibility: inherit;

@@ -107,7 +125,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.fade-up {
+.reveal .fragment.fade-up {
 	transform: translate(0, 40px);

 	&.visible {
@@ -115,7 +133,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.fade-down {
+.reveal .fragment.fade-down {
 	transform: translate(0, -40px);

 	&.visible {
@@ -123,7 +141,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.fade-right {
+.reveal .fragment.fade-right {
 	transform: translate(-40px, 0);

 	&.visible {
@@ -131,7 +149,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.fade-left {
+.reveal .fragment.fade-left {
 	transform: translate(40px, 0);

 	&.visible {
@@ -139,8 +157,8 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.fade-in-then-out,
-.reveal .slides section .fragment.current-visible {
+.reveal .fragment.fade-in-then-out,
+.reveal .fragment.current-visible {
 	opacity: 0;
 	visibility: hidden;

@@ -150,7 +168,7 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.fade-in-then-semi-out {
+.reveal .fragment.fade-in-then-semi-out {
 	opacity: 0;
 	visibility: hidden;

@@ -165,32 +183,32 @@ html.reveal-full-page {
 	}
 }

-.reveal .slides section .fragment.highlight-red,
-.reveal .slides section .fragment.highlight-current-red,
-.reveal .slides section .fragment.highlight-green,
-.reveal .slides section .fragment.highlight-current-green,
-.reveal .slides section .fragment.highlight-blue,
-.reveal .slides section .fragment.highlight-current-blue {
+.reveal .fragment.highlight-red,
+.reveal .fragment.highlight-current-red,
+.reveal .fragment.highlight-green,
+.reveal .fragment.highlight-current-green,
+.reveal .fragment.highlight-blue,
+.reveal .fragment.highlight-current-blue {
 	opacity: 1;
 	visibility: inherit;
 }
-	.reveal .slides section .fragment.highlight-red.visible {
+	.reveal .fragment.highlight-red.visible {
 		color: #ff2c2d
 	}
-	.reveal .slides section .fragment.highlight-green.visible {
+	.reveal .fragment.highlight-green.visible {
 		color: #17ff2e;
 	}
-	.reveal .slides section .fragment.highlight-blue.visible {
+	.reveal .fragment.highlight-blue.visible {
 		color: #1b91ff;
 	}

-.reveal .slides section .fragment.highlight-current-red.current-fragment {
+.reveal .fragment.highlight-current-red.current-fragment {
 	color: #ff2c2d
 }
-.reveal .slides section .fragment.highlight-current-green.current-fragment {
+.reveal .fragment.highlight-current-green.current-fragment {
 	color: #17ff2e;
 }
-.reveal .slides section .fragment.highlight-current-blue.current-fragment {
+.reveal .fragment.highlight-current-blue.current-fragment {
 	color: #1b91ff;
 }

@@ -247,22 +265,20 @@ $controlsArrowAngleActive: 36deg;

@mixin controlsArrowTransform( $angle ) {
 	&:before {
-		transform: translateX(($controlArrowSize - $controlArrowLength)/2) translateY(($controlArrowSize - $controlArrowThickness)/2) rotate( $angle );
+		transform: translateX(($controlArrowSize - $controlArrowLength)*0.5) translateY(($controlArrowSize - $controlArrowThickness)*0.5) rotate( $angle );
 	}

 	&:after {
-		transform: translateX(($controlArrowSize - $controlArrowLength)/2) translateY(($controlArrowSize - $controlArrowThickness)/2) rotate( -$angle );
+		transform: translateX(($controlArrowSize - $controlArrowLength)*0.5) translateY(($controlArrowSize - $controlArrowThickness)*0.5) rotate( -$angle );
 	}
 }

 .reveal .controls {
-	$spacing: 12px;
-
 	display: none;
 	position: absolute;
 	top: auto;
-	bottom: $spacing;
-	right: $spacing;
+	bottom: var(--r-controls-spacing);
+	right: var(--r-controls-spacing);
 	left: auto;
 	z-index: 11;
 	color: #000;
@@ -300,11 +316,11 @@ $controlsArrowAngleActive: 36deg;
 		left: 0;
 		width: $controlArrowLength;
 		height: $controlArrowThickness;
-		border-radius: $controlArrowThickness/2;
+		border-radius: $controlArrowThickness*0.5;
 		background-color: currentColor;

 		transition: all 0.15s ease, background-color 0.8s ease;
-		transform-origin: floor(($controlArrowThickness/2)*10)/10 50%;
+		transform-origin: math.div(floor(($controlArrowThickness*0.5)*10), 10) 50%;
 		will-change: transform;
 	}

@@ -326,7 +342,7 @@ $controlsArrowAngleActive: 36deg;

 	.navigate-left {
 		right: $controlArrowSize + $controlArrowSpacing*2;
-		bottom: $controlArrowSpacing + $controlArrowSize/2;
+		bottom: $controlArrowSpacing + $controlArrowSize*0.5;
 		transform: translateX( -10px );

 		&.highlight {
@@ -336,7 +352,7 @@ $controlsArrowAngleActive: 36deg;

 	.navigate-right {
 		right: 0;
-		bottom: $controlArrowSpacing + $controlArrowSize/2;
+		bottom: $controlArrowSpacing + $controlArrowSize*0.5;
 		transform: translateX( 10px );

 		.controls-arrow {
@@ -349,7 +365,7 @@ $controlsArrowAngleActive: 36deg;
 	}

 	.navigate-up {
-		right: $controlArrowSpacing + $controlArrowSize/2;
+		right: $controlArrowSpacing + $controlArrowSize*0.5;
 		bottom: $controlArrowSpacing*2 + $controlArrowSize;
 		transform: translateY( -10px );

@@ -359,7 +375,7 @@ $controlsArrowAngleActive: 36deg;
 	}

 	.navigate-down {
-		right: $controlArrowSpacing + $controlArrowSize/2;
+		right: $controlArrowSpacing + $controlArrowSize*0.5;
 		bottom: -$controlArrowSpacing;
 		padding-bottom: $controlArrowSpacing;
 		transform: translateY( 10px );
@@ -494,7 +510,9 @@ $controlsArrowAngleActive: 36deg;
 // Edge aligned controls layout
@media screen and (min-width: 500px) {

-	$spacing: 0.8em;
+	.reveal-viewport {
+		--r-controls-spacing: 0.8em;
+	}

 	.reveal .controls[data-controls-layout="edges"] {
 		& {
@@ -514,26 +532,26 @@ $controlsArrowAngleActive: 36deg;

 		.navigate-left {
 			top: 50%;
-			left: $spacing;
-			margin-top: -$controlArrowSize/2;
+			left: var(--r-controls-spacing);
+			margin-top: -$controlArrowSize*0.5;
 		}

 		.navigate-right {
 			top: 50%;
-			right: $spacing;
-			margin-top: -$controlArrowSize/2;
+			right: var(--r-controls-spacing);
+			margin-top: -$controlArrowSize*0.5;
 		}

 		.navigate-up {
-			top: $spacing;
+			top: var(--r-controls-spacing);
 			left: 50%;
-			margin-left: -$controlArrowSize/2;
+			margin-left: -$controlArrowSize*0.5;
 		}

 		.navigate-down {
-			bottom: $spacing - $controlArrowSpacing + 0.3em;
+			bottom: calc(var(--r-controls-spacing) - #{$controlArrowSpacing} + 0.3em);
 			left: 50%;
-			margin-left: -$controlArrowSize/2;
+			margin-left: -$controlArrowSize*0.5;
 		}
 	}

@@ -711,6 +729,8 @@ $controlsArrowAngleActive: 36deg;

 .reveal .slides>section.past,
 .reveal .slides>section.future,
+.reveal .slides>section.past>section,
+.reveal .slides>section.future>section,
 .reveal .slides>section>section.past,
 .reveal .slides>section>section.future {
 	opacity: 0;
@@ -769,9 +789,6 @@ $controlsArrowAngleActive: 36deg;
 *********************************************/

@each $stylename in slide, linear {
-	.reveal.#{$stylename} section {
-		backface-visibility: hidden;
-	}
 	@include transition-horizontal-past(#{$stylename}) {
 		transform: translate(-150%, 0);
 	}
@@ -1167,7 +1184,6 @@ $controlsArrowAngleActive: 36deg;
 .reveal[data-background-transition=slide]>.backgrounds .slide-background:not([data-background-transition]),
 .reveal>.backgrounds .slide-background[data-background-transition=slide] {
 	opacity: 1;
-	backface-visibility: hidden;
 }
 	.reveal[data-background-transition=slide]>.backgrounds .slide-background.past:not([data-background-transition]),
 	.reveal>.backgrounds .slide-background.past[data-background-transition=slide] {
@@ -1429,7 +1445,8 @@ $overlayHeaderPadding: 5px;
 	width: 100%;
 	height: 100%;
 	z-index: 1000;
-	background: rgba( 0, 0, 0, 0.9 );
+	background: rgba( 0, 0, 0, 0.95 );
+	backdrop-filter: blur( 6px );
 	transition: all 0.3s ease;
 }

@@ -1573,7 +1590,6 @@ $overlayHeaderPadding: 5px;
 		padding-bottom: 20px;
 	}

-
 /*********************************************
 * PLAYBACK COMPONENT
 *********************************************/
@@ -1623,6 +1639,10 @@ $overlayHeaderPadding: 5px;
 	opacity: 0.4;
 }

+.reveal .hljs.has-highlights.fragment {
+	transition: all .2s ease;
+}
+
 .reveal .hljs:not(:first-child).fragment {
 	position: absolute;
 	top: 0;
@@ -1701,7 +1721,7 @@ $notesWidthPercent: 25%;
 .reveal .speaker-notes {
 	display: none;
 	position: absolute;
-	width: $notesWidthPercent / (1-$notesWidthPercent/100) * 1%;
+	width: math.div($notesWidthPercent, (1 - math.div($notesWidthPercent,100))) * 1%;
 	height: 100%;
 	top: 0;
 	left: 100%;
@@ -1764,7 +1784,6 @@ $notesWidthPercent: 25%;
 		top: 100%;
 		left: 0;
 		width: 100%;
-		height: (30/0.7)*1%;
 		height: 30vh;
 		border: 0;
 	}
@@ -1778,7 +1797,6 @@ $notesWidthPercent: 25%;

 	.reveal.show-notes .speaker-notes {
 		top: 100%;
-		height: (40/0.6)*1%;
 		height: 40vh;
 	}

@@ -1788,6 +1806,43 @@ $notesWidthPercent: 25%;
 }


+/*********************************************
+ * JUMP-TO-SLIDE COMPONENT
+ *********************************************/
+
+ .reveal .jump-to-slide {
+	position: absolute;
+	top: 15px;
+	left: 15px;
+	z-index: 30;
+	font-size: 32px;
+	-webkit-tap-highlight-color: rgba( 0, 0, 0, 0 );
+}
+
+.reveal .jump-to-slide-input {
+	background: transparent;
+	padding: 8px;
+	font-size: inherit;
+	color: currentColor;
+	border: 0;
+}
+.reveal .jump-to-slide-input::placeholder {
+	color: currentColor;
+	opacity: 0.5;
+}
+
+.reveal.has-dark-background .jump-to-slide-input {
+	color: #fff;
+}
+.reveal.has-light-background .jump-to-slide-input {
+	color: #222;
+}
+
+.reveal .jump-to-slide-input:focus {
+	outline: none;
+}
+
+
 /*********************************************
 * ZOOM PLUGIN
 *********************************************/
@@ -1812,6 +1867,239 @@ $notesWidthPercent: 25%;
 }


+/*********************************************
+ * SCROLL VIEW
+ *********************************************/
+.reveal-viewport.loading-scroll-mode {
+	visibility: hidden;
+}
+
+.reveal-viewport.reveal-scroll {
+	& {
+		margin: 0 auto;
+		overflow: auto;
+		overflow-x: hidden;
+		overflow-y: auto;
+		z-index: 1;
+
+		--r-scrollbar-width: 7px;
+		--r-scrollbar-trigger-size: 5px;
+		--r-controls-spacing: 8px;
+	}
+
+	@media screen and (max-width: 500px) {
+		--r-scrollbar-width: 3px;
+		--r-scrollbar-trigger-size: 3px;
+	}
+
+	.controls,
+	.progress,
+	.playback,
+	.backgrounds,
+	.slide-number,
+	.speaker-notes {
+		display: none !important;
+	}
+
+	.overlay,
+	.pause-overlay {
+		position: fixed;
+	}
+
+	.reveal {
+		overflow: visible;
+		touch-action: manipulation;
+	}
+
+	.slides {
+		position: static;
+		pointer-events: initial;
+
+		left: auto;
+		top: auto;
+		width: 100% !important;
+		margin: 0;
+		padding: 0;
+
+		overflow: visible;
+		display: block;
+
+		perspective: none;
+		perspective-origin: 50% 50%;
+	}
+
+	.scroll-page {
+		position: relative;
+		width: 100%;
+		height: calc(var(--page-height) + var(--page-scroll-padding));
+		z-index: 1;
+		overflow: visible;
+	}
+
+	.scroll-page-sticky {
+		position: sticky;
+		height: var(--page-height);
+		top: 0px;
+	}
+
+	.scroll-page-content {
+		position: absolute;
+		top: 0;
+		left: 0;
+		width: 100%;
+		height: 100%;
+		overflow: hidden;
+	}
+
+	.scroll-page section {
+		visibility: visible !important;
+		display: block !important;
+		position: absolute !important;
+		width: var(--slide-width) !important;
+		height: var(--slide-height) !important;
+		top: 50% !important;
+		left: 50% !important;
+		opacity: 1 !important;
+		transform: scale(var(--slide-scale)) translate(-50%, -50%) !important;
+		transform-style: flat !important;
+		transform-origin: 0 0 !important;
+	}
+
+	.slide-background {
+		display: block !important;
+		position: absolute;
+		top: 0;
+		left: 0;
+		width: 100%;
+		height: 100%;
+		z-index: auto !important;
+		visibility: visible;
+		opacity: 1;
+		touch-action: manipulation;
+	}
+}
+
+// Chromium
+.reveal-viewport.reveal-scroll[data-scrollbar="true"]::-webkit-scrollbar,
+.reveal-viewport.reveal-scroll[data-scrollbar="auto"]::-webkit-scrollbar {
+  display: none;
+}
+
+// Firefox
+.reveal-viewport.reveal-scroll[data-scrollbar="true"],
+.reveal-viewport.reveal-scroll[data-scrollbar="auto"] {
+  scrollbar-width: none;
+}
+
+.reveal.has-dark-background,
+.reveal-viewport.has-dark-background {
+	--r-overlay-element-bg-color: 240, 240, 240;
+	--r-overlay-element-fg-color: 0, 0, 0;
+}
+.reveal.has-light-background,
+.reveal-viewport.has-light-background {
+	--r-overlay-element-bg-color: 0, 0, 0;
+	--r-overlay-element-fg-color: 240, 240, 240;
+}
+
+.reveal-viewport.reveal-scroll .scrollbar {
+	position: sticky;
+	top: 50%;
+	z-index: 20;
+	opacity: 0;
+	transition: all 0.3s ease;
+
+	&.visible,
+	&:hover {
+		opacity: 1;
+	}
+
+	.scrollbar-inner {
+		position: absolute;
+		width: var(--r-scrollbar-width);
+		height: calc(var(--viewport-height) - var(--r-controls-spacing) * 2);
+		right: var(--r-controls-spacing);
+		top: 0;
+		transform: translateY(-50%);
+		border-radius: var(--r-scrollbar-width);
+		z-index: 10;
+	}
+
+	.scrollbar-playhead {
+		position: absolute;
+		width: var(--r-scrollbar-width);
+		height: var(--r-scrollbar-width);
+		top: 0;
+		left: 0;
+		border-radius: var(--r-scrollbar-width);
+		background-color: rgba(var(--r-overlay-element-bg-color), 1);
+		z-index: 11;
+		transition: background-color 0.2s ease;
+	}
+
+	.scrollbar-slide {
+		position: absolute;
+		width: 100%;
+		background-color: rgba(var(--r-overlay-element-bg-color), 0.2);
+		box-shadow: 0 0 0px 1px rgba(var(--r-overlay-element-fg-color), 0.1);
+		border-radius: var(--r-scrollbar-width);
+		transition: background-color 0.2s ease;
+	}
+
+	// Hit area
+	.scrollbar-slide:after {
+		content: '';
+		position: absolute;
+		width: 200%;
+		height: 100%;
+		top: 0;
+		left: -50%;
+		background: rgba( 0, 0, 0, 0 );
+		z-index: -1;
+	}
+
+	.scrollbar-slide:hover,
+	.scrollbar-slide.active {
+		background-color: rgba(var(--r-overlay-element-bg-color), 0.4);
+	}
+
+	.scrollbar-trigger {
+		position: absolute;
+		width: 100%;
+		transition: background-color 0.2s ease;
+	}
+
+	.scrollbar-slide.active.has-triggers {
+		background-color: rgba(var(--r-overlay-element-bg-color), 0.4);
+		z-index: 10;
+	}
+
+	.scrollbar-slide.active .scrollbar-trigger:after {
+		content: '';
+		position: absolute;
+		width: var(--r-scrollbar-trigger-size);
+		height: var(--r-scrollbar-trigger-size);
+		border-radius: 20px;
+		top: 50%;
+		left: 50%;
+		transform: translate(-50%, -50%);
+		background-color: rgba(var(--r-overlay-element-bg-color), 1);
+		transition: transform 0.2s ease, opacity 0.2s ease;
+		opacity: 0.4;
+	}
+
+	.scrollbar-slide.active .scrollbar-trigger.active:after,
+	.scrollbar-slide.active .scrollbar-trigger.active ~ .scrollbar-trigger:after {
+		opacity: 1;
+	}
+
+	.scrollbar-slide.active .scrollbar-trigger ~ .scrollbar-trigger.active:after {
+		transform: translate(calc( var(--r-scrollbar-width) * -2), 0);
+		background-color: rgba(var(--r-overlay-element-bg-color), 1);
+	}
+}
+
+
 /*********************************************
 * PRINT STYLES
 *********************************************/
--- a/css/theme/source/beige.scss
+++ b/css/theme/source/beige.scss
@@ -27,6 +27,9 @@ $linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: rgba(79, 64, 28, 0.99);
 $heading1TextShadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0,0,0,.1), 0 0 5px rgba(0,0,0,.1), 0 1px 3px rgba(0,0,0,.3), 0 3px 5px rgba(0,0,0,.2), 0 5px 10px rgba(0,0,0,.25), 0 20px 20px rgba(0,0,0,.15);

+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
 // Background generator
@mixin bodyBackground() {
 	@include radial-gradient( rgba(247,242,211,1), rgba(255,255,255,1) );
--- a/css/theme/source/black-contrast.scss
+++ b/css/theme/source/black-contrast.scss
@@ -0,0 +1,49 @@
+/**
+ * Black compact & high contrast reveal.js theme, with headers not in capitals.
+ *
+ * By Peter Kehl. Based on black.(s)css by Hakim El Hattab, http://hakim.se
+ *
+ * - Keep the source similar to black.css - for easy comparison.
+ * - $mainFontSize controls code blocks, too (although under some ratio).
+ */
+
+
+// Default mixins and settings -----------------
+@import "../template/mixins";
+@import "../template/settings";
+// ---------------------------------------------
+
+
+// Include theme-specific fonts
+@import url(./fonts/source-sans-pro/source-sans-pro.css);
+
+
+// Override theme settings (see ../template/settings.scss)
+$backgroundColor: #000000;
+
+$mainColor: #fff;
+$headingColor: #fff;
+
+$mainFontSize: 42px;
+$mainFont: 'Source Sans Pro', Helvetica, sans-serif;
+$headingFont: 'Source Sans Pro', Helvetica, sans-serif;
+$headingTextShadow: none;
+$headingLetterSpacing: normal;
+$headingTextTransform: uppercase;
+$headingFontWeight: 600;
+$linkColor: #42affa;
+$linkColorHover: lighten( $linkColor, 15% );
+$selectionBackgroundColor: lighten( $linkColor, 25% );
+
+$heading1Size: 2.5em;
+$heading2Size: 1.6em;
+$heading3Size: 1.3em;
+$heading4Size: 1.0em;
+
+// Change text colors against light slide backgrounds
+@include light-bg-text-color(#000);
+
+
+// Theme template ------------------------------
+@import "../template/theme";
+// ---------------------------------------------
--- a/css/theme/source/black.scss
+++ b/css/theme/source/black.scss
@@ -30,7 +30,7 @@ $headingTextTransform: uppercase;
 $headingFontWeight: 600;
 $linkColor: #42affa;
 $linkColorHover: lighten( $linkColor, 15% );
-$selectionBackgroundColor: lighten( $linkColor, 25% );
+$selectionBackgroundColor: rgba( $linkColor, 0.75 );

 $heading1Size: 2.5em;
 $heading2Size: 1.6em;
--- a/css/theme/source/dracula.scss
+++ b/css/theme/source/dracula.scss
@@ -0,0 +1,106 @@
+/**
+ * Dracula Dark theme for reveal.js.
+ * Based on https://draculatheme.com
+ */
+
+
+// Default mixins and settings -----------------
+@import "../template/mixins";
+@import "../template/settings";
+// ---------------------------------------------
+
+
+
+// Include theme-specific fonts
+$systemFontsSansSerif: -apple-system,
+					   BlinkMacSystemFont,
+					   avenir next,
+					   avenir,
+					   segoe ui,
+					   helvetica neue,
+					   helvetica,
+					   Cantarell,
+					   Ubuntu,
+					   roboto,
+					   noto,
+					   arial,
+					   sans-serif;
+$systemFontsMono: Menlo,
+				  Consolas,
+				  Monaco,
+				  Liberation Mono,
+				  Lucida Console,
+				  monospace;
+
+/**
+ * Dracula colors by Zeno Rocha
+ * https://draculatheme.com/contribute
+ */
+html * {
+	color-profile: sRGB;
+	rendering-intent: auto;
+}
+
+$background: #282A36;
+$foreground: #F8F8F2;
+$selection: #44475A;
+$comment: #6272A4;
+$red: #FF5555;
+$orange: #FFB86C;
+$yellow: #F1FA8C;
+$green: #50FA7B;
+$purple: #BD93F9;
+$cyan: #8BE9FD;
+$pink: #FF79C6;
+
+
+
+// Override theme settings (see ../template/settings.scss)
+$mainColor: $foreground;
+$headingColor: $purple;
+$headingTextShadow: none;
+$headingTextTransform: none;
+$backgroundColor: $background;
+$linkColor: $pink;
+$linkColorHover: $cyan;
+$selectionBackgroundColor: $selection;
+$inlineCodeColor: $green;
+$listBulletColor: $cyan;
+
+$mainFont: $systemFontsSansSerif;
+$codeFont: "Fira Code", $systemFontsMono;
+
+// Change text colors against light slide backgrounds
+@include light-bg-text-color($background);
+
+// Theme template ------------------------------
+@import "../template/theme";
+// ---------------------------------------------
+
+// Define additional color effects based on Dracula spec
+// https://spec.draculatheme.com/
+:root {
+	--r-bold-color: #{$orange};
+	--r-italic-color: #{$yellow};
+	--r-inline-code-color: #{$inlineCodeColor};
+	--r-list-bullet-color: #{$listBulletColor};
+}
+
+.reveal {
+	strong, b {
+		color: var(--r-bold-color);
+	}
+	em, i, blockquote {
+		color: var(--r-italic-color);
+	}
+	code {
+		color: var(--r-inline-code-color);
+	}
+	// Dracula colored list bullets and numbers
+	ul, ol {
+		li::marker {
+			color: var(--r-list-bullet-color);
+		}
+	}
+}
+
--- a/css/theme/source/moon.scss
+++ b/css/theme/source/moon.scss
@@ -18,10 +18,6 @@
 /**
 * Solarized colors by Ethan Schoonover
 */
-html * {
-	color-profile: sRGB;
-	rendering-intent: auto;
-}

 // Solarized colors
 $base03:    #002b36;
--- a/css/theme/source/serif.scss
+++ b/css/theme/source/serif.scss
@@ -25,6 +25,9 @@ $linkColor: #51483D;
 $linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: #26351C;

+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
 .reveal a {
  line-height: 1.3em;
 }
--- a/css/theme/source/simple.scss
+++ b/css/theme/source/simple.scss
@@ -31,6 +31,9 @@ $linkColor: #00008B;
 $linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: rgba(0, 0, 0, 0.99);

+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
 // Change text colors against dark slide backgrounds
@include dark-bg-text-color(#fff);

--- a/css/theme/source/sky.scss
+++ b/css/theme/source/sky.scss
@@ -29,6 +29,9 @@ $linkColor: #3b759e;
 $linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: #134674;

+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
 // Fix links so they are not cut off
 .reveal a {
 	line-height: 1.3em;
--- a/css/theme/source/solarized.scss
+++ b/css/theme/source/solarized.scss
@@ -51,6 +51,9 @@ $linkColor: $blue;
 $linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: $magenta;

+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
 // Background generator
 // @mixin bodyBackground() {
 // 	@include radial-gradient( rgba($base3,1), rgba(lighten($base3, 20%),1) );
--- a/css/theme/source/white-contrast.scss
+++ b/css/theme/source/white-contrast.scss
@@ -0,0 +1,52 @@
+/**
+ * White compact & high contrast reveal.js theme, with headers not in capitals.
+ *
+ * By Peter Kehl. Based on white.(s)css by Hakim El Hattab, http://hakim.se
+ *
+ * - Keep the source similar to black.css - for easy comparison.
+ * - $mainFontSize controls code blocks, too (although under some ratio).
+ */
+
+
+// Default mixins and settings -----------------
+@import "../template/mixins";
+@import "../template/settings";
+// ---------------------------------------------
+
+
+// Include theme-specific fonts
+@import url(./fonts/source-sans-pro/source-sans-pro.css);
+
+
+// Override theme settings (see ../template/settings.scss)
+$backgroundColor: #fff;
+
+$mainColor: #000;
+$headingColor: #000;
+
+$mainFontSize: 42px;
+$mainFont: 'Source Sans Pro', Helvetica, sans-serif;
+$headingFont: 'Source Sans Pro', Helvetica, sans-serif;
+$headingTextShadow: none;
+$headingLetterSpacing: normal;
+$headingTextTransform: uppercase;
+$headingFontWeight: 600;
+$linkColor: #2a76dd;
+$linkColorHover: lighten( $linkColor, 15% );
+$selectionBackgroundColor: lighten( $linkColor, 25% );
+
+$heading1Size: 2.5em;
+$heading2Size: 1.6em;
+$heading3Size: 1.3em;
+$heading4Size: 1.0em;
+
+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
+// Change text colors against dark slide backgrounds
+@include dark-bg-text-color(#fff);
+
+
+// Theme template ------------------------------
+@import "../template/theme";
+// ---------------------------------------------
--- a/css/theme/source/white.scss
+++ b/css/theme/source/white.scss
@@ -37,6 +37,9 @@ $heading2Size: 1.6em;
 $heading3Size: 1.3em;
 $heading4Size: 1.0em;

+$overlayElementBgColor: 0, 0, 0;
+$overlayElementFgColor: 240, 240, 240;
+
 // Change text colors against dark slide backgrounds
@include dark-bg-text-color(#fff);

--- a/css/theme/template/exposer.scss
+++ b/css/theme/template/exposer.scss
@@ -1,28 +1,30 @@
 // Exposes theme's variables for easy re-use in CSS for plugin authors

 :root {
-  --background-color: #{$backgroundColor};
-  --main-font: #{$mainFont};
-  --main-font-size: #{$mainFontSize};
-  --main-color: #{$mainColor};
-  --block-margin: #{$blockMargin};
-  --heading-margin: #{$headingMargin};
-  --heading-font: #{$headingFont};
-  --heading-color: #{$headingColor};
-  --heading-line-height: #{$headingLineHeight};
-  --heading-letter-spacing: #{$headingLetterSpacing};
-  --heading-text-transform: #{$headingTextTransform};
-  --heading-text-shadow: #{$headingTextShadow};
-  --heading-font-weight: #{$headingFontWeight};
-  --heading1-text-shadow: #{$heading1TextShadow};
-  --heading1-size: #{$heading1Size};
-  --heading2-size: #{$heading2Size};
-  --heading3-size: #{$heading3Size};
-  --heading4-size: #{$heading4Size};
-  --code-font: #{$codeFont};
-  --link-color: #{$linkColor};
-  --link-color-dark: #{darken($linkColor , 15% )};
-  --link-color-hover: #{$linkColorHover};
-  --selection-background-color: #{$selectionBackgroundColor};
-  --selection-color: #{$selectionColor};
+  --r-background-color: #{$backgroundColor};
+  --r-main-font: #{$mainFont};
+  --r-main-font-size: #{$mainFontSize};
+  --r-main-color: #{$mainColor};
+  --r-block-margin: #{$blockMargin};
+  --r-heading-margin: #{$headingMargin};
+  --r-heading-font: #{$headingFont};
+  --r-heading-color: #{$headingColor};
+  --r-heading-line-height: #{$headingLineHeight};
+  --r-heading-letter-spacing: #{$headingLetterSpacing};
+  --r-heading-text-transform: #{$headingTextTransform};
+  --r-heading-text-shadow: #{$headingTextShadow};
+  --r-heading-font-weight: #{$headingFontWeight};
+  --r-heading1-text-shadow: #{$heading1TextShadow};
+  --r-heading1-size: #{$heading1Size};
+  --r-heading2-size: #{$heading2Size};
+  --r-heading3-size: #{$heading3Size};
+  --r-heading4-size: #{$heading4Size};
+  --r-code-font: #{$codeFont};
+  --r-link-color: #{$linkColor};
+  --r-link-color-dark: #{darken($linkColor , 15% )};
+  --r-link-color-hover: #{$linkColorHover};
+  --r-selection-background-color: #{$selectionBackgroundColor};
+  --r-selection-color: #{$selectionColor};
+  --r-overlay-element-bg-color: #{$overlayElementBgColor};
+  --r-overlay-element-fg-color: #{$overlayElementFgColor};
 }
--- a/css/theme/template/settings.scss
+++ b/css/theme/template/settings.scss
@@ -38,6 +38,11 @@ $linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: #FF5E99;
 $selectionColor: #fff;

+// Colors used for UI elements that are overlaid on top of
+// the presentation
+$overlayElementBgColor: 240, 240, 240;
+$overlayElementFgColor: 0, 0, 0;
+
 // Generates the presentation background, can be overridden
 // to return a background image or gradient
@mixin bodyBackground() {
--- a/css/theme/template/theme.scss
+++ b/css/theme/template/theme.scss
@@ -8,25 +8,25 @@

 .reveal-viewport {
 	@include bodyBackground();
-	background-color: var(--background-color);
+	background-color: var(--r-background-color);
 }

 .reveal {
-	font-family: var(--main-font);
-	font-size: var(--main-font-size);
+	font-family: var(--r-main-font);
+	font-size: var(--r-main-font-size);
 	font-weight: normal;
-	color: var(--main-color);
+	color: var(--r-main-color);
 }

 .reveal ::selection {
-	color: var(--selection-color);
-	background: var(--selection-background-color);
+	color: var(--r-selection-color);
+	background: var(--r-selection-background-color);
 	text-shadow: none;
 }

 .reveal ::-moz-selection {
-	color: var(--selection-color);
-	background: var(--selection-background-color);
+	color: var(--r-selection-color);
+	background: var(--r-selection-background-color);
 	text-shadow: none;
 }

@@ -46,27 +46,27 @@
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-	margin: var(--heading-margin);
-	color: var(--heading-color);
+	margin: var(--r-heading-margin);
+	color: var(--r-heading-color);

-	font-family: var(--heading-font);
-	font-weight: var(--heading-font-weight);
-	line-height: var(--heading-line-height);
-	letter-spacing: var(--heading-letter-spacing);
+	font-family: var(--r-heading-font);
+	font-weight: var(--r-heading-font-weight);
+	line-height: var(--r-heading-line-height);
+	letter-spacing: var(--r-heading-letter-spacing);

-	text-transform: var(--heading-text-transform);
-	text-shadow: var(--heading-text-shadow);
+	text-transform: var(--r-heading-text-transform);
+	text-shadow: var(--r-heading-text-shadow);

 	word-wrap: break-word;
 }

-.reveal h1 {font-size: var(--heading1-size); }
-.reveal h2 {font-size: var(--heading2-size); }
-.reveal h3 {font-size: var(--heading3-size); }
-.reveal h4 {font-size: var(--heading4-size); }
+.reveal h1 {font-size: var(--r-heading1-size); }
+.reveal h2 {font-size: var(--r-heading2-size); }
+.reveal h3 {font-size: var(--r-heading3-size); }
+.reveal h4 {font-size: var(--r-heading4-size); }

 .reveal h1 {
-	text-shadow: var(--heading1-text-shadow);
+	text-shadow: var(--r-heading1-text-shadow);
 }


@@ -75,7 +75,7 @@
 *********************************************/

 .reveal p {
-	margin: var(--block-margin) 0;
+	margin: var(--r-block-margin) 0;
 	line-height: 1.3;
 }

@@ -150,7 +150,7 @@
 	display: block;
 	position: relative;
 	width: 70%;
-	margin: var(--block-margin) auto;
+	margin: var(--r-block-margin) auto;
 	padding: 5px;

 	font-style: italic;
@@ -170,11 +170,11 @@
 	display: block;
 	position: relative;
 	width: 90%;
-	margin: var(--block-margin) auto;
+	margin: var(--r-block-margin) auto;

 	text-align: left;
 	font-size: 0.55em;
-	font-family: var(--code-font);
+	font-family: var(--r-code-font);
 	line-height: 1.2em;

 	word-wrap: break-word;
@@ -183,7 +183,7 @@
 }

 .reveal code {
-	font-family: var(--code-font);
+	font-family: var(--r-code-font);
 	text-transform: none;
 	tab-size: 2;
 }
@@ -257,7 +257,7 @@
 }

 .reveal img {
-	margin: var(--block-margin) 0;
+	margin: var(--r-block-margin) 0;
 }


@@ -266,20 +266,20 @@
 *********************************************/

 .reveal a {
-	color: var(--link-color);
+	color: var(--r-link-color);
 	text-decoration: none;
 	transition: color .15s ease;
 }
 	.reveal a:hover {
-		color: var(--link-color-hover);
+		color: var(--r-link-color-hover);
 		text-shadow: none;
 		border: none;
 	}

 .reveal .roll span:after {
 	color: #fff;
-	// background: darken( var(--link-color), 15% );
-	 background: var(--link-color-dark);
+	// background: darken( var(--r-link-color), 15% );
+	 background: var(--r-link-color-dark);

 }

@@ -289,7 +289,7 @@
 *********************************************/

 .reveal .r-frame {
-	border: 4px solid var(--main-color);
+	border: 4px solid var(--r-main-color);
 	box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -298,7 +298,7 @@
 }

 .reveal a:hover .r-frame {
-	border-color: var(--link-color);
+	border-color: var(--r-link-color);
 	box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -308,7 +308,7 @@
 *********************************************/

 .reveal .controls {
-	color: var(--link-color);
+	color: var(--r-link-color);
 }


@@ -318,7 +318,7 @@

 .reveal .progress {
 	background: rgba(0,0,0,0.2);
-	color: var(--link-color);
+	color: var(--r-link-color);
 }

 /*********************************************
@@ -326,6 +326,6 @@
 *********************************************/
 @media print {
    .backgrounds {
-        background-color: var(--background-color);
+        background-color: var(--r-background-color);
    }
 }
--- a/demo.html
+++ b/demo.html
@@ -52,7 +52,7 @@
 						<p>Slides can be nested inside of each other.</p>
 						<p>Use the <em>Space</em> key to navigate through all slides.</p>
 						<br>
-						<a href="#" class="navigate-down">
+						<a href="#/2/1" class="navigate-down">
 							<img class="r-frame" style="background: rgba(255,255,255,0.1);" width="178" height="238" data-src="https://static.slid.es/reveal/arrow.png" alt="Down arrow">
 						</a>
 					</section>
@@ -86,7 +86,7 @@

 				<section data-auto-animate>
 					<h2 data-id="code-title">Pretty Code</h2>
-					<pre data-id="code-animation"><code class="hljs" data-trim data-line-numbers>
+					<pre data-id="code-animation"><code class="hljs javascript" data-trim data-line-numbers>
 						import React, { useState } from 'react';

 						function Example() {
@@ -101,8 +101,8 @@
 				</section>

 				<section data-auto-animate>
-					<h2 data-id="code-title">With animations</h2>
-					<pre data-id="code-animation"><code class="hljs" data-trim data-line-numbers="|4,8-11|17|22-24"><script type="text/template">
+					<h2 data-id="code-title">With Animations</h2>
+					<pre data-id="code-animation"><code class="hljs javascript" data-trim data-line-numbers="|4,8-11|17|22-24"><script type="text/template">
 						import React, { useState } from 'react';

 						function Example() {
@@ -181,14 +181,14 @@

 				<section data-markdown>
 					<script type="text/template">
-						## Markdown support
+						## Markdown Support

 						Write content using inline or external Markdown.
 						Instructions and more info available in the [docs](https://revealjs.com/markdown/).

 						```html []
 						<section data-markdown>
-						  ## Markdown support
+						  ## Markdown Support

 						  Write content using inline or external Markdown.
 						  Instructions and more info available in the [docs](https://revealjs.com/markdown/).
@@ -249,17 +249,17 @@
 					<p>
 						reveal.js comes with a few themes built in: <br>
 						<!-- Hacks to swap themes after the page has loaded. Not flexible and only intended for the reveal.js demo deck. -->
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/black.css'); return false;">Black (default)</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/white.css'); return false;">White</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/league.css'); return false;">League</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/sky.css'); return false;">Sky</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/beige.css'); return false;">Beige</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/simple.css'); return false;">Simple</a> <br>
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/serif.css'); return false;">Serif</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/blood.css'); return false;">Blood</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/night.css'); return false;">Night</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/moon.css'); return false;">Moon</a> -
-						<a href="#" onclick="document.getElementById('theme').setAttribute('href','dist/theme/solarized.css'); return false;">Solarized</a>
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/black.css'); return false;">Black (default)</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/white.css'); return false;">White</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/league.css'); return false;">League</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/sky.css'); return false;">Sky</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/beige.css'); return false;">Beige</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/simple.css'); return false;">Simple</a> <br>
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/serif.css'); return false;">Serif</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/blood.css'); return false;">Blood</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/night.css'); return false;">Night</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/moon.css'); return false;">Moon</a> -
+						<a href="#/themes" onclick="document.getElementById('theme').setAttribute('href','dist/theme/solarized.css'); return false;">Solarized</a>
 					</p>
 				</section>

@@ -273,6 +273,11 @@
 							<img class="r-frame" style="background: rgba(255,255,255,0.1);" width="178" height="238" data-src="https://static.slid.es/reveal/arrow.png" alt="Down arrow">
 						</a>
 					</section>
+					<section data-background-gradient="linear-gradient(to bottom, #283b95, #17b2c3)">
+						<h2>Gradient Backgrounds</h2>
+						<pre><code class="hljs html wrap">&lt;section data-background-gradient=
+							"linear-gradient(to bottom, #ddd, #191919)"&gt;</code></pre>
+					</section>
 					<section data-background="https://static.slid.es/reveal/image-placeholder.png">
 						<h2>Image Backgrounds</h2>
 						<pre><code class="hljs html">&lt;section data-background="image.png"&gt;</code></pre>
@@ -281,7 +286,7 @@
 						<h2>Tiled Backgrounds</h2>
 						<pre><code class="hljs html" style="word-wrap: break-word;">&lt;section data-background="image.png" data-background-repeat="repeat" data-background-size="100px"&gt;</code></pre>
 					</section>
-					<section data-background-video="https://s3.amazonaws.com/static.slid.es/site/homepage/v1/homepage-video-editor.mp4" data-background-color="#000000">
+					<section data-background-video="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4" data-background-color="#000000">
 						<div style="background-color: rgba(0, 0, 0, 0.9); color: #fff; padding: 20px;">
 							<h2>Video Backgrounds</h2>
 							<pre><code class="hljs html" style="word-wrap: break-word;">&lt;section data-background-video="video.mp4,video.webm"&gt;</code></pre>
--- a/dist/reveal.css
+++ b/dist/reveal.css
--- a/dist/reveal.esm.js
+++ b/dist/reveal.esm.js
--- a/dist/reveal.esm.js.map
+++ b/dist/reveal.esm.js.map
--- a/dist/reveal.js
+++ b/dist/reveal.js
--- a/dist/reveal.js.map
+++ b/dist/reveal.js.map
--- a/dist/theme/beige.css
+++ b/dist/theme/beige.css
@@ -13,59 +13,61 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #f7f3de;
-  --main-font: Lato, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #333;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: League Gothic, Impact, sans-serif;
-  --heading-color: #333;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: none;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0, 0, 0, 0.1), 0 0 5px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.3), 0 3px 5px rgba(0, 0, 0, 0.2), 0 5px 10px rgba(0, 0, 0, 0.25), 0 20px 20px rgba(0, 0, 0, 0.15);
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #8b743d;
-  --link-color-dark: #564826;
-  --link-color-hover: #c0a86e;
-  --selection-background-color: rgba(79, 64, 28, 0.99);
-  --selection-color: #fff;
+  --r-background-color: #f7f3de;
+  --r-main-font: Lato, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #333;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: League Gothic, Impact, sans-serif;
+  --r-heading-color: #333;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0, 0, 0, 0.1), 0 0 5px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.3), 0 3px 5px rgba(0, 0, 0, 0.2), 0 5px 10px rgba(0, 0, 0, 0.25), 0 20px 20px rgba(0, 0, 0, 0.15);
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #8b743d;
+  --r-link-color-dark: #564826;
+  --r-link-color-hover: #c0a86e;
+  --r-selection-background-color: rgba(79, 64, 28, 0.99);
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 0, 0, 0;
+  --r-overlay-element-fg-color: 240, 240, 240;
 }

 .reveal-viewport {
-  background: #f7f2d3;
-  background: -moz-radial-gradient(center, circle cover, white 0%, #f7f2d3 100%);
-  background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%, white), color-stop(100%, #f7f2d3));
-  background: -webkit-radial-gradient(center, circle cover, white 0%, #f7f2d3 100%);
-  background: -o-radial-gradient(center, circle cover, white 0%, #f7f2d3 100%);
-  background: -ms-radial-gradient(center, circle cover, white 0%, #f7f2d3 100%);
-  background: radial-gradient(center, circle cover, white 0%, #f7f2d3 100%);
-  background-color: var(--background-color);
+  background: rgb(247, 242, 211);
+  background: -moz-radial-gradient(center, circle cover, rgb(255, 255, 255) 0%, rgb(247, 242, 211) 100%);
+  background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%, rgb(255, 255, 255)), color-stop(100%, rgb(247, 242, 211)));
+  background: -webkit-radial-gradient(center, circle cover, rgb(255, 255, 255) 0%, rgb(247, 242, 211) 100%);
+  background: -o-radial-gradient(center, circle cover, rgb(255, 255, 255) 0%, rgb(247, 242, 211) 100%);
+  background: -ms-radial-gradient(center, circle cover, rgb(255, 255, 255) 0%, rgb(247, 242, 211) 100%);
+  background: radial-gradient(center, circle cover, rgb(255, 255, 255) 0%, rgb(247, 242, 211) 100%);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -84,42 +86,42 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -194,7 +196,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -214,17 +216,17 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -299,34 +301,34 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -335,7 +337,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -343,7 +345,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -351,7 +353,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -359,6 +361,6 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/black-contrast.css
+++ b/dist/theme/black-contrast.css
@@ -0,0 +1,362 @@
+/**
+ * Black compact & high contrast reveal.js theme, with headers not in capitals.
+ *
+ * By Peter Kehl. Based on black.(s)css by Hakim El Hattab, http://hakim.se
+ *
+ * - Keep the source similar to black.css - for easy comparison.
+ * - $mainFontSize controls code blocks, too (although under some ratio).
+ */
+@import url(./fonts/source-sans-pro/source-sans-pro.css);
+section.has-light-background, section.has-light-background h1, section.has-light-background h2, section.has-light-background h3, section.has-light-background h4, section.has-light-background h5, section.has-light-background h6 {
+  color: #000;
+}
+
+/*********************************************
+ * GLOBAL STYLES
+ *********************************************/
+:root {
+  --r-background-color: #000000;
+  --r-main-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-main-font-size: 42px;
+  --r-main-color: #fff;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-heading-color: #fff;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: 600;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 2.5em;
+  --r-heading2-size: 1.6em;
+  --r-heading3-size: 1.3em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #42affa;
+  --r-link-color-dark: #068de9;
+  --r-link-color-hover: #8dcffc;
+  --r-selection-background-color: #bee4fd;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 240, 240, 240;
+  --r-overlay-element-fg-color: 0, 0, 0;
+}
+
+.reveal-viewport {
+  background: #000000;
+  background-color: var(--r-background-color);
+}
+
+.reveal {
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
+  font-weight: normal;
+  color: var(--r-main-color);
+}
+
+.reveal ::selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal ::-moz-selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal .slides section,
+.reveal .slides section > section {
+  line-height: 1.3;
+  font-weight: inherit;
+}
+
+/*********************************************
+ * HEADERS
+ *********************************************/
+.reveal h1,
+.reveal h2,
+.reveal h3,
+.reveal h4,
+.reveal h5,
+.reveal h6 {
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
+  word-wrap: break-word;
+}
+
+.reveal h1 {
+  font-size: var(--r-heading1-size);
+}
+
+.reveal h2 {
+  font-size: var(--r-heading2-size);
+}
+
+.reveal h3 {
+  font-size: var(--r-heading3-size);
+}
+
+.reveal h4 {
+  font-size: var(--r-heading4-size);
+}
+
+.reveal h1 {
+  text-shadow: var(--r-heading1-text-shadow);
+}
+
+/*********************************************
+ * OTHER
+ *********************************************/
+.reveal p {
+  margin: var(--r-block-margin) 0;
+  line-height: 1.3;
+}
+
+/* Remove trailing margins after titles */
+.reveal h1:last-child,
+.reveal h2:last-child,
+.reveal h3:last-child,
+.reveal h4:last-child,
+.reveal h5:last-child,
+.reveal h6:last-child {
+  margin-bottom: 0;
+}
+
+/* Ensure certain elements are never larger than the slide itself */
+.reveal img,
+.reveal video,
+.reveal iframe {
+  max-width: 95%;
+  max-height: 95%;
+}
+
+.reveal strong,
+.reveal b {
+  font-weight: bold;
+}
+
+.reveal em {
+  font-style: italic;
+}
+
+.reveal ol,
+.reveal dl,
+.reveal ul {
+  display: inline-block;
+  text-align: left;
+  margin: 0 0 0 1em;
+}
+
+.reveal ol {
+  list-style-type: decimal;
+}
+
+.reveal ul {
+  list-style-type: disc;
+}
+
+.reveal ul ul {
+  list-style-type: square;
+}
+
+.reveal ul ul ul {
+  list-style-type: circle;
+}
+
+.reveal ul ul,
+.reveal ul ol,
+.reveal ol ol,
+.reveal ol ul {
+  display: block;
+  margin-left: 40px;
+}
+
+.reveal dt {
+  font-weight: bold;
+}
+
+.reveal dd {
+  margin-left: 40px;
+}
+
+.reveal blockquote {
+  display: block;
+  position: relative;
+  width: 70%;
+  margin: var(--r-block-margin) auto;
+  padding: 5px;
+  font-style: italic;
+  background: rgba(255, 255, 255, 0.05);
+  box-shadow: 0px 0px 2px rgba(0, 0, 0, 0.2);
+}
+
+.reveal blockquote p:first-child,
+.reveal blockquote p:last-child {
+  display: inline-block;
+}
+
+.reveal q {
+  font-style: italic;
+}
+
+.reveal pre {
+  display: block;
+  position: relative;
+  width: 90%;
+  margin: var(--r-block-margin) auto;
+  text-align: left;
+  font-size: 0.55em;
+  font-family: var(--r-code-font);
+  line-height: 1.2em;
+  word-wrap: break-word;
+  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
+}
+
+.reveal code {
+  font-family: var(--r-code-font);
+  text-transform: none;
+  tab-size: 2;
+}
+
+.reveal pre code {
+  display: block;
+  padding: 5px;
+  overflow: auto;
+  max-height: 400px;
+  word-wrap: normal;
+}
+
+.reveal .code-wrapper {
+  white-space: normal;
+}
+
+.reveal .code-wrapper code {
+  white-space: pre;
+}
+
+.reveal table {
+  margin: auto;
+  border-collapse: collapse;
+  border-spacing: 0;
+}
+
+.reveal table th {
+  font-weight: bold;
+}
+
+.reveal table th,
+.reveal table td {
+  text-align: left;
+  padding: 0.2em 0.5em 0.2em 0.5em;
+  border-bottom: 1px solid;
+}
+
+.reveal table th[align=center],
+.reveal table td[align=center] {
+  text-align: center;
+}
+
+.reveal table th[align=right],
+.reveal table td[align=right] {
+  text-align: right;
+}
+
+.reveal table tbody tr:last-child th,
+.reveal table tbody tr:last-child td {
+  border-bottom: none;
+}
+
+.reveal sup {
+  vertical-align: super;
+  font-size: smaller;
+}
+
+.reveal sub {
+  vertical-align: sub;
+  font-size: smaller;
+}
+
+.reveal small {
+  display: inline-block;
+  font-size: 0.6em;
+  line-height: 1.2em;
+  vertical-align: top;
+}
+
+.reveal small * {
+  vertical-align: top;
+}
+
+.reveal img {
+  margin: var(--r-block-margin) 0;
+}
+
+/*********************************************
+ * LINKS
+ *********************************************/
+.reveal a {
+  color: var(--r-link-color);
+  text-decoration: none;
+  transition: color 0.15s ease;
+}
+
+.reveal a:hover {
+  color: var(--r-link-color-hover);
+  text-shadow: none;
+  border: none;
+}
+
+.reveal .roll span:after {
+  color: #fff;
+  background: var(--r-link-color-dark);
+}
+
+/*********************************************
+ * Frame helper
+ *********************************************/
+.reveal .r-frame {
+  border: 4px solid var(--r-main-color);
+  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
+}
+
+.reveal a .r-frame {
+  transition: all 0.15s linear;
+}
+
+.reveal a:hover .r-frame {
+  border-color: var(--r-link-color);
+  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
+}
+
+/*********************************************
+ * NAVIGATION CONTROLS
+ *********************************************/
+.reveal .controls {
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PROGRESS BAR
+ *********************************************/
+.reveal .progress {
+  background: rgba(0, 0, 0, 0.2);
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PRINT BACKGROUND
+ *********************************************/
+@media print {
+  .backgrounds {
+    background-color: var(--r-background-color);
+  }
+}
--- a/dist/theme/black.css
+++ b/dist/theme/black.css
@@ -12,53 +12,55 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #191919;
-  --main-font: Source Sans Pro, Helvetica, sans-serif;
-  --main-font-size: 42px;
-  --main-color: #fff;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: Source Sans Pro, Helvetica, sans-serif;
-  --heading-color: #fff;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: none;
-  --heading-font-weight: 600;
-  --heading1-text-shadow: none;
-  --heading1-size: 2.5em;
-  --heading2-size: 1.6em;
-  --heading3-size: 1.3em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #42affa;
-  --link-color-dark: #068de9;
-  --link-color-hover: #8dcffc;
-  --selection-background-color: #bee4fd;
-  --selection-color: #fff;
+  --r-background-color: #191919;
+  --r-main-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-main-font-size: 42px;
+  --r-main-color: #fff;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-heading-color: #fff;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: 600;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 2.5em;
+  --r-heading2-size: 1.6em;
+  --r-heading3-size: 1.3em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #42affa;
+  --r-link-color-dark: #068de9;
+  --r-link-color-hover: #8dcffc;
+  --r-selection-background-color: rgba(66, 175, 250, 0.75);
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 240, 240, 240;
+  --r-overlay-element-fg-color: 0, 0, 0;
 }

 .reveal-viewport {
  background: #191919;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -77,42 +79,42 @@ section.has-light-background, section.has-light-background h1, section.has-light
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -187,7 +189,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -207,17 +209,17 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -292,34 +294,34 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -328,7 +330,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -336,7 +338,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -344,7 +346,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -352,6 +354,6 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/blood.css
+++ b/dist/theme/blood.css
@@ -18,53 +18,55 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #222;
-  --main-font: Ubuntu, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #eee;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: Ubuntu, sans-serif;
-  --heading-color: #eee;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: 2px 2px 2px #222;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0, 0, 0, 0.1), 0 0 5px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.3), 0 3px 5px rgba(0, 0, 0, 0.2), 0 5px 10px rgba(0, 0, 0, 0.25), 0 20px 20px rgba(0, 0, 0, 0.15);
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #a23;
-  --link-color-dark: #6a1520;
-  --link-color-hover: #dd5566;
-  --selection-background-color: #a23;
-  --selection-color: #fff;
+  --r-background-color: #222;
+  --r-main-font: Ubuntu, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #eee;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Ubuntu, sans-serif;
+  --r-heading-color: #eee;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: 2px 2px 2px #222;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0, 0, 0, 0.1), 0 0 5px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.3), 0 3px 5px rgba(0, 0, 0, 0.2), 0 5px 10px rgba(0, 0, 0, 0.25), 0 20px 20px rgba(0, 0, 0, 0.15);
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #a23;
+  --r-link-color-dark: #6a1520;
+  --r-link-color-hover: #dd5566;
+  --r-selection-background-color: #a23;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 240, 240, 240;
+  --r-overlay-element-fg-color: 0, 0, 0;
 }

 .reveal-viewport {
  background: #222;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -83,42 +85,42 @@ section.has-light-background, section.has-light-background h1, section.has-light
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -193,7 +195,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -213,17 +215,17 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -298,34 +300,34 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -334,7 +336,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -342,7 +344,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -350,7 +352,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -358,7 +360,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
 .reveal p {
--- a/dist/theme/dracula.css
+++ b/dist/theme/dracula.css
@@ -0,0 +1,385 @@
+/**
+ * Dracula Dark theme for reveal.js.
+ * Based on https://draculatheme.com
+ */
+/**
+ * Dracula colors by Zeno Rocha
+ * https://draculatheme.com/contribute
+ */
+html * {
+  color-profile: sRGB;
+  rendering-intent: auto;
+}
+
+section.has-light-background, section.has-light-background h1, section.has-light-background h2, section.has-light-background h3, section.has-light-background h4, section.has-light-background h5, section.has-light-background h6 {
+  color: #282A36;
+}
+
+/*********************************************
+ * GLOBAL STYLES
+ *********************************************/
+:root {
+  --r-background-color: #282A36;
+  --r-main-font: -apple-system, BlinkMacSystemFont, avenir next, avenir, segoe ui, helvetica neue, helvetica, Cantarell, Ubuntu, roboto, noto, arial, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #F8F8F2;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: League Gothic, Impact, sans-serif;
+  --r-heading-color: #BD93F9;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: none;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: Fira Code, Menlo, Consolas, Monaco, Liberation Mono, Lucida Console, monospace;
+  --r-link-color: #FF79C6;
+  --r-link-color-dark: #ff2da5;
+  --r-link-color-hover: #8BE9FD;
+  --r-selection-background-color: #44475A;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 240, 240, 240;
+  --r-overlay-element-fg-color: 0, 0, 0;
+}
+
+.reveal-viewport {
+  background: #282A36;
+  background-color: var(--r-background-color);
+}
+
+.reveal {
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
+  font-weight: normal;
+  color: var(--r-main-color);
+}
+
+.reveal ::selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal ::-moz-selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal .slides section,
+.reveal .slides section > section {
+  line-height: 1.3;
+  font-weight: inherit;
+}
+
+/*********************************************
+ * HEADERS
+ *********************************************/
+.reveal h1,
+.reveal h2,
+.reveal h3,
+.reveal h4,
+.reveal h5,
+.reveal h6 {
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
+  word-wrap: break-word;
+}
+
+.reveal h1 {
+  font-size: var(--r-heading1-size);
+}
+
+.reveal h2 {
+  font-size: var(--r-heading2-size);
+}
+
+.reveal h3 {
+  font-size: var(--r-heading3-size);
+}
+
+.reveal h4 {
+  font-size: var(--r-heading4-size);
+}
+
+.reveal h1 {
+  text-shadow: var(--r-heading1-text-shadow);
+}
+
+/*********************************************
+ * OTHER
+ *********************************************/
+.reveal p {
+  margin: var(--r-block-margin) 0;
+  line-height: 1.3;
+}
+
+/* Remove trailing margins after titles */
+.reveal h1:last-child,
+.reveal h2:last-child,
+.reveal h3:last-child,
+.reveal h4:last-child,
+.reveal h5:last-child,
+.reveal h6:last-child {
+  margin-bottom: 0;
+}
+
+/* Ensure certain elements are never larger than the slide itself */
+.reveal img,
+.reveal video,
+.reveal iframe {
+  max-width: 95%;
+  max-height: 95%;
+}
+
+.reveal strong,
+.reveal b {
+  font-weight: bold;
+}
+
+.reveal em {
+  font-style: italic;
+}
+
+.reveal ol,
+.reveal dl,
+.reveal ul {
+  display: inline-block;
+  text-align: left;
+  margin: 0 0 0 1em;
+}
+
+.reveal ol {
+  list-style-type: decimal;
+}
+
+.reveal ul {
+  list-style-type: disc;
+}
+
+.reveal ul ul {
+  list-style-type: square;
+}
+
+.reveal ul ul ul {
+  list-style-type: circle;
+}
+
+.reveal ul ul,
+.reveal ul ol,
+.reveal ol ol,
+.reveal ol ul {
+  display: block;
+  margin-left: 40px;
+}
+
+.reveal dt {
+  font-weight: bold;
+}
+
+.reveal dd {
+  margin-left: 40px;
+}
+
+.reveal blockquote {
+  display: block;
+  position: relative;
+  width: 70%;
+  margin: var(--r-block-margin) auto;
+  padding: 5px;
+  font-style: italic;
+  background: rgba(255, 255, 255, 0.05);
+  box-shadow: 0px 0px 2px rgba(0, 0, 0, 0.2);
+}
+
+.reveal blockquote p:first-child,
+.reveal blockquote p:last-child {
+  display: inline-block;
+}
+
+.reveal q {
+  font-style: italic;
+}
+
+.reveal pre {
+  display: block;
+  position: relative;
+  width: 90%;
+  margin: var(--r-block-margin) auto;
+  text-align: left;
+  font-size: 0.55em;
+  font-family: var(--r-code-font);
+  line-height: 1.2em;
+  word-wrap: break-word;
+  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
+}
+
+.reveal code {
+  font-family: var(--r-code-font);
+  text-transform: none;
+  tab-size: 2;
+}
+
+.reveal pre code {
+  display: block;
+  padding: 5px;
+  overflow: auto;
+  max-height: 400px;
+  word-wrap: normal;
+}
+
+.reveal .code-wrapper {
+  white-space: normal;
+}
+
+.reveal .code-wrapper code {
+  white-space: pre;
+}
+
+.reveal table {
+  margin: auto;
+  border-collapse: collapse;
+  border-spacing: 0;
+}
+
+.reveal table th {
+  font-weight: bold;
+}
+
+.reveal table th,
+.reveal table td {
+  text-align: left;
+  padding: 0.2em 0.5em 0.2em 0.5em;
+  border-bottom: 1px solid;
+}
+
+.reveal table th[align=center],
+.reveal table td[align=center] {
+  text-align: center;
+}
+
+.reveal table th[align=right],
+.reveal table td[align=right] {
+  text-align: right;
+}
+
+.reveal table tbody tr:last-child th,
+.reveal table tbody tr:last-child td {
+  border-bottom: none;
+}
+
+.reveal sup {
+  vertical-align: super;
+  font-size: smaller;
+}
+
+.reveal sub {
+  vertical-align: sub;
+  font-size: smaller;
+}
+
+.reveal small {
+  display: inline-block;
+  font-size: 0.6em;
+  line-height: 1.2em;
+  vertical-align: top;
+}
+
+.reveal small * {
+  vertical-align: top;
+}
+
+.reveal img {
+  margin: var(--r-block-margin) 0;
+}
+
+/*********************************************
+ * LINKS
+ *********************************************/
+.reveal a {
+  color: var(--r-link-color);
+  text-decoration: none;
+  transition: color 0.15s ease;
+}
+
+.reveal a:hover {
+  color: var(--r-link-color-hover);
+  text-shadow: none;
+  border: none;
+}
+
+.reveal .roll span:after {
+  color: #fff;
+  background: var(--r-link-color-dark);
+}
+
+/*********************************************
+ * Frame helper
+ *********************************************/
+.reveal .r-frame {
+  border: 4px solid var(--r-main-color);
+  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
+}
+
+.reveal a .r-frame {
+  transition: all 0.15s linear;
+}
+
+.reveal a:hover .r-frame {
+  border-color: var(--r-link-color);
+  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
+}
+
+/*********************************************
+ * NAVIGATION CONTROLS
+ *********************************************/
+.reveal .controls {
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PROGRESS BAR
+ *********************************************/
+.reveal .progress {
+  background: rgba(0, 0, 0, 0.2);
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PRINT BACKGROUND
+ *********************************************/
+@media print {
+  .backgrounds {
+    background-color: var(--r-background-color);
+  }
+}
+:root {
+  --r-bold-color: #FFB86C;
+  --r-italic-color: #F1FA8C;
+  --r-inline-code-color: #50FA7B;
+  --r-list-bullet-color: #8BE9FD;
+}
+
+.reveal strong, .reveal b {
+  color: var(--r-bold-color);
+}
+.reveal em, .reveal i, .reveal blockquote {
+  color: var(--r-italic-color);
+}
+.reveal code {
+  color: var(--r-inline-code-color);
+}
+.reveal ul li::marker, .reveal ol li::marker {
+  color: var(--r-list-bullet-color);
+}
--- a/dist/theme/league.css
+++ b/dist/theme/league.css
@@ -15,59 +15,61 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #2b2b2b;
-  --main-font: Lato, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #eee;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: League Gothic, Impact, sans-serif;
-  --heading-color: #eee;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: 0px 0px 6px rgba(0, 0, 0, 0.2);
-  --heading-font-weight: normal;
-  --heading1-text-shadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0, 0, 0, 0.1), 0 0 5px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.3), 0 3px 5px rgba(0, 0, 0, 0.2), 0 5px 10px rgba(0, 0, 0, 0.25), 0 20px 20px rgba(0, 0, 0, 0.15);
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #13DAEC;
-  --link-color-dark: #0d99a5;
-  --link-color-hover: #71e9f4;
-  --selection-background-color: #FF5E99;
-  --selection-color: #fff;
+  --r-background-color: #2b2b2b;
+  --r-main-font: Lato, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #eee;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: League Gothic, Impact, sans-serif;
+  --r-heading-color: #eee;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: 0px 0px 6px rgba(0, 0, 0, 0.2);
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0, 0, 0, 0.1), 0 0 5px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.3), 0 3px 5px rgba(0, 0, 0, 0.2), 0 5px 10px rgba(0, 0, 0, 0.25), 0 20px 20px rgba(0, 0, 0, 0.15);
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #13DAEC;
+  --r-link-color-dark: #0d99a5;
+  --r-link-color-hover: #71e9f4;
+  --r-selection-background-color: #FF5E99;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 240, 240, 240;
+  --r-overlay-element-fg-color: 0, 0, 0;
 }

 .reveal-viewport {
-  background: #1c1e20;
-  background: -moz-radial-gradient(center, circle cover, #555a5f 0%, #1c1e20 100%);
-  background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%, #555a5f), color-stop(100%, #1c1e20));
-  background: -webkit-radial-gradient(center, circle cover, #555a5f 0%, #1c1e20 100%);
-  background: -o-radial-gradient(center, circle cover, #555a5f 0%, #1c1e20 100%);
-  background: -ms-radial-gradient(center, circle cover, #555a5f 0%, #1c1e20 100%);
-  background: radial-gradient(center, circle cover, #555a5f 0%, #1c1e20 100%);
-  background-color: var(--background-color);
+  background: rgb(28, 30, 32);
+  background: -moz-radial-gradient(center, circle cover, rgb(85, 90, 95) 0%, rgb(28, 30, 32) 100%);
+  background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%, rgb(85, 90, 95)), color-stop(100%, rgb(28, 30, 32)));
+  background: -webkit-radial-gradient(center, circle cover, rgb(85, 90, 95) 0%, rgb(28, 30, 32) 100%);
+  background: -o-radial-gradient(center, circle cover, rgb(85, 90, 95) 0%, rgb(28, 30, 32) 100%);
+  background: -ms-radial-gradient(center, circle cover, rgb(85, 90, 95) 0%, rgb(28, 30, 32) 100%);
+  background: radial-gradient(center, circle cover, rgb(85, 90, 95) 0%, rgb(28, 30, 32) 100%);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -86,42 +88,42 @@ section.has-light-background, section.has-light-background h1, section.has-light
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -196,7 +198,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -216,17 +218,17 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -301,34 +303,34 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -337,7 +339,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -345,7 +347,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -353,7 +355,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -361,6 +363,6 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/moon.css
+++ b/dist/theme/moon.css
@@ -7,11 +7,6 @@
 /**
 * Solarized colors by Ethan Schoonover
 */
-html * {
-  color-profile: sRGB;
-  rendering-intent: auto;
-}
-
 section.has-light-background, section.has-light-background h1, section.has-light-background h2, section.has-light-background h3, section.has-light-background h4, section.has-light-background h5, section.has-light-background h6 {
  color: #222;
 }
@@ -20,53 +15,55 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #002b36;
-  --main-font: Lato, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #93a1a1;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: League Gothic, Impact, sans-serif;
-  --heading-color: #eee8d5;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: none;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: none;
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #268bd2;
-  --link-color-dark: #1a6091;
-  --link-color-hover: #78b9e6;
-  --selection-background-color: #d33682;
-  --selection-color: #fff;
+  --r-background-color: #002b36;
+  --r-main-font: Lato, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #93a1a1;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: League Gothic, Impact, sans-serif;
+  --r-heading-color: #eee8d5;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #268bd2;
+  --r-link-color-dark: #1a6091;
+  --r-link-color-hover: #78b9e6;
+  --r-selection-background-color: #d33682;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 240, 240, 240;
+  --r-overlay-element-fg-color: 0, 0, 0;
 }

 .reveal-viewport {
  background: #002b36;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -85,42 +82,42 @@ section.has-light-background, section.has-light-background h1, section.has-light
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -195,7 +192,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -215,17 +212,17 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -300,34 +297,34 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -336,7 +333,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -344,7 +341,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -352,7 +349,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -360,6 +357,6 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/night.css
+++ b/dist/theme/night.css
@@ -13,53 +13,55 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #111;
-  --main-font: Open Sans, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #eee;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: Montserrat, Impact, sans-serif;
-  --heading-color: #eee;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: -0.03em;
-  --heading-text-transform: none;
-  --heading-text-shadow: none;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: none;
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #e7ad52;
-  --link-color-dark: #d08a1d;
-  --link-color-hover: #f3d7ac;
-  --selection-background-color: #e7ad52;
-  --selection-color: #fff;
+  --r-background-color: #111;
+  --r-main-font: Open Sans, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #eee;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Montserrat, Impact, sans-serif;
+  --r-heading-color: #eee;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: -0.03em;
+  --r-heading-text-transform: none;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #e7ad52;
+  --r-link-color-dark: #d08a1d;
+  --r-link-color-hover: #f3d7ac;
+  --r-selection-background-color: #e7ad52;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 240, 240, 240;
+  --r-overlay-element-fg-color: 0, 0, 0;
 }

 .reveal-viewport {
  background: #111;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -78,42 +80,42 @@ section.has-light-background, section.has-light-background h1, section.has-light
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -188,7 +190,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -208,17 +210,17 @@ section.has-light-background, section.has-light-background h1, section.has-light
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -293,34 +295,34 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -329,7 +331,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -337,7 +339,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -345,7 +347,7 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -353,6 +355,6 @@ section.has-light-background, section.has-light-background h1, section.has-light
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/serif.css
+++ b/dist/theme/serif.css
@@ -16,53 +16,55 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #F0F1EB;
-  --main-font: Palatino Linotype, Book Antiqua, Palatino, FreeSerif, serif;
-  --main-font-size: 40px;
-  --main-color: #000;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: Palatino Linotype, Book Antiqua, Palatino, FreeSerif, serif;
-  --heading-color: #383D3D;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: none;
-  --heading-text-shadow: none;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: none;
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #51483D;
-  --link-color-dark: #25211c;
-  --link-color-hover: #8b7c69;
-  --selection-background-color: #26351C;
-  --selection-color: #fff;
+  --r-background-color: #F0F1EB;
+  --r-main-font: Palatino Linotype, Book Antiqua, Palatino, FreeSerif, serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #000;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Palatino Linotype, Book Antiqua, Palatino, FreeSerif, serif;
+  --r-heading-color: #383D3D;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: none;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #51483D;
+  --r-link-color-dark: #25211c;
+  --r-link-color-hover: #8b7c69;
+  --r-selection-background-color: #26351C;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 0, 0, 0;
+  --r-overlay-element-fg-color: 240, 240, 240;
 }

 .reveal-viewport {
  background: #F0F1EB;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -81,42 +83,42 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -191,7 +193,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -211,17 +213,17 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -296,34 +298,34 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -332,7 +334,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -340,7 +342,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -348,7 +350,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -356,6 +358,6 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/simple.css
+++ b/dist/theme/simple.css
@@ -15,53 +15,55 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #fff;
-  --main-font: Lato, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #000;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: News Cycle, Impact, sans-serif;
-  --heading-color: #000;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: none;
-  --heading-text-shadow: none;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: none;
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #00008B;
-  --link-color-dark: #00003f;
-  --link-color-hover: #0000f1;
-  --selection-background-color: rgba(0, 0, 0, 0.99);
-  --selection-color: #fff;
+  --r-background-color: #fff;
+  --r-main-font: Lato, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #000;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: News Cycle, Impact, sans-serif;
+  --r-heading-color: #000;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: none;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #00008B;
+  --r-link-color-dark: #00003f;
+  --r-link-color-hover: #0000f1;
+  --r-selection-background-color: rgba(0, 0, 0, 0.99);
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 0, 0, 0;
+  --r-overlay-element-fg-color: 240, 240, 240;
 }

 .reveal-viewport {
  background: #fff;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -80,42 +82,42 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -190,7 +192,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -210,17 +212,17 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -295,34 +297,34 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -331,7 +333,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -339,7 +341,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -347,7 +349,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -355,6 +357,6 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/sky.css
+++ b/dist/theme/sky.css
@@ -17,30 +17,32 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #f7fbfc;
-  --main-font: Open Sans, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #333;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: Quicksand, sans-serif;
-  --heading-color: #333;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: -0.08em;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: none;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: none;
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #3b759e;
-  --link-color-dark: #264c66;
-  --link-color-hover: #74a7cb;
-  --selection-background-color: #134674;
-  --selection-color: #fff;
+  --r-background-color: #f7fbfc;
+  --r-main-font: Open Sans, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #333;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Quicksand, sans-serif;
+  --r-heading-color: #333;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: -0.08em;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #3b759e;
+  --r-link-color-dark: #264c66;
+  --r-link-color-hover: #74a7cb;
+  --r-selection-background-color: #134674;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 0, 0, 0;
+  --r-overlay-element-fg-color: 240, 240, 240;
 }

 .reveal-viewport {
@@ -51,25 +53,25 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  background: -o-radial-gradient(center, circle cover, #f7fbfc 0%, #add9e4 100%);
  background: -ms-radial-gradient(center, circle cover, #f7fbfc 0%, #add9e4 100%);
  background: radial-gradient(center, circle cover, #f7fbfc 0%, #add9e4 100%);
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -88,42 +90,42 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -198,7 +200,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -218,17 +220,17 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -303,34 +305,34 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -339,7 +341,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -347,7 +349,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -355,7 +357,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -363,6 +365,6 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/solarized.css
+++ b/dist/theme/solarized.css
@@ -16,53 +16,55 @@ html * {
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #fdf6e3;
-  --main-font: Lato, sans-serif;
-  --main-font-size: 40px;
-  --main-color: #657b83;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: League Gothic, Impact, sans-serif;
-  --heading-color: #586e75;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: none;
-  --heading-font-weight: normal;
-  --heading1-text-shadow: none;
-  --heading1-size: 3.77em;
-  --heading2-size: 2.11em;
-  --heading3-size: 1.55em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #268bd2;
-  --link-color-dark: #1a6091;
-  --link-color-hover: #78b9e6;
-  --selection-background-color: #d33682;
-  --selection-color: #fff;
+  --r-background-color: #fdf6e3;
+  --r-main-font: Lato, sans-serif;
+  --r-main-font-size: 40px;
+  --r-main-color: #657b83;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: League Gothic, Impact, sans-serif;
+  --r-heading-color: #586e75;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: normal;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 3.77em;
+  --r-heading2-size: 2.11em;
+  --r-heading3-size: 1.55em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #268bd2;
+  --r-link-color-dark: #1a6091;
+  --r-link-color-hover: #78b9e6;
+  --r-selection-background-color: #d33682;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 0, 0, 0;
+  --r-overlay-element-fg-color: 240, 240, 240;
 }

 .reveal-viewport {
  background: #fdf6e3;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -81,42 +83,42 @@ html * {
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -191,7 +193,7 @@ html * {
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -211,17 +213,17 @@ html * {
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -296,34 +298,34 @@ html * {
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -332,7 +334,7 @@ html * {
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -340,7 +342,7 @@ html * {
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -348,7 +350,7 @@ html * {
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -356,6 +358,6 @@ html * {
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/white-contrast.css
+++ b/dist/theme/white-contrast.css
@@ -0,0 +1,362 @@
+/**
+ * White compact & high contrast reveal.js theme, with headers not in capitals.
+ *
+ * By Peter Kehl. Based on white.(s)css by Hakim El Hattab, http://hakim.se
+ *
+ * - Keep the source similar to black.css - for easy comparison.
+ * - $mainFontSize controls code blocks, too (although under some ratio).
+ */
+@import url(./fonts/source-sans-pro/source-sans-pro.css);
+section.has-dark-background, section.has-dark-background h1, section.has-dark-background h2, section.has-dark-background h3, section.has-dark-background h4, section.has-dark-background h5, section.has-dark-background h6 {
+  color: #fff;
+}
+
+/*********************************************
+ * GLOBAL STYLES
+ *********************************************/
+:root {
+  --r-background-color: #fff;
+  --r-main-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-main-font-size: 42px;
+  --r-main-color: #000;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-heading-color: #000;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: 600;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 2.5em;
+  --r-heading2-size: 1.6em;
+  --r-heading3-size: 1.3em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #2a76dd;
+  --r-link-color-dark: #1a53a1;
+  --r-link-color-hover: #6ca0e8;
+  --r-selection-background-color: #98bdef;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 0, 0, 0;
+  --r-overlay-element-fg-color: 240, 240, 240;
+}
+
+.reveal-viewport {
+  background: #fff;
+  background-color: var(--r-background-color);
+}
+
+.reveal {
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
+  font-weight: normal;
+  color: var(--r-main-color);
+}
+
+.reveal ::selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal ::-moz-selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal .slides section,
+.reveal .slides section > section {
+  line-height: 1.3;
+  font-weight: inherit;
+}
+
+/*********************************************
+ * HEADERS
+ *********************************************/
+.reveal h1,
+.reveal h2,
+.reveal h3,
+.reveal h4,
+.reveal h5,
+.reveal h6 {
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
+  word-wrap: break-word;
+}
+
+.reveal h1 {
+  font-size: var(--r-heading1-size);
+}
+
+.reveal h2 {
+  font-size: var(--r-heading2-size);
+}
+
+.reveal h3 {
+  font-size: var(--r-heading3-size);
+}
+
+.reveal h4 {
+  font-size: var(--r-heading4-size);
+}
+
+.reveal h1 {
+  text-shadow: var(--r-heading1-text-shadow);
+}
+
+/*********************************************
+ * OTHER
+ *********************************************/
+.reveal p {
+  margin: var(--r-block-margin) 0;
+  line-height: 1.3;
+}
+
+/* Remove trailing margins after titles */
+.reveal h1:last-child,
+.reveal h2:last-child,
+.reveal h3:last-child,
+.reveal h4:last-child,
+.reveal h5:last-child,
+.reveal h6:last-child {
+  margin-bottom: 0;
+}
+
+/* Ensure certain elements are never larger than the slide itself */
+.reveal img,
+.reveal video,
+.reveal iframe {
+  max-width: 95%;
+  max-height: 95%;
+}
+
+.reveal strong,
+.reveal b {
+  font-weight: bold;
+}
+
+.reveal em {
+  font-style: italic;
+}
+
+.reveal ol,
+.reveal dl,
+.reveal ul {
+  display: inline-block;
+  text-align: left;
+  margin: 0 0 0 1em;
+}
+
+.reveal ol {
+  list-style-type: decimal;
+}
+
+.reveal ul {
+  list-style-type: disc;
+}
+
+.reveal ul ul {
+  list-style-type: square;
+}
+
+.reveal ul ul ul {
+  list-style-type: circle;
+}
+
+.reveal ul ul,
+.reveal ul ol,
+.reveal ol ol,
+.reveal ol ul {
+  display: block;
+  margin-left: 40px;
+}
+
+.reveal dt {
+  font-weight: bold;
+}
+
+.reveal dd {
+  margin-left: 40px;
+}
+
+.reveal blockquote {
+  display: block;
+  position: relative;
+  width: 70%;
+  margin: var(--r-block-margin) auto;
+  padding: 5px;
+  font-style: italic;
+  background: rgba(255, 255, 255, 0.05);
+  box-shadow: 0px 0px 2px rgba(0, 0, 0, 0.2);
+}
+
+.reveal blockquote p:first-child,
+.reveal blockquote p:last-child {
+  display: inline-block;
+}
+
+.reveal q {
+  font-style: italic;
+}
+
+.reveal pre {
+  display: block;
+  position: relative;
+  width: 90%;
+  margin: var(--r-block-margin) auto;
+  text-align: left;
+  font-size: 0.55em;
+  font-family: var(--r-code-font);
+  line-height: 1.2em;
+  word-wrap: break-word;
+  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
+}
+
+.reveal code {
+  font-family: var(--r-code-font);
+  text-transform: none;
+  tab-size: 2;
+}
+
+.reveal pre code {
+  display: block;
+  padding: 5px;
+  overflow: auto;
+  max-height: 400px;
+  word-wrap: normal;
+}
+
+.reveal .code-wrapper {
+  white-space: normal;
+}
+
+.reveal .code-wrapper code {
+  white-space: pre;
+}
+
+.reveal table {
+  margin: auto;
+  border-collapse: collapse;
+  border-spacing: 0;
+}
+
+.reveal table th {
+  font-weight: bold;
+}
+
+.reveal table th,
+.reveal table td {
+  text-align: left;
+  padding: 0.2em 0.5em 0.2em 0.5em;
+  border-bottom: 1px solid;
+}
+
+.reveal table th[align=center],
+.reveal table td[align=center] {
+  text-align: center;
+}
+
+.reveal table th[align=right],
+.reveal table td[align=right] {
+  text-align: right;
+}
+
+.reveal table tbody tr:last-child th,
+.reveal table tbody tr:last-child td {
+  border-bottom: none;
+}
+
+.reveal sup {
+  vertical-align: super;
+  font-size: smaller;
+}
+
+.reveal sub {
+  vertical-align: sub;
+  font-size: smaller;
+}
+
+.reveal small {
+  display: inline-block;
+  font-size: 0.6em;
+  line-height: 1.2em;
+  vertical-align: top;
+}
+
+.reveal small * {
+  vertical-align: top;
+}
+
+.reveal img {
+  margin: var(--r-block-margin) 0;
+}
+
+/*********************************************
+ * LINKS
+ *********************************************/
+.reveal a {
+  color: var(--r-link-color);
+  text-decoration: none;
+  transition: color 0.15s ease;
+}
+
+.reveal a:hover {
+  color: var(--r-link-color-hover);
+  text-shadow: none;
+  border: none;
+}
+
+.reveal .roll span:after {
+  color: #fff;
+  background: var(--r-link-color-dark);
+}
+
+/*********************************************
+ * Frame helper
+ *********************************************/
+.reveal .r-frame {
+  border: 4px solid var(--r-main-color);
+  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
+}
+
+.reveal a .r-frame {
+  transition: all 0.15s linear;
+}
+
+.reveal a:hover .r-frame {
+  border-color: var(--r-link-color);
+  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
+}
+
+/*********************************************
+ * NAVIGATION CONTROLS
+ *********************************************/
+.reveal .controls {
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PROGRESS BAR
+ *********************************************/
+.reveal .progress {
+  background: rgba(0, 0, 0, 0.2);
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PRINT BACKGROUND
+ *********************************************/
+@media print {
+  .backgrounds {
+    background-color: var(--r-background-color);
+  }
+}
--- a/dist/theme/white.css
+++ b/dist/theme/white.css
@@ -12,53 +12,55 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * GLOBAL STYLES
 *********************************************/
 :root {
-  --background-color: #fff;
-  --main-font: Source Sans Pro, Helvetica, sans-serif;
-  --main-font-size: 42px;
-  --main-color: #222;
-  --block-margin: 20px;
-  --heading-margin: 0 0 20px 0;
-  --heading-font: Source Sans Pro, Helvetica, sans-serif;
-  --heading-color: #222;
-  --heading-line-height: 1.2;
-  --heading-letter-spacing: normal;
-  --heading-text-transform: uppercase;
-  --heading-text-shadow: none;
-  --heading-font-weight: 600;
-  --heading1-text-shadow: none;
-  --heading1-size: 2.5em;
-  --heading2-size: 1.6em;
-  --heading3-size: 1.3em;
-  --heading4-size: 1em;
-  --code-font: monospace;
-  --link-color: #2a76dd;
-  --link-color-dark: #1a53a1;
-  --link-color-hover: #6ca0e8;
-  --selection-background-color: #98bdef;
-  --selection-color: #fff;
+  --r-background-color: #fff;
+  --r-main-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-main-font-size: 42px;
+  --r-main-color: #222;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-heading-color: #222;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: uppercase;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: 600;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 2.5em;
+  --r-heading2-size: 1.6em;
+  --r-heading3-size: 1.3em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #2a76dd;
+  --r-link-color-dark: #1a53a1;
+  --r-link-color-hover: #6ca0e8;
+  --r-selection-background-color: #98bdef;
+  --r-selection-color: #fff;
+  --r-overlay-element-bg-color: 0, 0, 0;
+  --r-overlay-element-fg-color: 240, 240, 240;
 }

 .reveal-viewport {
  background: #fff;
-  background-color: var(--background-color);
+  background-color: var(--r-background-color);
 }

 .reveal {
-  font-family: var(--main-font);
-  font-size: var(--main-font-size);
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
  font-weight: normal;
-  color: var(--main-color);
+  color: var(--r-main-color);
 }

 .reveal ::selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

 .reveal ::-moz-selection {
-  color: var(--selection-color);
-  background: var(--selection-background-color);
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
  text-shadow: none;
 }

@@ -77,42 +79,42 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 .reveal h4,
 .reveal h5,
 .reveal h6 {
-  margin: var(--heading-margin);
-  color: var(--heading-color);
-  font-family: var(--heading-font);
-  font-weight: var(--heading-font-weight);
-  line-height: var(--heading-line-height);
-  letter-spacing: var(--heading-letter-spacing);
-  text-transform: var(--heading-text-transform);
-  text-shadow: var(--heading-text-shadow);
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
  word-wrap: break-word;
 }

 .reveal h1 {
-  font-size: var(--heading1-size);
+  font-size: var(--r-heading1-size);
 }

 .reveal h2 {
-  font-size: var(--heading2-size);
+  font-size: var(--r-heading2-size);
 }

 .reveal h3 {
-  font-size: var(--heading3-size);
+  font-size: var(--r-heading3-size);
 }

 .reveal h4 {
-  font-size: var(--heading4-size);
+  font-size: var(--r-heading4-size);
 }

 .reveal h1 {
-  text-shadow: var(--heading1-text-shadow);
+  text-shadow: var(--r-heading1-text-shadow);
 }

 /*********************************************
 * OTHER
 *********************************************/
 .reveal p {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
  line-height: 1.3;
 }

@@ -187,7 +189,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 70%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  padding: 5px;
  font-style: italic;
  background: rgba(255, 255, 255, 0.05);
@@ -207,17 +209,17 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  display: block;
  position: relative;
  width: 90%;
-  margin: var(--block-margin) auto;
+  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.55em;
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  line-height: 1.2em;
  word-wrap: break-word;
  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
 }

 .reveal code {
-  font-family: var(--code-font);
+  font-family: var(--r-code-font);
  text-transform: none;
  tab-size: 2;
 }
@@ -292,34 +294,34 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal img {
-  margin: var(--block-margin) 0;
+  margin: var(--r-block-margin) 0;
 }

 /*********************************************
 * LINKS
 *********************************************/
 .reveal a {
-  color: var(--link-color);
+  color: var(--r-link-color);
  text-decoration: none;
  transition: color 0.15s ease;
 }

 .reveal a:hover {
-  color: var(--link-color-hover);
+  color: var(--r-link-color-hover);
  text-shadow: none;
  border: none;
 }

 .reveal .roll span:after {
  color: #fff;
-  background: var(--link-color-dark);
+  background: var(--r-link-color-dark);
 }

 /*********************************************
 * Frame helper
 *********************************************/
 .reveal .r-frame {
-  border: 4px solid var(--main-color);
+  border: 4px solid var(--r-main-color);
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
 }

@@ -328,7 +330,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 }

 .reveal a:hover .r-frame {
-  border-color: var(--link-color);
+  border-color: var(--r-link-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
 }

@@ -336,7 +338,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 * NAVIGATION CONTROLS
 *********************************************/
 .reveal .controls {
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -344,7 +346,7 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
 .reveal .progress {
  background: rgba(0, 0, 0, 0.2);
-  color: var(--link-color);
+  color: var(--r-link-color);
 }

 /*********************************************
@@ -352,6 +354,6 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
 *********************************************/
@media print {
  .backgrounds {
-    background-color: var(--background-color);
+    background-color: var(--r-background-color);
  }
 }
--- a/dist/theme/white_contrast_compact_verbatim_headers.css
+++ b/dist/theme/white_contrast_compact_verbatim_headers.css
@@ -0,0 +1,360 @@
+/**
+ * White compact & high contrast reveal.js theme, with headers not in capitals.
+ *
+ * By Peter Kehl. Based on white.(s)css by Hakim El Hattab, http://hakim.se
+ *
+ * - Keep the source similar to black.css - for easy comparison.
+ * - $mainFontSize controls code blocks, too (although under some ratio).
+ */
+@import url(./fonts/source-sans-pro/source-sans-pro.css);
+section.has-dark-background, section.has-dark-background h1, section.has-dark-background h2, section.has-dark-background h3, section.has-dark-background h4, section.has-dark-background h5, section.has-dark-background h6 {
+  color: #fff;
+}
+
+/*********************************************
+ * GLOBAL STYLES
+ *********************************************/
+:root {
+  --r-background-color: #fff;
+  --r-main-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-main-font-size: 25px;
+  --r-main-color: #000;
+  --r-block-margin: 20px;
+  --r-heading-margin: 0 0 20px 0;
+  --r-heading-font: Source Sans Pro, Helvetica, sans-serif;
+  --r-heading-color: #000;
+  --r-heading-line-height: 1.2;
+  --r-heading-letter-spacing: normal;
+  --r-heading-text-transform: none;
+  --r-heading-text-shadow: none;
+  --r-heading-font-weight: 450;
+  --r-heading1-text-shadow: none;
+  --r-heading1-size: 2.5em;
+  --r-heading2-size: 1.6em;
+  --r-heading3-size: 1.3em;
+  --r-heading4-size: 1em;
+  --r-code-font: monospace;
+  --r-link-color: #2a76dd;
+  --r-link-color-dark: #1a53a1;
+  --r-link-color-hover: #6ca0e8;
+  --r-selection-background-color: #98bdef;
+  --r-selection-color: #fff;
+}
+
+.reveal-viewport {
+  background: #fff;
+  background-color: var(--r-background-color);
+}
+
+.reveal {
+  font-family: var(--r-main-font);
+  font-size: var(--r-main-font-size);
+  font-weight: normal;
+  color: var(--r-main-color);
+}
+
+.reveal ::selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal ::-moz-selection {
+  color: var(--r-selection-color);
+  background: var(--r-selection-background-color);
+  text-shadow: none;
+}
+
+.reveal .slides section,
+.reveal .slides section > section {
+  line-height: 1.3;
+  font-weight: inherit;
+}
+
+/*********************************************
+ * HEADERS
+ *********************************************/
+.reveal h1,
+.reveal h2,
+.reveal h3,
+.reveal h4,
+.reveal h5,
+.reveal h6 {
+  margin: var(--r-heading-margin);
+  color: var(--r-heading-color);
+  font-family: var(--r-heading-font);
+  font-weight: var(--r-heading-font-weight);
+  line-height: var(--r-heading-line-height);
+  letter-spacing: var(--r-heading-letter-spacing);
+  text-transform: var(--r-heading-text-transform);
+  text-shadow: var(--r-heading-text-shadow);
+  word-wrap: break-word;
+}
+
+.reveal h1 {
+  font-size: var(--r-heading1-size);
+}
+
+.reveal h2 {
+  font-size: var(--r-heading2-size);
+}
+
+.reveal h3 {
+  font-size: var(--r-heading3-size);
+}
+
+.reveal h4 {
+  font-size: var(--r-heading4-size);
+}
+
+.reveal h1 {
+  text-shadow: var(--r-heading1-text-shadow);
+}
+
+/*********************************************
+ * OTHER
+ *********************************************/
+.reveal p {
+  margin: var(--r-block-margin) 0;
+  line-height: 1.3;
+}
+
+/* Remove trailing margins after titles */
+.reveal h1:last-child,
+.reveal h2:last-child,
+.reveal h3:last-child,
+.reveal h4:last-child,
+.reveal h5:last-child,
+.reveal h6:last-child {
+  margin-bottom: 0;
+}
+
+/* Ensure certain elements are never larger than the slide itself */
+.reveal img,
+.reveal video,
+.reveal iframe {
+  max-width: 95%;
+  max-height: 95%;
+}
+
+.reveal strong,
+.reveal b {
+  font-weight: bold;
+}
+
+.reveal em {
+  font-style: italic;
+}
+
+.reveal ol,
+.reveal dl,
+.reveal ul {
+  display: inline-block;
+  text-align: left;
+  margin: 0 0 0 1em;
+}
+
+.reveal ol {
+  list-style-type: decimal;
+}
+
+.reveal ul {
+  list-style-type: disc;
+}
+
+.reveal ul ul {
+  list-style-type: square;
+}
+
+.reveal ul ul ul {
+  list-style-type: circle;
+}
+
+.reveal ul ul,
+.reveal ul ol,
+.reveal ol ol,
+.reveal ol ul {
+  display: block;
+  margin-left: 40px;
+}
+
+.reveal dt {
+  font-weight: bold;
+}
+
+.reveal dd {
+  margin-left: 40px;
+}
+
+.reveal blockquote {
+  display: block;
+  position: relative;
+  width: 70%;
+  margin: var(--r-block-margin) auto;
+  padding: 5px;
+  font-style: italic;
+  background: rgba(255, 255, 255, 0.05);
+  box-shadow: 0px 0px 2px rgba(0, 0, 0, 0.2);
+}
+
+.reveal blockquote p:first-child,
+.reveal blockquote p:last-child {
+  display: inline-block;
+}
+
+.reveal q {
+  font-style: italic;
+}
+
+.reveal pre {
+  display: block;
+  position: relative;
+  width: 90%;
+  margin: var(--r-block-margin) auto;
+  text-align: left;
+  font-size: 0.55em;
+  font-family: var(--r-code-font);
+  line-height: 1.2em;
+  word-wrap: break-word;
+  box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.15);
+}
+
+.reveal code {
+  font-family: var(--r-code-font);
+  text-transform: none;
+  tab-size: 2;
+}
+
+.reveal pre code {
+  display: block;
+  padding: 5px;
+  overflow: auto;
+  max-height: 400px;
+  word-wrap: normal;
+}
+
+.reveal .code-wrapper {
+  white-space: normal;
+}
+
+.reveal .code-wrapper code {
+  white-space: pre;
+}
+
+.reveal table {
+  margin: auto;
+  border-collapse: collapse;
+  border-spacing: 0;
+}
+
+.reveal table th {
+  font-weight: bold;
+}
+
+.reveal table th,
+.reveal table td {
+  text-align: left;
+  padding: 0.2em 0.5em 0.2em 0.5em;
+  border-bottom: 1px solid;
+}
+
+.reveal table th[align=center],
+.reveal table td[align=center] {
+  text-align: center;
+}
+
+.reveal table th[align=right],
+.reveal table td[align=right] {
+  text-align: right;
+}
+
+.reveal table tbody tr:last-child th,
+.reveal table tbody tr:last-child td {
+  border-bottom: none;
+}
+
+.reveal sup {
+  vertical-align: super;
+  font-size: smaller;
+}
+
+.reveal sub {
+  vertical-align: sub;
+  font-size: smaller;
+}
+
+.reveal small {
+  display: inline-block;
+  font-size: 0.6em;
+  line-height: 1.2em;
+  vertical-align: top;
+}
+
+.reveal small * {
+  vertical-align: top;
+}
+
+.reveal img {
+  margin: var(--r-block-margin) 0;
+}
+
+/*********************************************
+ * LINKS
+ *********************************************/
+.reveal a {
+  color: var(--r-link-color);
+  text-decoration: none;
+  transition: color 0.15s ease;
+}
+
+.reveal a:hover {
+  color: var(--r-link-color-hover);
+  text-shadow: none;
+  border: none;
+}
+
+.reveal .roll span:after {
+  color: #fff;
+  background: var(--r-link-color-dark);
+}
+
+/*********************************************
+ * Frame helper
+ *********************************************/
+.reveal .r-frame {
+  border: 4px solid var(--r-main-color);
+  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
+}
+
+.reveal a .r-frame {
+  transition: all 0.15s linear;
+}
+
+.reveal a:hover .r-frame {
+  border-color: var(--r-link-color);
+  box-shadow: 0 0 20px rgba(0, 0, 0, 0.55);
+}
+
+/*********************************************
+ * NAVIGATION CONTROLS
+ *********************************************/
+.reveal .controls {
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PROGRESS BAR
+ *********************************************/
+.reveal .progress {
+  background: rgba(0, 0, 0, 0.2);
+  color: var(--r-link-color);
+}
+
+/*********************************************
+ * PRINT BACKGROUND
+ *********************************************/
+@media print {
+  .backgrounds {
+    background-color: var(--r-background-color);
+  }
+}
--- a/examples/500-slides.html
+++ b/examples/500-slides.html
@@ -0,0 +1,526 @@
+<!doctype html>
+<html lang="en">
+	<head>
+		<meta charset="utf-8">
+
+		<title>reveal.js - 500 slides</title>
+
+		<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
+
+		<link rel="stylesheet" href="../dist/reveal.css">
+		<link rel="stylesheet" href="../dist/theme/black.css">
+	</head>
+
+	<body>
+		<div class="reveal">
+			<div class="slides">
+				<section><h1>1</h1></section>
+				<section><h1>2</h1></section>
+				<section><h1>3</h1></section>
+				<section><h1>4</h1></section>
+				<section><h1>5</h1></section>
+				<section><h1>6</h1></section>
+				<section><h1>7</h1></section>
+				<section><h1>8</h1></section>
+				<section><h1>9</h1></section>
+				<section><h1>10</h1></section>
+				<section><h1>11</h1></section>
+				<section><h1>12</h1></section>
+				<section><h1>13</h1></section>
+				<section><h1>14</h1></section>
+				<section><h1>15</h1></section>
+				<section><h1>16</h1></section>
+				<section><h1>17</h1></section>
+				<section><h1>18</h1></section>
+				<section><h1>19</h1></section>
+				<section><h1>20</h1></section>
+				<section><h1>21</h1></section>
+				<section><h1>22</h1></section>
+				<section><h1>23</h1></section>
+				<section><h1>24</h1></section>
+				<section><h1>25</h1></section>
+				<section><h1>26</h1></section>
+				<section><h1>27</h1></section>
+				<section><h1>28</h1></section>
+				<section><h1>29</h1></section>
+				<section><h1>30</h1></section>
+				<section><h1>31</h1></section>
+				<section><h1>32</h1></section>
+				<section><h1>33</h1></section>
+				<section><h1>34</h1></section>
+				<section><h1>35</h1></section>
+				<section><h1>36</h1></section>
+				<section><h1>37</h1></section>
+				<section><h1>38</h1></section>
+				<section><h1>39</h1></section>
+				<section><h1>40</h1></section>
+				<section><h1>41</h1></section>
+				<section><h1>42</h1></section>
+				<section><h1>43</h1></section>
+				<section><h1>44</h1></section>
+				<section><h1>45</h1></section>
+				<section><h1>46</h1></section>
+				<section><h1>47</h1></section>
+				<section><h1>48</h1></section>
+				<section><h1>49</h1></section>
+				<section><h1>50</h1></section>
+				<section><h1>51</h1></section>
+				<section><h1>52</h1></section>
+				<section><h1>53</h1></section>
+				<section><h1>54</h1></section>
+				<section><h1>55</h1></section>
+				<section><h1>56</h1></section>
+				<section><h1>57</h1></section>
+				<section><h1>58</h1></section>
+				<section><h1>59</h1></section>
+				<section><h1>60</h1></section>
+				<section><h1>61</h1></section>
+				<section><h1>62</h1></section>
+				<section><h1>63</h1></section>
+				<section><h1>64</h1></section>
+				<section><h1>65</h1></section>
+				<section><h1>66</h1></section>
+				<section><h1>67</h1></section>
+				<section><h1>68</h1></section>
+				<section><h1>69</h1></section>
+				<section><h1>70</h1></section>
+				<section><h1>71</h1></section>
+				<section><h1>72</h1></section>
+				<section><h1>73</h1></section>
+				<section><h1>74</h1></section>
+				<section><h1>75</h1></section>
+				<section><h1>76</h1></section>
+				<section><h1>77</h1></section>
+				<section><h1>78</h1></section>
+				<section><h1>79</h1></section>
+				<section><h1>80</h1></section>
+				<section><h1>81</h1></section>
+				<section><h1>82</h1></section>
+				<section><h1>83</h1></section>
+				<section><h1>84</h1></section>
+				<section><h1>85</h1></section>
+				<section><h1>86</h1></section>
+				<section><h1>87</h1></section>
+				<section><h1>88</h1></section>
+				<section><h1>89</h1></section>
+				<section><h1>90</h1></section>
+				<section><h1>91</h1></section>
+				<section><h1>92</h1></section>
+				<section><h1>93</h1></section>
+				<section><h1>94</h1></section>
+				<section><h1>95</h1></section>
+				<section><h1>96</h1></section>
+				<section><h1>97</h1></section>
+				<section><h1>98</h1></section>
+				<section><h1>99</h1></section>
+				<section><h1>100</h1></section>
+				<section><h1>101</h1></section>
+				<section><h1>102</h1></section>
+				<section><h1>103</h1></section>
+				<section><h1>104</h1></section>
+				<section><h1>105</h1></section>
+				<section><h1>106</h1></section>
+				<section><h1>107</h1></section>
+				<section><h1>108</h1></section>
+				<section><h1>109</h1></section>
+				<section><h1>110</h1></section>
+				<section><h1>111</h1></section>
+				<section><h1>112</h1></section>
+				<section><h1>113</h1></section>
+				<section><h1>114</h1></section>
+				<section><h1>115</h1></section>
+				<section><h1>116</h1></section>
+				<section><h1>117</h1></section>
+				<section><h1>118</h1></section>
+				<section><h1>119</h1></section>
+				<section><h1>120</h1></section>
+				<section><h1>121</h1></section>
+				<section><h1>122</h1></section>
+				<section><h1>123</h1></section>
+				<section><h1>124</h1></section>
+				<section><h1>125</h1></section>
+				<section><h1>126</h1></section>
+				<section><h1>127</h1></section>
+				<section><h1>128</h1></section>
+				<section><h1>129</h1></section>
+				<section><h1>130</h1></section>
+				<section><h1>131</h1></section>
+				<section><h1>132</h1></section>
+				<section><h1>133</h1></section>
+				<section><h1>134</h1></section>
+				<section><h1>135</h1></section>
+				<section><h1>136</h1></section>
+				<section><h1>137</h1></section>
+				<section><h1>138</h1></section>
+				<section><h1>139</h1></section>
+				<section><h1>140</h1></section>
+				<section><h1>141</h1></section>
+				<section><h1>142</h1></section>
+				<section><h1>143</h1></section>
+				<section><h1>144</h1></section>
+				<section><h1>145</h1></section>
+				<section><h1>146</h1></section>
+				<section><h1>147</h1></section>
+				<section><h1>148</h1></section>
+				<section><h1>149</h1></section>
+				<section><h1>150</h1></section>
+				<section><h1>151</h1></section>
+				<section><h1>152</h1></section>
+				<section><h1>153</h1></section>
+				<section><h1>154</h1></section>
+				<section><h1>155</h1></section>
+				<section><h1>156</h1></section>
+				<section><h1>157</h1></section>
+				<section><h1>158</h1></section>
+				<section><h1>159</h1></section>
+				<section><h1>160</h1></section>
+				<section><h1>161</h1></section>
+				<section><h1>162</h1></section>
+				<section><h1>163</h1></section>
+				<section><h1>164</h1></section>
+				<section><h1>165</h1></section>
+				<section><h1>166</h1></section>
+				<section><h1>167</h1></section>
+				<section><h1>168</h1></section>
+				<section><h1>169</h1></section>
+				<section><h1>170</h1></section>
+				<section><h1>171</h1></section>
+				<section><h1>172</h1></section>
+				<section><h1>173</h1></section>
+				<section><h1>174</h1></section>
+				<section><h1>175</h1></section>
+				<section><h1>176</h1></section>
+				<section><h1>177</h1></section>
+				<section><h1>178</h1></section>
+				<section><h1>179</h1></section>
+				<section><h1>180</h1></section>
+				<section><h1>181</h1></section>
+				<section><h1>182</h1></section>
+				<section><h1>183</h1></section>
+				<section><h1>184</h1></section>
+				<section><h1>185</h1></section>
+				<section><h1>186</h1></section>
+				<section><h1>187</h1></section>
+				<section><h1>188</h1></section>
+				<section><h1>189</h1></section>
+				<section><h1>190</h1></section>
+				<section><h1>191</h1></section>
+				<section><h1>192</h1></section>
+				<section><h1>193</h1></section>
+				<section><h1>194</h1></section>
+				<section><h1>195</h1></section>
+				<section><h1>196</h1></section>
+				<section><h1>197</h1></section>
+				<section><h1>198</h1></section>
+				<section><h1>199</h1></section>
+				<section><h1>200</h1></section>
+				<section><h1>201</h1></section>
+				<section><h1>202</h1></section>
+				<section><h1>203</h1></section>
+				<section><h1>204</h1></section>
+				<section><h1>205</h1></section>
+				<section><h1>206</h1></section>
+				<section><h1>207</h1></section>
+				<section><h1>208</h1></section>
+				<section><h1>209</h1></section>
+				<section><h1>210</h1></section>
+				<section><h1>211</h1></section>
+				<section><h1>212</h1></section>
+				<section><h1>213</h1></section>
+				<section><h1>214</h1></section>
+				<section><h1>215</h1></section>
+				<section><h1>216</h1></section>
+				<section><h1>217</h1></section>
+				<section><h1>218</h1></section>
+				<section><h1>219</h1></section>
+				<section><h1>220</h1></section>
+				<section><h1>221</h1></section>
+				<section><h1>222</h1></section>
+				<section><h1>223</h1></section>
+				<section><h1>224</h1></section>
+				<section><h1>225</h1></section>
+				<section><h1>226</h1></section>
+				<section><h1>227</h1></section>
+				<section><h1>228</h1></section>
+				<section><h1>229</h1></section>
+				<section><h1>230</h1></section>
+				<section><h1>231</h1></section>
+				<section><h1>232</h1></section>
+				<section><h1>233</h1></section>
+				<section><h1>234</h1></section>
+				<section><h1>235</h1></section>
+				<section><h1>236</h1></section>
+				<section><h1>237</h1></section>
+				<section><h1>238</h1></section>
+				<section><h1>239</h1></section>
+				<section><h1>240</h1></section>
+				<section><h1>241</h1></section>
+				<section><h1>242</h1></section>
+				<section><h1>243</h1></section>
+				<section><h1>244</h1></section>
+				<section><h1>245</h1></section>
+				<section><h1>246</h1></section>
+				<section><h1>247</h1></section>
+				<section><h1>248</h1></section>
+				<section><h1>249</h1></section>
+				<section><h1>250</h1></section>
+				<section><h1>251</h1></section>
+				<section><h1>252</h1></section>
+				<section><h1>253</h1></section>
+				<section><h1>254</h1></section>
+				<section><h1>255</h1></section>
+				<section><h1>256</h1></section>
+				<section><h1>257</h1></section>
+				<section><h1>258</h1></section>
+				<section><h1>259</h1></section>
+				<section><h1>260</h1></section>
+				<section><h1>261</h1></section>
+				<section><h1>262</h1></section>
+				<section><h1>263</h1></section>
+				<section><h1>264</h1></section>
+				<section><h1>265</h1></section>
+				<section><h1>266</h1></section>
+				<section><h1>267</h1></section>
+				<section><h1>268</h1></section>
+				<section><h1>269</h1></section>
+				<section><h1>270</h1></section>
+				<section><h1>271</h1></section>
+				<section><h1>272</h1></section>
+				<section><h1>273</h1></section>
+				<section><h1>274</h1></section>
+				<section><h1>275</h1></section>
+				<section><h1>276</h1></section>
+				<section><h1>277</h1></section>
+				<section><h1>278</h1></section>
+				<section><h1>279</h1></section>
+				<section><h1>280</h1></section>
+				<section><h1>281</h1></section>
+				<section><h1>282</h1></section>
+				<section><h1>283</h1></section>
+				<section><h1>284</h1></section>
+				<section><h1>285</h1></section>
+				<section><h1>286</h1></section>
+				<section><h1>287</h1></section>
+				<section><h1>288</h1></section>
+				<section><h1>289</h1></section>
+				<section><h1>290</h1></section>
+				<section><h1>291</h1></section>
+				<section><h1>292</h1></section>
+				<section><h1>293</h1></section>
+				<section><h1>294</h1></section>
+				<section><h1>295</h1></section>
+				<section><h1>296</h1></section>
+				<section><h1>297</h1></section>
+				<section><h1>298</h1></section>
+				<section><h1>299</h1></section>
+				<section><h1>300</h1></section>
+				<section><h1>301</h1></section>
+				<section><h1>302</h1></section>
+				<section><h1>303</h1></section>
+				<section><h1>304</h1></section>
+				<section><h1>305</h1></section>
+				<section><h1>306</h1></section>
+				<section><h1>307</h1></section>
+				<section><h1>308</h1></section>
+				<section><h1>309</h1></section>
+				<section><h1>310</h1></section>
+				<section><h1>311</h1></section>
+				<section><h1>312</h1></section>
+				<section><h1>313</h1></section>
+				<section><h1>314</h1></section>
+				<section><h1>315</h1></section>
+				<section><h1>316</h1></section>
+				<section><h1>317</h1></section>
+				<section><h1>318</h1></section>
+				<section><h1>319</h1></section>
+				<section><h1>320</h1></section>
+				<section><h1>321</h1></section>
+				<section><h1>322</h1></section>
+				<section><h1>323</h1></section>
+				<section><h1>324</h1></section>
+				<section><h1>325</h1></section>
+				<section><h1>326</h1></section>
+				<section><h1>327</h1></section>
+				<section><h1>328</h1></section>
+				<section><h1>329</h1></section>
+				<section><h1>330</h1></section>
+				<section><h1>331</h1></section>
+				<section><h1>332</h1></section>
+				<section><h1>333</h1></section>
+				<section><h1>334</h1></section>
+				<section><h1>335</h1></section>
+				<section><h1>336</h1></section>
+				<section><h1>337</h1></section>
+				<section><h1>338</h1></section>
+				<section><h1>339</h1></section>
+				<section><h1>340</h1></section>
+				<section><h1>341</h1></section>
+				<section><h1>342</h1></section>
+				<section><h1>343</h1></section>
+				<section><h1>344</h1></section>
+				<section><h1>345</h1></section>
+				<section><h1>346</h1></section>
+				<section><h1>347</h1></section>
+				<section><h1>348</h1></section>
+				<section><h1>349</h1></section>
+				<section><h1>350</h1></section>
+				<section><h1>351</h1></section>
+				<section><h1>352</h1></section>
+				<section><h1>353</h1></section>
+				<section><h1>354</h1></section>
+				<section><h1>355</h1></section>
+				<section><h1>356</h1></section>
+				<section><h1>357</h1></section>
+				<section><h1>358</h1></section>
+				<section><h1>359</h1></section>
+				<section><h1>360</h1></section>
+				<section><h1>361</h1></section>
+				<section><h1>362</h1></section>
+				<section><h1>363</h1></section>
+				<section><h1>364</h1></section>
+				<section><h1>365</h1></section>
+				<section><h1>366</h1></section>
+				<section><h1>367</h1></section>
+				<section><h1>368</h1></section>
+				<section><h1>369</h1></section>
+				<section><h1>370</h1></section>
+				<section><h1>371</h1></section>
+				<section><h1>372</h1></section>
+				<section><h1>373</h1></section>
+				<section><h1>374</h1></section>
+				<section><h1>375</h1></section>
+				<section><h1>376</h1></section>
+				<section><h1>377</h1></section>
+				<section><h1>378</h1></section>
+				<section><h1>379</h1></section>
+				<section><h1>380</h1></section>
+				<section><h1>381</h1></section>
+				<section><h1>382</h1></section>
+				<section><h1>383</h1></section>
+				<section><h1>384</h1></section>
+				<section><h1>385</h1></section>
+				<section><h1>386</h1></section>
+				<section><h1>387</h1></section>
+				<section><h1>388</h1></section>
+				<section><h1>389</h1></section>
+				<section><h1>390</h1></section>
+				<section><h1>391</h1></section>
+				<section><h1>392</h1></section>
+				<section><h1>393</h1></section>
+				<section><h1>394</h1></section>
+				<section><h1>395</h1></section>
+				<section><h1>396</h1></section>
+				<section><h1>397</h1></section>
+				<section><h1>398</h1></section>
+				<section><h1>399</h1></section>
+				<section><h1>400</h1></section>
+				<section><h1>401</h1></section>
+				<section><h1>402</h1></section>
+				<section><h1>403</h1></section>
+				<section><h1>404</h1></section>
+				<section><h1>405</h1></section>
+				<section><h1>406</h1></section>
+				<section><h1>407</h1></section>
+				<section><h1>408</h1></section>
+				<section><h1>409</h1></section>
+				<section><h1>410</h1></section>
+				<section><h1>411</h1></section>
+				<section><h1>412</h1></section>
+				<section><h1>413</h1></section>
+				<section><h1>414</h1></section>
+				<section><h1>415</h1></section>
+				<section><h1>416</h1></section>
+				<section><h1>417</h1></section>
+				<section><h1>418</h1></section>
+				<section><h1>419</h1></section>
+				<section><h1>420</h1></section>
+				<section><h1>421</h1></section>
+				<section><h1>422</h1></section>
+				<section><h1>423</h1></section>
+				<section><h1>424</h1></section>
+				<section><h1>425</h1></section>
+				<section><h1>426</h1></section>
+				<section><h1>427</h1></section>
+				<section><h1>428</h1></section>
+				<section><h1>429</h1></section>
+				<section><h1>430</h1></section>
+				<section><h1>431</h1></section>
+				<section><h1>432</h1></section>
+				<section><h1>433</h1></section>
+				<section><h1>434</h1></section>
+				<section><h1>435</h1></section>
+				<section><h1>436</h1></section>
+				<section><h1>437</h1></section>
+				<section><h1>438</h1></section>
+				<section><h1>439</h1></section>
+				<section><h1>440</h1></section>
+				<section><h1>441</h1></section>
+				<section><h1>442</h1></section>
+				<section><h1>443</h1></section>
+				<section><h1>444</h1></section>
+				<section><h1>445</h1></section>
+				<section><h1>446</h1></section>
+				<section><h1>447</h1></section>
+				<section><h1>448</h1></section>
+				<section><h1>449</h1></section>
+				<section><h1>450</h1></section>
+				<section><h1>451</h1></section>
+				<section><h1>452</h1></section>
+				<section><h1>453</h1></section>
+				<section><h1>454</h1></section>
+				<section><h1>455</h1></section>
+				<section><h1>456</h1></section>
+				<section><h1>457</h1></section>
+				<section><h1>458</h1></section>
+				<section><h1>459</h1></section>
+				<section><h1>460</h1></section>
+				<section><h1>461</h1></section>
+				<section><h1>462</h1></section>
+				<section><h1>463</h1></section>
+				<section><h1>464</h1></section>
+				<section><h1>465</h1></section>
+				<section><h1>466</h1></section>
+				<section><h1>467</h1></section>
+				<section><h1>468</h1></section>
+				<section><h1>469</h1></section>
+				<section><h1>470</h1></section>
+				<section><h1>471</h1></section>
+				<section><h1>472</h1></section>
+				<section><h1>473</h1></section>
+				<section><h1>474</h1></section>
+				<section><h1>475</h1></section>
+				<section><h1>476</h1></section>
+				<section><h1>477</h1></section>
+				<section><h1>478</h1></section>
+				<section><h1>479</h1></section>
+				<section><h1>480</h1></section>
+				<section><h1>481</h1></section>
+				<section><h1>482</h1></section>
+				<section><h1>483</h1></section>
+				<section><h1>484</h1></section>
+				<section><h1>485</h1></section>
+				<section><h1>486</h1></section>
+				<section><h1>487</h1></section>
+				<section><h1>488</h1></section>
+				<section><h1>489</h1></section>
+				<section><h1>490</h1></section>
+				<section><h1>491</h1></section>
+				<section><h1>492</h1></section>
+				<section><h1>493</h1></section>
+				<section><h1>494</h1></section>
+				<section><h1>495</h1></section>
+				<section><h1>496</h1></section>
+				<section><h1>497</h1></section>
+				<section><h1>498</h1></section>
+				<section><h1>499</h1></section>
+			</div>
+		</div>
+
+		<script src="../dist/reveal.js"></script>
+		<script>
+			Reveal.initialize({
+				transition: 'linear'
+			});
+		</script>
+	</body>
+</html>
--- a/examples/auto-animate.html
+++ b/examples/auto-animate.html
@@ -125,7 +125,7 @@
 				</section>

 				<section data-auto-animate style="height: 600px">
-					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 1</h2>
+					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 1</h3>
 					<h2 data-id="title" style="margin-top: 260px;">Animate Anything</h2>
 					<div data-id="1" style="background: white; position: absolute; top: 150px; left: 16%; width: 60px; height: 60px;"></div>
 					<div data-id="2" style="background: white; position: absolute; top: 150px; left: 36%; width: 60px; height: 60px;"></div>
@@ -133,7 +133,7 @@
 					<div data-id="4" style="background: white; position: absolute; top: 150px; left: 76%; width: 60px; height: 60px;"></div>
 				</section>
 				<section data-auto-animate style="height: 600px">
-					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 2</h2>
+					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 2</h3>
 					<h2 data-id="title" style="margin-top: 500px">With Auto Animate</h2>
 					<div data-id="1" style="background: cyan; position: absolute; bottom: 190px; left: 16%; width: 60px; height: 60px;"></div>
 					<div data-id="2" style="background: magenta; position: absolute; bottom: 190px; left: 36%; width: 60px; height: 160px;"></div>
@@ -141,7 +141,7 @@
 					<div data-id="4" style="background: red; position: absolute; bottom: 190px; left: 76%; width: 60px; height: 360px;"></div>
 				</section>
 				<section data-auto-animate style="height: 600px">
-					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 3</h2>
+					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 3</h3>
 					<h2 data-id="title" style="margin-top: 500px; opacity: 0;">With Auto Animate</h2>
 					<div data-id="1" style="background: cyan; position: absolute; top: 50%; left: 50%; width: 400px; height: 400px; margin: -200px 0 0 -200px; border-radius: 400px;"></div>
 					<div data-id="2" style="background: magenta; position: absolute; top: 50%; left: 50%; width: 300px; height: 300px; margin: -150px 0 0 -150px; border-radius: 400px;"></div>
@@ -149,7 +149,7 @@
 					<div data-id="4" style="background: red; position: absolute; top: 50%; left: 50%; width: 100px; height: 100px; margin: -50px 0 0 -50px; border-radius: 400px;"></div>
 				</section>
 				<section data-auto-animate style="height: 600px">
-					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 3</h2>
+					<h3 style="opacity: 0.3; font-size: 18px;">SLIDE 3</h3>
 					<h2 data-id="title" style="margin-top: 500px; opacity: 0;">With Auto Animate</h2>
 					<div data-id="1" style="background: red; position: absolute; top: 250px; left: 16%; width: 60px; height: 60px;"></div>
 					<div data-id="2" style="background: yellow; position: absolute; top: 250px; left: 36%; width: 60px; height: 60px;"></div>
@@ -176,6 +176,37 @@
 					<h3>B2</h3>
 				</section>

+				<section>
+					<section id="stacked-slide-1" data-auto-animate>
+						<a href="#/stacked-slide-1">Slide 1</a><br>
+						<a href="#/stacked-slide-2">Slide 2</a><br>
+						<a href="#/stacked-slide-3">Slide 3</a><br>
+						<a href="#/stacked-slide-4">Slide 4</a><br>
+						<div data-id="anim" style="background: indigo; padding: 8px; width: 50px; height: 50px; position: absolute; left: 0px;">A</div>
+					</section>
+					<section id="stacked-slide-2" data-auto-animate>
+						<a href="#/stacked-slide-1">Slide 1</a><br>
+						<a href="#/stacked-slide-2">Slide 2</a><br>
+						<a href="#/stacked-slide-3">Slide 3</a><br>
+						<a href="#/stacked-slide-4">Slide 4</a><br>
+						<div data-id="anim" style="background: indigo; padding: 8px; width: 50px; height: 50px; position: absolute; left: 25%;">A</div>
+					</section>
+					<section id="stacked-slide-3" data-auto-animate>
+						<a href="#/stacked-slide-1">Slide 1</a><br>
+						<a href="#/stacked-slide-2">Slide 2</a><br>
+						<a href="#/stacked-slide-3">Slide 3</a><br>
+						<a href="#/stacked-slide-4">Slide 4</a><br>
+						<div data-id="anim" style="background: indigo; padding: 8px; width: 50px; height: 50px; position: absolute; left: 50%;">A</div>
+					</section>
+					<section id="stacked-slide-4" data-auto-animate>
+						<a href="#/stacked-slide-1">Slide 1</a><br>
+						<a href="#/stacked-slide-2">Slide 2</a><br>
+						<a href="#/stacked-slide-3">Slide 3</a><br>
+						<a href="#/stacked-slide-4">Slide 4</a><br>
+						<div data-id="anim" style="background: indigo; padding: 8px; width: 50px; height: 50px; position: absolute; left: 75%;">A</div>
+					</section>
+				</section>
+
 			</div>

 		</div>
--- a/examples/layout-helpers.html
+++ b/examples/layout-helpers.html
@@ -123,7 +123,7 @@

 				<section id="vstack">
 					<h2>VStack</h2>
-					<p>Stacks multiple elements horizontally.</p>
+					<p>Stacks multiple elements vertically.</p>
 					<pre><code class="html" data-trim data-line-numbers>
 					  <div class="r-vstack">
 					    &lt;img width="450" height="300" src="..."&gt;
--- a/examples/markdown.html
+++ b/examples/markdown.html
@@ -21,8 +21,8 @@
                <!-- Use external markdown resource, separate slides by three newlines; vertical slides by two newlines -->
                <section data-markdown="markdown.md" data-separator="^\n\n\n" data-separator-vertical="^\n\n"></section>

-                <!-- Slides are separated by three dashes (quick 'n dirty regular expression) -->
-                <section data-markdown data-separator="---">
+                <!-- Slides are separated by three dashes (the default) -->
+                <section data-markdown>
                    <script type="text/template">
                        ## Demo 1
                        Slide 1
@@ -35,7 +35,7 @@
                    </script>
                </section>

-                <!-- Slides are separated by newline + three dashes + newline, vertical slides identical but two dashes -->
+                <!-- Slides are separated by regexp matching newline + three dashes + newline, vertical slides identical but two dashes -->
                <section data-markdown data-separator="^\n---\n$" data-separator-vertical="^\n--\n$">
                    <script type="text/template">
                        ## Demo 2
@@ -53,8 +53,8 @@
                    </script>
                </section>

-                <!-- No "extra" slides, since there are no separators defined (so they'll become horizontal rulers) -->
-                <section data-markdown>
+                <!-- No "extra" slides, since the separator can't be matched ("---" will become horizontal rulers) -->
+                <section data-markdown data-separator="$x">
                    <script type="text/template">
                        A

@@ -99,6 +99,25 @@
                    </script>
                </section>

+                <!-- add optional line count offset, in this case 287 -->
+                <section data-markdown>
+                    <script type="text/template">
+                        ## echo.c
+
+                        ```c [287: 2|4,6]
+                        /* All of the options in this arg are valid, so handle them. */
+                        p = arg + 1;
+                        do {
+                            if (*p == 'n')
+                                nflag = 0;
+                            if (*p == 'e')
+                                eflag = '\\';
+                        } while (*++p); 
+                        ```
+                        [source](https://git.busybox.net/busybox/tree/coreutils/echo.c?h=1_36_stable#n287)
+                    </script>
+                </section>
+
                <!-- Images -->
                <section data-markdown>
                    <script type="text/template">
@@ -106,6 +125,16 @@
                    </script>
                </section>

+                <!-- Math -->
+                <section data-markdown>
+					## The Lorenz Equations
+					`\[\begin{aligned}
+					\dot{x} &amp; = \sigma(y-x) \\
+					\dot{y} &amp; = \rho x - y - xz \\
+					\dot{z} &amp; = -\beta z + xy
+					\end{aligned} \]`
+                </section>
+
            </div>
 		</div>

@@ -113,6 +142,7 @@
        <script src="../plugin/markdown/markdown.js"></script>
        <script src="../plugin/highlight/highlight.js"></script>
        <script src="../plugin/notes/notes.js"></script>
+        <script src="../plugin/math/math.js"></script>

 		<script>

@@ -122,7 +152,7 @@
 				history: true,
 				center: true,

-				plugins: [ RevealMarkdown, RevealHighlight, RevealNotes ]
+				plugins: [ RevealMarkdown, RevealHighlight, RevealNotes, RevealMath.KaTeX ]
 			});

 		</script>
--- a/examples/markdown.md
+++ b/examples/markdown.md
@@ -31,6 +31,11 @@ Content 3.1
 Content 3.2


-## External 3.3
+## External 3.3 (Image)

 ![External Image](https://s3.amazonaws.com/static.slid.es/logo/v2/slides-symbol-512x512.png)
+
+
+## External 3.4 (Math)
+
+`\[ J(\theta_0,\theta_1) = \sum_{i=0} \]`
--- a/examples/math.html
+++ b/examples/math.html
@@ -20,7 +20,7 @@

 				<section>
 					<h2>reveal.js Math Plugin</h2>
-					<p>A thin wrapper for MathJax</p>
+					<p>Render math with KaTeX, MathJax 2 or MathJax 3</p>
 				</section>

 				<section>
@@ -182,8 +182,7 @@
 				history: true,
 				transition: 'linear',

-				math: {
-					// mathjax: 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js',
+				mathjax2: {
 					config: 'TeX-AMS_HTML-full',
 					TeX: {
 						Macros: {
@@ -193,7 +192,13 @@
 					}
 				},

-				plugins: [ RevealMath ]
+				// There are three typesetters available
+				// RevealMath.MathJax2 (default)
+				// RevealMath.MathJax3
+				// RevealMath.KaTeX
+				//
+				// More info at https://revealjs.com/math/
+				plugins: [ RevealMath.MathJax2 ]
 			});
 		</script>

--- a/examples/scroll.html
+++ b/examples/scroll.html
@@ -0,0 +1,118 @@
+<!doctype html>
+<html lang="en">
+
+	<head>
+		<meta charset="utf-8">
+
+		<title>reveal.js - Scroll View</title>
+
+		<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
+
+		<link rel="stylesheet" href="../dist/reset.css">
+		<link rel="stylesheet" href="../dist/reveal.css">
+		<link rel="stylesheet" href="../dist/theme/black.css" id="theme">
+    <link rel="stylesheet" href="../plugin/highlight/monokai.css">
+	</head>
+
+	<body>
+
+		<div class="reveal">
+
+			<div class="slides">
+
+				<section><h1>Scroll View</h1></section>
+				<section data-background="indigo">
+					<h2>Scroll triggered fragments</h2>
+					<ul>
+						<li class="fragment fade-left">Step one</li>
+						<li class="fragment fade-left">Step two</li>
+						<li class="fragment fade-left">Step three</li>
+					</ul>
+				</section>
+				<section data-background-color="#fff"><h2>Scrollbar inverts<br>based on slide bg</h2></section>
+				<section data-auto-animate data-auto-animate-easing="cubic-bezier(0.770, 0.000, 0.175, 1.000)">
+					<h2>Auto-Animate</h2>
+					<p>Scroll triggered auto-animations 😍</p>
+					<div class="r-hstack justify-center">
+						<div data-id="box1" style="background: #999; width: 50px; height: 50px; margin: 10px; border-radius: 5px;"></div>
+						<div data-id="box2" style="background: #999; width: 50px; height: 50px; margin: 10px; border-radius: 5px;"></div>
+						<div data-id="box3" style="background: #999; width: 50px; height: 50px; margin: 10px; border-radius: 5px;"></div>
+					</div>
+				</section>
+				<section data-auto-animate data-auto-animate-easing="cubic-bezier(0.770, 0.000, 0.175, 1.000)">
+					<div class="r-hstack justify-center">
+						<div data-id="box1" data-auto-animate-delay="0" style="background: cyan; width: 150px; height: 100px; margin: 10px;"></div>
+						<div data-id="box2" data-auto-animate-delay="0.1" style="background: magenta; width: 150px; height: 100px; margin: 10px;"></div>
+						<div data-id="box3" data-auto-animate-delay="0.2" style="background: yellow; width: 150px; height: 100px; margin: 10px;"></div>
+					</div>
+					<h2 style="margin-top: 20px;">Auto-Animate</h2>
+				</section>
+				<section data-auto-animate data-auto-animate-easing="cubic-bezier(0.770, 0.000, 0.175, 1.000)">
+					<div class="r-stack">
+						<div data-id="box1" style="background: cyan; width: 300px; height: 300px; border-radius: 200px;"></div>
+						<div data-id="box2" style="background: magenta; width: 200px; height: 200px; border-radius: 200px;"></div>
+						<div data-id="box3" style="background: yellow; width: 100px; height: 100px; border-radius: 200px;"></div>
+					</div>
+					<h2 style="margin-top: 20px;">Auto-Animate</h2>
+				</section>
+				<section data-background-gradient="linear-gradient(to bottom, #283b95, #17b2c3)" id="gradient-bg">
+					<h2 data-id="code-title">Code highlights,<br />meet scroll triggers</h2>
+					<pre data-id="code-animation"><code class="hljs javascript" data-trim data-line-numbers="|4,8-11|17|22-24"><script type="text/template">
+						import React, { useState } from 'react';
+
+						function Example() {
+						  const [count, setCount] = useState(0);
+
+						  return (
+						    <div>
+						      <p>You clicked {count} times</p>
+						      <button onClick={() => setCount(count + 1)}>
+						        Click me
+						      </button>
+						    </div>
+						  );
+						}
+
+						function SecondExample() {
+						  const [count, setCount] = useState(0);
+
+						  return (
+						    <div>
+						      <p>You clicked {count} times</p>
+						      <button onClick={() => setCount(count + 1)}>
+						        Click me
+						      </button>
+						    </div>
+						  );
+						}
+					</script></code></pre>
+				</section>
+				<section class="stack">
+          <section data-background="https://static.slid.es/reveal/image-placeholder.png" id="image-bg">
+            <h2>Image Backgrounds</h2>
+          </section>
+          <section data-background-video-muted data-background-video="https://s3.amazonaws.com/static.slid.es/site/homepage/v1/homepage-video-editor.mp4,https://s3.amazonaws.com/static.slid.es/site/homepage/v1/homepage-video-editor.webm">
+            <h2>Video background</h2>
+          </section>
+        </section>
+				<section><h2>The end</h2></section>
+
+			</div>
+
+		</div>
+
+		<script src="../dist/reveal.js"></script>
+		<script src="../plugin/notes/notes.js"></script>
+		<script src="../plugin/markdown/markdown.js"></script>
+		<script src="../plugin/highlight/highlight.js"></script>
+		<script>
+      Reveal.initialize({
+        view: 'scroll',
+        hash: true,
+
+				plugins: [ RevealMarkdown, RevealHighlight, RevealNotes ]
+			});
+    </script>
+
+	</body>
+</html>
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -1,13 +1,11 @@
 const pkg = require('./package.json')
-const path = require('path')
 const glob = require('glob')
 const yargs = require('yargs')
-const colors = require('colors')
 const through = require('through2');
 const qunit = require('node-qunit-puppeteer')

 const {rollup} = require('rollup')
-const {terser} = require('rollup-plugin-terser')
+const terser = require('@rollup/plugin-terser')
 const babel = require('@rollup/plugin-babel').default
 const commonjs = require('@rollup/plugin-commonjs')
 const resolve = require('@rollup/plugin-node-resolve').default
@@ -24,13 +22,14 @@ const autoprefixer = require('gulp-autoprefixer')

 const root = yargs.argv.root || '.'
 const port = yargs.argv.port || 8000
+const host = yargs.argv.host || 'localhost'

 const banner = `/*!
 * reveal.js ${pkg.version}
 * ${pkg.homepage}
 * MIT licensed
 *
-* Copyright (C) 2020 Hakim El Hattab, https://hakim.se
+* Copyright (C) 2011-2023 Hakim El Hattab, https://hakim.se
 */\n`

 // Prevents warnings from opening too many test pages
@@ -60,11 +59,11 @@ const babelConfig = {
 // polyfilling older browsers and a larger bundle.
 const babelConfigESM = JSON.parse( JSON.stringify( babelConfig ) );
 babelConfigESM.presets[0][1].targets = { browsers: [
-    'last 2 Chrome versions', 'not Chrome < 60',
-    'last 2 Safari versions', 'not Safari < 10.1',
-    'last 2 iOS versions', 'not iOS < 10.3',
-    'last 2 Firefox versions', 'not Firefox < 60',
-    'last 2 Edge versions', 'not Edge < 16',
+    'last 2 Chrome versions',
+    'last 2 Safari versions',
+    'last 2 iOS versions',
+    'last 2 Firefox versions',
+    'last 2 Edge versions',
 ] };

 let cache = {};
@@ -163,11 +162,10 @@ function compileSass() {

    sass.render({
        data: transformedFile.contents.toString(),
-        includePaths: ['css/', 'css/theme/template']
+        file: transformedFile.path,
    }, ( err, result ) => {
        if( err ) {
-            console.log( vinylFile.path );
-            console.log( err.formatted );
+            callback(err);
        }
        else {
            transformedFile.extname = '.css';
@@ -196,7 +194,7 @@ gulp.task('qunit', () => {
    let serverConfig = {
        root,
        port: 8009,
-        host: '0.0.0.0',
+        host: 'localhost',
        name: 'test-server'
    }

@@ -268,20 +266,24 @@ gulp.task('default', gulp.series(gulp.parallel('js', 'css', 'plugins'), 'test'))

 gulp.task('build', gulp.parallel('js', 'css', 'plugins'))

-gulp.task('package', gulp.series('default', () =>
+gulp.task('package', gulp.series(() =>

-    gulp.src([
-        './index.html',
-        './dist/**',
-        './lib/**',
-        './images/**',
-        './plugin/**',
-        './**.md'
-    ]).pipe(zip('reveal-js-presentation.zip')).pipe(gulp.dest('./'))
+    gulp.src(
+        [
+            './index.html',
+            './dist/**',
+            './lib/**',
+            './images/**',
+            './plugin/**',
+            './**/*.md'
+        ],
+        { base: './' }
+    )
+    .pipe(zip('reveal-js-presentation.zip')).pipe(gulp.dest('./'))

 ))

-gulp.task('reload', () => gulp.src(['*.html', '*.md'])
+gulp.task('reload', () => gulp.src(['index.html'])
    .pipe(connect.reload()));

 gulp.task('serve', () => {
@@ -289,18 +291,23 @@ gulp.task('serve', () => {
    connect.server({
        root: root,
        port: port,
-        host: '0.0.0.0',
+        host: host,
        livereload: true
    })

-    gulp.watch(['*.html', '*.md'], gulp.series('reload'))
+    const slidesRoot = root.endsWith('/') ? root : root + '/'
+    gulp.watch([
+        slidesRoot + '**/*.html',
+        slidesRoot + '**/*.md',
+        `!${slidesRoot}**/node_modules/**`, // ignore node_modules
+    ], gulp.series('reload'))

-    gulp.watch(['js/**'], gulp.series('js', 'reload', 'test'))
+    gulp.watch(['js/**'], gulp.series('js', 'reload', 'eslint'))

-    gulp.watch(['plugin/**/plugin.js'], gulp.series('plugins', 'reload'))
+    gulp.watch(['plugin/**/plugin.js', 'plugin/**/*.html'], gulp.series('plugins', 'reload'))

    gulp.watch([
-        'css/theme/source/*.{sass,scss}',
+        'css/theme/source/**/*.{sass,scss}',
        'css/theme/template/*.{sass,scss}',
    ], gulp.series('css-themes', 'reload'))

@@ -311,4 +318,4 @@ gulp.task('serve', () => {

    gulp.watch(['test/*.html'], gulp.series('test'))

-})
+})
--- a/images/avatar.jpg
+++ b/images/avatar.jpg
--- a/images/elephant.png
+++ b/images/elephant.png
--- a/images/grafana_logo-web-white-text.svg
+++ b/images/grafana_logo-web-white-text.svg
--- a/images/heimoshuiyu.jpg
+++ b/images/heimoshuiyu.jpg
--- a/images/logo.png
+++ b/images/logo.png
--- a/images/mikufans.jpg
+++ b/images/mikufans.jpg
--- a/images/photo_2022-11-20_17-55-46.jpg
+++ b/images/photo_2022-11-20_17-55-46.jpg
--- a/images/tg_image_1349760345.jpeg
+++ b/images/tg_image_1349760345.jpeg
--- a/images/workflow.svg
+++ b/images/workflow.svg
--- a/index.html
+++ b/index.html
@@ -1,131 +1,41 @@
-<!DOCTYPE html>
-<html>
-  <head>
-    <meta charset="utf-8" />
-    <meta
-      name="viewport"
-      content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"
-    />
+<!doctype html>
+<html lang="en">
+	<head>
+		<meta charset="utf-8">
+		<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">

-    <title>reveal.js</title>
+		<title>reveal.js</title>

-    <link rel="stylesheet" href="dist/reset.css" />
-    <link rel="stylesheet" href="dist/reveal.css" />
-    <link rel="stylesheet" href="dist/theme/black.css" />
+		<link rel="stylesheet" href="dist/reset.css">
+		<link rel="stylesheet" href="dist/reveal.css">
+		<link rel="stylesheet" href="dist/theme/black.css">

-    <!-- Theme used for syntax highlighted code -->
-    <link rel="stylesheet" href="plugin/highlight/monokai.css" />
-  </head>
-  <body>
-    <div class="reveal">
-      <div class="slides">
-	      <section data-markdown
-                 data-background-image="./images/mikufans.jpg"
-            data-background-opacity="0.39"
-            data-background-color="white"
-          >
-          ### 峰悦交易看板
+		<!-- Theme used for syntax highlighted code -->
+		<link rel="stylesheet" href="plugin/highlight/monokai.css">
+	</head>
+	<body>
+		<div class="reveal">
+			<div class="slides">
+				<section data-markdown="ai_lecture.md"></section>
+			</div>
+		</div>

-          By `mikufans`
-        </section>
-          <section
-              data-background-image="./images/tg_image_1349760345.jpeg"
-              data-background-size="contain"
-            >
-            <img src="./images/photo_2022-11-20_17-55-46.jpg" width="400" />
-          </section>
-        <section 
-                 data-background-image="./images/workflow.svg"
-                 data-background-size="contain"
-          >
-          <div style="padding: 3em; background-color: rgba(0,0,0,0.39);">
-            整体架构图
-            <br />
+		<script src="dist/reveal.js"></script>
+		<script src="plugin/notes/notes.js"></script>
+		<script src="plugin/markdown/markdown.js"></script>
+		<script src="plugin/highlight/highlight.js"></script>
+		<script>
+			// More info about initialization & config:
+			// - https://revealjs.com/initialization/
+			// - https://revealjs.com/config/
+			Reveal.initialize({
+				hash: true,
+				width: 1920,
+				height: 1080,

-            <small>全部模块采用 Docker 容器化部署</small>
-          </div>
-        </section>
-        <section>
-          <section data-markdown
-            data-background-image="./images/elephant.png"
-            data-background-opacity="0.39"
-            data-background-size="cover"
-            >
-            ### 后端数据库 - PostgreSQL
-
-            - 开源、稳定、高性能的混合式数据库后端
-            - 能够储存结构化和非结构化的混合式数据
-            - 储存股票时序记录
-            - 超过1000只股票的10年数据纪录
-          </section>
-          <section data-markdown
-                   data-background-image="./images/logo.png"
-            data-background-opacity="0.39"
-            >
-            ### 后端数据源 - RSSHub
-
-            - 活跃开源项目，超过8000个commit
-            - 聚合超过数十家金融平台的新闻、文章、评论
-          </section>
-            <section data-markdown
-                     data-background-image="./images/grafana_logo-web-white-text.svg"
-                     data-background-size="contain"
-            data-background-opacity="0.39"
-              >
-              ### 前端数据面板 - Grafana
-
-              - 开源的专业实时数据监控面板
-              - 组件化配置各个数据源模块
-              - 自定义筛选各类数据源
-              - 跨平台支持PC、手机，自适应屏幕大小
-              - 设置监控警告事件，及时处理突发情况
-            </section>
-        </section>
-        <section>
-          <section>
-            <h3>DEMO !</h3>
-            <a href="https://baka.link/zv2w" target="_blank">Snapshot https://baka.link/zv2w</a>
-            <small>
-              <p>or</p>
-            <a href="https://home.bakaawt.com:3000/d/BKKLA5dVz/feng-yue-jiao-yi-kan-ban">
-              https://home.bakaawt.com:3000/d/BKKLA5dVz/feng-yue-jiao-yi-kan-ban
-            </a></small>
-          </section>
-        </section>
-        <section>
-          <div>
-            <h2>Creators</h2>
-            <div style="display: flex; justify-content: space-evenly;">
-              <div style="display: flex; flex-direction: column;">
-                <img src="./images/avatar.jpg" width="200" style="border-radius: 50%;" />
-                <span>艾文韬</span>
-              </div>
-              <div style="display: flex; flex-direction: column;">
-                <img src="./images/heimoshuiyu.jpg" width="200" style="border-radius: 50%;" />
-                <span>陈永源</span>
-              </div>
-            </div>
-          </div>
-        </section>
-      </div>
-    </div>
-
-    <script src="dist/reveal.js"></script>
-    <script src="plugin/notes/notes.js"></script>
-    <script src="plugin/markdown/markdown.js"></script>
-    <script src="plugin/highlight/highlight.js"></script>
-    <script>
-      // More info about initialization & config:
-      // - https://revealjs.com/initialization/
-      // - https://revealjs.com/config/
-      Reveal.initialize({
-        hash: true,
-        heigh: 1920,
-        wdith: 1080,
-
-        // Learn about plugins: https://revealjs.com/plugins/
-        plugins: [RevealMarkdown, RevealHighlight, RevealNotes],
-      });
-    </script>
-  </body>
+				// Learn about plugins: https://revealjs.com/plugins/
+				plugins: [ RevealMarkdown, RevealHighlight, RevealNotes ]
+			});
+		</script>
+	</body>
 </html>
--- a/js/config.js
+++ b/js/config.js
@@ -65,6 +65,9 @@ export default {
 	// Flags if we should monitor the hash and change slides accordingly
 	respondToHashChanges: true,

+	// Enable support for jump-to-slide navigation shortcuts
+	jumpToSlide: true,
+
 	// Push each slide change to the browser history.  Implies `hash: true`
 	history: false,

@@ -253,6 +256,36 @@ export default {
 	parallaxBackgroundHorizontal: null,
 	parallaxBackgroundVertical: null,

+	// Can be used to initialize reveal.js in one of the following views:
+	// - print:   Render the presentation so that it can be printed to PDF
+	// - scroll:  Show the presentation as a tall scrollable page with scroll
+	//            triggered animations
+	view: null,
+
+	// Adjusts the height of each slide in the scroll view.
+	// - full:       Each slide is as tall as the viewport
+	// - compact:    Slides are as small as possible, allowing multiple slides
+	//               to be visible in parallel on tall devices
+	scrollLayout: 'full',
+
+	// Control how scroll snapping works in the scroll view.
+	// - false:   	No snapping, scrolling is continuous
+	// - proximity:  Snap when close to a slide
+	// - mandatory:  Always snap to the closest slide
+	//
+	// Only applies to presentations in scroll view.
+	scrollSnap: 'mandatory',
+
+	// Enables and configure the scroll view progress bar.
+	// - 'auto':    Show the scrollbar while scrolling, hide while idle
+	// - true:      Always show the scrollbar
+	// - false:     Never show the scrollbar
+	scrollProgress: 'auto',
+
+	// Automatically activate the scroll view when we the viewport falls
+	// below the given width.
+	scrollActivationWidth: 435,
+
 	// The maximum number of pages a single slide can expand onto when printing
 	// to PDF, unlimited by default
 	pdfMaxPagesPerSlide: Number.POSITIVE_INFINITY,
@@ -284,6 +317,10 @@ export default {
 	// Time before the cursor is hidden (in ms)
 	hideCursorTime: 5000,

+	// Should we automatically sort and set indices for fragments
+	// at each sync? (See Reveal.sync)
+	sortFragmentsOnSync: true,
+
 	// Script dependencies to load
 	dependencies: [],

--- a/js/controllers/autoanimate.js
+++ b/js/controllers/autoanimate.js
@@ -50,11 +50,19 @@ export default class AutoAnimate {
 			// Flag the navigation direction, needed for fragment buildup
 			animationOptions.slideDirection = toSlideIndex > fromSlideIndex ? 'forward' : 'backward';

+			// If the from-slide is hidden because it has moved outside
+			// the view distance, we need to temporarily show it while
+			// measuring
+			let fromSlideIsHidden = fromSlide.style.display === 'none';
+			if( fromSlideIsHidden ) fromSlide.style.display = this.Reveal.getConfig().display;
+
 			// Inject our auto-animate styles for this transition
 			let css = this.getAutoAnimatableElements( fromSlide, toSlide ).map( elements => {
 				return this.autoAnimateElements( elements.from, elements.to, elements.options || {}, animationOptions, autoAnimateCounter++ );
 			} );

+			if( fromSlideIsHidden ) fromSlide.style.display = 'none';
+
 			// Animate unmatched elements, if enabled
 			if( toSlide.dataset.autoAnimateUnmatched !== 'false' && this.Reveal.getConfig().autoAnimateUnmatched === true ) {

@@ -391,7 +399,14 @@ export default class AutoAnimate {
 				value = { value: style.to, explicitValue: true };
 			}
 			else {
-				value = computedStyles[style.property];
+				// Use a unitless value for line-height so that it inherits properly
+				if( style.property === 'line-height' ) {
+					value = parseFloat( computedStyles['line-height'] ) / parseFloat( computedStyles['font-size'] );
+				}
+
+				if( isNaN(value) ) {
+					value = computedStyles[style.property];
+				}
 			}

 			if( value !== '' ) {
@@ -446,7 +461,7 @@ export default class AutoAnimate {
 		const textNodes = 'h1, h2, h3, h4, h5, h6, p, li';
 		const mediaNodes = 'img, video, iframe';

-		// Eplicit matches via data-id
+		// Explicit matches via data-id
 		this.findAutoAnimateMatches( pairs, fromSlide, toSlide, '[data-id]', node => {
 			return node.nodeName + ':::' + node.getAttribute( 'data-id' );
 		} );
@@ -467,7 +482,6 @@ export default class AutoAnimate {
 		} );

 		pairs.forEach( pair => {
-
 			// Disable scale transformations on text nodes, we transition
 			// each individual text property instead
 			if( matches( pair.from, textNodes ) ) {
@@ -490,7 +504,7 @@ export default class AutoAnimate {
 				} );

 				// Line numbers
-				this.findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-line[data-line-number]', node => {
+				this.findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-numbers[data-line-number]', node => {
 					return node.getAttribute( 'data-line-number' );
 				}, {
 					scale: false,
@@ -559,14 +573,14 @@ export default class AutoAnimate {

 			// Retrieve the 'from' element
 			if( fromMatches[key] ) {
-				const pimaryIndex = toMatches[key].length - 1;
+				const primaryIndex = toMatches[key].length - 1;
 				const secondaryIndex = fromMatches[key].length - 1;

 				// If there are multiple identical from elements, retrieve
 				// the one at the same index as our to-element.
-				if( fromMatches[key][ pimaryIndex ] ) {
-					fromElement = fromMatches[key][ pimaryIndex ];
-					fromMatches[key][ pimaryIndex ] = null;
+				if( fromMatches[key][ primaryIndex ] ) {
+					fromElement = fromMatches[key][ primaryIndex ];
+					fromMatches[key][ primaryIndex ] = null;
 				}
 				// If there are no matching from-elements at the same index,
 				// use the last one.
@@ -594,7 +608,7 @@ export default class AutoAnimate {
 	 * fading of unmatched elements is turned on, these elements
 	 * will fade when going between auto-animate slides.
 	 *
-	 * Note that parents of auto-animate targets are NOT considerd
+	 * Note that parents of auto-animate targets are NOT considered
 	 * unmatched since fading them would break the auto-animation.
 	 *
 	 * @param {HTMLElement} rootElement
--- a/js/controllers/backgrounds.js
+++ b/js/controllers/backgrounds.js
@@ -122,6 +122,7 @@ export default class Backgrounds {
 			backgroundVideo: slide.getAttribute( 'data-background-video' ),
 			backgroundIframe: slide.getAttribute( 'data-background-iframe' ),
 			backgroundColor: slide.getAttribute( 'data-background-color' ),
+			backgroundGradient: slide.getAttribute( 'data-background-gradient' ),
 			backgroundRepeat: slide.getAttribute( 'data-background-repeat' ),
 			backgroundPosition: slide.getAttribute( 'data-background-position' ),
 			backgroundTransition: slide.getAttribute( 'data-background-transition' ),
@@ -150,7 +151,7 @@ export default class Backgrounds {

 		if( data.background ) {
 			// Auto-wrap image urls in url(...)
-			if( /^(http|file|\/\/)/gi.test( data.background ) || /\.(svg|png|jpg|jpeg|gif|bmp)([?#\s]|$)/gi.test( data.background ) ) {
+			if( /^(http|file|\/\/)/gi.test( data.background ) || /\.(svg|png|jpg|jpeg|gif|bmp|webp)([?#\s]|$)/gi.test( data.background ) ) {
 				slide.setAttribute( 'data-background-image', data.background );
 			}
 			else {
@@ -161,13 +162,14 @@ export default class Backgrounds {
 		// Create a hash for this combination of background settings.
 		// This is used to determine when two slide backgrounds are
 		// the same.
-		if( data.background || data.backgroundColor || data.backgroundImage || data.backgroundVideo || data.backgroundIframe ) {
+		if( data.background || data.backgroundColor || data.backgroundGradient || data.backgroundImage || data.backgroundVideo || data.backgroundIframe ) {
 			element.setAttribute( 'data-background-hash', data.background +
 															data.backgroundSize +
 															data.backgroundImage +
 															data.backgroundVideo +
 															data.backgroundIframe +
 															data.backgroundColor +
+															data.backgroundGradient +
 															data.backgroundRepeat +
 															data.backgroundPosition +
 															data.backgroundTransition +
@@ -177,6 +179,7 @@ export default class Backgrounds {
 		// Additional and optional background properties
 		if( data.backgroundSize ) element.setAttribute( 'data-background-size', data.backgroundSize );
 		if( data.backgroundColor ) element.style.backgroundColor = data.backgroundColor;
+		if( data.backgroundGradient ) element.style.backgroundImage = data.backgroundGradient;
 		if( data.backgroundTransition ) element.setAttribute( 'data-background-transition', data.backgroundTransition );

 		if( dataPreload ) element.setAttribute( 'data-preload', '' );
@@ -187,10 +190,30 @@ export default class Backgrounds {
 		if( data.backgroundPosition ) contentElement.style.backgroundPosition = data.backgroundPosition;
 		if( data.backgroundOpacity ) contentElement.style.opacity = data.backgroundOpacity;

+		const contrastClass = this.getContrastClass( slide );
+
+		if( typeof contrastClass === 'string' ) {
+			slide.classList.add( contrastClass );
+		}
+
+	}
+
+	/**
+	 * Returns a class name that can be applied to a slide to indicate
+	 * if it has a light or dark background.
+	 *
+	 * @param {*} slide
+	 *
+	 * @returns {string|null}
+	 */
+	getContrastClass( slide ) {
+
+		const element = slide.slideBackgroundElement;
+
 		// If this slide has a background color, we add a class that
 		// signals if it is light or dark. If the slide has no background
 		// color, no class will be added
-		let contrastColor = data.backgroundColor;
+		let contrastColor = slide.getAttribute( 'data-background-color' );

 		// If no bg color was found, or it cannot be converted by colorToRgb, check the computed background
 		if( !contrastColor || !colorToRgb( contrastColor ) ) {
@@ -208,14 +231,32 @@ export default class Backgrounds {
 			// an element with no background
 			if( rgb && rgb.a !== 0 ) {
 				if( colorBrightness( contrastColor ) < 128 ) {
-					slide.classList.add( 'has-dark-background' );
+					return 'has-dark-background';
 				}
 				else {
-					slide.classList.add( 'has-light-background' );
+					return 'has-light-background';
 				}
 			}
 		}

+		return null;
+
+	}
+
+	/**
+	 * Bubble the 'has-light-background'/'has-dark-background' classes.
+	 */
+	bubbleSlideContrastClassToElement( slide, target ) {
+
+		[ 'has-light-background', 'has-dark-background' ].forEach( classToBubble => {
+			if( slide.classList.contains( classToBubble ) ) {
+				target.classList.add( classToBubble );
+			}
+			else {
+				target.classList.remove( classToBubble );
+			}
+		}, this );
+
 	}

 	/**
@@ -260,10 +301,12 @@ export default class Backgrounds {

 					backgroundv.classList.remove( 'past', 'present', 'future' );

-					if( v < indices.v ) {
+					const indexv = typeof indices.v === 'number' ? indices.v : 0;
+
+					if( v < indexv ) {
 						backgroundv.classList.add( 'past' );
 					}
-					else if ( v > indices.v ) {
+					else if ( v > indexv ) {
 						backgroundv.classList.add( 'future' );
 					}
 					else {
@@ -319,14 +362,7 @@ export default class Backgrounds {
 		// If there's a background brightness flag for this slide,
 		// bubble it to the .reveal container
 		if( currentSlide ) {
-			[ 'has-light-background', 'has-dark-background' ].forEach( classToBubble => {
-				if( currentSlide.classList.contains( classToBubble ) ) {
-					this.Reveal.getRevealElement().classList.add( classToBubble );
-				}
-				else {
-					this.Reveal.getRevealElement().classList.remove( classToBubble );
-				}
-			}, this );
+			this.bubbleSlideContrastClassToElement( currentSlide, this.Reveal.getRevealElement() );
 		}

 		// Allow the first background to apply without transition
@@ -394,4 +430,10 @@ export default class Backgrounds {

 	}

+	destroy() {
+
+		this.element.remove();
+
+	}
+
 }
--- a/js/controllers/controls.js
+++ b/js/controllers/controls.js
@@ -188,6 +188,13 @@ export default class Controls {
 		}
 	}

+	destroy() {
+
+		this.unbind();
+		this.element.remove();
+
+	}
+
 	/**
 	 * Event handlers for navigation control buttons.
 	 */
--- a/js/controllers/focus.js
+++ b/js/controllers/focus.js
@@ -79,6 +79,12 @@ export default class Focus {

 	}

+	destroy() {
+
+		this.Reveal.getRevealElement().classList.remove( 'focused' );
+
+	}
+
 	onRevealPointerDown( event ) {

 		this.focus();
--- a/js/controllers/fragments.js
+++ b/js/controllers/fragments.js
@@ -174,24 +174,23 @@ export default class Fragments {
 	 *
 	 * @return {{shown: array, hidden: array}}
 	 */
-	update( index, fragments ) {
+	update( index, fragments, slide = this.Reveal.getCurrentSlide() ) {

 		let changedFragments = {
 			shown: [],
 			hidden: []
 		};

-		let currentSlide = this.Reveal.getCurrentSlide();
-		if( currentSlide && this.Reveal.getConfig().fragments ) {
+		if( slide && this.Reveal.getConfig().fragments ) {

-			fragments = fragments || this.sort( currentSlide.querySelectorAll( '.fragment' ) );
+			fragments = fragments || this.sort( slide.querySelectorAll( '.fragment' ) );

 			if( fragments.length ) {

 				let maxIndex = 0;

 				if( typeof index !== 'number' ) {
-					let currentFragment = this.sort( currentSlide.querySelectorAll( '.fragment.visible' ) ).pop();
+					let currentFragment = this.sort( slide.querySelectorAll( '.fragment.visible' ) ).pop();
 					if( currentFragment ) {
 						index = parseInt( currentFragment.getAttribute( 'data-fragment-index' ) || 0, 10 );
 					}
@@ -252,7 +251,7 @@ export default class Fragments {
 				// the current fragment index.
 				index = typeof index === 'number' ? index : -1;
 				index = Math.max( Math.min( index, maxIndex ), -1 );
-				currentSlide.setAttribute( 'data-fragment', index );
+				slide.setAttribute( 'data-fragment', index );

 			}

--- a/js/controllers/jumptoslide.js
+++ b/js/controllers/jumptoslide.js
@@ -0,0 +1,197 @@
+import {
+	SLIDE_NUMBER_FORMAT_CURRENT,
+	SLIDE_NUMBER_FORMAT_CURRENT_SLASH_TOTAL
+} from "../utils/constants";
+
+/**
+ * Makes it possible to jump to a slide by entering its
+ * slide number or id.
+ */
+export default class JumpToSlide {
+
+	constructor( Reveal ) {
+
+		this.Reveal = Reveal;
+
+		this.onInput = this.onInput.bind( this );
+		this.onBlur = this.onBlur.bind( this );
+		this.onKeyDown = this.onKeyDown.bind( this );
+
+	}
+
+	render() {
+
+		this.element = document.createElement( 'div' );
+		this.element.className = 'jump-to-slide';
+
+    this.jumpInput = document.createElement( 'input' );
+    this.jumpInput.type = 'text';
+    this.jumpInput.className = 'jump-to-slide-input';
+    this.jumpInput.placeholder = 'Jump to slide';
+		this.jumpInput.addEventListener( 'input', this.onInput );
+		this.jumpInput.addEventListener( 'keydown', this.onKeyDown );
+		this.jumpInput.addEventListener( 'blur', this.onBlur );
+
+    this.element.appendChild( this.jumpInput );
+
+	}
+
+	show() {
+
+		this.indicesOnShow = this.Reveal.getIndices();
+
+		this.Reveal.getRevealElement().appendChild( this.element );
+		this.jumpInput.focus();
+
+	}
+
+	hide() {
+
+		if( this.isVisible() ) {
+			this.element.remove();
+			this.jumpInput.value = '';
+
+			clearTimeout( this.jumpTimeout );
+			delete this.jumpTimeout;
+		}
+
+	}
+
+	isVisible() {
+
+		return !!this.element.parentNode;
+
+	}
+
+	/**
+	 * Parses the current input and jumps to the given slide.
+	 */
+	jump() {
+
+		clearTimeout( this.jumpTimeout );
+		delete this.jumpTimeout;
+
+		let query = this.jumpInput.value.trim( '' );
+		let indices;
+
+		// When slide numbers are formatted to be a single linear mumber
+		// (instead of showing a separate horizontal/vertical index) we
+		// use the same format for slide jumps
+		if( /^\d+$/.test( query ) ) {
+			const slideNumberFormat = this.Reveal.getConfig().slideNumber;
+			if( slideNumberFormat === SLIDE_NUMBER_FORMAT_CURRENT || slideNumberFormat === SLIDE_NUMBER_FORMAT_CURRENT_SLASH_TOTAL ) {
+				const slide = this.Reveal.getSlides()[ parseInt( query, 10 ) - 1 ];
+				if( slide ) {
+					indices = this.Reveal.getIndices( slide );
+				}
+			}
+		}
+
+		if( !indices ) {
+			// If the query uses "horizontal.vertical" format, convert to
+			// "horizontal/vertical" so that our URL parser can understand
+			if( /^\d+\.\d+$/.test( query ) ) {
+				query = query.replace( '.', '/' );
+			}
+
+			indices = this.Reveal.location.getIndicesFromHash( query, { oneBasedIndex: true } );
+		}
+
+		// Still no valid index? Fall back on a text search
+		if( !indices && /\S+/i.test( query ) && query.length > 1 ) {
+			indices = this.search( query );
+		}
+
+		if( indices && query !== '' ) {
+			this.Reveal.slide( indices.h, indices.v, indices.f );
+			return true;
+		}
+		else {
+			this.Reveal.slide( this.indicesOnShow.h, this.indicesOnShow.v, this.indicesOnShow.f );
+			return false;
+		}
+
+	}
+
+	jumpAfter( delay ) {
+
+		clearTimeout( this.jumpTimeout );
+		this.jumpTimeout = setTimeout( () => this.jump(), delay );
+
+	}
+
+	/**
+	 * A lofi search that looks for the given query in all
+	 * of our slides and returns the first match.
+	 */
+	search( query ) {
+
+		const regex = new RegExp( '\\b' + query.trim() + '\\b', 'i' );
+
+		const slide = this.Reveal.getSlides().find( ( slide ) => {
+			return regex.test( slide.innerText );
+		} );
+
+		if( slide ) {
+			return this.Reveal.getIndices( slide );
+		}
+		else {
+			return null;
+		}
+
+	}
+
+	/**
+	 * Reverts back to the slide we were on when jump to slide was
+	 * invoked.
+	 */
+	cancel() {
+
+		this.Reveal.slide( this.indicesOnShow.h, this.indicesOnShow.v, this.indicesOnShow.f );
+		this.hide();
+
+	}
+
+	confirm() {
+
+		this.jump();
+		this.hide();
+
+	}
+
+	destroy() {
+
+		this.jumpInput.removeEventListener( 'input', this.onInput );
+		this.jumpInput.removeEventListener( 'keydown', this.onKeyDown );
+		this.jumpInput.removeEventListener( 'blur', this.onBlur );
+
+		this.element.remove();
+
+	}
+
+	onKeyDown( event ) {
+
+		if( event.keyCode === 13 ) {
+			this.confirm();
+		}
+		else if( event.keyCode === 27 ) {
+			this.cancel();
+
+			event.stopImmediatePropagation();
+		}
+
+	}
+
+	onInput( event ) {
+
+		this.jumpAfter( 200 );
+
+	}
+
+	onBlur() {
+
+		setTimeout( () => this.hide(), 1 );
+
+	}
+
+}
--- a/js/controllers/keyboard.js
+++ b/js/controllers/keyboard.js
@@ -17,7 +17,6 @@ export default class Keyboard {
 		this.bindings = {};

 		this.onDocumentKeyDown = this.onDocumentKeyDown.bind( this );
-		this.onDocumentKeyPress = this.onDocumentKeyPress.bind( this );

 	}

@@ -32,17 +31,18 @@ export default class Keyboard {
 		}
 		else {
 			this.shortcuts['N  ,  SPACE']   = 'Next slide';
-			this.shortcuts['P']             = 'Previous slide';
+			this.shortcuts['P  ,  Shift SPACE']             = 'Previous slide';
 			this.shortcuts['&#8592;  ,  H'] = 'Navigate left';
 			this.shortcuts['&#8594;  ,  L'] = 'Navigate right';
 			this.shortcuts['&#8593;  ,  K'] = 'Navigate up';
 			this.shortcuts['&#8595;  ,  J'] = 'Navigate down';
 		}

-		this.shortcuts['Home  ,  Shift &#8592;']        = 'First slide';
-		this.shortcuts['End  ,  Shift &#8594;']         = 'Last slide';
+		this.shortcuts['Alt + &#8592;/&#8593/&#8594;/&#8595;']        = 'Navigate without fragments';
+		this.shortcuts['Shift + &#8592;/&#8593/&#8594;/&#8595;']      = 'Jump to first/last slide';
 		this.shortcuts['B  ,  .']                       = 'Pause';
 		this.shortcuts['F']                             = 'Fullscreen';
+		this.shortcuts['G']                             = 'Jump to slide';
 		this.shortcuts['ESC, O']                        = 'Slide overview';

 	}
@@ -53,7 +53,6 @@ export default class Keyboard {
 	bind() {

 		document.addEventListener( 'keydown', this.onDocumentKeyDown, false );
-		document.addEventListener( 'keypress', this.onDocumentKeyPress, false );

 	}

@@ -63,7 +62,6 @@ export default class Keyboard {
 	unbind() {

 		document.removeEventListener( 'keydown', this.onDocumentKeyDown, false );
-		document.removeEventListener( 'keypress', this.onDocumentKeyPress, false );

 	}

@@ -134,20 +132,6 @@ export default class Keyboard {

 	}

-	/**
-	 * Handler for the document level 'keypress' event.
-	 *
-	 * @param {object} event
-	 */
-	onDocumentKeyPress( event ) {
-
-		// Check if the pressed key is question mark
-		if( event.shiftKey && event.charCode === 63 ) {
-			this.Reveal.toggleHelp();
-		}
-
-	}
-
 	/**
 	 * Handler for the document level 'keydown' event.
 	 *
@@ -182,13 +166,11 @@ export default class Keyboard {
 		let activeElementIsInput = document.activeElement && document.activeElement.tagName && /input|textarea/i.test( document.activeElement.tagName );
 		let activeElementIsNotes = document.activeElement && document.activeElement.className && /speaker-notes/i.test( document.activeElement.className);

-		// Whitelist specific modified + keycode combinations
-		let prevSlideShortcut = event.shiftKey && event.keyCode === 32;
-		let firstSlideShortcut = event.shiftKey && keyCode === 37;
-		let lastSlideShortcut = event.shiftKey && keyCode === 39;
+		// Whitelist certain modifiers for slide navigation shortcuts
+		let keyCodeUsesModifier = [32, 37, 38, 39, 40, 78, 80, 191].indexOf( event.keyCode ) !== -1;

 		// Prevent all other events when a modifier is pressed
-		let unusedModifier = 	!prevSlideShortcut && !firstSlideShortcut && !lastSlideShortcut &&
+		let unusedModifier = 	!( keyCodeUsesModifier && event.shiftKey || event.altKey ) &&
 								( event.shiftKey || event.altKey || event.ctrlKey || event.metaKey );

 		// Disregard the event if there's a focused element or a
@@ -277,52 +259,58 @@ export default class Keyboard {

 			// P, PAGE UP
 			if( keyCode === 80 || keyCode === 33 ) {
-				this.Reveal.prev();
+				this.Reveal.prev({skipFragments: event.altKey});
 			}
 			// N, PAGE DOWN
 			else if( keyCode === 78 || keyCode === 34 ) {
-				this.Reveal.next();
+				this.Reveal.next({skipFragments: event.altKey});
 			}
 			// H, LEFT
 			else if( keyCode === 72 || keyCode === 37 ) {
-				if( firstSlideShortcut ) {
+				if( event.shiftKey ) {
 					this.Reveal.slide( 0 );
 				}
 				else if( !this.Reveal.overview.isActive() && useLinearMode ) {
-					this.Reveal.prev();
+					this.Reveal.prev({skipFragments: event.altKey});
 				}
 				else {
-					this.Reveal.left();
+					this.Reveal.left({skipFragments: event.altKey});
 				}
 			}
 			// L, RIGHT
 			else if( keyCode === 76 || keyCode === 39 ) {
-				if( lastSlideShortcut ) {
-					this.Reveal.slide( Number.MAX_VALUE );
+				if( event.shiftKey ) {
+					this.Reveal.slide( this.Reveal.getHorizontalSlides().length - 1 );
 				}
 				else if( !this.Reveal.overview.isActive() && useLinearMode ) {
-					this.Reveal.next();
+					this.Reveal.next({skipFragments: event.altKey});
 				}
 				else {
-					this.Reveal.right();
+					this.Reveal.right({skipFragments: event.altKey});
 				}
 			}
 			// K, UP
 			else if( keyCode === 75 || keyCode === 38 ) {
-				if( !this.Reveal.overview.isActive() && useLinearMode ) {
-					this.Reveal.prev();
+				if( event.shiftKey ) {
+					this.Reveal.slide( undefined, 0 );
+				}
+				else if( !this.Reveal.overview.isActive() && useLinearMode ) {
+					this.Reveal.prev({skipFragments: event.altKey});
 				}
 				else {
-					this.Reveal.up();
+					this.Reveal.up({skipFragments: event.altKey});
 				}
 			}
 			// J, DOWN
 			else if( keyCode === 74 || keyCode === 40 ) {
-				if( !this.Reveal.overview.isActive() && useLinearMode ) {
-					this.Reveal.next();
+				if( event.shiftKey ) {
+					this.Reveal.slide( undefined, Number.MAX_VALUE );
+				}
+				else if( !this.Reveal.overview.isActive() && useLinearMode ) {
+					this.Reveal.next({skipFragments: event.altKey});
 				}
 				else {
-					this.Reveal.down();
+					this.Reveal.down({skipFragments: event.altKey});
 				}
 			}
 			// HOME
@@ -331,7 +319,7 @@ export default class Keyboard {
 			}
 			// END
 			else if( keyCode === 35 ) {
-				this.Reveal.slide( Number.MAX_VALUE );
+				this.Reveal.slide( this.Reveal.getHorizontalSlides().length - 1 );
 			}
 			// SPACE
 			else if( keyCode === 32 ) {
@@ -339,14 +327,14 @@ export default class Keyboard {
 					this.Reveal.overview.deactivate();
 				}
 				if( event.shiftKey ) {
-					this.Reveal.prev();
+					this.Reveal.prev({skipFragments: event.altKey});
 				}
 				else {
-					this.Reveal.next();
+					this.Reveal.next({skipFragments: event.altKey});
 				}
 			}
 			// TWO-SPOT, SEMICOLON, B, V, PERIOD, LOGITECH PRESENTER TOOLS "BLACK SCREEN" BUTTON
-			else if( keyCode === 58 || keyCode === 59 || keyCode === 66 || keyCode === 86 || keyCode === 190 || keyCode === 191 ) {
+			else if( [58, 59, 66, 86, 190].includes( keyCode ) || ( keyCode === 191 && !event.shiftKey ) ) {
 				this.Reveal.togglePause();
 			}
 			// F
@@ -355,10 +343,20 @@ export default class Keyboard {
 			}
 			// A
 			else if( keyCode === 65 ) {
-				if ( config.autoSlideStoppable ) {
+				if( config.autoSlideStoppable ) {
 					this.Reveal.toggleAutoSlide( autoSlideWasPaused );
 				}
 			}
+			// G
+			else if( keyCode === 71 ) {
+				if( config.jumpToSlide ) {
+					this.Reveal.toggleJumpToSlide();
+				}
+			}
+			// ?
+			else if( keyCode === 191 && event.shiftKey ) {
+				this.Reveal.toggleHelp();
+			}
 			else {
 				triggered = false;
 			}
--- a/js/controllers/location.js
+++ b/js/controllers/location.js
@@ -3,6 +3,10 @@
 */
 export default class Location {

+	// The minimum number of milliseconds that must pass between
+	// calls to history.replaceState
+	MAX_REPLACE_STATE_FREQUENCY = 1000
+
 	constructor( Reveal ) {

 		this.Reveal = Reveal;
@@ -10,6 +14,8 @@ export default class Location {
 		// Delays updates to the URL due to a Chrome thumbnailer bug
 		this.writeURLTimeout = 0;

+		this.replaceStateTimestamp = 0;
+
 		this.onWindowHashChange = this.onWindowHashChange.bind( this );

 	}
@@ -27,24 +33,23 @@ export default class Location {
 	}

 	/**
-	 * Reads the current URL (hash) and navigates accordingly.
+	 * Returns the slide indices for the given hash link.
+	 *
+	 * @param {string} [hash] the hash string that we want to
+	 * find the indices for
+	 *
+	 * @returns slide indices or null
 	 */
-	readURL() {
-
-		let config = this.Reveal.getConfig();
-		let indices = this.Reveal.getIndices();
-		let currentSlide = this.Reveal.getCurrentSlide();
-
-		let hash = window.location.hash;
+	getIndicesFromHash( hash=window.location.hash, options={} ) {

 		// Attempt to parse the hash as either an index or name
-		let bits = hash.slice( 2 ).split( '/' ),
-			name = hash.replace( /#\/?/gi, '' );
+		let name = hash.replace( /^#\/?/, '' );
+		let bits = name.split( '/' );

 		// If the first bit is not fully numeric and there is a name we
 		// can assume that this is a named link
 		if( !/^[0-9]*$/.test( bits[0] ) && name.length ) {
-			let element;
+			let slide;

 			let f;

@@ -57,28 +62,19 @@ export default class Location {

 			// Ensure the named link is a valid HTML ID attribute
 			try {
-				element = document.getElementById( decodeURIComponent( name ) );
+				slide = document
+					.getElementById( decodeURIComponent( name ) )
+					.closest('.slides section');
 			}
 			catch ( error ) { }

-			// Ensure that we're not already on a slide with the same name
-			let isSameNameAsCurrentSlide = currentSlide ? currentSlide.getAttribute( 'id' ) === name : false;
-
-			if( element ) {
-				// If the slide exists and is not the current slide...
-				if ( !isSameNameAsCurrentSlide || typeof f !== 'undefined' ) {
-					// ...find the position of the named slide and navigate to it
-					let slideIndices = this.Reveal.getIndices( element );
-					this.Reveal.slide( slideIndices.h, slideIndices.v, f );
-				}
-			}
-			// If the slide doesn't exist, navigate to the current slide
-			else {
-				this.Reveal.slide( indices.h || 0, indices.v || 0 );
+			if( slide ) {
+				return { ...this.Reveal.getIndices( slide ), f };
 			}
 		}
 		else {
-			let hashIndexBase = config.hashOneBasedIndex ? 1 : 0;
+			const config = this.Reveal.getConfig();
+			let hashIndexBase = config.hashOneBasedIndex || options.oneBasedIndex ? 1 : 0;

 			// Read the index components of the hash
 			let h = ( parseInt( bits[0], 10 ) - hashIndexBase ) || 0,
@@ -92,10 +88,32 @@ export default class Location {
 				}
 			}

-			if( h !== indices.h || v !== indices.v || f !== undefined ) {
-				this.Reveal.slide( h, v, f );
+			return { h, v, f };
+		}
+
+		// The hash couldn't be parsed or no matching named link was found
+		return null
+
+	}
+
+	/**
+	 * Reads the current URL (hash) and navigates accordingly.
+	 */
+	readURL() {
+
+		const currentIndices = this.Reveal.getIndices();
+		const newIndices = this.getIndicesFromHash();
+
+		if( newIndices ) {
+			if( ( newIndices.h !== currentIndices.h || newIndices.v !== currentIndices.v || newIndices.f !== undefined ) ) {
+					this.Reveal.slide( newIndices.h, newIndices.v, newIndices.f );
 			}
 		}
+		// If no new indices are available, we're trying to navigate to
+		// a slide hash that does not exist
+		else {
+			this.Reveal.slide( currentIndices.h || 0, currentIndices.v || 0 );
+		}

 	}

@@ -123,7 +141,7 @@ export default class Location {
 			let hash = this.getHash();

 			// If we're configured to push to history OR the history
-			// API is not avaialble.
+			// API is not available.
 			if( config.history ) {
 				window.location.hash = hash;
 			}
@@ -132,10 +150,10 @@ export default class Location {
 			else if( config.hash ) {
 				// If the hash is empty, don't add it to the URL
 				if( hash === '/' ) {
-					window.history.replaceState( null, null, window.location.pathname + window.location.search );
+					this.debouncedReplaceState( window.location.pathname + window.location.search );
 				}
 				else {
-					window.history.replaceState( null, null, '#' + hash );
+					this.debouncedReplaceState( '#' + hash );
 				}
 			}
 			// UPDATE: The below nuking of all hash changes breaks
@@ -153,6 +171,26 @@ export default class Location {

 	}

+	replaceState( url ) {
+
+		window.history.replaceState( null, null, url );
+		this.replaceStateTimestamp = Date.now();
+
+	}
+
+	debouncedReplaceState( url ) {
+
+		clearTimeout( this.replaceStateTimeout );
+
+		if( Date.now() - this.replaceStateTimestamp > this.MAX_REPLACE_STATE_FREQUENCY ) {
+			this.replaceState( url );
+		}
+		else {
+			this.replaceStateTimeout = setTimeout( () => this.replaceState( url ), this.MAX_REPLACE_STATE_FREQUENCY );
+		}
+
+	}
+
 	/**
 	 * Return a hash URL that will resolve to the given slide location.
 	 *
--- a/js/controllers/notes.js
+++ b/js/controllers/notes.js
@@ -1,5 +1,5 @@
 /**
- * Handles the showing and 
+ * Handles the showing of speaker notes
 */
 export default class Notes {

@@ -38,10 +38,12 @@ export default class Notes {
 	 */
 	update() {

-		if( this.Reveal.getConfig().showNotes && this.element && this.Reveal.getCurrentSlide() && !this.Reveal.print.isPrintingPDF() ) {
-
+		if( this.Reveal.getConfig().showNotes &&
+			this.element && this.Reveal.getCurrentSlide() &&
+			!this.Reveal.isScrollView() &&
+			!this.Reveal.isPrintView()
+		) {
 			this.element.innerHTML = this.getSlideNotes() || '<span class="notes-placeholder">No notes on this slide.</span>';
-
 		}

 	}
@@ -54,7 +56,11 @@ export default class Notes {
 	 */
 	updateVisibility() {

-		if( this.Reveal.getConfig().showNotes && this.hasNotes() && !this.Reveal.print.isPrintingPDF() ) {
+		if( this.Reveal.getConfig().showNotes &&
+			this.hasNotes() &&
+			!this.Reveal.isScrollView() &&
+			!this.Reveal.isPrintView()
+		) {
 			this.Reveal.getRevealElement().classList.add( 'show-notes' );
 		}
 		else {
@@ -89,7 +95,7 @@ export default class Notes {
 	 * Retrieves the speaker notes from a slide. Notes can be
 	 * defined in two ways:
 	 * 1. As a data-notes attribute on the slide <section>
-	 * 2. As an <aside class="notes"> inside of the slide
+	 * 2. With <aside class="notes"> elements inside the slide
 	 *
 	 * @param {HTMLElement} [slide=currentSlide]
 	 * @return {(string|null)}
@@ -101,14 +107,20 @@ export default class Notes {
 			return slide.getAttribute( 'data-notes' );
 		}

-		// ... or using an <aside class="notes"> element
-		let notesElement = slide.querySelector( 'aside.notes' );
-		if( notesElement ) {
-			return notesElement.innerHTML;
+		// ... or using <aside class="notes"> elements
+		let notesElements = slide.querySelectorAll( 'aside.notes' );
+		if( notesElements ) {
+			return Array.from(notesElements).map( notesElement => notesElement.innerHTML ).join( '\n' );
 		}

 		return null;

 	}

+	destroy() {
+
+		this.element.remove();
+
+	}
+
 }
--- a/js/controllers/overview.js
+++ b/js/controllers/overview.js
@@ -24,7 +24,7 @@ export default class Overview {
 	activate() {

 		// Only proceed if enabled in config
-		if( this.Reveal.getConfig().overview && !this.isActive() ) {
+		if( this.Reveal.getConfig().overview && !this.Reveal.isScrollView() && !this.isActive() ) {

 			this.active = true;

--- a/js/controllers/plugins.js
+++ b/js/controllers/plugins.js
@@ -12,7 +12,7 @@ export default class Plugins {
 		// Flags our current state (idle -> loading -> loaded)
 		this.state = 'idle';

-		// An id:instance map of currently registed plugins
+		// An id:instance map of currently registered plugins
 		this.registeredPlugins = {};

 		this.asyncDependencies = [];
@@ -171,7 +171,7 @@ export default class Plugins {
 	/**
 	 * Registers a new plugin with this reveal.js instance.
 	 *
-	 * reveal.js waits for all regisered plugins to initialize
+	 * reveal.js waits for all registered plugins to initialize
 	 * before considering itself ready, as long as the plugin
 	 * is registered before calling `Reveal.initialize()`.
 	 */
@@ -238,4 +238,17 @@ export default class Plugins {

 	}

+	destroy() {
+
+		Object.values( this.registeredPlugins ).forEach( plugin => {
+			if( typeof plugin.destroy === 'function' ) {
+				plugin.destroy();
+			}
+		} );
+
+		this.registeredPlugins = {};
+		this.asyncDependencies = [];
+
+	}
+
 }
--- a/js/controllers/pointer.js
+++ b/js/controllers/pointer.js
@@ -27,12 +27,10 @@ export default class Pointer {
 	configure( config, oldConfig ) {

 		if( config.mouseWheel ) {
-			document.addEventListener( 'DOMMouseScroll', this.onDocumentMouseScroll, false ); // FF
-			document.addEventListener( 'mousewheel', this.onDocumentMouseScroll, false );
+			document.addEventListener( 'wheel', this.onDocumentMouseScroll, false );
 		}
 		else {
-			document.removeEventListener( 'DOMMouseScroll', this.onDocumentMouseScroll, false ); // FF
-			document.removeEventListener( 'mousewheel', this.onDocumentMouseScroll, false );
+			document.removeEventListener( 'wheel', this.onDocumentMouseScroll, false );
 		}

 		// Auto-hide the mouse pointer when its inactive
@@ -75,6 +73,16 @@ export default class Pointer {

 	}

+	destroy() {
+
+		this.showCursor();
+
+		document.removeEventListener( 'wheel', this.onDocumentMouseScroll, false );
+		document.removeEventListener( 'mousemove', this.onDocumentCursorActive, false );
+		document.removeEventListener( 'mousedown', this.onDocumentCursorActive, false );
+
+	}
+
 	/**
 	 * Called whenever there is mouse input at the document level
 	 * to determine if the cursor is active or not.
@@ -115,4 +123,4 @@ export default class Pointer {

 	}

-}
+}
--- a/js/controllers/printview.js
+++ b/js/controllers/printview.js
@@ -4,7 +4,7 @@ import { queryAll, createStyleSheet } from '../utils/util.js'
 /**
 * Setups up our presentation for printing/exporting to PDF.
 */
-export default class Print {
+export default class PrintView {

 	constructor( Reveal ) {

@@ -16,13 +16,13 @@ export default class Print {
 	 * Configures the presentation for printing to a static
 	 * PDF.
 	 */
-	async setupPDF() {
+	async activate() {

 		const config = this.Reveal.getConfig();
 		const slides = queryAll( this.Reveal.getRevealElement(), SLIDES_SELECTOR )

 		// Compute slide numbers now, before we start duplicating slides
-		const doingSlideNumbers = config.slideNumber && /all|print/i.test( config.showSlideNumber );
+		const injectPageNumbers = config.slideNumber && /all|print/i.test( config.showSlideNumber );

 		const slideSize = this.Reveal.getComputedSlideSize( window.innerWidth, window.innerHeight );

@@ -42,18 +42,23 @@ export default class Print {
 		// Limit the size of certain elements to the dimensions of the slide
 		createStyleSheet( '.reveal section>img, .reveal section>video, .reveal section>iframe{max-width: '+ slideWidth +'px; max-height:'+ slideHeight +'px}' );

-		document.documentElement.classList.add( 'print-pdf' );
+		document.documentElement.classList.add( 'reveal-print', 'print-pdf' );
 		document.body.style.width = pageWidth + 'px';
 		document.body.style.height = pageHeight + 'px';

+		const viewportElement = this.Reveal.getViewportElement();
+		let presentationBackground;
+		if( viewportElement ) {
+			const viewportStyles = window.getComputedStyle( viewportElement );
+			if( viewportStyles && viewportStyles.background ) {
+				presentationBackground = viewportStyles.background;
+			}
+		}
+
 		// Make sure stretch elements fit on slide
 		await new Promise( requestAnimationFrame );
 		this.Reveal.layoutSlideContents( slideWidth, slideHeight );

-		// Re-run the slide layout so that r-fit-text is applied based on
-		// the printed slide size
-		slides.forEach( slide => this.Reveal.slideContent.layout( slide ) );
-
 		// Batch scrollHeight access to prevent layout thrashing
 		await new Promise( requestAnimationFrame );

@@ -61,6 +66,7 @@ export default class Print {

 		const pages = [];
 		const pageContainer = slides[0].parentNode;
+		let slideNumber = 1;

 		// Slide and slide background layout
 		slides.forEach( function( slide, index ) {
@@ -90,6 +96,13 @@ export default class Print {

 				page.className = 'pdf-page';
 				page.style.height = ( ( pageHeight + config.pdfPageHeightOffset ) * numberOfPages ) + 'px';
+
+				// Copy the presentation-wide background to each individual
+				// page when printing
+				if( presentationBackground ) {
+					page.style.background = presentationBackground;
+				}
+
 				page.appendChild( slide );

 				// Position the slide inside of the page
@@ -97,6 +110,8 @@ export default class Print {
 				slide.style.top = top + 'px';
 				slide.style.width = slideWidth + 'px';

+				this.Reveal.slideContent.layout( slide );
+
 				if( slide.slideBackgroundElement ) {
 					page.insertBefore( slide.slideBackgroundElement, slide );
 				}
@@ -130,13 +145,12 @@ export default class Print {

 				}

-				// Inject slide numbers if `slideNumbers` are enabled
-				if( doingSlideNumbers ) {
-					const slideNumber = index + 1;
+				// Inject page numbers if `slideNumbers` are enabled
+				if( injectPageNumbers ) {
 					const numberElement = document.createElement( 'div' );
 					numberElement.classList.add( 'slide-number' );
 					numberElement.classList.add( 'slide-number-pdf' );
-					numberElement.innerHTML = slideNumber;
+					numberElement.innerHTML = slideNumber++;
 					page.appendChild( numberElement );
 				}

@@ -150,7 +164,7 @@ export default class Print {

 					let previousFragmentStep;

-					fragmentGroups.forEach( function( fragments ) {
+					fragmentGroups.forEach( function( fragments, index ) {

 						// Remove 'current-fragment' from the previous group
 						if( previousFragmentStep ) {
@@ -166,6 +180,14 @@ export default class Print {

 						// Create a separate page for the current fragment state
 						const clonedPage = page.cloneNode( true );
+
+						// Inject unique page numbers for fragments
+						if( injectPageNumbers ) {
+							const numberElement = clonedPage.querySelector( '.slide-number-pdf' );
+							const fragmentNumber = index + 1;
+							numberElement.innerHTML += '.' + fragmentNumber;
+						}
+
 						pages.push( clonedPage );

 						previousFragmentStep = fragments;
@@ -195,18 +217,23 @@ export default class Print {

 		pages.forEach( page => pageContainer.appendChild( page ) );

+		// Re-run JS-based content layout after the slide is added to page DOM
+		this.Reveal.slideContent.layout( this.Reveal.getSlidesElement() );
+
 		// Notify subscribers that the PDF layout is good to go
 		this.Reveal.dispatchEvent({ type: 'pdf-ready' });

+		viewportElement.classList.remove( 'loading-scroll-mode' );
+
 	}

 	/**
-	 * Checks if this instance is being used to print a PDF.
+	 * Checks if the print mode is/should be activated.
 	 */
-	isPrintingPDF() {
+	isActive() {

-		return ( /print-pdf/gi ).test( window.location.search );
+		return this.Reveal.getConfig().view === 'print';

 	}

-}
+}
--- a/js/controllers/progress.js
+++ b/js/controllers/progress.js
@@ -101,5 +101,10 @@ export default class Progress {

 	}

+	destroy() {
+
+		this.element.remove();
+
+	}

 }
--- a/js/controllers/scrollview.js
+++ b/js/controllers/scrollview.js
@@ -0,0 +1,888 @@
+import { HORIZONTAL_SLIDES_SELECTOR } from '../utils/constants.js'
+import { queryAll } from '../utils/util.js'
+
+const HIDE_SCROLLBAR_TIMEOUT = 500;
+const MAX_PROGRESS_SPACING = 4;
+const MIN_PROGRESS_SEGMENT_HEIGHT = 6;
+const MIN_PLAYHEAD_HEIGHT = 8;
+
+/**
+ * The scroll view lets you read a reveal.js presentation
+ * as a linear scrollable page.
+ */
+export default class ScrollView {
+
+	constructor( Reveal ) {
+
+		this.Reveal = Reveal;
+
+		this.active = false;
+		this.activatedCallbacks = [];
+
+		this.onScroll = this.onScroll.bind( this );
+
+	}
+
+	/**
+	 * Activates the scroll view. This rearranges the presentation DOM
+	 * by—among other things—wrapping each slide in a page element.
+	 */
+	activate() {
+
+		if( this.active ) return;
+
+		const stateBeforeActivation = this.Reveal.getState();
+
+		this.active = true;
+
+		// Store the full presentation HTML so that we can restore it
+		// when/if the scroll view is deactivated
+		this.slideHTMLBeforeActivation = this.Reveal.getSlidesElement().innerHTML;
+
+		const horizontalSlides = queryAll( this.Reveal.getRevealElement(), HORIZONTAL_SLIDES_SELECTOR );
+
+		this.viewportElement.classList.add( 'loading-scroll-mode', 'reveal-scroll' );
+
+		let presentationBackground;
+
+		const viewportStyles = window.getComputedStyle( this.viewportElement );
+		if( viewportStyles && viewportStyles.background ) {
+			presentationBackground = viewportStyles.background;
+		}
+
+		const pageElements = [];
+		const pageContainer = horizontalSlides[0].parentNode;
+
+		let previousSlide;
+
+		// Creates a new page element and appends the given slide/bg
+		// to it.
+		const createPageElement = ( slide, h, v ) => {
+
+			let contentContainer;
+
+			// If this slide is part of an auto-animation sequence, we
+			// group it under the same page element as the previous slide
+			if( previousSlide && this.Reveal.shouldAutoAnimateBetween( previousSlide, slide ) ) {
+				contentContainer = document.createElement( 'div' );
+				contentContainer.className = 'scroll-page-content scroll-auto-animate-page';
+				contentContainer.style.display = 'none';
+				previousSlide.closest( '.scroll-page-content' ).parentNode.appendChild( contentContainer );
+			}
+			else {
+				// Wrap the slide in a page element and hide its overflow
+				// so that no page ever flows onto another
+				const page = document.createElement( 'div' );
+				page.className = 'scroll-page';
+				pageElements.push( page );
+
+				// Copy the presentation-wide background to each page
+				if( presentationBackground ) {
+					page.style.background = presentationBackground;
+				}
+
+				const stickyContainer = document.createElement( 'div' );
+				stickyContainer.className = 'scroll-page-sticky';
+				page.appendChild( stickyContainer );
+
+				contentContainer = document.createElement( 'div' );
+				contentContainer.className = 'scroll-page-content';
+				stickyContainer.appendChild( contentContainer );
+			}
+
+			contentContainer.appendChild( slide );
+
+			slide.classList.remove( 'past', 'future' );
+			slide.setAttribute( 'data-index-h', h );
+			slide.setAttribute( 'data-index-v', v );
+
+			if( slide.slideBackgroundElement ) {
+				slide.slideBackgroundElement.remove( 'past', 'future' );
+				contentContainer.insertBefore( slide.slideBackgroundElement, slide );
+			}
+
+			previousSlide = slide;
+
+		}
+
+		// Slide and slide background layout
+		horizontalSlides.forEach( ( horizontalSlide, h ) => {
+
+			if( this.Reveal.isVerticalStack( horizontalSlide ) ) {
+				horizontalSlide.querySelectorAll( 'section' ).forEach( ( verticalSlide, v ) => {
+					createPageElement( verticalSlide, h, v );
+				});
+			}
+			else {
+				createPageElement( horizontalSlide, h, 0 );
+			}
+
+		}, this );
+
+		this.createProgressBar();
+
+		// Remove leftover stacks
+		queryAll( this.Reveal.getRevealElement(), '.stack' ).forEach( stack => stack.remove() );
+
+		// Add our newly created pages to the DOM
+		pageElements.forEach( page => pageContainer.appendChild( page ) );
+
+		// Re-run JS-based content layout after the slide is added to page DOM
+		this.Reveal.slideContent.layout( this.Reveal.getSlidesElement() );
+
+		this.Reveal.layout();
+		this.Reveal.setState( stateBeforeActivation );
+
+		this.activatedCallbacks.forEach( callback => callback() );
+		this.activatedCallbacks = [];
+
+		this.restoreScrollPosition();
+
+		this.viewportElement.classList.remove( 'loading-scroll-mode' );
+		this.viewportElement.addEventListener( 'scroll', this.onScroll, { passive: true } );
+
+	}
+
+	/**
+	 * Deactivates the scroll view and restores the standard slide-based
+	 * presentation.
+	 */
+	deactivate() {
+
+		if( !this.active ) return;
+
+		const stateBeforeDeactivation = this.Reveal.getState();
+
+		this.active = false;
+
+		this.viewportElement.removeEventListener( 'scroll', this.onScroll );
+		this.viewportElement.classList.remove( 'reveal-scroll' );
+
+		this.removeProgressBar();
+
+		this.Reveal.getSlidesElement().innerHTML = this.slideHTMLBeforeActivation;
+		this.Reveal.sync();
+		this.Reveal.setState( stateBeforeDeactivation );
+
+		this.slideHTMLBeforeActivation = null;
+
+	}
+
+	toggle( override ) {
+
+		if( typeof override === 'boolean' ) {
+			override ? this.activate() : this.deactivate();
+		}
+		else {
+			this.isActive() ? this.deactivate() : this.activate();
+		}
+
+	}
+
+	/**
+	 * Checks if the scroll view is currently active.
+	 */
+	isActive() {
+
+		return this.active;
+
+	}
+
+	/**
+	 * Renders the progress bar component.
+	 */
+	createProgressBar() {
+
+		this.progressBar = document.createElement( 'div' );
+		this.progressBar.className = 'scrollbar';
+
+		this.progressBarInner = document.createElement( 'div' );
+		this.progressBarInner.className = 'scrollbar-inner';
+		this.progressBar.appendChild( this.progressBarInner );
+
+		this.progressBarPlayhead = document.createElement( 'div' );
+		this.progressBarPlayhead.className = 'scrollbar-playhead';
+		this.progressBarInner.appendChild( this.progressBarPlayhead );
+
+		this.viewportElement.insertBefore( this.progressBar, this.viewportElement.firstChild );
+
+		const handleDocumentMouseMove	= ( event ) => {
+
+			let progress = ( event.clientY - this.progressBarInner.getBoundingClientRect().top ) / this.progressBarHeight;
+			progress = Math.max( Math.min( progress, 1 ), 0 );
+
+			this.viewportElement.scrollTop = progress * ( this.viewportElement.scrollHeight - this.viewportElement.offsetHeight );
+
+		};
+
+		const handleDocumentMouseUp = ( event ) => {
+
+			this.draggingProgressBar = false;
+			this.showProgressBar();
+
+			document.removeEventListener( 'mousemove', handleDocumentMouseMove );
+			document.removeEventListener( 'mouseup', handleDocumentMouseUp );
+
+		};
+
+		const handleMouseDown = ( event ) => {
+
+			event.preventDefault();
+
+			this.draggingProgressBar = true;
+
+			document.addEventListener( 'mousemove', handleDocumentMouseMove );
+			document.addEventListener( 'mouseup', handleDocumentMouseUp );
+
+			handleDocumentMouseMove( event );
+
+		};
+
+		this.progressBarInner.addEventListener( 'mousedown', handleMouseDown );
+
+	}
+
+	removeProgressBar() {
+
+		if( this.progressBar ) {
+			this.progressBar.remove();
+			this.progressBar = null;
+		}
+
+	}
+
+	layout() {
+
+		if( this.isActive() ) {
+			this.syncPages();
+			this.syncScrollPosition();
+		}
+
+	}
+
+	/**
+	 * Updates our pages to match the latest configuration and
+	 * presentation size.
+	 */
+	syncPages() {
+
+		const config = this.Reveal.getConfig();
+
+		const slideSize = this.Reveal.getComputedSlideSize( window.innerWidth, window.innerHeight );
+		const scale = this.Reveal.getScale();
+		const useCompactLayout = config.scrollLayout === 'compact';
+
+		const viewportHeight = this.viewportElement.offsetHeight;
+		const compactHeight = slideSize.height * scale;
+		const pageHeight = useCompactLayout ? compactHeight : viewportHeight;
+
+		// The height that needs to be scrolled between scroll triggers
+		const scrollTriggerHeight = useCompactLayout ? compactHeight : viewportHeight;
+
+		this.viewportElement.style.setProperty( '--page-height', pageHeight + 'px' );
+		this.viewportElement.style.scrollSnapType = typeof config.scrollSnap === 'string' ? `y ${config.scrollSnap}` : '';
+
+		// This will hold all scroll triggers used to show/hide slides
+		this.slideTriggers = [];
+
+		const pageElements = Array.from( this.Reveal.getRevealElement().querySelectorAll( '.scroll-page' ) );
+
+		this.pages = pageElements.map( pageElement => {
+			const page = this.createPage({
+				pageElement,
+				slideElement: pageElement.querySelector( 'section' ),
+				stickyElement: pageElement.querySelector( '.scroll-page-sticky' ),
+				contentElement: pageElement.querySelector( '.scroll-page-content' ),
+				backgroundElement: pageElement.querySelector( '.slide-background' ),
+				autoAnimateElements: pageElement.querySelectorAll( '.scroll-auto-animate-page' ),
+				autoAnimatePages: []
+			});
+
+			page.pageElement.style.setProperty( '--slide-height', config.center === true ? 'auto' : slideSize.height + 'px' );
+
+			this.slideTriggers.push({
+				page: page,
+				activate: () => this.activatePage( page ),
+				deactivate: () => this.deactivatePage( page )
+			});
+
+			// Create scroll triggers that show/hide fragments
+			this.createFragmentTriggersForPage( page );
+
+			// Create scroll triggers for triggering auto-animate steps
+			if( page.autoAnimateElements.length > 0 ) {
+				this.createAutoAnimateTriggersForPage( page );
+			}
+
+			let totalScrollTriggerCount = Math.max( page.scrollTriggers.length - 1, 0 );
+
+			// Each auto-animate step may include its own scroll triggers
+			// for fragments, ensure we count those as well
+			totalScrollTriggerCount += page.autoAnimatePages.reduce( ( total, page ) => {
+				return total + Math.max( page.scrollTriggers.length - 1, 0 );
+			}, page.autoAnimatePages.length );
+
+			// Clean up from previous renders
+			page.pageElement.querySelectorAll( '.scroll-snap-point' ).forEach( el => el.remove() );
+
+			// Create snap points for all scroll triggers
+			// - Can't be absolute in FF
+			// - Can't be 0-height in Safari
+			// - Can't use snap-align on parent in Safari because then
+			//   inner triggers won't work
+			for( let i = 0; i < totalScrollTriggerCount + 1; i++ ) {
+				const triggerStick = document.createElement( 'div' );
+				triggerStick.className = 'scroll-snap-point';
+				triggerStick.style.height = scrollTriggerHeight + 'px';
+				triggerStick.style.scrollSnapAlign = useCompactLayout ? 'center' : 'start';
+				page.pageElement.appendChild( triggerStick );
+
+				if( i === 0 ) {
+					triggerStick.style.marginTop = -scrollTriggerHeight + 'px';
+				}
+			}
+
+			// In the compact layout, only slides with scroll triggers cover the
+			// full viewport height. This helps avoid empty gaps before or after
+			// a sticky slide.
+			if( useCompactLayout && page.scrollTriggers.length > 0 ) {
+				page.pageHeight = viewportHeight;
+				page.pageElement.style.setProperty( '--page-height', viewportHeight + 'px' );
+			}
+			else {
+				page.pageHeight = pageHeight;
+				page.pageElement.style.removeProperty( '--page-height' );
+			}
+
+			// Add scroll padding based on how many scroll triggers we have
+			page.scrollPadding = scrollTriggerHeight * totalScrollTriggerCount;
+
+			// The total height including scrollable space
+			page.totalHeight = page.pageHeight + page.scrollPadding;
+
+			// This is used to pad the height of our page in CSS
+			page.pageElement.style.setProperty( '--page-scroll-padding', page.scrollPadding + 'px' );
+
+			// If this is a sticky page, stick it to the vertical center
+			if( totalScrollTriggerCount > 0 ) {
+				page.stickyElement.style.position = 'sticky';
+				page.stickyElement.style.top = Math.max( ( viewportHeight - page.pageHeight ) / 2, 0 ) + 'px';
+			}
+			else {
+				page.stickyElement.style.position = 'relative';
+				page.pageElement.style.scrollSnapAlign = page.pageHeight < viewportHeight ? 'center' : 'start';
+			}
+
+			return page;
+		} );
+
+		this.setTriggerRanges();
+
+		/*
+		console.log(this.slideTriggers.map( t => {
+			return {
+				range: `${t.range[0].toFixed(2)}-${t.range[1].toFixed(2)}`,
+				triggers: t.page.scrollTriggers.map( t => {
+					return `${t.range[0].toFixed(2)}-${t.range[1].toFixed(2)}`
+				}).join( ', ' ),
+			}
+		}))
+		*/
+
+		this.viewportElement.setAttribute( 'data-scrollbar', config.scrollProgress );
+
+		if( config.scrollProgress && this.totalScrollTriggerCount > 1 ) {
+			// Create the progress bar if it doesn't already exist
+			if( !this.progressBar ) this.createProgressBar();
+
+			this.syncProgressBar();
+		}
+		else {
+			this.removeProgressBar();
+		}
+
+	}
+
+	/**
+	 * Calculates and sets the scroll range for all of our scroll
+	 * triggers.
+	 */
+	setTriggerRanges() {
+
+		// Calculate the total number of scroll triggers
+		this.totalScrollTriggerCount = this.slideTriggers.reduce( ( total, trigger ) => {
+			return total + Math.max( trigger.page.scrollTriggers.length, 1 );
+		}, 0 );
+
+		let rangeStart = 0;
+
+		// Calculate the scroll range of each scroll trigger on a scale
+		// of 0-1
+		this.slideTriggers.forEach( ( trigger, i ) => {
+			trigger.range = [
+				rangeStart,
+				rangeStart + Math.max( trigger.page.scrollTriggers.length, 1 ) / this.totalScrollTriggerCount
+			];
+
+			const scrollTriggerSegmentSize = ( trigger.range[1] - trigger.range[0] ) / trigger.page.scrollTriggers.length;
+			// Set the range for each inner scroll trigger
+			trigger.page.scrollTriggers.forEach( ( scrollTrigger, i ) => {
+				scrollTrigger.range = [
+					rangeStart + i * scrollTriggerSegmentSize,
+					rangeStart + ( i + 1 ) * scrollTriggerSegmentSize
+				];
+			} );
+
+			rangeStart = trigger.range[1];
+		} );
+
+	}
+
+	/**
+	 * Creates one scroll trigger for each fragments in the given page.
+	 *
+	 * @param {*} page
+	 */
+	createFragmentTriggersForPage( page, slideElement ) {
+
+		slideElement = slideElement || page.slideElement;
+
+		// Each fragment 'group' is an array containing one or more
+		// fragments. Multiple fragments that appear at the same time
+		// are part of the same group.
+		const fragmentGroups = this.Reveal.fragments.sort( slideElement.querySelectorAll( '.fragment' ), true );
+
+		// Create scroll triggers that show/hide fragments
+		if( fragmentGroups.length ) {
+			page.fragments = this.Reveal.fragments.sort( slideElement.querySelectorAll( '.fragment:not(.disabled)' ) );
+			page.scrollTriggers.push(
+				// Trigger for the initial state with no fragments visible
+				{
+					activate: () => {
+						this.Reveal.fragments.update( -1, page.fragments, slideElement );
+					}
+				}
+			);
+
+			// Triggers for each fragment group
+			fragmentGroups.forEach( ( fragments, i ) => {
+				page.scrollTriggers.push({
+					activate: () => {
+						this.Reveal.fragments.update( i, page.fragments, slideElement );
+					}
+				});
+			} );
+		}
+
+
+		return page.scrollTriggers.length;
+
+	}
+
+	/**
+	 * Creates scroll triggers for the auto-animate steps in the
+	 * given page.
+	 *
+	 * @param {*} page
+	 */
+	createAutoAnimateTriggersForPage( page ) {
+
+		if( page.autoAnimateElements.length > 0 ) {
+
+			// Triggers for each subsequent auto-animate slide
+			this.slideTriggers.push( ...Array.from( page.autoAnimateElements ).map( ( autoAnimateElement, i ) => {
+				let autoAnimatePage = this.createPage({
+					slideElement: autoAnimateElement.querySelector( 'section' ),
+					contentElement: autoAnimateElement,
+					backgroundElement: autoAnimateElement.querySelector( '.slide-background' )
+				});
+
+				// Create fragment scroll triggers for the auto-animate slide
+				this.createFragmentTriggersForPage( autoAnimatePage, autoAnimatePage.slideElement );
+
+				page.autoAnimatePages.push( autoAnimatePage );
+
+				// Return our slide trigger
+				return {
+					page: autoAnimatePage,
+					activate: () => this.activatePage( autoAnimatePage ),
+					deactivate: () => this.deactivatePage( autoAnimatePage )
+				};
+			}));
+		}
+
+	}
+
+	/**
+	 * Helper method for creating a page definition and adding
+	 * required fields. A "page" is a slide or auto-animate step.
+	 */
+	createPage( page ) {
+
+		page.scrollTriggers = [];
+		page.indexh = parseInt( page.slideElement.getAttribute( 'data-index-h' ), 10 );
+		page.indexv = parseInt( page.slideElement.getAttribute( 'data-index-v' ), 10 );
+
+		return page;
+
+	}
+
+	/**
+	 * Rerenders progress bar segments so that they match the current
+	 * reveal.js config and size.
+	 */
+	syncProgressBar() {
+
+		this.progressBarInner.querySelectorAll( '.scrollbar-slide' ).forEach( slide => slide.remove() );
+
+		const scrollHeight = this.viewportElement.scrollHeight;
+		const viewportHeight = this.viewportElement.offsetHeight;
+		const viewportHeightFactor = viewportHeight / scrollHeight;
+
+		this.progressBarHeight = this.progressBarInner.offsetHeight;
+		this.playheadHeight = Math.max( viewportHeightFactor * this.progressBarHeight, MIN_PLAYHEAD_HEIGHT );
+		this.progressBarScrollableHeight = this.progressBarHeight - this.playheadHeight;
+
+		const progressSegmentHeight = viewportHeight / scrollHeight * this.progressBarHeight;
+		const spacing = Math.min( progressSegmentHeight / 8, MAX_PROGRESS_SPACING );
+
+		this.progressBarPlayhead.style.height = this.playheadHeight - spacing + 'px';
+
+		// Don't show individual segments if they're too small
+		if( progressSegmentHeight > MIN_PROGRESS_SEGMENT_HEIGHT ) {
+
+			this.slideTriggers.forEach( slideTrigger => {
+
+				const { page } = slideTrigger;
+
+				// Visual representation of a slide
+				page.progressBarSlide = document.createElement( 'div' );
+				page.progressBarSlide.className = 'scrollbar-slide';
+				page.progressBarSlide.style.top = slideTrigger.range[0] * this.progressBarHeight + 'px';
+				page.progressBarSlide.style.height = ( slideTrigger.range[1] - slideTrigger.range[0] ) * this.progressBarHeight - spacing + 'px';
+				page.progressBarSlide.classList.toggle( 'has-triggers', page.scrollTriggers.length > 0 );
+				this.progressBarInner.appendChild( page.progressBarSlide );
+
+				// Visual representations of each scroll trigger
+				page.scrollTriggerElements = page.scrollTriggers.map( ( trigger, i ) => {
+
+					const triggerElement = document.createElement( 'div' );
+					triggerElement.className = 'scrollbar-trigger';
+					triggerElement.style.top = ( trigger.range[0] - slideTrigger.range[0] ) * this.progressBarHeight + 'px';
+					triggerElement.style.height = ( trigger.range[1] - trigger.range[0] ) * this.progressBarHeight - spacing + 'px';
+					page.progressBarSlide.appendChild( triggerElement );
+
+					if( i === 0 ) triggerElement.style.display = 'none';
+
+					return triggerElement;
+
+				} );
+
+			} );
+
+		}
+		else {
+
+			this.pages.forEach( page => page.progressBarSlide = null );
+
+		}
+
+	}
+
+	/**
+	 * Reads the current scroll position and updates our active
+	 * trigger states accordingly.
+	 */
+	syncScrollPosition() {
+
+		const viewportHeight = this.viewportElement.offsetHeight;
+		const viewportHeightFactor = viewportHeight / this.viewportElement.scrollHeight;
+
+		const scrollTop = this.viewportElement.scrollTop;
+		const scrollHeight = this.viewportElement.scrollHeight - viewportHeight
+		const scrollProgress = Math.max( Math.min( scrollTop / scrollHeight, 1 ), 0 );
+		const scrollProgressMid = Math.max( Math.min( ( scrollTop + viewportHeight / 2 ) / this.viewportElement.scrollHeight, 1 ), 0 );
+
+		let activePage;
+
+		this.slideTriggers.forEach( ( trigger ) => {
+			const { page } = trigger;
+
+			const shouldPreload = scrollProgress >= trigger.range[0] - viewportHeightFactor*2 &&
+														scrollProgress <= trigger.range[1] + viewportHeightFactor*2;
+
+			// Load slides that are within the preload range
+			if( shouldPreload && !page.loaded ) {
+				page.loaded = true;
+				this.Reveal.slideContent.load( page.slideElement );
+			}
+			else if( page.loaded ) {
+				page.loaded = false;
+				this.Reveal.slideContent.unload( page.slideElement );
+			}
+
+			// If we're within this trigger range, activate it
+			if( scrollProgress >= trigger.range[0] && scrollProgress <= trigger.range[1] ) {
+				this.activateTrigger( trigger );
+				activePage = trigger.page;
+			}
+			// .. otherwise deactivate
+			else if( trigger.active ) {
+				this.deactivateTrigger( trigger );
+			}
+		} );
+
+		// Each page can have its own scroll triggers, check if any of those
+		// need to be activated/deactivated
+		if( activePage ) {
+			activePage.scrollTriggers.forEach( ( trigger ) => {
+				if( scrollProgressMid >= trigger.range[0] && scrollProgressMid <= trigger.range[1] ) {
+					this.activateTrigger( trigger );
+				}
+				else if( trigger.active ) {
+					this.deactivateTrigger( trigger );
+				}
+			} );
+		}
+
+		// Update our visual progress indication
+		this.setProgressBarValue( scrollTop / ( this.viewportElement.scrollHeight - viewportHeight ) );
+
+	}
+
+	/**
+	 * Moves the progress bar playhead to the specified position.
+	 *
+	 * @param {number} progress 0-1
+	 */
+	setProgressBarValue( progress ) {
+
+		if( this.progressBar ) {
+
+			this.progressBarPlayhead.style.transform = `translateY(${progress * this.progressBarScrollableHeight}px)`;
+
+			this.getAllPages()
+				.filter( page => page.progressBarSlide )
+				.forEach( ( page ) => {
+					page.progressBarSlide.classList.toggle( 'active', page.active === true );
+
+					page.scrollTriggers.forEach( ( trigger, i ) => {
+						page.scrollTriggerElements[i].classList.toggle( 'active', page.active === true && trigger.active === true );
+					} );
+				} );
+
+			this.showProgressBar();
+
+		}
+
+	}
+
+	/**
+	 * Show the progress bar and, if configured, automatically hide
+	 * it after a delay.
+	 */
+	showProgressBar() {
+
+		this.progressBar.classList.add( 'visible' );
+
+		clearTimeout( this.hideProgressBarTimeout );
+
+		if( this.Reveal.getConfig().scrollProgress === 'auto' && !this.draggingProgressBar ) {
+
+			this.hideProgressBarTimeout = setTimeout( () => {
+				if( this.progressBar ) {
+					this.progressBar.classList.remove( 'visible' );
+				}
+			}, HIDE_SCROLLBAR_TIMEOUT );
+
+		}
+
+	}
+
+	/**
+	 * Scrolls the given slide element into view.
+	 *
+	 * @param {HTMLElement} slideElement
+	 */
+	scrollToSlide( slideElement ) {
+
+		// If the scroll view isn't active yet, queue this action
+		if( !this.active ) {
+			this.activatedCallbacks.push( () => this.scrollToSlide( slideElement ) );
+		}
+		else {
+			// Find the trigger for this slide
+			const trigger = this.getScrollTriggerBySlide( slideElement );
+
+			if( trigger ) {
+				// Use the trigger's range to calculate the scroll position
+				this.viewportElement.scrollTop = trigger.range[0] * ( this.viewportElement.scrollHeight - this.viewportElement.offsetHeight );
+			}
+		}
+
+	}
+
+	/**
+	 * Persists the current scroll position to session storage
+	 * so that it can be restored.
+	 */
+	storeScrollPosition() {
+
+		clearTimeout( this.storeScrollPositionTimeout );
+
+		this.storeScrollPositionTimeout = setTimeout( () => {
+			sessionStorage.setItem( 'reveal-scroll-top', this.viewportElement.scrollTop );
+			sessionStorage.setItem( 'reveal-scroll-origin', location.origin + location.pathname );
+
+			this.storeScrollPositionTimeout = null;
+		}, 50 );
+
+	}
+
+	/**
+	 * Restores the scroll position when a deck is reloader.
+	 */
+	restoreScrollPosition() {
+
+		const scrollPosition = sessionStorage.getItem( 'reveal-scroll-top' );
+		const scrollOrigin = sessionStorage.getItem( 'reveal-scroll-origin' );
+
+		if( scrollPosition && scrollOrigin === location.origin + location.pathname ) {
+			this.viewportElement.scrollTop = parseInt( scrollPosition, 10 );
+		}
+
+	}
+
+	/**
+	 * Activates the given page and starts its embedded content
+	 * if there is any.
+	 *
+	 * @param {object} page
+	 */
+	activatePage( page ) {
+
+		if( !page.active ) {
+
+			page.active = true;
+
+			const { slideElement, backgroundElement, contentElement, indexh, indexv } = page;
+
+			contentElement.style.display = 'block';
+
+			slideElement.classList.add( 'present' );
+
+			if( backgroundElement ) {
+				backgroundElement.classList.add( 'present' );
+			}
+
+			this.Reveal.setCurrentScrollPage( slideElement, indexh, indexv );
+			this.Reveal.backgrounds.bubbleSlideContrastClassToElement( slideElement, this.viewportElement );
+
+			// If this page is part of an auto-animation there will be one
+			// content element per auto-animated page. We need to show the
+			// current page and hide all others.
+			Array.from( contentElement.parentNode.querySelectorAll( '.scroll-page-content' ) ).forEach( sibling => {
+				if( sibling !== contentElement ) {
+					sibling.style.display = 'none';
+				}
+			});
+
+		}
+
+	}
+
+	/**
+	 * Deactivates the page after it has been visible.
+	 *
+	 * @param {object} page
+	 */
+	deactivatePage( page ) {
+
+		if( page.active ) {
+
+			page.active = false;
+			if( page.slideElement ) page.slideElement.classList.remove( 'present' );
+			if( page.backgroundElement ) page.backgroundElement.classList.remove( 'present' );
+
+		}
+
+	}
+
+	activateTrigger( trigger ) {
+
+		if( !trigger.active ) {
+			trigger.active = true;
+			trigger.activate();
+		}
+
+	}
+
+	deactivateTrigger( trigger ) {
+
+		if( trigger.active ) {
+			trigger.active = false;
+
+			if( trigger.deactivate ) {
+				trigger.deactivate();
+			}
+		}
+
+	}
+
+	/**
+	 * Retrieve a slide by its original h/v index (i.e. the indices the
+	 * slide had before being linearized).
+	 *
+	 * @param {number} h
+	 * @param {number} v
+	 * @returns {HTMLElement}
+	 */
+	getSlideByIndices( h, v ) {
+
+		const page = this.getAllPages().find( page => {
+			return page.indexh === h && page.indexv === v;
+		} );
+
+		return page ? page.slideElement : null;
+
+	}
+
+	/**
+	 * Retrieve a list of all scroll triggers for the given slide
+	 * DOM element.
+	 *
+	 * @param {HTMLElement} slide
+	 * @returns {Array}
+	 */
+	getScrollTriggerBySlide( slide ) {
+
+		return this.slideTriggers.find( trigger => trigger.page.slideElement === slide );
+
+	}
+
+	/**
+	 * Get a list of all pages in the scroll view. This includes
+	 * both top-level slides and auto-animate steps.
+	 *
+	 * @returns {Array}
+	 */
+	getAllPages() {
+
+		return this.pages.flatMap( page => [page, ...(page.autoAnimatePages || [])] );
+
+	}
+
+	onScroll() {
+
+		this.syncScrollPosition();
+		this.storeScrollPosition();
+
+	}
+
+	get viewportElement() {
+
+		return this.Reveal.getViewportElement();
+
+	}
+
+}
--- a/js/controllers/slidecontent.js
+++ b/js/controllers/slidecontent.js
@@ -1,5 +1,4 @@
-import { HORIZONTAL_SLIDES_SELECTOR, VERTICAL_SLIDES_SELECTOR } from '../utils/constants.js'
-import { extend, queryAll, closest } from '../utils/util.js'
+import { extend, queryAll, closest, getMimeTypeFromFile, encodeRFC3986URI } from '../utils/util.js'
 import { isMobile } from '../utils/device.js'

 import fitty from 'fitty';
@@ -26,6 +25,10 @@ export default class SlideContent {
 	 */
 	shouldPreload( element ) {

+		if( this.Reveal.isScrollView() ) {
+			return true;
+		}
+
 		// Prefer an explicit global preload setting
 		let preload = this.Reveal.getConfig().preloadIframes;

@@ -102,9 +105,18 @@ export default class SlideContent {

 				// Images
 				if( backgroundImage ) {
-					backgroundContent.style.backgroundImage = backgroundImage.split( ',' ).map( background => {
-						return `url(${encodeURI(background.trim())})`;
-					}).join( ',' );
+					// base64
+					if(  /^data:/.test( backgroundImage.trim() ) ) {
+						backgroundContent.style.backgroundImage = `url(${backgroundImage.trim()})`;
+					}
+					// URL(s)
+					else {
+						backgroundContent.style.backgroundImage = backgroundImage.split( ',' ).map( background => {
+							// Decode URL(s) that are already encoded first
+							let decoded = decodeURI(background.trim());
+							return `url(${encodeRFC3986URI(decoded)})`;
+						}).join( ',' );
+					}
 				}
 				// Videos
 				else if ( backgroundVideo && !this.Reveal.isSpeakerNotes() ) {
@@ -130,7 +142,15 @@ export default class SlideContent {

 					// Support comma separated lists of video sources
 					backgroundVideo.split( ',' ).forEach( source => {
-						video.innerHTML += '<source src="'+ source +'">';
+						const sourceElement = document.createElement( 'source' );
+						sourceElement.setAttribute( 'src', source );
+
+						let type = getMimeTypeFromFile( source );
+						if( type ) {
+							sourceElement.setAttribute( 'type', type );
+						}
+
+						video.appendChild( sourceElement );
 					} );

 					backgroundContent.appendChild( video );
@@ -174,15 +194,14 @@ export default class SlideContent {
 	}

 	/**
-	 * Applies JS-dependent layout helpers for the given slide,
-	 * if there are any.
+	 * Applies JS-dependent layout helpers for the scope.
 	 */
-	layout( slide ) {
+	layout( scopeElement ) {

 		// Autosize text with the r-fit-text class based on the
 		// size of its container. This needs to happen after the
 		// slide is visible in order to measure the text.
-		Array.from( slide.querySelectorAll( '.r-fit-text' ) ).forEach( element => {
+		Array.from( scopeElement.querySelectorAll( '.r-fit-text' ) ).forEach( element => {
 			fitty( element, {
 				minSize: 24,
 				maxSize: this.Reveal.getConfig().height * 0.8,
@@ -464,4 +483,4 @@ export default class SlideContent {

 	}

-}
+}
--- a/js/controllers/slidenumber.js
+++ b/js/controllers/slidenumber.js
@@ -1,3 +1,10 @@
+import {
+	SLIDE_NUMBER_FORMAT_CURRENT,
+	SLIDE_NUMBER_FORMAT_CURRENT_SLASH_TOTAL,
+	SLIDE_NUMBER_FORMAT_HORIZONTAL_DOT_VERTICAL,
+	SLIDE_NUMBER_FORMAT_HORIZONTAL_SLASH_VERTICAL
+} from "../utils/constants";
+
 /**
 * Handles the display of reveal.js' optional slide number.
 */
@@ -23,7 +30,7 @@ export default class SlideNumber {
 	configure( config, oldConfig ) {

 		let slideNumberDisplay = 'none';
-		if( config.slideNumber && !this.Reveal.isPrintingPDF() ) {
+		if( config.slideNumber && !this.Reveal.isPrintView() ) {
 			if( config.showSlideNumber === 'all' ) {
 				slideNumberDisplay = 'block';
 			}
@@ -56,7 +63,7 @@ export default class SlideNumber {

 		let config = this.Reveal.getConfig();
 		let value;
-		let format = 'h.v';
+		let format = SLIDE_NUMBER_FORMAT_HORIZONTAL_DOT_VERTICAL;

 		if ( typeof config.slideNumber === 'function' ) {
 			value = config.slideNumber( slide );
@@ -69,7 +76,7 @@ export default class SlideNumber {
 			// If there are ONLY vertical slides in this deck, always use
 			// a flattened slide number
 			if( !/c/.test( format ) && this.Reveal.getHorizontalSlides().length === 1 ) {
-				format = 'c';
+				format = SLIDE_NUMBER_FORMAT_CURRENT;
 			}

 			// Offset the current slide number by 1 to make it 1-indexed
@@ -77,16 +84,16 @@ export default class SlideNumber {

 			value = [];
 			switch( format ) {
-				case 'c':
+				case SLIDE_NUMBER_FORMAT_CURRENT:
 					value.push( this.Reveal.getSlidePastCount( slide ) + horizontalOffset );
 					break;
-				case 'c/t':
+				case SLIDE_NUMBER_FORMAT_CURRENT_SLASH_TOTAL:
 					value.push( this.Reveal.getSlidePastCount( slide ) + horizontalOffset, '/', this.Reveal.getTotalSlides() );
 					break;
 				default:
 					let indices = this.Reveal.getIndices( slide );
 					value.push( indices.h + horizontalOffset );
-					let sep = format === 'h/v' ? '/' : '.';
+					let sep = format === SLIDE_NUMBER_FORMAT_HORIZONTAL_SLASH_VERTICAL ? '/' : '.';
 					if( this.Reveal.isVerticalSlide( slide ) ) value.push( sep, indices.v + 1 );
 			}
 		}
@@ -123,4 +130,10 @@ export default class SlideNumber {

 	}

+	destroy() {
+
+		this.element.remove();
+
+	}
+
 }
--- a/js/reveal.js
+++ b/js/reveal.js
--- a/js/utils/color.js
+++ b/js/utils/color.js
@@ -29,9 +29,9 @@ export const colorToRgb = ( color ) => {
 	if( hex6 && hex6[1] ) {
 		hex6 = hex6[1];
 		return {
-			r: parseInt( hex6.substr( 0, 2 ), 16 ),
-			g: parseInt( hex6.substr( 2, 2 ), 16 ),
-			b: parseInt( hex6.substr( 4, 2 ), 16 )
+			r: parseInt( hex6.slice( 0, 2 ), 16 ),
+			g: parseInt( hex6.slice( 2, 4 ), 16 ),
+			b: parseInt( hex6.slice( 4, 6 ), 16 )
 		};
 	}

--- a/js/utils/constants.js
+++ b/js/utils/constants.js
@@ -4,7 +4,13 @@ export const HORIZONTAL_SLIDES_SELECTOR = '.slides>section';
 export const VERTICAL_SLIDES_SELECTOR = '.slides>section.present>section';

 // Methods that may not be invoked via the postMessage API
-export const POST_MESSAGE_METHOD_BLACKLIST = /registerPlugin|registerKeyboardShortcut|addKeyBinding|addEventListener/;
+export const POST_MESSAGE_METHOD_BLACKLIST = /registerPlugin|registerKeyboardShortcut|addKeyBinding|addEventListener|showPreview/;

 // Regex for retrieving the fragment style from a class attribute
-export const FRAGMENT_STYLE_REGEX = /fade-(down|up|right|left|out|in-then-out|in-then-semi-out)|semi-fade-out|current-visible|shrink|grow/;
+export const FRAGMENT_STYLE_REGEX = /fade-(down|up|right|left|out|in-then-out|in-then-semi-out)|semi-fade-out|current-visible|shrink|grow/;
+
+// Slide number formats
+export const SLIDE_NUMBER_FORMAT_HORIZONTAL_DOT_VERTICAL = 'h.v';
+export const SLIDE_NUMBER_FORMAT_HORIZONTAL_SLASH_VERTICAL = 'h/v';
+export const SLIDE_NUMBER_FORMAT_CURRENT = 'c';
+export const SLIDE_NUMBER_FORMAT_CURRENT_SLASH_TOTAL = 'c/t';
--- a/js/utils/device.js
+++ b/js/utils/device.js
@@ -1,15 +1,8 @@
 const UA = navigator.userAgent;
-const testElement = document.createElement( 'div' );

 export const isMobile = /(iphone|ipod|ipad|android)/gi.test( UA ) ||
 						( navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1 ); // iPadOS

 export const isChrome = /chrome/i.test( UA ) && !/edge/i.test( UA );

-export const isAndroid = /android/gi.test( UA );
-
-// Flags if we should use zoom instead of transform to scale
-// up slides. Zoom produces crisper results but has a lot of
-// xbrowser quirks so we only use it in whitelisted browsers.
-export const supportsZoom = 'zoom' in testElement.style && !isMobile &&
-				( isChrome || /Version\/[\d\.]+.*Safari/.test( UA ) );
+export const isAndroid = /android/gi.test( UA );
--- a/js/utils/util.js
+++ b/js/utils/util.js
@@ -279,4 +279,35 @@ export const getRemainingHeight = ( element, height = 0 ) => {

 	return height;

+}
+
+const fileExtensionToMimeMap = {
+	'mp4': 'video/mp4',
+	'm4a': 'video/mp4',
+	'ogv': 'video/ogg',
+	'mpeg': 'video/mpeg',
+	'webm': 'video/webm'
+}
+
+/**
+ * Guess the MIME type for common file formats.
+ */
+export const getMimeTypeFromFile = ( filename='' ) => {
+	return fileExtensionToMimeMap[filename.split('.').pop()]
+}
+
+/**
+ * Encodes a string for RFC3986-compliant URL format.
+ * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURI#encoding_for_rfc3986
+ *
+ * @param {string} url
+ */
+export const encodeRFC3986URI = ( url='' ) => {
+	return encodeURI(url)
+	  .replace(/%5B/g, "[")
+	  .replace(/%5D/g, "]")
+	  .replace(
+		/[!'()*]/g,
+		(c) => `%${c.charCodeAt(0).toString(16).toUpperCase()}`
+	  );
 }
--- a/[PeMlggyqz0Y].tsv
+++ b/[PeMlggyqz0Y].tsv
@@ -0,0 +1,31 @@
+start	end	text
+0	6480	 Machine learning. Teach a computer how to perform a task, without explicitly programming it to perform said task.
+6620	13420	 Instead, feed data into an algorithm to gradually improve outcomes with experience, similar to how organic life learns.
+13580	20400	 The term was coined in 1959 by Arthur Samuel at IBM, who was developing artificial intelligence that could play checkers.
+20540	26880	 Half a century later, and predictive models are embedded in many of the products we use every day, which perform two fundamental jobs.
+26880	32040	 One is to classify data, like "Is there another car on the road?" or "Does this patient have cancer?"
+32040	38600	 The other is to make predictions about future outcomes, like "Will this stock go up?" or "Which YouTube video do you want to watch next?"
+38600	43280	 The first step in the process is to acquire and clean up data. Lots and lots of data.
+43480	47780	 The better the data represents the problem, the better the results. Garbage in, garbage out.
+47900	52160	 The data needs to have some kind of signal to be valuable to the algorithm for making predictions.
+52160	59920	 And data scientists perform a job called feature engineering to transform raw data into features that better represent the underlying problem.
+60240	64240	 The next step is to separate the data into a training set and testing set.
+64460	71800	 The training data is fed into an algorithm to build a model, then the testing data is used to validate the accuracy or error of the model.
+71980	77700	 The next step is to choose an algorithm, which might be a simple statistical model like linear or logistic regression,
+77940	81260	 or a decision tree that assigns different weights to features in the data.
+81260	86640	 Or you might get fancy with a convolutional neural network, which is an algorithm that also assigns
+86640	91300	 weights to features, but also takes the input data and creates additional features automatically.
+91640	96300	 And that's extremely useful for datasets that contain things like images or natural language,
+96420	99020	 where manual feature engineering is virtually impossible.
+99260	103960	 Every one of these algorithms learns to get better by comparing its predictions to an error function.
+104160	109840	 If it's a classification problem, like "Is this animal a cat or a dog?" the error function might be accuracy.
+109840	115900	 If it's a regression problem, like "How much will a loaf of bread cost next year?" then it might be mean absolute error.
+116220	121780	 Python is the language of choice among data scientists, but R and Julia are also popular options,
+121920	125320	 and there are many supporting frameworks out there to make the process approachable.
+125500	132680	 The end result of the machine learning process is a model, which is just a file that takes some input data in the same shape that it was trained on,
+132860	136900	 then spits out a prediction that tries to minimize the error that it was optimized for.
+136900	141980	 It can then be embedded on an actual device or deployed to the cloud to build a real-world product.
+142180	144500	 This has been Machine Learning in 100 Seconds.
+144580	147160	 Like and subscribe if you want to see more short videos like this,
+147320	150500	 and leave a comment if you want to see more machine learning content on this channel.
+150620	153040	 Thanks for watching, and I will see you in the next one.
--- a/media/minst.jpg
+++ b/media/minst.jpg
--- a/media/mlp.jpeg
+++ b/media/mlp.jpeg
--- a/media/nn.png
+++ b/media/nn.png
--- a/media/optimizer.gif
+++ b/media/optimizer.gif
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
  "name": "reveal.js",
-  "version": "4.1.1",
+  "version": "5.0.4",
  "description": "The HTML Presentation Framework",
  "homepage": "https://revealjs.com",
  "subdomain": "revealjs",
@@ -22,7 +22,7 @@
    "url": "git://github.com/hakimel/reveal.js.git"
  },
  "engines": {
-    "node": ">=10.0.0"
+    "node": ">=18.0.0"
  },
  "keywords": [
    "reveal",
@@ -30,35 +30,39 @@
    "presentation"
  ],
  "devDependencies": {
-    "@babel/core": "^7.14.3",
-    "@babel/eslint-parser": "^7.14.3",
-    "@babel/preset-env": "^7.14.2",
-    "@rollup/plugin-babel": "^5.3.0",
-    "@rollup/plugin-commonjs": "^19.0.0",
-    "@rollup/plugin-node-resolve": "^13.0.0",
-    "babel-plugin-transform-html-import-to-string": "0.0.1",
+    "@babel/core": "^7.23.2",
+    "@babel/eslint-parser": "^7.22.15",
+    "@babel/preset-env": "^7.23.2",
+    "@rollup/plugin-babel": "^6.0.4",
+    "@rollup/plugin-commonjs": "^25.0.7",
+    "@rollup/plugin-node-resolve": "^15.2.3",
+    "@rollup/plugin-terser": "^0.4.4",
+    "babel-plugin-transform-html-import-to-string": "2.0.0",
    "colors": "^1.4.0",
-    "core-js": "^3.12.1",
-    "fitty": "^2.3.0",
-    "glob": "^7.1.7",
+    "core-js": "^3.33.1",
+    "fitty": "^2.3.7",
+    "glob": "^10.3.10",
    "gulp": "^4.0.2",
-    "gulp-autoprefixer": "^5.0.0",
-    "gulp-clean-css": "^4.2.0",
+    "gulp-autoprefixer": "^8.0.0",
+    "gulp-clean-css": "^4.3.0",
    "gulp-connect": "^5.7.0",
    "gulp-eslint": "^6.0.0",
    "gulp-header": "^2.0.9",
    "gulp-tap": "^2.0.0",
-    "gulp-zip": "^4.2.0",
-    "highlight.js": "^10.0.3",
-    "marked": "^2.0.3",
-    "node-qunit-puppeteer": "^2.0.1",
-    "qunit": "^2.10.0",
-    "rollup": "^2.48.0",
-    "rollup-plugin-terser": "^7.0.2",
-    "sass": "^1.32.13",
-    "yargs": "^15.1.0"
+    "gulp-zip": "^5.1.0",
+    "highlight.js": "^11.9.0",
+    "marked": "^4.3.0",
+    "node-qunit-puppeteer": "^2.1.2",
+    "qunit": "^2.20.0",
+    "rollup": "^4.1.5",
+    "sass": "^1.69.5",
+    "yargs": "^17.7.2"
  },
-  "browserslist": "> 0.5%, IE 11, not dead",
+  "overrides": {
+    "chokidar": "3.5.3",
+    "glob-parent": "6.0.2"
+  },
+  "browserslist": "> 2%, not dead",
  "eslintConfig": {
    "env": {
      "browser": true,
--- a/plugin/highlight/highlight.esm.js
+++ b/plugin/highlight/highlight.esm.js
--- a/plugin/highlight/highlight.js
+++ b/plugin/highlight/highlight.js
--- a/plugin/highlight/plugin.js
+++ b/plugin/highlight/plugin.js
@@ -1,8 +1,8 @@
-import hljs from 'highlight.js'
+import hljs from 'highlight.js';
+
+/* highlightjs-line-numbers.js 2.8.0 | (C) 2018 Yauheni Pakala | MIT License | github.com/wcoder/highlightjs-line-numbers.js */
+!function(r,o){"use strict";var e,i="hljs-ln",l="hljs-ln-line",h="hljs-ln-code",s="hljs-ln-numbers",c="hljs-ln-n",m="data-line-number",a=/\r\n|\r|\n/g;function u(e){for(var n=e.toString(),t=e.anchorNode;"TD"!==t.nodeName;)t=t.parentNode;for(var r=e.focusNode;"TD"!==r.nodeName;)r=r.parentNode;var o=parseInt(t.dataset.lineNumber),a=parseInt(r.dataset.lineNumber);if(o==a)return n;var i,l=t.textContent,s=r.textContent;for(a<o&&(i=o,o=a,a=i,i=l,l=s,s=i);0!==n.indexOf(l);)l=l.slice(1);for(;-1===n.lastIndexOf(s);)s=s.slice(0,-1);for(var c=l,u=function(e){for(var n=e;"TABLE"!==n.nodeName;)n=n.parentNode;return n}(t),d=o+1;d<a;++d){var f=p('.{0}[{1}="{2}"]',[h,m,d]);c+="\n"+u.querySelector(f).textContent}return c+="\n"+s}function n(e){try{var n=o.querySelectorAll("code.hljs,code.nohighlight");for(var t in n)n.hasOwnProperty(t)&&(n[t].classList.contains("nohljsln")||d(n[t],e))}catch(e){r.console.error("LineNumbers error: ",e)}}function d(e,n){if("object"==typeof e)e.innerHTML=f(e,n)}function f(e,n){var t,r,o=(t=e,{singleLine:function(e){return!!e.singleLine&&e.singleLine}(r=(r=n)||{}),startFrom:function(e,n){var t=1;isFinite(n.startFrom)&&(t=n.startFrom);var r=function(e,n){return e.hasAttribute(n)?e.getAttribute(n):null}(e,"data-ln-start-from");return null!==r&&(t=function(e,n){if(!e)return n;var t=Number(e);return isFinite(t)?t:n}(r,1)),t}(t,r)});return function e(n){var t=n.childNodes;for(var r in t){var o;t.hasOwnProperty(r)&&(o=t[r],0<(o.textContent.trim().match(a)||[]).length&&(0<o.childNodes.length?e(o):v(o.parentNode)))}}(e),function(e,n){var t=g(e);""===t[t.length-1].trim()&&t.pop();if(1<t.length||n.singleLine){for(var r="",o=0,a=t.length;o<a;o++)r+=p('<tr><td class="{0} {1}" {3}="{5}"><div class="{2}" {3}="{5}"></div></td><td class="{0} {4}" {3}="{5}">{6}</td></tr>',[l,s,c,m,h,o+n.startFrom,0<t[o].length?t[o]:" "]);return p('<table class="{0}">{1}</table>',[i,r])}return e}(e.innerHTML,o)}function v(e){var n=e.className;if(/hljs-/.test(n)){for(var t=g(e.innerHTML),r=0,o="";r<t.length;r++){o+=p('<span class="{0}">{1}</span>\n',[n,0<t[r].length?t[r]:" "])}e.innerHTML=o.trim()}}function g(e){return 0===e.length?[]:e.split(a)}function p(e,t){return e.replace(/\{(\d+)\}/g,function(e,n){return void 0!==t[n]?t[n]:e})}hljs?(hljs.initLineNumbersOnLoad=function(e){"interactive"===o.readyState||"complete"===o.readyState?n(e):r.addEventListener("DOMContentLoaded",function(){n(e)})},hljs.lineNumbersBlock=d,hljs.lineNumbersValue=function(e,n){if("string"!=typeof e)return;var t=document.createElement("code");return t.innerHTML=e,f(t,n)},(e=o.createElement("style")).type="text/css",e.innerHTML=p(".{0}{border-collapse:collapse}.{0} td{padding:0}.{1}:before{content:attr({2})}",[i,c,m]),o.getElementsByTagName("head")[0].appendChild(e)):r.console.error("highlight.js not detected!"),document.addEventListener("copy",function(e){var n,t=window.getSelection();!function(e){for(var n=e;n;){if(n.className&&-1!==n.className.indexOf("hljs-ln-code"))return 1;n=n.parentNode}}(t.anchorNode)||(n=-1!==window.navigator.userAgent.indexOf("Edge")?u(t):t.toString(),e.clipboardData.setData("text/plain",n),e.preventDefault())})}(window,document);

-/* highlightjs-line-numbers.js 2.6.0 | (C) 2018 Yauheni Pakala | MIT License | github.com/wcoder/highlightjs-line-numbers.js */
-/* Edited by Hakim for reveal.js; removed async timeout */
-!function(n,e){"use strict";function t(){var n=e.createElement("style");n.type="text/css",n.innerHTML=g(".{0}{border-collapse:collapse}.{0} td{padding:0}.{1}:before{content:attr({2})}",[v,L,b]),e.getElementsByTagName("head")[0].appendChild(n)}function r(t){"interactive"===e.readyState||"complete"===e.readyState?i(t):n.addEventListener("DOMContentLoaded",function(){i(t)})}function i(t){try{var r=e.querySelectorAll("code.hljs,code.nohighlight");for(var i in r)r.hasOwnProperty(i)&&l(r[i],t)}catch(o){n.console.error("LineNumbers error: ",o)}}function l(n,e){"object"==typeof n&&f(function(){n.innerHTML=s(n,e)})}function o(n,e){if("string"==typeof n){var t=document.createElement("code");return t.innerHTML=n,s(t,e)}}function s(n,e){e=e||{singleLine:!1};var t=e.singleLine?0:1;return c(n),a(n.innerHTML,t)}function a(n,e){var t=u(n);if(""===t[t.length-1].trim()&&t.pop(),t.length>e){for(var r="",i=0,l=t.length;i<l;i++)r+=g('<tr><td class="{0}"><div class="{1} {2}" {3}="{5}"></div></td><td class="{4}"><div class="{1}">{6}</div></td></tr>',[j,m,L,b,p,i+1,t[i].length>0?t[i]:" "]);return g('<table class="{0}">{1}</table>',[v,r])}return n}function c(n){var e=n.childNodes;for(var t in e)if(e.hasOwnProperty(t)){var r=e[t];h(r.textContent)>0&&(r.childNodes.length>0?c(r):d(r.parentNode))}}function d(n){var e=n.className;if(/hljs-/.test(e)){for(var t=u(n.innerHTML),r=0,i="";r<t.length;r++){var l=t[r].length>0?t[r]:" ";i+=g('<span class="{0}">{1}</span>\n',[e,l])}n.innerHTML=i.trim()}}function u(n){return 0===n.length?[]:n.split(y)}function h(n){return(n.trim().match(y)||[]).length}function f(e){e()}function g(n,e){return n.replace(/\{(\d+)\}/g,function(n,t){return e[t]?e[t]:n})}var v="hljs-ln",m="hljs-ln-line",p="hljs-ln-code",j="hljs-ln-numbers",L="hljs-ln-n",b="data-line-number",y=/\r\n|\r|\n/g;hljs?(hljs.initLineNumbersOnLoad=r,hljs.lineNumbersBlock=l,hljs.lineNumbersValue=o,t()):n.console.error("highlight.js not detected!")}(window,document);

 /*!
 * reveal.js plugin that adds syntax highlight support.
@@ -16,10 +16,10 @@ const Plugin = {
 	HIGHLIGHT_LINE_DELIMITER: ',',
 	HIGHLIGHT_LINE_RANGE_DELIMITER: '-',

-	hljs: hljs,
+	hljs,

 	/**
-	 * Highlights code blocks withing the given deck.
+	 * Highlights code blocks within the given deck.
 	 *
 	 * Note that this can be called multiple times if
 	 * there are multiple presentations on one page.
@@ -30,12 +30,13 @@ const Plugin = {

 		// Read the plugin config options and provide fallbacks
 		let config = reveal.getConfig().highlight || {};
+
 		config.highlightOnLoad = typeof config.highlightOnLoad === 'boolean' ? config.highlightOnLoad : true;
 		config.escapeHTML = typeof config.escapeHTML === 'boolean' ? config.escapeHTML : true;

 		Array.from( reveal.getRevealElement().querySelectorAll( 'pre code' ) ).forEach( block => {

-			block.parentNode.className = 'code-wrapper';
+			block.parentNode.classList.add('code-wrapper');

 			// Code can optionally be wrapped in script template to avoid
 			// HTML being parsed by the browser (i.e. when you need to
@@ -61,12 +62,20 @@ const Plugin = {
 				hljs.highlightElement( event.currentTarget );
 			}, false );

-			if( config.highlightOnLoad ) {
-				Plugin.highlightBlock( block );
-			}
-
 		} );

+		// Triggers a callback function before we trigger highlighting
+		if( typeof config.beforeHighlight === 'function' ) {
+			config.beforeHighlight( hljs );
+		}
+
+		// Run initial highlighting for all code
+		if( config.highlightOnLoad ) {
+			Array.from( reveal.getRevealElement().querySelectorAll( 'pre code' ) ).forEach( block => {
+				Plugin.highlightBlock( block );
+			} );
+		}
+
 		// If we're printing to PDF, scroll the code highlights of
 		// all blocks in the deck into view at once
 		reveal.on( 'pdf-ready', function() {
@@ -97,7 +106,7 @@ const Plugin = {

 			var scrollState = { currentBlock: block };

-			// If there is at least one highlight step, generate
+			// If there is more than one highlight step, generate
 			// fragments
 			var highlightSteps = Plugin.deserializeHighlightSteps( block.getAttribute( 'data-line-numbers' ) );
 			if( highlightSteps.length > 1 ) {
@@ -129,11 +138,11 @@ const Plugin = {

 					// Scroll highlights into view as we step through them
 					fragmentBlock.addEventListener( 'visible', Plugin.scrollHighlightedLineIntoView.bind( Plugin, fragmentBlock, scrollState ) );
-					fragmentBlock.addEventListener( 'hidden', Plugin.scrollHighlightedLineIntoView.bind( Plugin, fragmentBlock.previousSibling, scrollState ) );
+					fragmentBlock.addEventListener( 'hidden', Plugin.scrollHighlightedLineIntoView.bind( Plugin, fragmentBlock.previousElementSibling, scrollState ) );

 				} );

-				block.removeAttribute( 'data-fragment-index' )
+				block.removeAttribute( 'data-fragment-index' );
 				block.setAttribute( 'data-line-numbers', Plugin.serializeHighlightSteps( [ highlightSteps[0] ] ) );

 			}
--- a/plugin/markdown/markdown.esm.js
+++ b/plugin/markdown/markdown.esm.js
--- a/plugin/markdown/markdown.js
+++ b/plugin/markdown/markdown.js
--- a/plugin/markdown/plugin.js
+++ b/plugin/markdown/plugin.js
@@ -4,16 +4,19 @@
 * of external markdown documents.
 */

-import marked from 'marked'
+import { marked } from 'marked';

 const DEFAULT_SLIDE_SEPARATOR = '\r?\n---\r?\n',
-	  DEFAULT_NOTES_SEPARATOR = 'notes?:',
+	  DEFAULT_VERTICAL_SEPARATOR = null,
+	  DEFAULT_NOTES_SEPARATOR = '^\s*notes?:',
 	  DEFAULT_ELEMENT_ATTRIBUTES_SEPARATOR = '\\\.element\\\s*?(.+?)$',
 	  DEFAULT_SLIDE_ATTRIBUTES_SEPARATOR = '\\\.slide:\\\s*?(\\\S.+?)$';

 const SCRIPT_END_PLACEHOLDER = '__SCRIPT_END__';

-const CODE_LINE_NUMBER_REGEX = /\[([\s\d,|-]*)\]/;
+// match an optional line number offset and highlight line numbers
+// [<line numbers>] or [<offset>: <line numbers>]
+const CODE_LINE_NUMBER_REGEX = /\[\s*((\d*):)?\s*([\s\d,|-]*)\]/;

 const HTML_ESCAPE_MAP = {
  '&': '&amp;',
@@ -35,22 +38,22 @@ const Plugin = () => {
 	function getMarkdownFromSlide( section ) {

 		// look for a <script> or <textarea data-template> wrapper
-		var template = section.querySelector( '[data-template]' ) || section.querySelector( 'script' );
+		const template = section.querySelector( '[data-template]' ) || section.querySelector( 'script' );

 		// strip leading whitespace so it isn't evaluated as code
-		var text = ( template || section ).textContent;
+		let text = ( template || section ).textContent;

 		// restore script end tags
 		text = text.replace( new RegExp( SCRIPT_END_PLACEHOLDER, 'g' ), '</script>' );

-		var leadingWs = text.match( /^\n?(\s*)/ )[1].length,
+		const leadingWs = text.match( /^\n?(\s*)/ )[1].length,
 			leadingTabs = text.match( /^\n?(\t*)/ )[1].length;

 		if( leadingTabs > 0 ) {
-			text = text.replace( new RegExp('\\n?\\t{' + leadingTabs + '}','g'), '\n' );
+			text = text.replace( new RegExp('\\n?\\t{' + leadingTabs + '}(.*)','g'), function(m, p1) { return '\n' + p1 ; } );
 		}
 		else if( leadingWs > 1 ) {
-			text = text.replace( new RegExp('\\n? {' + leadingWs + '}', 'g'), '\n' );
+			text = text.replace( new RegExp('\\n? {' + leadingWs + '}(.*)', 'g'), function(m, p1) { return '\n' + p1 ; } );
 		}

 		return text;
@@ -65,11 +68,11 @@ const Plugin = () => {
 	 */
 	function getForwardedAttributes( section ) {

-		var attributes = section.attributes;
-		var result = [];
+		const attributes = section.attributes;
+		const result = [];

-		for( var i = 0, len = attributes.length; i < len; i++ ) {
-			var name = attributes[i].name,
+		for( let i = 0, len = attributes.length; i < len; i++ ) {
+			const name = attributes[i].name,
 				value = attributes[i].value;

 			// disregard attributes that are used for markdown loading/parsing
@@ -92,10 +95,12 @@ const Plugin = () => {
 	 * values for what's not defined.
 	 */
 	function getSlidifyOptions( options ) {
+		const markdownConfig = deck?.getConfig?.().markdown;

 		options = options || {};
-		options.separator = options.separator || DEFAULT_SLIDE_SEPARATOR;
-		options.notesSeparator = options.notesSeparator || DEFAULT_NOTES_SEPARATOR;
+		options.separator = options.separator || markdownConfig?.separator || DEFAULT_SLIDE_SEPARATOR;
+		options.verticalSeparator = options.verticalSeparator || markdownConfig?.verticalSeparator || DEFAULT_VERTICAL_SEPARATOR;
+		options.notesSeparator = options.notesSeparator || markdownConfig?.notesSeparator || DEFAULT_NOTES_SEPARATOR;
 		options.attributes = options.attributes || '';

 		return options;
@@ -109,7 +114,7 @@ const Plugin = () => {

 		options = getSlidifyOptions( options );

-		var notesMatch = content.split( new RegExp( options.notesSeparator, 'mgi' ) );
+		const notesMatch = content.split( new RegExp( options.notesSeparator, 'mgi' ) );

 		if( notesMatch.length === 2 ) {
 			content = notesMatch[0] + '<aside class="notes">' + marked(notesMatch[1].trim()) + '</aside>';
@@ -131,10 +136,10 @@ const Plugin = () => {

 		options = getSlidifyOptions( options );

-		var separatorRegex = new RegExp( options.separator + ( options.verticalSeparator ? '|' + options.verticalSeparator : '' ), 'mg' ),
+		const separatorRegex = new RegExp( options.separator + ( options.verticalSeparator ? '|' + options.verticalSeparator : '' ), 'mg' ),
 			horizontalSeparatorRegex = new RegExp( options.separator );

-		var matches,
+		let matches,
 			lastIndex = 0,
 			isHorizontal,
 			wasHorizontal = true,
@@ -143,7 +148,7 @@ const Plugin = () => {

 		// iterate until all blocks between separators are stacked up
 		while( matches = separatorRegex.exec( markdown ) ) {
-			var notes = null;
+			const notes = null;

 			// determine direction (horizontal by default)
 			isHorizontal = horizontalSeparatorRegex.test( matches[0] );
@@ -172,10 +177,10 @@ const Plugin = () => {
 		// add the remaining slide
 		( wasHorizontal ? sectionStack : sectionStack[sectionStack.length-1] ).push( markdown.substring( lastIndex ) );

-		var markdownSections = '';
+		let markdownSections = '';

 		// flatten the hierarchical stack, and insert <section data-markdown> tags
-		for( var i = 0, len = sectionStack.length; i < len; i++ ) {
+		for( let i = 0, len = sectionStack.length; i < len; i++ ) {
 			// vertical
 			if( sectionStack[i] instanceof Array ) {
 				markdownSections += '<section '+ options.attributes +'>';
@@ -204,9 +209,9 @@ const Plugin = () => {

 		return new Promise( function( resolve ) {

-			var externalPromises = [];
+			const externalPromises = [];

-			[].slice.call( scope.querySelectorAll( '[data-markdown]:not([data-markdown-parsed])') ).forEach( function( section, i ) {
+			[].slice.call( scope.querySelectorAll( 'section[data-markdown]:not([data-markdown-parsed])') ).forEach( function( section, i ) {

 				if( section.getAttribute( 'data-markdown' ).length ) {

@@ -257,13 +262,13 @@ const Plugin = () => {

 		return new Promise( function( resolve, reject ) {

-			var xhr = new XMLHttpRequest(),
+			const xhr = new XMLHttpRequest(),
 				url = section.getAttribute( 'data-markdown' );

-			var datacharset = section.getAttribute( 'data-charset' );
+			const datacharset = section.getAttribute( 'data-charset' );

 			// see https://developer.mozilla.org/en-US/docs/Web/API/element.getAttribute#Notes
-			if( datacharset != null && datacharset != '' ) {
+			if( datacharset !== null && datacharset !== '' ) {
 				xhr.overrideMimeType( 'text/html; charset=' + datacharset );
 			}

@@ -308,17 +313,17 @@ const Plugin = () => {
 	 */
 	function addAttributeInElement( node, elementTarget, separator ) {

-		var mardownClassesInElementsRegex = new RegExp( separator, 'mg' );
-		var mardownClassRegex = new RegExp( "([^\"= ]+?)=\"([^\"]+?)\"|(data-[^\"= ]+?)(?=[\" ])", 'mg' );
-		var nodeValue = node.nodeValue;
-		var matches,
+		const markdownClassesInElementsRegex = new RegExp( separator, 'mg' );
+		const markdownClassRegex = new RegExp( "([^\"= ]+?)=\"([^\"]+?)\"|(data-[^\"= ]+?)(?=[\" ])", 'mg' );
+		let nodeValue = node.nodeValue;
+		let matches,
 			matchesClass;
-		if( matches = mardownClassesInElementsRegex.exec( nodeValue ) ) {
+		if( matches = markdownClassesInElementsRegex.exec( nodeValue ) ) {

-			var classes = matches[1];
-			nodeValue = nodeValue.substring( 0, matches.index ) + nodeValue.substring( mardownClassesInElementsRegex.lastIndex );
+			const classes = matches[1];
+			nodeValue = nodeValue.substring( 0, matches.index ) + nodeValue.substring( markdownClassesInElementsRegex.lastIndex );
 			node.nodeValue = nodeValue;
-			while( matchesClass = mardownClassRegex.exec( classes ) ) {
+			while( matchesClass = markdownClassRegex.exec( classes ) ) {
 				if( matchesClass[2] ) {
 					elementTarget.setAttribute( matchesClass[1], matchesClass[2] );
 				} else {
@@ -336,34 +341,34 @@ const Plugin = () => {
 	 */
 	function addAttributes( section, element, previousElement, separatorElementAttributes, separatorSectionAttributes ) {

-		if ( element != null && element.childNodes != undefined && element.childNodes.length > 0 ) {
-			var previousParentElement = element;
-			for( var i = 0; i < element.childNodes.length; i++ ) {
-				var childElement = element.childNodes[i];
+		if ( element !== null && element.childNodes !== undefined && element.childNodes.length > 0 ) {
+			let previousParentElement = element;
+			for( let i = 0; i < element.childNodes.length; i++ ) {
+				const childElement = element.childNodes[i];
 				if ( i > 0 ) {
-					var j = i - 1;
+					let j = i - 1;
 					while ( j >= 0 ) {
-						var aPreviousChildElement = element.childNodes[j];
-						if ( typeof aPreviousChildElement.setAttribute == 'function' && aPreviousChildElement.tagName != "BR" ) {
+						const aPreviousChildElement = element.childNodes[j];
+						if ( typeof aPreviousChildElement.setAttribute === 'function' && aPreviousChildElement.tagName !== "BR" ) {
 							previousParentElement = aPreviousChildElement;
 							break;
 						}
 						j = j - 1;
 					}
 				}
-				var parentSection = section;
-				if( childElement.nodeName ==  "section" ) {
+				let parentSection = section;
+				if( childElement.nodeName ===  "section" ) {
 					parentSection = childElement ;
 					previousParentElement = childElement ;
 				}
-				if ( typeof childElement.setAttribute == 'function' || childElement.nodeType == Node.COMMENT_NODE ) {
+				if ( typeof childElement.setAttribute === 'function' || childElement.nodeType === Node.COMMENT_NODE ) {
 					addAttributes( parentSection, childElement, previousParentElement, separatorElementAttributes, separatorSectionAttributes );
 				}
 			}
 		}

-		if ( element.nodeType == Node.COMMENT_NODE ) {
-			if ( addAttributeInElement( element, previousElement, separatorElementAttributes ) == false ) {
+		if ( element.nodeType === Node.COMMENT_NODE ) {
+			if ( addAttributeInElement( element, previousElement, separatorElementAttributes ) === false ) {
 				addAttributeInElement( element, section, separatorSectionAttributes );
 			}
 		}
@@ -375,14 +380,14 @@ const Plugin = () => {
 	 */
 	function convertSlides() {

-		var sections = deck.getRevealElement().querySelectorAll( '[data-markdown]:not([data-markdown-parsed])');
+		const sections = deck.getRevealElement().querySelectorAll( '[data-markdown]:not([data-markdown-parsed])');

 		[].slice.call( sections ).forEach( function( section ) {

 			section.setAttribute( 'data-markdown-parsed', true )

-			var notes = section.querySelector( 'aside.notes' );
-			var markdown = getMarkdownFromSlide( section );
+			const notes = section.querySelector( 'aside.notes' );
+			const markdown = getMarkdownFromSlide( section );

 			section.innerHTML = marked( markdown );
 			addAttributes( 	section, section, null, section.getAttribute( 'data-element-attributes' ) ||
@@ -429,14 +434,23 @@ const Plugin = () => {
 				renderer.code = ( code, language ) => {

 					// Off by default
+					let lineNumberOffset = '';
 					let lineNumbers = '';

 					// Users can opt in to show line numbers and highlight
 					// specific lines.
 					// ```javascript []        show line numbers
 					// ```javascript [1,4-8]   highlights lines 1 and 4-8
+					// optional line number offset:
+					// ```javascript [25: 1,4-8]   start line numbering at 25,
+					//                             highlights lines 1 (numbered as 25) and 4-8 (numbered as 28-32)
 					if( CODE_LINE_NUMBER_REGEX.test( language ) ) {
-						lineNumbers = language.match( CODE_LINE_NUMBER_REGEX )[1].trim();
+						let lineNumberOffsetMatch =  language.match( CODE_LINE_NUMBER_REGEX )[2];
+						if (lineNumberOffsetMatch){
+							lineNumberOffset =  `data-ln-start-from="${lineNumberOffsetMatch.trim()}"`;
+						}
+
+						lineNumbers = language.match( CODE_LINE_NUMBER_REGEX )[3].trim();
 						lineNumbers = `data-line-numbers="${lineNumbers}"`;
 						language = language.replace( CODE_LINE_NUMBER_REGEX, '' ).trim();
 					}
@@ -446,7 +460,9 @@ const Plugin = () => {
 					// highlight.js is able to read it
 					code = escapeForHTML( code );

-					return `<pre><code ${lineNumbers} class="${language}">${code}</code></pre>`;
+					// return `<pre><code ${lineNumbers} class="${language}">${code}</code></pre>`;
+
+					return `<pre><code ${lineNumbers} ${lineNumberOffset} class="${language}">${code}</code></pre>`;
 				};
 			}

--- a/Show More
+++ b/Show More