internship: change word

internship: modify
internship: go to sleep
2022-11-09 09:51:11 +08:00 · 2022-11-09 08:46:56 +08:00 · 2022-11-09 03:00:01 +08:00
131 changed files with 14054 additions and 14380 deletions
--- a/.codespellrc
+++ b/.codespellrc
@@ -1,8 +0,0 @@
-[codespell]
-# Ref: https://github.com/codespell-project/codespell#using-a-config-file
-skip = .git*,node_modules,package-lock.json,*.css,.codespellrc
-check-hidden = true
-# Ignore super long lines -- must be minimized etc, acronyms
-# and some near hit variables
-ignore-regex = ^.{120,}|\b(currentY|FOM)\b
-# ignore-words-list =
--- a/.github/workflows/js.yml
+++ b/.github/workflows/js.yml
@@ -0,0 +1,24 @@
+name: tests
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [10.x, 14.x, 16.x]
+
+    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
--- a/.github/workflows/spellcheck.yml
+++ b/.github/workflows/spellcheck.yml
@@ -1,23 +0,0 @@
-# Codespell configuration is within .codespellrc
---
-name: Spellcheck
-
-on:
-  push:
-    branches: [master]
-  pull_request:
-    branches: [master]
-
-permissions:
-  contents: read
-
-jobs:
-  codespell:
-    name: Check for spelling errors
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Codespell
-        uses: codespell-project/actions-codespell@v2
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,31 +0,0 @@
-name: Tests
-
-on:
-  - push
-
-permissions:
-  contents: read
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        node-version:
-          - 18
-          - 20
-
-    steps:
-      - 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/.npmignore
+++ b/.npmignore
@@ -1,5 +1,7 @@
 /test
 /examples
 .github
+.gulpfile
 .sass-cache
 gulpfile.js
+CONTRIBUTING.md
--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-Copyright (C) 2011-2024 Hakim El Hattab, http://hakim.se, and reveal.js contributors
+Copyright (C) 2011-2022 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
@@ -4,7 +4,7 @@
  </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://static.slid.es/images/slides-github-banner-320x40.png?1" alt="Slides" width="160" height="20"></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 beautiful presentations for free. Check out the live demo at [revealjs.com](https://revealjs.com/).
@@ -17,6 +17,26 @@ Want to create reveal.js presentation in a graphical editor? Try <https://slides

 ---

+### 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>
+
+---
+
 ### Getting started
 - 🚀 [Install reveal.js](https://revealjs.com/installation)
 - 👀 [View the demo presentation](https://revealjs.com/demo)
@@ -26,5 +46,5 @@ Want to create reveal.js presentation in a graphical editor? Try <https://slides

 --- 
 <div align="center">
-  MIT licensed | Copyright © 2011-2024 Hakim El Hattab, https://hakim.se
+  MIT licensed | Copyright © 2011-2022 Hakim El Hattab, https://hakim.se
 </div>
--- a/css/layout.scss
+++ b/css/layout.scss
@@ -25,7 +25,6 @@
 // Stack multiple elements on top of each other
 .reveal .r-stack {
 	display: grid;
-	grid-template-rows: 100%;
 }

 .reveal .r-stack > * {
--- a/css/print/paper.scss
+++ b/css/print/paper.scss
@@ -1,30 +1,42 @@
+/* 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) {
-		overflow: visible;
+
+		background: #fff;
 		width: auto;
 		height: auto;
+		overflow: visible;

 		body {
-			margin: 0;
+			background: #fff;
+			font-size: 20pt;
+			width: auto;
+			height: auto;
+			border: 0;
+			margin: 0 5%;
 			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,
-		.progress,
-		.backgrounds,
-		.slide-number {
+		.reveal .progress,
+		.reveal .backgrounds,
+		.reveal .slide-number {
 			display: none !important;
 		}

-		p, td, li {
+		body, p, td, li {
 			font-size: 20pt!important;
 			color: #000;
 		}
@@ -37,6 +49,7 @@
 			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; }
@@ -61,19 +74,18 @@
 			margin: 0;
 			text-align: left !important;
 		}
-		pre,
-		table {
+		.reveal pre,
+		.reveal table {
 			margin-left: 0;
 			margin-right: 0;
 		}
-		pre code {
+		.reveal pre code {
 			padding: 20px;
 		}
-		blockquote {
+		.reveal blockquote {
 			margin: 20px 0;
 		}
-
-		.slides {
+		.reveal .slides {
 			position: static !important;
 			width: auto !important;
 			height: auto !important;
@@ -94,7 +106,7 @@

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

 			transform: none !important;
 		}

-		.r-fit-text {
+		.reveal .r-fit-text {
 			white-space: normal !important;
 		}

-		section img {
+		.reveal section img {
 			display: block;
 			margin: 15px 0px;
 			background: rgba(255,255,255,1);
@@ -142,11 +154,11 @@
 			box-shadow: none;
 		}

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

-		.hljs {
+		.reveal .hljs {
 			max-height: 100%;
 			white-space: pre-wrap;
 			word-wrap: break-word;
@@ -154,11 +166,11 @@
 			font-size: 15pt;
 		}

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

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

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

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

-	.reveal .slides .pdf-page:last-of-type {
-		page-break-after: avoid;
-	}
-
 	.reveal .slides section {
 		visibility: visible !important;
 		display: block !important;
@@ -149,7 +146,6 @@ html.reveal-print {
 		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
@@ -6,7 +8,6 @@
 * Copyright (C) Hakim El Hattab, https://hakim.se
 */

-@use "sass:math";
@import 'layout';

 /*********************************************
@@ -18,7 +19,6 @@ html.reveal-full-page {
 	height: 100%;
 	height: 100vh;
 	height: calc( var(--vh, 1vh) * 100 );
-	height: 100dvh;
 	overflow: hidden;
 }

@@ -31,18 +31,6 @@ html.reveal-full-page {

 	background-color: #fff;
 	color: #000;
-
-	--r-controls-spacing: 12px;
-	--r-overlay-header-height: 40px;
-	--r-overlay-margin: 0px;
-	--r-overlay-padding: 6px;
-	--r-overlay-gap: 5px;
-}
-
-@media screen and (max-width: 1024px), (max-height: 768px) {
-	.reveal-viewport {
-		--r-overlay-header-height: 26px;
-	}
 }

 // Force the presentation to cover the full viewport when we
@@ -60,14 +48,11 @@ html.reveal-full-page {
 * VIEW FRAGMENTS
 *********************************************/

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

 	&.visible {
 		opacity: 1;
@@ -79,7 +64,7 @@ html.reveal-full-page {
 	}
 }

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

@@ -88,7 +73,7 @@ html.reveal-full-page {
 	}
 }

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

@@ -97,7 +82,7 @@ html.reveal-full-page {
 	}
 }

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

 	&.visible {
@@ -105,7 +90,7 @@ html.reveal-full-page {
 	}
 }

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

@@ -115,7 +100,7 @@ html.reveal-full-page {
 	}
 }

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

@@ -125,7 +110,7 @@ html.reveal-full-page {
 	}
 }

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

@@ -134,7 +119,7 @@ html.reveal-full-page {
 	}
 }

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

 	&.visible {
@@ -142,7 +127,7 @@ html.reveal-full-page {
 	}
 }

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

 	&.visible {
@@ -150,7 +135,7 @@ html.reveal-full-page {
 	}
 }

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

 	&.visible {
@@ -158,7 +143,7 @@ html.reveal-full-page {
 	}
 }

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

 	&.visible {
@@ -166,8 +151,8 @@ html.reveal-full-page {
 	}
 }

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

@@ -177,7 +162,7 @@ html.reveal-full-page {
 	}
 }

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

@@ -192,32 +177,32 @@ html.reveal-full-page {
 	}
 }

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

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

@@ -283,11 +268,13 @@ $controlsArrowAngleActive: 36deg;
 }

 .reveal .controls {
+	$spacing: 12px;
+
 	display: none;
 	position: absolute;
 	top: auto;
-	bottom: var(--r-controls-spacing);
-	right: var(--r-controls-spacing);
+	bottom: $spacing;
+	right: $spacing;
 	left: auto;
 	z-index: 11;
 	color: #000;
@@ -519,9 +506,7 @@ $controlsArrowAngleActive: 36deg;
 // Edge aligned controls layout
@media screen and (min-width: 500px) {

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

 	.reveal .controls[data-controls-layout="edges"] {
 		& {
@@ -541,24 +526,24 @@ $controlsArrowAngleActive: 36deg;

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

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

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

 		.navigate-down {
-			bottom: calc(var(--r-controls-spacing) - #{$controlArrowSpacing} + 0.3em);
+			bottom: $spacing - $controlArrowSpacing + 0.3em;
 			left: 50%;
 			margin-left: -$controlArrowSize*0.5;
 		}
@@ -640,16 +625,11 @@ $controlsArrowAngleActive: 36deg;
 	touch-action: pinch-zoom;
 }

-// Swiping on an embedded deck should not block page scrolling...
+// Swiping on an embedded deck should not block page scrolling
 .reveal.embedded {
 	touch-action: pan-y;
 }

-// ... unless we're on a vertical slide
-.reveal.embedded.is-vertical-slide {
-	touch-action: none;
-}
-
 .reveal .slides {
 	position: absolute;
 	width: 100%;
@@ -1009,7 +989,7 @@ $controlsArrowAngleActive: 36deg;
 		border-radius: 4px;
 		box-shadow: 0px 95px 25px rgba(0,0,0,0.2);

-		transform: translateZ(-90px) rotateX( 65deg );
+		-webkit-transform: translateZ(-90px) rotateX( 65deg );
 	}

 .reveal.page .slides>section.stack {
@@ -1328,6 +1308,12 @@ $controlsArrowAngleActive: 36deg;
 	perspective-origin: 50% 50%;
 	perspective: 700px;

+	.slides {
+		// Fixes overview rendering errors in FF48+, not applied to
+		// other browsers since it degrades performance
+		-moz-transform-style: preserve-3d;
+	}
+
 	.slides section {
 		height: 100%;
 		top: 0 !important;
@@ -1339,12 +1325,9 @@ $controlsArrowAngleActive: 36deg;
 	}
 	.slides section:hover,
 	.slides section.present {
-		outline: 10px solid rgba(150,150,150,0.6);
+		outline: 10px solid rgba(150,150,150,0.4);
 		outline-offset: 10px;
 	}
-	.slides section.present {
-		outline: 10px solid var(--r-link-color);
-	}
 	.slides section .fragment {
 		opacity: 1;
 		transition: none;
@@ -1363,6 +1346,10 @@ $controlsArrowAngleActive: 36deg;

 	.backgrounds {
 		perspective: inherit;
+
+		// Fixes overview rendering errors in FF48+, not applied to
+		// other browsers since it degrades performance
+		-moz-transform-style: preserve-3d;
 	}

 	.backgrounds .slide-background {
@@ -1442,234 +1429,160 @@ $controlsArrowAngleActive: 36deg;
 * OVERLAY FOR LINK PREVIEWS AND HELP
 *********************************************/

-@keyframes fade-in {
-	from { opacity: 0; }
-	to { opacity: 1; }
-}
+$overlayHeaderHeight: 40px;
+$overlayHeaderPadding: 5px;

-@keyframes scale-up {
-	from { transform: scale( 0.95 ); }
-	to { transform: scale( 1 ); }
-}
-
-.reveal [data-preview-image],
-.reveal [data-preview-video],
-.reveal [data-preview-link]:not(a):not([data-preview-link=false]) {
-	cursor: zoom-in;
-}
-
-.r-overlay {
+.reveal > .overlay {
 	position: absolute;
-	top: var(--r-overlay-margin);
-	right: var(--r-overlay-margin);
-	bottom: var(--r-overlay-margin);
-	left: var(--r-overlay-margin);
-	border-radius: min( var(--r-overlay-margin), 6px );
-	z-index: 99;
-	background: rgba( 0, 0, 0, 0.95 );
-	backdrop-filter: blur( 10px );
-	transition: all 0.3s ease;
-	color: #fff;
-	animation: fade-in 0.3s ease;
-	font-family: ui-sans-serif, system-ui, -apple-system, Helvetica, sans-serif;
-}
-
-.r-overlay-viewport {
-	position: absolute;
-	top: var(--r-overlay-padding);
-	right: var(--r-overlay-padding);
-	bottom: var(--r-overlay-padding);
-	left: var(--r-overlay-padding);
-	gap: var(--r-overlay-gap);
-	display: flex;
-	flex-direction: column;
-}
-
-.r-overlay-header {
-	display: flex;
-	z-index: 2;
-	box-sizing: border-box;
-	align-items: center;
-	justify-content: flex-end;
-	height: var(--r-overlay-header-height);
-	gap: 6px;
-}
-.r-overlay-header .r-overlay-button {
-	all: unset;
-	display: flex;
-	align-items: center;
-	justify-content: center;
-	min-width: var(--r-overlay-header-height);
-	min-height: var(--r-overlay-header-height);
-	padding: 0 calc(var(--r-overlay-header-height) / 4);
-	opacity: 1;
-	border-radius: 6px;
-	font-size: 18px;
-	gap: 8px;
-	cursor: pointer;
-
-	box-sizing: border-box;
-}
-.r-overlay-header .r-overlay-button:hover {
-	opacity: 1;
-	background-color: rgba( 255, 255, 255, 0.15 );
-}
-.r-overlay-header .icon {
-	display: inline-block;
-	width: 20px;
-	height: 20px;
-
-	background-position: 50% 50%;
-	background-size: 100%;
-	background-repeat: no-repeat;
-}
-.r-overlay-close .icon {
-	background-image: url(data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIxNSIgaGVpZ2h0PSIxNSIgZmlsbD0ibm9uZSI+PHBhdGggZmlsbD0iI2ZmZiIgZmlsbC1ydWxlPSJldmVub2RkIiBkPSJNMTIuODU0IDIuODU0YS41LjUgMCAwIDAtLjcwOC0uNzA4TDcuNSA2Ljc5MyAyLjg1NCAyLjE0NmEuNS41IDAgMSAwLS43MDguNzA4TDYuNzkzIDcuNWwtNC42NDcgNC42NDZhLjUuNSAwIDAgMCAuNzA4LjcwOEw3LjUgOC4yMDdsNC42NDYgNC42NDdhLjUuNSAwIDAgMCAuNzA4LS43MDhMOC4yMDcgNy41bDQuNjQ3LTQuNjQ2WiIgY2xpcC1ydWxlPSJldmVub2RkIi8+PC9zdmc+);
-}
-.r-overlay-external .icon {
-	background-image: url(data:image/svg+xml;base64,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);
-}
-
-.r-overlay-content {
-	position: relative;
-	display: grid;
-	place-items: center;
-	border-radius: 6px;
-	overflow: hidden;
-	flex-grow: 1;
-	background-color: rgba(20, 20, 20, 0.8);
-	animation: scale-up 0.5s cubic-bezier(0.260, 0.860, 0.440, 0.985);
-}
-
-.r-overlay-spinner {
-	position: absolute;
-	display: block;
-	top: 50%;
-	left: 50%;
-	width: 32px;
-	height: 32px;
-	margin: -16px 0 0 -16px;
-	z-index: 10;
-	background-image: url(data:image/gif;base64,R0lGODlhIAAgAPMAAJmZmf%2F%2F%2F6%2Bvr8nJybW1tcDAwOjo6Nvb26ioqKOjo7Ozs%2FLy8vz8%2FAAAAAAAAAAAACH%2FC05FVFNDQVBFMi4wAwEAAAAh%2FhpDcmVhdGVkIHdpdGggYWpheGxvYWQuaW5mbwAh%2BQQJCgAAACwAAAAAIAAgAAAE5xDISWlhperN52JLhSSdRgwVo1ICQZRUsiwHpTJT4iowNS8vyW2icCF6k8HMMBkCEDskxTBDAZwuAkkqIfxIQyhBQBFvAQSDITM5VDW6XNE4KagNh6Bgwe60smQUB3d4Rz1ZBApnFASDd0hihh12BkE9kjAJVlycXIg7CQIFA6SlnJ87paqbSKiKoqusnbMdmDC2tXQlkUhziYtyWTxIfy6BE8WJt5YJvpJivxNaGmLHT0VnOgSYf0dZXS7APdpB309RnHOG5gDqXGLDaC457D1zZ%2FV%2FnmOM82XiHRLYKhKP1oZmADdEAAAh%2BQQJCgAAACwAAAAAIAAgAAAE6hDISWlZpOrNp1lGNRSdRpDUolIGw5RUYhhHukqFu8DsrEyqnWThGvAmhVlteBvojpTDDBUEIFwMFBRAmBkSgOrBFZogCASwBDEY%2FCZSg7GSE0gSCjQBMVG023xWBhklAnoEdhQEfyNqMIcKjhRsjEdnezB%2BA4k8gTwJhFuiW4dokXiloUepBAp5qaKpp6%2BHo7aWW54wl7obvEe0kRuoplCGepwSx2jJvqHEmGt6whJpGpfJCHmOoNHKaHx61WiSR92E4lbFoq%2BB6QDtuetcaBPnW6%2BO7wDHpIiK9SaVK5GgV543tzjgGcghAgAh%2BQQJCgAAACwAAAAAIAAgAAAE7hDISSkxpOrN5zFHNWRdhSiVoVLHspRUMoyUakyEe8PTPCATW9A14E0UvuAKMNAZKYUZCiBMuBakSQKG8G2FzUWox2AUtAQFcBKlVQoLgQReZhQlCIJesQXI5B0CBnUMOxMCenoCfTCEWBsJColTMANldx15BGs8B5wlCZ9Po6OJkwmRpnqkqnuSrayqfKmqpLajoiW5HJq7FL1Gr2mMMcKUMIiJgIemy7xZtJsTmsM4xHiKv5KMCXqfyUCJEonXPN2rAOIAmsfB3uPoAK%2B%2BG%2Bw48edZPK%2BM6hLJpQg484enXIdQFSS1u6UhksENEQAAIfkECQoAAAAsAAAAACAAIAAABOcQyEmpGKLqzWcZRVUQnZYg1aBSh2GUVEIQ2aQOE%2BG%2BcD4ntpWkZQj1JIiZIogDFFyHI0UxQwFugMSOFIPJftfVAEoZLBbcLEFhlQiqGp1Vd140AUklUN3eCA51C1EWMzMCezCBBmkxVIVHBWd3HHl9JQOIJSdSnJ0TDKChCwUJjoWMPaGqDKannasMo6WnM562R5YluZRwur0wpgqZE7NKUm%2BFNRPIhjBJxKZteWuIBMN4zRMIVIhffcgojwCF117i4nlLnY5ztRLsnOk%2BaV%2BoJY7V7m76PdkS4trKcdg0Zc0tTcKkRAAAIfkECQoAAAAsAAAAACAAIAAABO4QyEkpKqjqzScpRaVkXZWQEximw1BSCUEIlDohrft6cpKCk5xid5MNJTaAIkekKGQkWyKHkvhKsR7ARmitkAYDYRIbUQRQjWBwJRzChi9CRlBcY1UN4g0%2FVNB0AlcvcAYHRyZPdEQFYV8ccwR5HWxEJ02YmRMLnJ1xCYp0Y5idpQuhopmmC2KgojKasUQDk5BNAwwMOh2RtRq5uQuPZKGIJQIGwAwGf6I0JXMpC8C7kXWDBINFMxS4DKMAWVWAGYsAdNqW5uaRxkSKJOZKaU3tPOBZ4DuK2LATgJhkPJMgTwKCdFjyPHEnKxFCDhEAACH5BAkKAAAALAAAAAAgACAAAATzEMhJaVKp6s2nIkolIJ2WkBShpkVRWqqQrhLSEu9MZJKK9y1ZrqYK9WiClmvoUaF8gIQSNeF1Er4MNFn4SRSDARWroAIETg1iVwuHjYB1kYc1mwruwXKC9gmsJXliGxc%2BXiUCby9ydh1sOSdMkpMTBpaXBzsfhoc5l58Gm5yToAaZhaOUqjkDgCWNHAULCwOLaTmzswadEqggQwgHuQsHIoZCHQMMQgQGubVEcxOPFAcMDAYUA85eWARmfSRQCdcMe0zeP1AAygwLlJtPNAAL19DARdPzBOWSm1brJBi45soRAWQAAkrQIykShQ9wVhHCwCQCACH5BAkKAAAALAAAAAAgACAAAATrEMhJaVKp6s2nIkqFZF2VIBWhUsJaTokqUCoBq%2BE71SRQeyqUToLA7VxF0JDyIQh%2FMVVPMt1ECZlfcjZJ9mIKoaTl1MRIl5o4CUKXOwmyrCInCKqcWtvadL2SYhyASyNDJ0uIiRMDjI0Fd30%2FiI2UA5GSS5UDj2l6NoqgOgN4gksEBgYFf0FDqKgHnyZ9OX8HrgYHdHpcHQULXAS2qKpENRg7eAMLC7kTBaixUYFkKAzWAAnLC7FLVxLWDBLKCwaKTULgEwbLA4hJtOkSBNqITT3xEgfLpBtzE%2FjiuL04RGEBgwWhShRgQExHBAAh%2BQQJCgAAACwAAAAAIAAgAAAE7xDISWlSqerNpyJKhWRdlSAVoVLCWk6JKlAqAavhO9UkUHsqlE6CwO1cRdCQ8iEIfzFVTzLdRAmZX3I2SfZiCqGk5dTESJeaOAlClzsJsqwiJwiqnFrb2nS9kmIcgEsjQydLiIlHehhpejaIjzh9eomSjZR%2BipslWIRLAgMDOR2DOqKogTB9pCUJBagDBXR6XB0EBkIIsaRsGGMMAxoDBgYHTKJiUYEGDAzHC9EACcUGkIgFzgwZ0QsSBcXHiQvOwgDdEwfFs0sDzt4S6BK4xYjkDOzn0unFeBzOBijIm1Dgmg5YFQwsCMjp1oJ8LyIAACH5BAkKAAAALAAAAAAgACAAAATwEMhJaVKp6s2nIkqFZF2VIBWhUsJaTokqUCoBq%2BE71SRQeyqUToLA7VxF0JDyIQh%2FMVVPMt1ECZlfcjZJ9mIKoaTl1MRIl5o4CUKXOwmyrCInCKqcWtvadL2SYhyASyNDJ0uIiUd6GGl6NoiPOH16iZKNlH6KmyWFOggHhEEvAwwMA0N9GBsEC6amhnVcEwavDAazGwIDaH1ipaYLBUTCGgQDA8NdHz0FpqgTBwsLqAbWAAnIA4FWKdMLGdYGEgraigbT0OITBcg5QwPT4xLrROZL6AuQAPUS7bxLpoWidY0JtxLHKhwwMJBTHgPKdEQAACH5BAkKAAAALAAAAAAgACAAAATrEMhJaVKp6s2nIkqFZF2VIBWhUsJaTokqUCoBq%2BE71SRQeyqUToLA7VxF0JDyIQh%2FMVVPMt1ECZlfcjZJ9mIKoaTl1MRIl5o4CUKXOwmyrCInCKqcWtvadL2SYhyASyNDJ0uIiUd6GAULDJCRiXo1CpGXDJOUjY%2BYip9DhToJA4RBLwMLCwVDfRgbBAaqqoZ1XBMHswsHtxtFaH1iqaoGNgAIxRpbFAgfPQSqpbgGBqUD1wBXeCYp1AYZ19JJOYgH1KwA4UBvQwXUBxPqVD9L3sbp2BNk2xvvFPJd%2BMFCN6HAAIKgNggY0KtEBAAh%2BQQJCgAAACwAAAAAIAAgAAAE6BDISWlSqerNpyJKhWRdlSAVoVLCWk6JKlAqAavhO9UkUHsqlE6CwO1cRdCQ8iEIfzFVTzLdRAmZX3I2SfYIDMaAFdTESJeaEDAIMxYFqrOUaNW4E4ObYcCXaiBVEgULe0NJaxxtYksjh2NLkZISgDgJhHthkpU4mW6blRiYmZOlh4JWkDqILwUGBnE6TYEbCgevr0N1gH4At7gHiRpFaLNrrq8HNgAJA70AWxQIH1%2BvsYMDAzZQPC9VCNkDWUhGkuE5PxJNwiUK4UfLzOlD4WvzAHaoG9nxPi5d%2BjYUqfAhhykOFwJWiAAAIfkECQoAAAAsAAAAACAAIAAABPAQyElpUqnqzaciSoVkXVUMFaFSwlpOCcMYlErAavhOMnNLNo8KsZsMZItJEIDIFSkLGQoQTNhIsFehRww2CQLKF0tYGKYSg%2BygsZIuNqJksKgbfgIGepNo2cIUB3V1B3IvNiBYNQaDSTtfhhx0CwVPI0UJe0%2Bbm4g5VgcGoqOcnjmjqDSdnhgEoamcsZuXO1aWQy8KAwOAuTYYGwi7w5h%2BKr0SJ8MFihpNbx%2B4Erq7BYBuzsdiH1jCAzoSfl0rVirNbRXlBBlLX%2BBP0XJLAPGzTkAuAOqb0WT5AH7OcdCm5B8TgRwSRKIHQtaLCwg1RAAAOwAAAAAAAAAAAA%3D%3D);
-
-	visibility: hidden;
-	opacity: 0;
-}
-
-// Preview overlay
-.r-overlay-preview .r-overlay-content iframe {
-	width: 100%;
-	height: 100%;
-	max-width: 100%;
-	max-height: 100%;
-	border: 0;
-
-	opacity: 0;
-	visibility: hidden;
-	transition: all 0.3s ease;
-}
-
-.r-overlay-preview[data-state="loaded"] iframe {
-	opacity: 1;
-	visibility: visible;
-}
-
-.r-overlay-preview .r-overlay-content img,
-.r-overlay-preview .r-overlay-content video {
-	position: absolute;
-	max-width: 100%;
-	max-height: 100%;
-	width: 100%;
-	height: 100%;
-	margin: 0;
-	object-fit: scale-down;
-}
-
-.r-overlay-preview[data-preview-fit="none"] img,
-.r-overlay-preview[data-preview-fit="none"] video {
-	object-fit: none;
-}
-
-.r-overlay-preview[data-preview-fit="scale-down"] img,
-.r-overlay-preview[data-preview-fit="scale-down"] video {
-	object-fit: scale-down;
-}
-
-.r-overlay-preview[data-preview-fit="contain"] img,
-.r-overlay-preview[data-preview-fit="contain"] video {
-	object-fit: contain;
-}
-
-.r-overlay-preview[data-preview-fit="cover"] img,
-.r-overlay-preview[data-preview-fit="cover"] video {
-	object-fit: cover;
-}
-
-.r-overlay-preview[data-state="loaded"] .r-overlay-content-inner  {
-	position: absolute;
-	z-index: -1;
+	top: 0;
 	left: 0;
-	top: 45%;
 	width: 100%;
-	text-align: center;
-	letter-spacing: normal;
-}
-.r-overlay-preview .r-overlay-error {
-	font-size: 18px;
-	color: orange;
+	height: 100%;
+	z-index: 1000;
+	background: rgba( 0, 0, 0, 0.9 );
+	transition: all 0.3s ease;
 }

-.r-overlay-preview .x-frame-error  {
-	opacity: 0;
-	transition: opacity 0.3s ease 0.3s;
-}
-.r-overlay-preview[data-state="loaded"] .x-frame-error  {
-	opacity: 1;
-}
+	.reveal > .overlay .spinner {
+		position: absolute;
+		display: block;
+		top: 50%;
+		left: 50%;
+		width: 32px;
+		height: 32px;
+		margin: -16px 0 0 -16px;
+		z-index: 10;
+		background-image: url(data:image/gif;base64,R0lGODlhIAAgAPMAAJmZmf%2F%2F%2F6%2Bvr8nJybW1tcDAwOjo6Nvb26ioqKOjo7Ozs%2FLy8vz8%2FAAAAAAAAAAAACH%2FC05FVFNDQVBFMi4wAwEAAAAh%2FhpDcmVhdGVkIHdpdGggYWpheGxvYWQuaW5mbwAh%2BQQJCgAAACwAAAAAIAAgAAAE5xDISWlhperN52JLhSSdRgwVo1ICQZRUsiwHpTJT4iowNS8vyW2icCF6k8HMMBkCEDskxTBDAZwuAkkqIfxIQyhBQBFvAQSDITM5VDW6XNE4KagNh6Bgwe60smQUB3d4Rz1ZBApnFASDd0hihh12BkE9kjAJVlycXIg7CQIFA6SlnJ87paqbSKiKoqusnbMdmDC2tXQlkUhziYtyWTxIfy6BE8WJt5YJvpJivxNaGmLHT0VnOgSYf0dZXS7APdpB309RnHOG5gDqXGLDaC457D1zZ%2FV%2FnmOM82XiHRLYKhKP1oZmADdEAAAh%2BQQJCgAAACwAAAAAIAAgAAAE6hDISWlZpOrNp1lGNRSdRpDUolIGw5RUYhhHukqFu8DsrEyqnWThGvAmhVlteBvojpTDDBUEIFwMFBRAmBkSgOrBFZogCASwBDEY%2FCZSg7GSE0gSCjQBMVG023xWBhklAnoEdhQEfyNqMIcKjhRsjEdnezB%2BA4k8gTwJhFuiW4dokXiloUepBAp5qaKpp6%2BHo7aWW54wl7obvEe0kRuoplCGepwSx2jJvqHEmGt6whJpGpfJCHmOoNHKaHx61WiSR92E4lbFoq%2BB6QDtuetcaBPnW6%2BO7wDHpIiK9SaVK5GgV543tzjgGcghAgAh%2BQQJCgAAACwAAAAAIAAgAAAE7hDISSkxpOrN5zFHNWRdhSiVoVLHspRUMoyUakyEe8PTPCATW9A14E0UvuAKMNAZKYUZCiBMuBakSQKG8G2FzUWox2AUtAQFcBKlVQoLgQReZhQlCIJesQXI5B0CBnUMOxMCenoCfTCEWBsJColTMANldx15BGs8B5wlCZ9Po6OJkwmRpnqkqnuSrayqfKmqpLajoiW5HJq7FL1Gr2mMMcKUMIiJgIemy7xZtJsTmsM4xHiKv5KMCXqfyUCJEonXPN2rAOIAmsfB3uPoAK%2B%2BG%2Bw48edZPK%2BM6hLJpQg484enXIdQFSS1u6UhksENEQAAIfkECQoAAAAsAAAAACAAIAAABOcQyEmpGKLqzWcZRVUQnZYg1aBSh2GUVEIQ2aQOE%2BG%2BcD4ntpWkZQj1JIiZIogDFFyHI0UxQwFugMSOFIPJftfVAEoZLBbcLEFhlQiqGp1Vd140AUklUN3eCA51C1EWMzMCezCBBmkxVIVHBWd3HHl9JQOIJSdSnJ0TDKChCwUJjoWMPaGqDKannasMo6WnM562R5YluZRwur0wpgqZE7NKUm%2BFNRPIhjBJxKZteWuIBMN4zRMIVIhffcgojwCF117i4nlLnY5ztRLsnOk%2BaV%2BoJY7V7m76PdkS4trKcdg0Zc0tTcKkRAAAIfkECQoAAAAsAAAAACAAIAAABO4QyEkpKqjqzScpRaVkXZWQEximw1BSCUEIlDohrft6cpKCk5xid5MNJTaAIkekKGQkWyKHkvhKsR7ARmitkAYDYRIbUQRQjWBwJRzChi9CRlBcY1UN4g0%2FVNB0AlcvcAYHRyZPdEQFYV8ccwR5HWxEJ02YmRMLnJ1xCYp0Y5idpQuhopmmC2KgojKasUQDk5BNAwwMOh2RtRq5uQuPZKGIJQIGwAwGf6I0JXMpC8C7kXWDBINFMxS4DKMAWVWAGYsAdNqW5uaRxkSKJOZKaU3tPOBZ4DuK2LATgJhkPJMgTwKCdFjyPHEnKxFCDhEAACH5BAkKAAAALAAAAAAgACAAAATzEMhJaVKp6s2nIkolIJ2WkBShpkVRWqqQrhLSEu9MZJKK9y1ZrqYK9WiClmvoUaF8gIQSNeF1Er4MNFn4SRSDARWroAIETg1iVwuHjYB1kYc1mwruwXKC9gmsJXliGxc%2BXiUCby9ydh1sOSdMkpMTBpaXBzsfhoc5l58Gm5yToAaZhaOUqjkDgCWNHAULCwOLaTmzswadEqggQwgHuQsHIoZCHQMMQgQGubVEcxOPFAcMDAYUA85eWARmfSRQCdcMe0zeP1AAygwLlJtPNAAL19DARdPzBOWSm1brJBi45soRAWQAAkrQIykShQ9wVhHCwCQCACH5BAkKAAAALAAAAAAgACAAAATrEMhJaVKp6s2nIkqFZF2VIBWhUsJaTokqUCoBq%2BE71SRQeyqUToLA7VxF0JDyIQh%2FMVVPMt1ECZlfcjZJ9mIKoaTl1MRIl5o4CUKXOwmyrCInCKqcWtvadL2SYhyASyNDJ0uIiRMDjI0Fd30%2FiI2UA5GSS5UDj2l6NoqgOgN4gksEBgYFf0FDqKgHnyZ9OX8HrgYHdHpcHQULXAS2qKpENRg7eAMLC7kTBaixUYFkKAzWAAnLC7FLVxLWDBLKCwaKTULgEwbLA4hJtOkSBNqITT3xEgfLpBtzE%2FjiuL04RGEBgwWhShRgQExHBAAh%2BQQJCgAAACwAAAAAIAAgAAAE7xDISWlSqerNpyJKhWRdlSAVoVLCWk6JKlAqAavhO9UkUHsqlE6CwO1cRdCQ8iEIfzFVTzLdRAmZX3I2SfZiCqGk5dTESJeaOAlClzsJsqwiJwiqnFrb2nS9kmIcgEsjQydLiIlHehhpejaIjzh9eomSjZR%2BipslWIRLAgMDOR2DOqKogTB9pCUJBagDBXR6XB0EBkIIsaRsGGMMAxoDBgYHTKJiUYEGDAzHC9EACcUGkIgFzgwZ0QsSBcXHiQvOwgDdEwfFs0sDzt4S6BK4xYjkDOzn0unFeBzOBijIm1Dgmg5YFQwsCMjp1oJ8LyIAACH5BAkKAAAALAAAAAAgACAAAATwEMhJaVKp6s2nIkqFZF2VIBWhUsJaTokqUCoBq%2BE71SRQeyqUToLA7VxF0JDyIQh%2FMVVPMt1ECZlfcjZJ9mIKoaTl1MRIl5o4CUKXOwmyrCInCKqcWtvadL2SYhyASyNDJ0uIiUd6GGl6NoiPOH16iZKNlH6KmyWFOggHhEEvAwwMA0N9GBsEC6amhnVcEwavDAazGwIDaH1ipaYLBUTCGgQDA8NdHz0FpqgTBwsLqAbWAAnIA4FWKdMLGdYGEgraigbT0OITBcg5QwPT4xLrROZL6AuQAPUS7bxLpoWidY0JtxLHKhwwMJBTHgPKdEQAACH5BAkKAAAALAAAAAAgACAAAATrEMhJaVKp6s2nIkqFZF2VIBWhUsJaTokqUCoBq%2BE71SRQeyqUToLA7VxF0JDyIQh%2FMVVPMt1ECZlfcjZJ9mIKoaTl1MRIl5o4CUKXOwmyrCInCKqcWtvadL2SYhyASyNDJ0uIiUd6GAULDJCRiXo1CpGXDJOUjY%2BYip9DhToJA4RBLwMLCwVDfRgbBAaqqoZ1XBMHswsHtxtFaH1iqaoGNgAIxRpbFAgfPQSqpbgGBqUD1wBXeCYp1AYZ19JJOYgH1KwA4UBvQwXUBxPqVD9L3sbp2BNk2xvvFPJd%2BMFCN6HAAIKgNggY0KtEBAAh%2BQQJCgAAACwAAAAAIAAgAAAE6BDISWlSqerNpyJKhWRdlSAVoVLCWk6JKlAqAavhO9UkUHsqlE6CwO1cRdCQ8iEIfzFVTzLdRAmZX3I2SfYIDMaAFdTESJeaEDAIMxYFqrOUaNW4E4ObYcCXaiBVEgULe0NJaxxtYksjh2NLkZISgDgJhHthkpU4mW6blRiYmZOlh4JWkDqILwUGBnE6TYEbCgevr0N1gH4At7gHiRpFaLNrrq8HNgAJA70AWxQIH1%2BvsYMDAzZQPC9VCNkDWUhGkuE5PxJNwiUK4UfLzOlD4WvzAHaoG9nxPi5d%2BjYUqfAhhykOFwJWiAAAIfkECQoAAAAsAAAAACAAIAAABPAQyElpUqnqzaciSoVkXVUMFaFSwlpOCcMYlErAavhOMnNLNo8KsZsMZItJEIDIFSkLGQoQTNhIsFehRww2CQLKF0tYGKYSg%2BygsZIuNqJksKgbfgIGepNo2cIUB3V1B3IvNiBYNQaDSTtfhhx0CwVPI0UJe0%2Bbm4g5VgcGoqOcnjmjqDSdnhgEoamcsZuXO1aWQy8KAwOAuTYYGwi7w5h%2BKr0SJ8MFihpNbx%2B4Erq7BYBuzsdiH1jCAzoSfl0rVirNbRXlBBlLX%2BBP0XJLAPGzTkAuAOqb0WT5AH7OcdCm5B8TgRwSRKIHQtaLCwg1RAAAOwAAAAAAAAAAAA%3D%3D);

-.r-overlay-preview[data-state="loading"] .r-overlay-spinner {
-	opacity: 0.6;
-	visibility: visible;
-}
+		visibility: visible;
+		opacity: 0.6;
+		transition: all 0.3s ease;
+	}

-// Help overlay
-.r-overlay-help .r-overlay-content {
-	overflow: auto;
-}
+	.reveal > .overlay header {
+		position: absolute;
+		left: 0;
+		top: 0;
+		width: 100%;
+		padding: $overlayHeaderPadding;
+		z-index: 2;
+		box-sizing: border-box;
+	}
+		.reveal > .overlay header a {
+			display: inline-block;
+			width: $overlayHeaderHeight;
+			height: $overlayHeaderHeight;
+			line-height: 36px;
+			padding: 0 10px;
+			float: right;
+			opacity: 0.6;

-.r-overlay-help-content {
-	max-width: 560px;
-	padding: 20px 0;
-	margin: auto;
-	text-align: center;
-	letter-spacing: normal;
-}
+			box-sizing: border-box;
+		}
+			.reveal > .overlay header a:hover {
+				opacity: 1;
+			}
+			.reveal > .overlay header a .icon {
+				display: inline-block;
+				width: 20px;
+				height: 20px;

-.r-overlay-help-content .title {
-	font-size: 20px;
-	margin-top: 0;
-}
+				background-position: 50% 50%;
+				background-size: 100%;
+				background-repeat: no-repeat;
+			}
+			.reveal > .overlay header a.close .icon {
+				background-image: url(data:image/png;base64,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);
+			}
+			.reveal > .overlay header a.external .icon {
+				background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACAAAAAgCAYAAABzenr0AAAAcElEQVRYR+2WSQoAIQwEzf8f7XiOMkUQxUPlGkM3hVmiQfQR9GYnH1SsAQlI4DiBqkCMoNb9y2e90IAEJPAcgdznU9+engMaeJ7Azh5Y1U67gAho4DqBqmB1buAf0MB1AlVBek83ZPkmJMGc1wAR+AAqod/B97TRpQAAAABJRU5ErkJggg==);
+			}

-/* Specificity battle with reveal.js theme table styles */
-.r-overlay-help .r-overlay-help-content table {
-	border: 1px solid #fff;
-	border-collapse: collapse;
-	font-size: 16px;
-	text-align: left;
-}
+	.reveal > .overlay .viewport {
+		position: absolute;
+		display: flex;
+		top: $overlayHeaderHeight + $overlayHeaderPadding*2;
+		right: 0;
+		bottom: 0;
+		left: 0;
+	}

-.r-overlay-help .r-overlay-help-content table th,
-.r-overlay-help .r-overlay-help-content table td {
-	width: 240px;
-	padding: 14px;
-	border: 1px solid #fff;
-	vertical-align: middle;
-}
+	.reveal > .overlay.overlay-preview .viewport iframe {
+		width: 100%;
+		height: 100%;
+		max-width: 100%;
+		max-height: 100%;
+		border: 0;
+
+		opacity: 0;
+		visibility: hidden;
+		transition: all 0.3s ease;
+	}
+
+	.reveal > .overlay.overlay-preview.loaded .viewport iframe {
+		opacity: 1;
+		visibility: visible;
+	}
+
+	.reveal > .overlay.overlay-preview.loaded .viewport-inner  {
+		position: absolute;
+		z-index: -1;
+		left: 0;
+		top: 45%;
+		width: 100%;
+		text-align: center;
+		letter-spacing: normal;
+	}
+	.reveal > .overlay.overlay-preview .x-frame-error  {
+		opacity: 0;
+		transition: opacity 0.3s ease 0.3s;
+	}
+	.reveal > .overlay.overlay-preview.loaded .x-frame-error  {
+		opacity: 1;
+	}
+
+	.reveal > .overlay.overlay-preview.loaded .spinner {
+		opacity: 0;
+		visibility: hidden;
+		transform: scale(0.2);
+	}
+
+	.reveal > .overlay.overlay-help .viewport {
+		overflow: auto;
+		color: #fff;
+	}
+
+	.reveal > .overlay.overlay-help .viewport .viewport-inner {
+		width: 600px;
+		margin: auto;
+		padding: 20px 20px 80px 20px;
+		text-align: center;
+		letter-spacing: normal;
+	}
+
+	.reveal > .overlay.overlay-help .viewport .viewport-inner .title {
+		font-size: 20px;
+	}
+
+	.reveal > .overlay.overlay-help .viewport .viewport-inner table {
+		border: 1px solid #fff;
+		border-collapse: collapse;
+		font-size: 16px;
+	}
+
+	.reveal > .overlay.overlay-help .viewport .viewport-inner table th,
+	.reveal > .overlay.overlay-help .viewport .viewport-inner table td {
+		width: 200px;
+		padding: 14px;
+		border: 1px solid #fff;
+		vertical-align: middle;
+	}
+
+	.reveal > .overlay.overlay-help .viewport .viewport-inner table th {
+		padding-top: 20px;
+		padding-bottom: 20px;
+	}

-.r-overlay-help .r-overlay-help-content table th {
-	padding-top: 20px;
-	padding-bottom: 20px;
-}

 /*********************************************
 * PLAYBACK COMPONENT
@@ -1720,10 +1633,6 @@ $controlsArrowAngleActive: 36deg;
 	opacity: 0.4;
 }

-.reveal .hljs.has-highlights.fragment {
-	transition: all .2s ease;
-}
-
 .reveal .hljs:not(:first-child).fragment {
 	position: absolute;
 	top: 0;
@@ -1887,43 +1796,6 @@ $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
 *********************************************/
@@ -1948,239 +1820,6 @@ $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;
-	}
-
-	.r-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
@@ -6,7 +6,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -24,13 +23,10 @@ $headingColor: #333;
 $headingTextShadow: none;
 $backgroundColor: #f7f3de;
 $linkColor: #8b743d;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$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
@@ -1,50 +0,0 @@
-/**
- * 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.
- * - $mainFontSize controls code blocks, too (although under some ratio).
- */
-
-
-// Default mixins and settings -----------------
-@use "sass:color";
-@import "../template/mixins";
-@import "../template/settings";
-// ---------------------------------------------
-
-
-// Include theme-specific fonts
-@import url(./fonts/source-sans-pro/source-sans-pro.css);
-
-
-// Override theme settings (see ../template/settings.scss)
-$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: color.scale( $linkColor, $lightness: 15% );
-$selectionBackgroundColor: color.scale( $linkColor, $lightness: 25% );
-
-$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
@@ -6,7 +6,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -30,8 +29,8 @@ $headingLetterSpacing: normal;
 $headingTextTransform: uppercase;
 $headingFontWeight: 600;
 $linkColor: #42affa;
-$linkColorHover: color.scale( $linkColor, $lightness: 15% );
-$selectionBackgroundColor: rgba( $linkColor, 0.75 );
+$linkColorHover: lighten( $linkColor, 15% );
+$selectionBackgroundColor: lighten( $linkColor, 25% );

 $heading1Size: 2.5em;
 $heading2Size: 1.6em;
--- a/css/theme/source/blood.scss
+++ b/css/theme/source/blood.scss
@@ -10,8 +10,7 @@
 *
 */

-// Default mixins and settings -----------------
-@use "sass:color";
+ // Default mixins and settings -----------------
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -41,7 +40,7 @@ $heading1TextShadow: 0 1px 0 #ccc, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b

 // Links
 $linkColor: $blood;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$linkColorHover: lighten( $linkColor, 20% );

 // Text selection
 $selectionBackgroundColor: $blood;
--- a/css/theme/source/dracula.scss
+++ b/css/theme/source/dracula.scss
@@ -1,107 +0,0 @@
-/**
- * Dracula Dark theme for reveal.js.
- * Based on https://draculatheme.com
- */
-
-
-// Default mixins and settings -----------------
-@import "../template/mixins";
-@import "../template/settings";
-// ---------------------------------------------
-
-// Include theme-specific fonts
-@import url(./fonts/league-gothic/league-gothic.css);
-@import url(https://fonts.googleapis.com/css?family=Lato:400,700,400italic,700italic);
-
-$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
@@ -5,7 +5,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -19,6 +18,10 @@
 /**
 * Solarized colors by Ethan Schoonover
 */
+html * {
+	color-profile: sRGB;
+	rendering-intent: auto;
+}

 // Solarized colors
 $base03:    #002b36;
@@ -44,7 +47,7 @@ $headingColor: $base2;
 $headingTextShadow: none;
 $backgroundColor: $base03;
 $linkColor: $blue;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: $magenta;

 // Change text colors against light slide backgrounds
--- a/css/theme/source/night.scss
+++ b/css/theme/source/night.scss
@@ -6,7 +6,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -22,7 +21,7 @@ $backgroundColor: #111;

 $mainFont: 'Open Sans', sans-serif;
 $linkColor: #e7ad52;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$linkColorHover: lighten( $linkColor, 20% );
 $headingFont: 'Montserrat', Impact, sans-serif;
 $headingTextShadow: none;
 $headingLetterSpacing: -0.03em;
--- a/css/theme/source/serif.scss
+++ b/css/theme/source/serif.scss
@@ -7,7 +7,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -23,12 +22,9 @@ $headingTextShadow: none;
 $headingTextTransform: none;
 $backgroundColor: #F0F1EB;
 $linkColor: #51483D;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$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
@@ -8,7 +8,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -29,12 +28,9 @@ $headingTextShadow: none;
 $headingTextTransform: none;
 $backgroundColor: #fff;
 $linkColor: #00008B;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$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
@@ -6,7 +6,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -27,12 +26,9 @@ $headingLetterSpacing: -0.08em;
 $headingTextShadow: none;
 $backgroundColor: #f7fbfc;
 $linkColor: #3b759e;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$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
@@ -5,7 +5,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -49,12 +48,9 @@ $headingColor: $base01;
 $headingTextShadow: none;
 $backgroundColor: $base3;
 $linkColor: $blue;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$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
@@ -1,53 +0,0 @@
-/**
- * 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.
- * - $mainFontSize controls code blocks, too (although under some ratio).
- */
-
-
-// Default mixins and settings -----------------
-@use "sass:color";
-@import "../template/mixins";
-@import "../template/settings";
-// ---------------------------------------------
-
-
-// Include theme-specific fonts
-@import url(./fonts/source-sans-pro/source-sans-pro.css);
-
-
-// Override theme settings (see ../template/settings.scss)
-$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: color.scale( $linkColor, $lightness: 15% );
-$selectionBackgroundColor: color.scale( $linkColor, $lightness: 25% );
-
-$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
@@ -6,7 +6,6 @@


 // Default mixins and settings -----------------
-@use "sass:color";
@import "../template/mixins";
@import "../template/settings";
 // ---------------------------------------------
@@ -30,17 +29,14 @@ $headingLetterSpacing: normal;
 $headingTextTransform: uppercase;
 $headingFontWeight: 600;
 $linkColor: #2a76dd;
-$linkColorHover: color.scale( $linkColor, $lightness: 15% );
-$selectionBackgroundColor: color.scale( $linkColor, $lightness: 25% );
+$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);

--- a/css/theme/template/exposer.scss
+++ b/css/theme/template/exposer.scss
@@ -1,6 +1,4 @@
-// Exposes theme's variables for easy reuse in CSS for plugin authors
-
-@use "sass:color";
+// Exposes theme's variables for easy re-use in CSS for plugin authors

 :root {
  --r-background-color: #{$backgroundColor};
@@ -23,10 +21,8 @@
  --r-heading4-size: #{$heading4Size};
  --r-code-font: #{$codeFont};
  --r-link-color: #{$linkColor};
-  --r-link-color-dark: #{color.scale( $linkColor, $lightness: -15% )};
+  --r-link-color-dark: #{darken($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
@@ -1,5 +1,3 @@
-@use "sass:color";
-
 // Base settings for all themes that can optionally be
 // overridden by the super-theme

@@ -34,17 +32,12 @@ $codeFont: monospace;

 // Links and actions
 $linkColor: #13DAEC;
-$linkColorHover: color.scale( $linkColor, $lightness: 20% );
+$linkColorHover: lighten( $linkColor, 20% );

 // Text selection
 $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
@@ -278,7 +278,8 @@

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

 }

--- a/demo.html
+++ b/demo.html
@@ -86,7 +86,7 @@

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

 						function Example() {
@@ -165,9 +165,9 @@
 				</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;"></div>
-						<div data-id="box2" style="background: magenta; width: 200px; height: 200px;"></div>
-						<div data-id="box3" style="background: yellow; width: 100px; height: 100px;"></div>
+						<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>
@@ -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/).
@@ -197,25 +197,6 @@
 					</script>
 				</section>

-				<section>
-					<h2>Lightbox</h2>
-					Turn any element into a <a href="https://revealjs.com/lightbox/">lightbox</a> using <strong>data‑preview‑image</strong> & <strong>data‑preview‑video</strong>.
-					<div class="r-hstack" style="gap: 2rem;">
-						<div>
-							<pre style="font-size: 12px; width: 100%"><code class="html" data-trim>
-								&lt;img src="image.png" data-preview-image="image.png"&gt;
-							</code></pre>
-							<img src="https://static.slid.es/logo/v2/slides-symbol-1024x1024.png" height="100" data-preview-image>
-						</div>
-						<div>
-							<pre style="font-size: 12px; width: 100%"><code class="html" data-trim>
-								&lt;img src="video.png" data-preview-video="video.mp4"&gt;
-							</code></pre>
-							<img src="https://static.slid.es/site/homepage/v1/homepage-video-editor.png" height="100" data-preview-video="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4">
-						</div>
-					</div>
-				</section>
-
 				<section>
 					<p>Add the <code>r-fit-text</code> class to auto-size text</p>
 					<h2 class="r-fit-text">FIT TEXT</h2>
@@ -268,17 +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="#/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>
+						<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>
 					</p>
 				</section>

--- 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
@@ -33,22 +33,20 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #8b743d;
-  --r-link-color-dark: rgb(118.15, 98.6, 51.85);
-  --r-link-color-hover: rgb(179.36, 150.84, 82.64);
+  --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: 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: #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(--r-background-color);
 }

--- a/dist/theme/black-contrast.css
+++ b/dist/theme/black-contrast.css
@@ -1,362 +0,0 @@
-/**
- * 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: rgb(19.8216494845, 155.4536082474, 248.7783505155);
-  --r-link-color-hover: rgb(94.35, 187, 250.75);
-  --r-selection-background-color: rgb(113.25, 195, 251.25);
-  --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
@@ -32,12 +32,10 @@ section.has-light-background, section.has-light-background h1, section.has-light
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #42affa;
-  --r-link-color-dark: rgb(19.8216494845, 155.4536082474, 248.7783505155);
-  --r-link-color-hover: rgb(94.35, 187, 250.75);
-  --r-selection-background-color: rgba(66, 175, 250, 0.75);
+  --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 {
--- a/dist/theme/blood.css
+++ b/dist/theme/blood.css
@@ -38,12 +38,10 @@ section.has-light-background, section.has-light-background h1, section.has-light
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #a23;
-  --r-link-color-dark: rgb(144.5, 28.9, 43.35);
-  --r-link-color-hover: rgb(214.2, 51, 71.4);
+  --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 {
--- a/dist/theme/dracula.css
+++ b/dist/theme/dracula.css
@@ -1,387 +0,0 @@
-/**
- * Dracula Dark theme for reveal.js.
- * Based on https://draculatheme.com
- */
-@import url(./fonts/league-gothic/league-gothic.css);
-@import url(https://fonts.googleapis.com/css?family=Lato:400,700,400italic,700italic);
-/**
- * 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: rgb(255, 64.6, 174.0089552239);
-  --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
@@ -35,22 +35,20 @@ section.has-light-background, section.has-light-background h1, section.has-light
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #13DAEC;
-  --r-link-color-dark: rgb(16.15, 185.3, 200.6);
-  --r-link-color-hover: rgb(66.2, 225.4, 239.8);
+  --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: 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: #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(--r-background-color);
 }

--- a/dist/theme/moon.css
+++ b/dist/theme/moon.css
@@ -7,6 +7,11 @@
 /**
 * 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;
 }
@@ -35,12 +40,10 @@ section.has-light-background, section.has-light-background h1, section.has-light
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #268bd2;
-  --r-link-color-dark: rgb(32.3, 118.15, 178.5);
-  --r-link-color-hover: rgb(77.5161290323, 162.8774193548, 222.8838709677);
+  --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 {
--- a/dist/theme/night.css
+++ b/dist/theme/night.css
@@ -33,12 +33,10 @@ section.has-light-background, section.has-light-background h1, section.has-light
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #e7ad52;
-  --r-link-color-dark: rgb(225.2802030457, 153.4573604061, 40.7697969543);
-  --r-link-color-hover: rgb(235.8, 189.4, 116.6);
+  --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 {
--- a/dist/theme/serif.css
+++ b/dist/theme/serif.css
@@ -36,12 +36,10 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #51483D;
-  --r-link-color-dark: rgb(68.85, 61.2, 51.85);
-  --r-link-color-hover: rgb(122.9830985915, 109.3183098592, 92.6169014085);
+  --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 {
--- a/dist/theme/simple.css
+++ b/dist/theme/simple.css
@@ -35,12 +35,10 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #00008B;
-  --r-link-color-dark: rgb(0, 0, 118.15);
-  --r-link-color-hover: rgb(0, 0, 213.2);
+  --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 {
--- a/dist/theme/sky.css
+++ b/dist/theme/sky.css
@@ -37,12 +37,10 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #3b759e;
-  --r-link-color-dark: rgb(50.15, 99.45, 134.3);
-  --r-link-color-hover: rgb(84.330875576, 146.9815668203, 191.269124424);
+  --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 {
--- a/dist/theme/solarized.css
+++ b/dist/theme/solarized.css
@@ -36,12 +36,10 @@ html * {
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #268bd2;
-  --r-link-color-dark: rgb(32.3, 118.15, 178.5);
-  --r-link-color-hover: rgb(77.5161290323, 162.8774193548, 222.8838709677);
+  --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 {
--- a/dist/theme/white-contrast.css
+++ b/dist/theme/white-contrast.css
@@ -1,362 +0,0 @@
-/**
- * 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;
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-  --r-heading4-size: 1em;
-  --r-code-font: monospace;
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-  --r-selection-color: #fff;
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-  --r-overlay-element-fg-color: 240, 240, 240;
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-.reveal h5,
-.reveal h6 {
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-  vertical-align: top;
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-.reveal img {
-  margin: var(--r-block-margin) 0;
-}
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- *********************************************/
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-    background-color: var(--r-background-color);
-  }
-}
--- a/dist/theme/white.css
+++ b/dist/theme/white.css
@@ -32,12 +32,10 @@ section.has-dark-background, section.has-dark-background h1, section.has-dark-ba
  --r-heading4-size: 1em;
  --r-code-font: monospace;
  --r-link-color: #2a76dd;
-  --r-link-color-dark: rgb(30.7720647773, 99.5566801619, 192.7779352227);
-  --r-link-color-hover: rgb(73.95, 138.55, 226.1);
-  --r-selection-background-color: rgb(95.25, 152.25, 229.5);
+  --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 {
--- a/dist/theme/white_contrast_compact_verbatim_headers.css
+++ b/dist/theme/white_contrast_compact_verbatim_headers.css
@@ -1,360 +0,0 @@
-/**
- * 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
- *********************************************/
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-  --r-main-font: Source Sans Pro, Helvetica, sans-serif;
-  --r-main-font-size: 25px;
-  --r-main-color: #000;
-  --r-block-margin: 20px;
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--- a/examples/500-slides.html
+++ b/examples/500-slides.html
@@ -1,526 +0,0 @@
-<!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/backgrounds.html
+++ b/examples/backgrounds.html
@@ -89,7 +89,7 @@
 					<h2>Same background twice (2/2)</h2>
 				</section>

-				<section data-background-video="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4,https://static.slid.es/site/homepage/v1/homepage-video-editor.webm">
+				<section 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>

--- a/examples/lightbox.html
+++ b/examples/lightbox.html
@@ -1,144 +0,0 @@
-<!doctype html>
-<html lang="en">
-
-	<head>
-		<meta charset="utf-8">
-
-		<title>reveal.js - Ligthbox</title>
-
-		<link rel="stylesheet" href="../dist/reveal.css">
-		<link rel="stylesheet" href="../dist/theme/black.css" id="theme">
-
-		<style>
-			.reveal {
-				font-size: 24px;
-			}
-			.reveal figure {
-				margin: 0 0 1rem 0;
-				text-align: left;
-			}
-			.reveal figure img,
-			.reveal figure video {
-				margin: 0.25rem 0 0 0;
-			}
-			figcaption, a {
-				font-size: 16px;
-			}
-		</style>
-	</head>
-
-	<body>
-
-		<div class="reveal">
-
-			<div class="slides">
-
-				<section>
-
-					<h2>Preview Overlays</h2>
-
-					<div class="r-hstack items-start">
-						<div class="r-vstack items-start">
-							<h5>Images</h5>
-							<figure>
-								<figcaption>Preview with default settings:</figcaption>
-								<img height="50" src="https://static.slid.es/images/alphabet/v1/a.png" data-preview-image>
-							</figure>
-							<figure>
-								<figcaption>Preview with data-preview-fit="contain"</figcaption>
-								<img height="50" src="https://static.slid.es/images/alphabet/v1/a.png" data-preview-image data-preview-fit="contain">
-							</figure>
-							<figure>
-								<figcaption>Preview with data-preview-fit="cover"</figcaption>
-								<img height="50" src="https://static.slid.es/images/alphabet/v1/a.png" data-preview-image data-preview-fit="cover">
-							</figure>
-							<figure>
-								<figcaption>Preview another image (c)</figcaption>
-								<img height="50" src="https://static.slid.es/images/alphabet/v1/b.png" data-preview-image="https://static.slid.es/images/alphabet/v1/c.png">
-							</figure>
-							<a href="#" data-preview-image="https://static.slid.es/images/alphabet/v1/x.png">
-								Preview image from a link.
-							</a>
-						</div>
-
-						<div style="width: 1px; height: 30vh; margin: 0 3rem;background-color: #999;"></div>
-
-						<div class="r-vstack items-start">
-							<h5>Videos</h5>
-							<figure>
-								<figcaption>Preview video</figcaption>
-								<img height="50" src="https://static.slid.es/images/alphabet/v1/x.png" data-preview-video="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4">
-							</figure>
-							<figure>
-								<figcaption>Preview video</figcaption>
-								<video height="50" src="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4" data-preview-video></video>
-							</figure>
-							<a href="#" data-preview-video="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4">
-								Preview video from a link.
-							</a>
-						</div>
-
-						<div style="width: 1px; height: 30vh; margin: 0 3rem;background-color: #999;"></div>
-
-						<div class="r-vstack items-start">
-							<h5>Iframes</h5>
-							<a href="https://hakim.se">https://hakim.se | data-preview-link</a>
-							<a data-preview-link href="https://hakim.se">https://hakim.se | data-preview-link</a>
-							<br />
-							<a data-preview-link="false" href="https://hakim.se">https://hakim.se | data-preview-link=false</a>
-							<br />
-							<figure>
-								<figcaption>Preview link from an image</figcaption>
-								<img height="50" src="https://static.slid.es/images/alphabet/v1/a.png" data-preview-link="https://hakim.se">
-							</figure>
-						</div>
-					</div>
-
-				</section>
-
-				<section style="text-align: left;">
-
-					<h2>Lightbox</h2>
-
-					<div class="r-hstack items-start justify-start">
-						<div class="r-vstack items-start">
-							<h5>Images</h5>
-							<figure>
-								<img height="100" src="https://static.slid.es/images/alphabet/v1/a.png" data-preview-image data-preview-fit="contain">
-							</figure>
-						</div>
-
-						<div style="width: 1px; height: 20vh; margin: 0 3rem;background-color: #222;"></div>
-
-						<div class="r-vstack items-start">
-							<h5>Videos</h5>
-							<figure>
-								<video height="100" src="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4" data-preview-video></video>
-							</figure>
-						</div>
-
-						<div style="width: 1px; height: 20vh; margin: 0 3rem;background-color: #222;"></div>
-
-						<div class="r-vstack items-start">
-							<h5>Iframes</h5>
-							<a style="font-size: 28px;" data-preview-link href="https://hakim.se">https://hakim.se</a>
-						</div>
-					</div>
-
-				</section>
-
-			</div>
-
-		</div>
-
-		<script src="../dist/reveal.js"></script>
-		<script>
-			Reveal.initialize({
-				previewLinks: false,
-				width: 1280,
-				height: 720
-			});
-		</script>
-
-	</body>
-</html>
--- a/examples/markdown.html
+++ b/examples/markdown.html
@@ -99,29 +99,10 @@
                    </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">
-                        ![Sample image](https://static.slid.es/logo/v2/slides-symbol-512x512.png)
+                        ![Sample image](https://s3.amazonaws.com/static.slid.es/logo/v2/slides-symbol-512x512.png)
                    </script>
                </section>

--- a/examples/markdown.md
+++ b/examples/markdown.md
@@ -33,7 +33,7 @@ Content 3.2

 ## External 3.3 (Image)

-![External Image](https://static.slid.es/logo/v2/slides-symbol-512x512.png)
+![External Image](https://s3.amazonaws.com/static.slid.es/logo/v2/slides-symbol-512x512.png)


 ## External 3.4 (Math)
--- a/examples/media.html
+++ b/examples/media.html
@@ -33,10 +33,10 @@

 				<section>
 					<h2>Video</h2>
-					<video src="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4" data-autoplay></video>
+					<video src="http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4" data-autoplay></video>
 				</section>

-				<section data-background-video="https://static.slid.es/site/homepage/v1/homepage-video-editor.mp4">
+				<section data-background-video="http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4">
 					<h2>Background Video</h2>
 				</section>

--- a/examples/scroll.html
+++ b/examples/scroll.html
@@ -1,120 +0,0 @@
-<!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://static.slid.es/site/homepage/v1/homepage-video-editor.mp4,https://static.slid.es/site/homepage/v1/homepage-video-editor.webm">
-            <div style="background-color: rgba(0, 0, 0, 0.9); color: #fff; padding: 20px;">
-              <h2>Video background</h2>
-            </div>
-          </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
@@ -1,20 +1,22 @@
-const fs = require('fs');
 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
 const sass = require('sass')

 const gulp = require('gulp')
+const tap = require('gulp-tap')
 const zip = require('gulp-zip')
-const header = require('gulp-header-comment')
+const header = require('gulp-header')
 const eslint = require('gulp-eslint')
 const minify = require('gulp-clean-css')
 const connect = require('gulp-connect')
@@ -24,21 +26,13 @@ const root = yargs.argv.root || '.'
 const port = yargs.argv.port || 8000
 const host = yargs.argv.host || 'localhost'

-const cssLicense = `
-reveal.js ${pkg.version}
-${pkg.homepage}
-MIT licensed
-
-Copyright (C) 2011-2024 Hakim El Hattab, https://hakim.se
-`;
-
-const jsLicense = `/*!
- * reveal.js ${pkg.version}
- * ${pkg.homepage}
- * MIT licensed
- *
- * Copyright (C) 2011-2024 Hakim El Hattab, https://hakim.se
- */\n`;
+const banner = `/*!
+* reveal.js ${pkg.version}
+* ${pkg.homepage}
+* MIT licensed
+*
+* Copyright (C) 2011-2022 Hakim El Hattab, https://hakim.se
+*/\n`

 // Prevents warnings from opening too many test pages
 process.setMaxListeners(20);
@@ -94,7 +88,7 @@ gulp.task('js-es5', () => {
            name: 'Reveal',
            file: './dist/reveal.js',
            format: 'umd',
-            banner: jsLicense,
+            banner: banner,
            sourcemap: true
        });
    });
@@ -116,7 +110,7 @@ gulp.task('js-es6', () => {
        return bundle.write({
            file: './dist/reveal.esm.js',
            format: 'es',
-            banner: jsLicense,
+            banner: banner,
            sourcemap: true
        });
    });
@@ -169,12 +163,12 @@ function compileSass() {
    const transformedFile = vinylFile.clone();

    sass.render({
-        silenceDeprecations: ['legacy-js-api'],
        data: transformedFile.contents.toString(),
-        file: transformedFile.path,
+        includePaths: ['css/', 'css/theme/template']
    }, ( err, result ) => {
        if( err ) {
-            callback(err);
+            console.log( vinylFile.path );
+            console.log( err.formatted );
        }
        else {
            transformedFile.extname = '.css';
@@ -193,7 +187,7 @@ gulp.task('css-core', () => gulp.src(['css/reveal.scss'])
    .pipe(compileSass())
    .pipe(autoprefixer())
    .pipe(minify({compatibility: 'ie9'}))
-    .pipe(header(cssLicense))
+    .pipe(header(banner))
    .pipe(gulp.dest('./dist')))

 gulp.task('css', gulp.parallel('css-themes', 'css-core'))
@@ -220,7 +214,7 @@ gulp.task('qunit', () => {
                targetUrl: `http://${serverConfig.host}:${serverConfig.port}/${filename}`,
                timeout: 20000,
                redirectConsole: false,
-                puppeteerArgs: ['--allow-file-access-from-files', '--no-sandbox']
+                puppeteerArgs: ['--allow-file-access-from-files']
            })
                .then(result => {
                    if( result.stats.failed > 0 ) {
@@ -275,25 +269,24 @@ gulp.task('default', gulp.series(gulp.parallel('js', 'css', 'plugins'), 'test'))

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

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

-    let dirs = [
-        './index.html',
-        './dist/**',
-        './plugin/**',
-        './*/*.md'
-    ];
-
-    if (fs.existsSync('./lib')) dirs.push('./lib/**');
-    if (fs.existsSync('./images')) dirs.push('./images/**');
-    if (fs.existsSync('./slides')) dirs.push('./slides/**');
-
-    return gulp.src( dirs, { base: './', encoding: false } )
+    gulp.src(
+        [
+            './index.html',
+            './dist/**',
+            './lib/**',
+            './images/**',
+            './plugin/**',
+            './**.md'
+        ],
+        { base: './' }
+    )
    .pipe(zip('reveal-js-presentation.zip')).pipe(gulp.dest('./'))

-}))
+))

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

 gulp.task('serve', () => {
@@ -305,19 +298,14 @@ gulp.task('serve', () => {
        livereload: true
    })

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

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

    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'))

@@ -328,4 +316,4 @@ gulp.task('serve', () => {

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

-})
+})
--- a/images/excel.png
+++ b/images/excel.png
--- a/images/filebrowser.png
+++ b/images/filebrowser.png
--- a/images/guquanjiegou.png
+++ b/images/guquanjiegou.png
--- a/images/haiyoulogo.png
+++ b/images/haiyoulogo.png
--- a/images/highlight.png
+++ b/images/highlight.png
--- a/images/logo.png
+++ b/images/logo.png
--- a/images/oil.jpg
+++ b/images/oil.jpg
--- a/images/paper.jpg
+++ b/images/paper.jpg
--- a/images/report.png
+++ b/images/report.png
--- a/index.html
+++ b/index.html
@@ -1,122 +1,217 @@
-<!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">
+<!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"
+    />

-		<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/serif.css" />

-		<!-- Theme used for syntax highlighted code -->
-		<link rel="stylesheet" href="plugin/highlight/monokai.css">
-	</head>
-	<body>
-		<div class="reveal">
-			<div class="slides">
-				<!-- Slide 1: Title -->
-				<section>
-					<h1>PostgreSQL JSONB Performance Optimization</h1>
-					<h2>A Comprehensive Survey</h2>
-					<p>
-						<small>陈永源 225002025</small>
-					</p>
-					<aside class="notes">
-						"Hello everyone! Today we will talk about PostgreSQL JSONB performance optimization. 
-						Nowaday jsonb is a very import driver of PostgreSQL, postgresql became the most popular database
-						when the jsonb was asdd. most programming language support json. developer likes to use json.
-						Howevery when you trys to store json in trad database, you need to defind the schma, the relationship.
-						and there alwasy will be conflict between developer and DBA.
-						when storeaged in jsonb, you don't need to worry about the schema, That's why developer love to use json database. and we needs to understand the perform of jsonb.
-					</aside>
-				</section>
+    <!-- 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>
+          ![logo](./images/logo.png)

-				<section>
-					<h2>The TOAST Threshold Problem</h2>
-					<img src="paper/1.png" alt="TOAST Performance Degradation" style="height: 400px; margin: 0 auto;">
-					<div class="r-vstack">
-						<p><strong>The 2KB Critical Threshold</strong></p>
-						<ul>
-							<li>Before TOAST: Constant access time</li>
-							<li>After TOAST: Linear degradation</li>
-							<li>3 additional buffer reads per access</li>
-						</ul>
-					</div>
-					<aside class="notes">
-						"Let's talk about one of the most important concepts in JSONB performance: the TOAST threshold. TOAST stands for 'The Oversized-Attribute Storage Technique' - it's PostgreSQL's way of handling large data. The key thing to understand is the 2KB threshold. When your JSONB document is smaller than 2KB, access time remains constant regardless of size. But once it crosses 2KB, PostgreSQL moves the data to TOAST storage, and performance degrades linearly. Each access now requires 3 additional buffer reads: two for the TOAST index and one for the actual data. This explains why developers often report sudden performance drops when their JSON documents grow beyond this threshold."
-					</aside>
-				</section>
+          ### Accounting Internship Report

-				<section>
-					<h2>JSONB Operator Performance</h2>
-					<img src="paper/2.png" alt="JSONB Operator Performance" style="height: 900px; margin: 0 auto;">
-					<aside class="notes">
-						"This chart shows the performance characteristics of different JSONB operators in PostgreSQL. There are several ways to access data in JSONB: the arrow operator (->), the hash arrow operator (->>), subscripting, and JSON path functions. What we see here is very interesting: for small JSONB documents under 2KB, the arrow operator performs well at the root level. But as document size increases and nesting levels go deeper, performance varies significantly. Subscripting tends to be the fastest for large documents, while JSON path functions are the slowest but most flexible for complex queries. The key takeaway is that your choice of operator matters, especially for large, nested JSONB documents."
-					</aside>
-				</section>
+          - Author: CHEN Yongyuan (Walter)
+          - Report date: 2022-11-09

-				<section>
-					<h2>Partial Update Challenges</h2>
-					<div class="r-vstack">
-						<div class="fragment fade-up">
-							<h3>Current Limitations</h3>
-							<ul>
-								<li>TOAST treats JSONB as atomic BLOB</li>
-								<li>Full document rewrites for small changes</li>
-								<li>WAL write amplification</li>
-							</ul>
-						</div>
-						<div class="fragment fade-up">
-							<h3>Emerging Solutions</h3>
-							<ul>
-								<li>Partial decompression: 5-10x faster</li>
-								<li>In-place updates: 10-50x improvement</li>
-								<li>Shared TOAST: 90% WAL reduction</li>
-							</ul>
-						</div>
-					</div>
-					<aside class="notes">
-						"One of the biggest challenges with JSONB today is partial updates. Currently, PostgreSQL treats JSONB as an atomic BLOB from TOAST's perspective. This means even if you want to update just one small key in a large JSONB document, PostgreSQL has to rewrite the entire document. This causes significant WAL write amplification - you generate much more write-ahead logging than necessary. The good news is that there are emerging solutions. Partial decompression can give us 5-10x performance improvements. In-place updates can provide 10-50x improvements. And something called shared TOAST can reduce WAL traffic by up to 90%. These optimizations are crucial for making JSONB truly efficient for OLTP workloads."
-					</aside>
-				</section>
+          Note:
+          My name is Walter.

-				<section>
-					<h2>Advanced Optimization Techniques</h2>
-					<img src="paper/3.png" alt="JSONB Optimization Techniques" style="height: 900px; margin: 0 auto;">
-					<aside class="notes">
-						"This slide shows various optimization techniques being developed for JSONB. The graph demonstrates performance improvements through different approaches. Key techniques include partial decompression - where only the parts of JSONB you need are decompressed rather than the entire document. Sorted-keys means sorte the key by their length, so the access time of a key is O(logN), not linear. Array slicing optimizate read of large slice. After adding these optimization, we most access pattern execution time reduce a lot.
-					</aside>
-				</section>
+          First of all, I am very happy that I can share my accounting internship experience here.

-				<section>
-					<h2>PostgreSQL JSONB vs MongoDB</h2>
-					<img src="paper/4.png" alt="PostgreSQL vs MongoDB Performance" style="height: 900px; margin: 0 auto;">
-					<aside class="notes">
-						"Now let's compare PostgreSQL JSONB with MongoDB, MongoDB is the most popular document database. The results here are quite interesing. First they start at time same level. After applying these optimization. the execution time is halfed. After turn on parallel processing, postgresql is significant faster than MongoDB. But we know mongodb is very memory hungry. So we give more memory to mongodb, we increase the memory from 4G to 16G, the mongodb perfrom better but still, postgresql win."
-					</aside>
-				</section>
+          During last summer holiday, I took an internship at Grant Thornton.
+        </section>
+        <section data-markdown>
+          ### Agenda

-			</div>
-		</div>
+          1. About the accounting internship
+          2. Details of the internship project
+          3. Key lessons learned
+          4. Suggestion
+        </section>
+        <section>
+          <section
+            data-background-image="./images/haiyoulogo.png"
+            data-background-size="contain"
+            data-background-opacity="0.139"
+            >
+            <h3>Accounting Internship Overview</h3>
+            <ul>
+              <li class="fragment">
+              🏠 Company: China National Offshore Oil Corp
+                (<b>CNOOC Guangdong Sales Co. Ltd</b>)
+              </li>
+              <aside class="notes">
+              <p>
+                The company we audited was CNOOC which this is a huge group coporation.
+                Our team is focusing on the CNOOC Guangdong sales company.
+              </p>
+              </aside>
+              <li class="fragment">👨 Supervisor: FU Kaijun</li>
+              <aside class="notes">
+                <p>
+                My supervisor, also our team leader, is FU kaijun.
+                </p>
+              </aside>
+              <li class="fragment">👕 Role: Audit assistant of Guangdong audit team</li>
+              <aside class="notes">
+                <p>
+                My role in the audit team is audit assistant.
+                I assist the team to do some of the perform substantive procedures.
+                Also, I check for errors in the subsidiary's financial reports and parent's consolidated financial statements.
+                Then I summarize my work into audit working paper.
+                </p>
+              </aside>
+              <li class="fragment">🌍 Location: Guangdong area (Zhanjiang, Zhuhai, Jiangmen, and Guangzhou)</li>
+              <aside class="notes">
+                <p>
+                There are many subsidiaries in Guangdong, and our team is mainly responsible for (these places).
+                and finally, we returned to the parent company in Guangzhou to do the work related to consolidation.
+                </p>
+              </aside>
+            </ul>
+            <p class="fragment" style="text-align: left;">
+              My job is to perform
+              <span class="fragment highlight-red">substantive procedures</span>,
+              <span class="fragment highlight-green">prepare audit working paper</span>,
+              and <span class="fragment highlight-blue">write programs</span> to reduce repetitive work.
+            </p>
+          </section>
+          <section data-background-image="./images/guquanjiegou.png" data-background-size="contain">
+            <aside class="notes">
+              This is the equity strcture.
+              Our team is focusing on the CNOOC Guangdong sales company which has more than 27 subsidiaries.
+            </aside>
+          </section>
+          <section data-background-image="./images/oil.jpg" data-background-size="contain">
+            <aside class="notes">
+              We go to each subsidiary's gas station to check fixed assets and oil inventory.
+            </aside>
+          </section>
+          <section data-background-image="./images/paper.jpg" data-background-size="contain">
+            <aside class="notes">
+              In this photo, we use sampling method to get a checklist, and then we go to the office to look for the corresponding accounting documents according to the checklist.
+            </aside>
+          </section>
+          <section data-background-image="./images/report.png" data-background-size="contain">
+            <aside class="notes">
+              And another of my job, which is probably why I got hired, is to write a computer program to automatically transfer some data from excel to word report.
+              Because during the interview they asked my lots of question about the PDF and excel processing.
+            </aside>
+          </section>
+          <section data-background-image="./images/highlight.png" data-background-size="contain"></section>
+          <section data-background-image="./images/excel.png" data-background-size="contain"></section>
+        </section>
+        <section>
+        <section data-markdown>
+            ### Key Lessons Learned

-		<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({
-				width: 1920,
-				height: 1080,
-				hash: true,
+            > If there is anything unsure, be sure to ask.

-				// Learn about plugins: https://revealjs.com/plugins/
-				plugins: [ RevealMarkdown, RevealHighlight, RevealNotes ]
-			});
-		</script>
-	</body>
-</html>
+            Notes:
+            Although I had not taken any auditing course when I start the internship, I still manage to learn some basic concept before I went to workplace.
+            During the internship, I learned a lot, not just accounting and auditing standard such as consolidated financial statement.
+            Also include work etiquette, communication methods, etc.
+
+            The first lessons I learned, also the first thing my supervisor told my in the work, is if there anything unsure, be sure to ask.
+            Let me explain.
+
+            Our audit schedule is very tight.
+            We spent most of our time in reviewing and correcting errors in financial statements.
+            After we audit the subsidiaries individual financial statement, then we will put them together and review the consolidated financial statement.
+            At the same time, we will also prepare audit papers.
+            So that means if there are errors in subsidiary's statement, but found it during the consolidated process, that means we need to go back to readjust the consolidated statement and audit worksheet.
+            This will not only slow down the entire audit project, but also add extra workload to other team members.
+          </section>
+          <section data-markdown>
+            ### Key Lessons Learned
+
+            > Don't work hard, work smart!
+
+            Notes:
+            The difference between work hard and work smart is how much time you spend in completing tasks. Hard work tends to be when someone spends a great amout of time completing many things, while smart work is when they spend more time to find the right way to complete right things.
+
+            A very typically example during my internship is. Once we use scanner to scan hundreds of documents and needed to rename those file in certain order. On of my co-worker said "Okey, just give me one hour I will rename them one by one". However the correct way to do that is simply select all files, and press F2 then you can rename all files at once.
+            
+            At that time I didn't know that F2 is the shortcut to rename files, but I am sure there must be some way to do this task quickly, so I spent two minutes seaerching on Baidu, and spend one minute to complete the task.
+
+            In general, if you find yourself doing a very repetitive task, there may be a smater way to accomplish the task. Never stop learning new knowledge.
+          </section>
+        </section>
+        <section>
+          <section data-markdown>
+            ## Suggestion
+          </section>
+          <section data-markdown>
+            ## For the Company
+
+            > Information Island: Data in system that has no external connectivity.
+
+            - Can't sync/compare data between systems
+            - Require manually input data
+            - Involve more errors
+            - Increase complexity
+
+            Invest on developing a all-in-one solution system or pipeline between system, and traning employee to use the system.
+
+            Notes:
+
+            SAP, 久其报表，海油卡
+          </section>
+          <section data-markdown>
+            ## For the Accounting Program
+
+            - Set a file naming standard
+              - Instead of something like `Water final ver.2 (1).docx`
+            - Set a version control system for the files
+            - Automate repetitive tasks
+          </section>
+          <section>
+            <h2>For Future Accounting Interns</h2>
+            <ul>
+              <li class="fragment">Get an accounting certification</li>
+              <li class="fragment">Be familiar with Chinese tax & laws</li>
+              <li class="fragment">Learn a programming language (Recommend: <code>Python</code>)</li>
+            </ul>
+          </section>
+        </section>
+        <section>
+          <h1>Thank you</h1>
+          <p>for listining</p>
+        </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 src="plugin/zoom/zoom.js"></script>
+    <script>
+      // More info about initialization & config:
+      // - https://revealjs.com/initialization/
+      // - https://revealjs.com/config/
+      Reveal.initialize({
+        hash: true,
+        width: 1920,
+        height: 1080,
+
+        // Learn about plugins: https://revealjs.com/plugins/
+        plugins: [RevealMarkdown, RevealHighlight, RevealNotes, RevealZoom],
+      });
+    </script>
+  </body>
+</html>
--- a/js/config.js
+++ b/js/config.js
@@ -15,10 +15,7 @@ export default {
 	minScale: 0.2,
 	maxScale: 2.0,

-	// Display presentation control arrows.
-	// - true: Display controls on all screens
-	// - false: Hide controls on all screens
-	// - "speaker-only": Only display controls in the speaker view
+	// Display presentation control arrows
 	controls: true,

 	// Help the user learn the controls by providing hints, for example by
@@ -68,16 +65,13 @@ 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,

 	// Enable keyboard shortcuts for navigation
 	keyboard: true,

-	// Optional function that blocks keyboard events when returning false
+	// Optional function that blocks keyboard events when retuning false
 	//
 	// If you set this to 'focused', we will only capture keyboard events
 	// for embedded decks when they are in focus
@@ -168,9 +162,6 @@ export default {
 	// - false:  All iframes with data-src will be loaded only when visible
 	preloadIframes: null,

-	// Prevent embedded iframes from automatically focusing on themselves
-	preventIframeAutoFocus: true,
-
 	// Can be used to globally disable auto-animation
 	autoAnimate: true,

@@ -262,36 +253,6 @@ 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,
@@ -323,10 +284,6 @@ 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
@@ -31,13 +31,10 @@ export default class AutoAnimate {
 		let toSlideIndex = allSlides.indexOf( toSlide );
 		let fromSlideIndex = allSlides.indexOf( fromSlide );

-		// Ensure that;
-		// 1. Both slides exist.
-		// 2. Both slides are auto-animate targets with the same
-		//    data-auto-animate-id value (including null if absent on both).
-		// 3. data-auto-animate-restart isn't set on the physically latter
-		//    slide (independent of slide direction).
-		if( fromSlide && toSlide && fromSlide.hasAttribute( 'data-auto-animate' ) && toSlide.hasAttribute( 'data-auto-animate' )
+		// Ensure that both slides are auto-animate targets with the same data-auto-animate-id value
+		// (including null if absent on both) and that data-auto-animate-restart isn't set on the
+		// physically latter slide (independent of slide direction)
+		if( fromSlide.hasAttribute( 'data-auto-animate' ) && toSlide.hasAttribute( 'data-auto-animate' )
 				&& fromSlide.getAttribute( 'data-auto-animate-id' ) === toSlide.getAttribute( 'data-auto-animate-id' ) 
 				&& !( toSlideIndex > fromSlideIndex ? toSlide : fromSlide ).hasAttribute( 'data-auto-animate-restart' ) ) {

@@ -178,12 +175,28 @@ export default class AutoAnimate {
 		let fromProps = this.getAutoAnimatableProperties( 'from', from, elementOptions ),
 			toProps = this.getAutoAnimatableProperties( 'to', to, elementOptions );

+		// Maintain fragment visibility for matching elements when
+		// we're navigating forwards, this way the viewer won't need
+		// to step through the same fragments twice
 		if( to.classList.contains( 'fragment' ) ) {

 			// Don't auto-animate the opacity of fragments to avoid
 			// conflicts with fragment animations
 			delete toProps.styles['opacity'];

+			if( from.classList.contains( 'fragment' ) ) {
+
+				let fromFragmentStyle = ( from.className.match( FRAGMENT_STYLE_REGEX ) || [''] )[0];
+				let toFragmentStyle = ( to.className.match( FRAGMENT_STYLE_REGEX ) || [''] )[0];
+
+				// Only skip the fragment if the fragment animation style
+				// remains unchanged
+				if( fromFragmentStyle === toFragmentStyle && animationOptions.slideDirection === 'forward' ) {
+					to.classList.add( 'visible', 'disabled' );
+				}
+
+			}
+
 		}

 		// If translation and/or scaling are enabled, css transform
@@ -448,14 +461,14 @@ export default class AutoAnimate {
 		const textNodes = 'h1, h2, h3, h4, h5, h6, p, li';
 		const mediaNodes = 'img, video, iframe';

-		// Explicit matches via data-id
+		// Eplicit matches via data-id
 		this.findAutoAnimateMatches( pairs, fromSlide, toSlide, '[data-id]', node => {
 			return node.nodeName + ':::' + node.getAttribute( 'data-id' );
 		} );

 		// Text
 		this.findAutoAnimateMatches( pairs, fromSlide, toSlide, textNodes, node => {
-			return node.nodeName + ':::' + node.textContent.trim();
+			return node.nodeName + ':::' + node.innerText;
 		} );

 		// Media
@@ -465,7 +478,7 @@ export default class AutoAnimate {

 		// Code
 		this.findAutoAnimateMatches( pairs, fromSlide, toSlide, codeNodes, node => {
-			return node.nodeName + ':::' + node.textContent.trim();
+			return node.nodeName + ':::' + node.innerText;
 		} );

 		pairs.forEach( pair => {
@@ -491,7 +504,7 @@ export default class AutoAnimate {
 				} );

 				// Line numbers
-				this.findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-numbers[data-line-number]', node => {
+				this.findAutoAnimateMatches( pairs, pair.from, pair.to, '.hljs .hljs-ln-line[data-line-number]', node => {
 					return node.getAttribute( 'data-line-number' );
 				}, {
 					scale: false,
@@ -560,14 +573,14 @@ export default class AutoAnimate {

 			// Retrieve the 'from' element
 			if( fromMatches[key] ) {
-				const primaryIndex = toMatches[key].length - 1;
+				const pimaryIndex = 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][ primaryIndex ] ) {
-					fromElement = fromMatches[key][ primaryIndex ];
-					fromMatches[key][ primaryIndex ] = null;
+				if( fromMatches[key][ pimaryIndex ] ) {
+					fromElement = fromMatches[key][ pimaryIndex ];
+					fromMatches[key][ pimaryIndex ] = null;
 				}
 				// If there are no matching from-elements at the same index,
 				// use the last one.
@@ -595,7 +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 considered
+	 * Note that parents of auto-animate targets are NOT considerd
 	 * unmatched since fading them would break the auto-animation.
 	 *
 	 * @param {HTMLElement} rootElement
--- a/js/controllers/backgrounds.js
+++ b/js/controllers/backgrounds.js
@@ -190,30 +190,10 @@ 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 = slide.getAttribute( 'data-background-color' );
+		let contrastColor = data.backgroundColor;

 		// If no bg color was found, or it cannot be converted by colorToRgb, check the computed background
 		if( !contrastColor || !colorToRgb( contrastColor ) ) {
@@ -231,32 +211,14 @@ export default class Backgrounds {
 			// an element with no background
 			if( rgb && rgb.a !== 0 ) {
 				if( colorBrightness( contrastColor ) < 128 ) {
-					return 'has-dark-background';
+					slide.classList.add( 'has-dark-background' );
 				}
 				else {
-					return 'has-light-background';
+					slide.classList.add( '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 );
-
 	}

 	/**
@@ -268,15 +230,14 @@ export default class Backgrounds {
 	 */
 	update( includeAll = false ) {

-		let config = this.Reveal.getConfig();
 		let currentSlide = this.Reveal.getCurrentSlide();
 		let indices = this.Reveal.getIndices();

 		let currentBackground = null;

 		// Reverse past/future classes when in RTL mode
-		let horizontalPast = config.rtl ? 'future' : 'past',
-			horizontalFuture = config.rtl ? 'past' : 'future';
+		let horizontalPast = this.Reveal.getConfig().rtl ? 'future' : 'past',
+			horizontalFuture = this.Reveal.getConfig().rtl ? 'past' : 'future';

 		// Update the classes of all backgrounds to match the
 		// states of their slides (past/present/future)
@@ -302,12 +263,10 @@ export default class Backgrounds {

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

-					const indexv = typeof indices.v === 'number' ? indices.v : 0;
-
-					if( v < indexv ) {
+					if( v < indices.v ) {
 						backgroundv.classList.add( 'past' );
 					}
-					else if ( v > indexv ) {
+					else if ( v > indices.v ) {
 						backgroundv.classList.add( 'future' );
 					}
 					else {
@@ -322,53 +281,15 @@ export default class Backgrounds {

 		} );

-		// The previous background may refer to a DOM element that has
-		// been removed after a presentation is synced & bgs are recreated
-		if( this.previousBackground && !this.previousBackground.closest( 'body' ) ) {
-			this.previousBackground = null;
-		}
-
-		if( currentBackground && this.previousBackground ) {
-
-			// Don't transition between identical backgrounds. This
-			// prevents unwanted flicker.
-			let previousBackgroundHash = this.previousBackground.getAttribute( 'data-background-hash' );
-			let currentBackgroundHash = currentBackground.getAttribute( 'data-background-hash' );
-
-			if( currentBackgroundHash && currentBackgroundHash === previousBackgroundHash && currentBackground !== this.previousBackground ) {
-				this.element.classList.add( 'no-transition' );
-
-				// If multiple slides have the same background video, carry
-				// the <video> element forward so that it plays continuously
-				// across multiple slides
-				const currentVideo = currentBackground.querySelector( 'video' );
-				const previousVideo = this.previousBackground.querySelector( 'video' );
-
-				if( currentVideo && previousVideo ) {
-
-					const currentVideoParent = currentVideo.parentNode;
-					const previousVideoParent = previousVideo.parentNode;
-
-					// Swap the two videos
-					previousVideoParent.appendChild( currentVideo );
-					currentVideoParent.appendChild( previousVideo );
-
-				}
-			}
-
-		}
-
-		const backgroundChanged = currentBackground !== this.previousBackground;
-
 		// Stop content inside of previous backgrounds
-		if( backgroundChanged && this.previousBackground ) {
+		if( this.previousBackground ) {

 			this.Reveal.slideContent.stopEmbeddedContent( this.previousBackground, { unloadIframes: !this.Reveal.slideContent.shouldPreload( this.previousBackground ) } );

 		}

 		// Start content in the current background
-		if( backgroundChanged && currentBackground ) {
+		if( currentBackground ) {

 			this.Reveal.slideContent.startEmbeddedContent( currentBackground );

@@ -386,6 +307,14 @@ export default class Backgrounds {

 			}

+			// Don't transition between identical backgrounds. This
+			// prevents unwanted flicker.
+			let previousBackgroundHash = this.previousBackground ? this.previousBackground.getAttribute( 'data-background-hash' ) : null;
+			let currentBackgroundHash = currentBackground.getAttribute( 'data-background-hash' );
+			if( currentBackgroundHash && currentBackgroundHash === previousBackgroundHash && currentBackground !== this.previousBackground ) {
+				this.element.classList.add( 'no-transition' );
+			}
+
 			this.previousBackground = currentBackground;

 		}
@@ -393,13 +322,20 @@ export default class Backgrounds {
 		// If there's a background brightness flag for this slide,
 		// bubble it to the .reveal container
 		if( currentSlide ) {
-			this.bubbleSlideContrastClassToElement( currentSlide, this.Reveal.getRevealElement() );
+			[ '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 );
 		}

 		// Allow the first background to apply without transition
 		setTimeout( () => {
 			this.element.classList.remove( 'no-transition' );
-		}, 10 );
+		}, 1 );

 	}

--- a/js/controllers/controls.js
+++ b/js/controllers/controls.js
@@ -1,4 +1,4 @@
-import { queryAll, enterFullscreen } from '../utils/util.js'
+import { queryAll } from '../utils/util.js'
 import { isAndroid } from '../utils/device.js'

 /**
@@ -12,7 +12,6 @@ import { isAndroid } from '../utils/device.js'
 * - .navigate-left
 * - .navigate-next
 * - .navigate-prev
- * - .enter-fullscreen
 */
 export default class Controls {

@@ -26,7 +25,6 @@ export default class Controls {
 		this.onNavigateDownClicked = this.onNavigateDownClicked.bind( this );
 		this.onNavigatePrevClicked = this.onNavigatePrevClicked.bind( this );
 		this.onNavigateNextClicked = this.onNavigateNextClicked.bind( this );
-		this.onEnterFullscreen = this.onEnterFullscreen.bind( this );

 	}

@@ -52,7 +50,6 @@ export default class Controls {
 		this.controlsDown = queryAll( revealElement, '.navigate-down' );
 		this.controlsPrev = queryAll( revealElement, '.navigate-prev' );
 		this.controlsNext = queryAll( revealElement, '.navigate-next' );
-		this.controlsFullscreen = queryAll( revealElement, '.enter-fullscreen' );

 		// The left, right and down arrows in the standard reveal.js controls
 		this.controlsRightArrow = this.element.querySelector( '.navigate-right' );
@@ -66,10 +63,7 @@ export default class Controls {
 	 */
 	configure( config, oldConfig ) {

-		this.element.style.display = (
-			config.controls &&
-			(config.controls !== 'speaker-only' || this.Reveal.isSpeakerNotes())
-		) ? 'block' : 'none';
+		this.element.style.display = config.controls ? 'block' : 'none';

 		this.element.setAttribute( 'data-controls-layout', config.controlsLayout );
 		this.element.setAttribute( 'data-controls-back-arrows', config.controlsBackArrows );
@@ -83,10 +77,9 @@ export default class Controls {
 		let pointerEvents = [ 'touchstart', 'click' ];

 		// Only support touch for Android, fixes double navigations in
-		// stock browser. Use touchend for it to be considered a valid
-		// user interaction (so we're allowed to autoplay media).
+		// stock browser
 		if( isAndroid ) {
-			pointerEvents = [ 'touchend' ];
+			pointerEvents = [ 'touchstart' ];
 		}

 		pointerEvents.forEach( eventName => {
@@ -96,21 +89,19 @@ export default class Controls {
 			this.controlsDown.forEach( el => el.addEventListener( eventName, this.onNavigateDownClicked, false ) );
 			this.controlsPrev.forEach( el => el.addEventListener( eventName, this.onNavigatePrevClicked, false ) );
 			this.controlsNext.forEach( el => el.addEventListener( eventName, this.onNavigateNextClicked, false ) );
-			this.controlsFullscreen.forEach( el => el.addEventListener( eventName, this.onEnterFullscreen, false ) );
 		} );

 	}

 	unbind() {

-		[ 'touchstart', 'touchend', 'click' ].forEach( eventName => {
+		[ 'touchstart', 'click' ].forEach( eventName => {
 			this.controlsLeft.forEach( el => el.removeEventListener( eventName, this.onNavigateLeftClicked, false ) );
 			this.controlsRight.forEach( el => el.removeEventListener( eventName, this.onNavigateRightClicked, false ) );
 			this.controlsUp.forEach( el => el.removeEventListener( eventName, this.onNavigateUpClicked, false ) );
 			this.controlsDown.forEach( el => el.removeEventListener( eventName, this.onNavigateDownClicked, false ) );
 			this.controlsPrev.forEach( el => el.removeEventListener( eventName, this.onNavigatePrevClicked, false ) );
 			this.controlsNext.forEach( el => el.removeEventListener( eventName, this.onNavigateNextClicked, false ) );
-			this.controlsFullscreen.forEach( el => el.removeEventListener( eventName, this.onEnterFullscreen, false ) );
 		} );

 	}
@@ -150,14 +141,9 @@ export default class Controls {
 			if( fragmentsRoutes.prev ) this.controlsPrev.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
 			if( fragmentsRoutes.next ) this.controlsNext.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );

-			const isVerticalStack = this.Reveal.isVerticalSlide( currentSlide );
-			const hasVerticalSiblings = isVerticalStack &&
-																	currentSlide.parentElement &&
-																	currentSlide.parentElement.querySelectorAll( ':scope > section' ).length > 1;
-
 			// Apply fragment decorators to directional buttons based on
 			// what slide axis they are in
-			if( isVerticalStack && hasVerticalSiblings ) {
+			if( this.Reveal.isVerticalSlide( currentSlide ) ) {
 				if( fragmentsRoutes.prev ) this.controlsUp.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
 				if( fragmentsRoutes.next ) this.controlsDown.forEach( el => { el.classList.add( 'fragmented', 'enabled' ); el.removeAttribute( 'disabled' ); } );
 			}
@@ -276,13 +262,5 @@ export default class Controls {

 	}

-	onEnterFullscreen( event ) {
-
-		const config = this.Reveal.getConfig();
-		const viewport = this.Reveal.getViewportElement();
-
-		enterFullscreen( config.embedded ? viewport : viewport.parentElement );
-
-	}

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

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

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

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

 			if( fragments.length ) {

 				let maxIndex = 0;

 				if( typeof index !== 'number' ) {
-					let currentFragment = this.sort( slide.querySelectorAll( '.fragment.visible' ) ).pop();
+					let currentFragment = this.sort( currentSlide.querySelectorAll( '.fragment.visible' ) ).pop();
 					if( currentFragment ) {
 						index = parseInt( currentFragment.getAttribute( 'data-fragment-index' ) || 0, 10 );
 					}
@@ -251,32 +252,12 @@ export default class Fragments {
 				// the current fragment index.
 				index = typeof index === 'number' ? index : -1;
 				index = Math.max( Math.min( index, maxIndex ), -1 );
-				slide.setAttribute( 'data-fragment', index );
+				currentSlide.setAttribute( 'data-fragment', index );

 			}

 		}

-		if( changedFragments.hidden.length ) {
-			this.Reveal.dispatchEvent({
-				type: 'fragmenthidden',
-				data: {
-					fragment: changedFragments.hidden[0],
-					fragments: changedFragments.hidden
-				}
-			});
-		}
-
-		if( changedFragments.shown.length ) {
-			this.Reveal.dispatchEvent({
-				type: 'fragmentshown',
-				data: {
-					fragment: changedFragments.shown[0],
-					fragments: changedFragments.shown
-				}
-			});
-		}
-
 		return changedFragments;

 	}
@@ -331,6 +312,26 @@ export default class Fragments {

 				let changedFragments = this.update( index, fragments );

+				if( changedFragments.hidden.length ) {
+					this.Reveal.dispatchEvent({
+						type: 'fragmenthidden',
+						data: {
+							fragment: changedFragments.hidden[0],
+							fragments: changedFragments.hidden
+						}
+					});
+				}
+
+				if( changedFragments.shown.length ) {
+					this.Reveal.dispatchEvent({
+						type: 'fragmentshown',
+						data: {
+							fragment: changedFragments.shown[0],
+							fragments: changedFragments.shown
+						}
+					});
+				}
+
 				this.Reveal.controls.update();
 				this.Reveal.progress.update();

--- a/js/controllers/jumptoslide.js
+++ b/js/controllers/jumptoslide.js
@@ -1,197 +0,0 @@
-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 number
-		// (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
@@ -17,6 +17,7 @@ export default class Keyboard {
 		this.bindings = {};

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

 	}

@@ -42,7 +43,6 @@ export default class Keyboard {
 		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';

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

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

 	}

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

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

 	}

@@ -132,6 +134,20 @@ 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.
 	 *
@@ -167,10 +183,10 @@ export default class Keyboard {
 		let activeElementIsNotes = document.activeElement && document.activeElement.className && /speaker-notes/i.test( document.activeElement.className);

 		// Whitelist certain modifiers for slide navigation shortcuts
-		let keyCodeUsesModifier = [32, 37, 38, 39, 40, 63, 78, 80, 191].indexOf( event.keyCode ) !== -1;
+		let isNavigationKey = [32, 37, 38, 39, 40, 78, 80].indexOf( event.keyCode ) !== -1;

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

 		// Disregard the event if there's a focused element or a
@@ -178,7 +194,7 @@ export default class Keyboard {
 		if( activeElementIsCE || activeElementIsInput || activeElementIsNotes || unusedModifier ) return;

 		// While paused only allow resume keyboard events; 'b', 'v', '.'
-		let resumeKeyCodes = [66,86,190,191,112];
+		let resumeKeyCodes = [66,86,190,191];
 		let key;

 		// Custom key bindings for togglePause should be able to resume
@@ -190,10 +206,6 @@ export default class Keyboard {
 			}
 		}

-		if( this.Reveal.isOverlayOpen() && !["Escape", "f", "c", "b", "."].includes(event.key) ) {
-			return false;
-		}
-
 		if( this.Reveal.isPaused() && resumeKeyCodes.indexOf( keyCode ) === -1 ) {
 			return false;
 		}
@@ -275,12 +287,7 @@ export default class Keyboard {
 					this.Reveal.slide( 0 );
 				}
 				else if( !this.Reveal.overview.isActive() && useLinearMode ) {
-					if( config.rtl ) {
-						this.Reveal.next({skipFragments: event.altKey});
-					}
-					else {
-						this.Reveal.prev({skipFragments: event.altKey});
-					}
+					this.Reveal.prev({skipFragments: event.altKey});
 				}
 				else {
 					this.Reveal.left({skipFragments: event.altKey});
@@ -292,12 +299,7 @@ export default class Keyboard {
 					this.Reveal.slide( this.Reveal.getHorizontalSlides().length - 1 );
 				}
 				else if( !this.Reveal.overview.isActive() && useLinearMode ) {
-					if( config.rtl ) {
-						this.Reveal.prev({skipFragments: event.altKey});
-					}
-					else {
-						this.Reveal.next({skipFragments: event.altKey});
-					}
+					this.Reveal.next({skipFragments: event.altKey});
 				}
 				else {
 					this.Reveal.right({skipFragments: event.altKey});
@@ -348,7 +350,7 @@ export default class Keyboard {
 				}
 			}
 			// TWO-SPOT, SEMICOLON, B, V, PERIOD, LOGITECH PRESENTER TOOLS "BLACK SCREEN" BUTTON
-			else if( [58, 59, 66, 86, 190].includes( keyCode ) || ( keyCode === 191 && !event.shiftKey ) ) {
+			else if( keyCode === 58 || keyCode === 59 || keyCode === 66 || keyCode === 86 || keyCode === 190 || keyCode === 191 ) {
 				this.Reveal.togglePause();
 			}
 			// F
@@ -357,28 +359,10 @@ 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();
-				}
-			}
-			// C
-			else if( keyCode === 67 && this.Reveal.isOverlayOpen() ) {
-				this.Reveal.closeOverlay();
-			}
-			// ?
-			else if( ( keyCode === 63 || keyCode === 191 ) && event.shiftKey ) {
-				this.Reveal.toggleHelp();
-			}
-			// F1
-			else if( keyCode === 112 ) {
-				this.Reveal.toggleHelp();
-			}
 			else {
 				triggered = false;
 			}
@@ -398,12 +382,6 @@ export default class Keyboard {

 			event.preventDefault && event.preventDefault();
 		}
-		
-		// Enter to exit overview mode
-		else if (keyCode === 13 && this.Reveal.overview.isActive()) {
-			this.Reveal.overview.deactivate();
-			event.preventDefault && event.preventDefault();
-		}

 		// If auto-sliding is enabled we need to cue up
 		// another timeout
@@ -411,4 +389,4 @@ export default class Keyboard {

 	}

-}
+}
--- a/js/controllers/location.js
+++ b/js/controllers/location.js
@@ -40,7 +40,7 @@ export default class Location {
 	 *
 	 * @returns slide indices or null
 	 */
-	getIndicesFromHash( hash=window.location.hash, options={} ) {
+	getIndicesFromHash( hash=window.location.hash ) {

 		// Attempt to parse the hash as either an index or name
 		let name = hash.replace( /^#\/?/, '' );
@@ -49,7 +49,7 @@ export default class Location {
 		// 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 slide;
+			let element;

 			let f;

@@ -60,23 +60,19 @@ export default class Location {
 				name = name.split( '/' ).shift();
 			}

-			// Ensure the named link is a valid HTML id or data-id attribute
+			// Ensure the named link is a valid HTML ID attribute
 			try {
-				const decodedName = decodeURIComponent( name );
-				slide = (
-					document.getElementById( decodedName ) ||
-					document.querySelector( `[data-id="${decodedName}"]` )
-				).closest('.slides section');
+				element = document.getElementById( decodeURIComponent( name ) );
 			}
 			catch ( error ) { }

-			if( slide ) {
-				return { ...this.Reveal.getIndices( slide ), f };
+			if( element ) {
+				return { ...this.Reveal.getIndices( element ), f };
 			}
 		}
 		else {
 			const config = this.Reveal.getConfig();
-			let hashIndexBase = config.hashOneBasedIndex || options.oneBasedIndex ? 1 : 0;
+			let hashIndexBase = config.hashOneBasedIndex ? 1 : 0;

 			// Read the index components of the hash
 			let h = ( parseInt( bits[0], 10 ) - hashIndexBase ) || 0,
@@ -143,7 +139,7 @@ export default class Location {
 			let hash = this.getHash();

 			// If we're configured to push to history OR the history
-			// API is not available.
+			// API is not avaialble.
 			if( config.history ) {
 				window.location.hash = hash;
 			}
--- a/js/controllers/notes.js
+++ b/js/controllers/notes.js
@@ -38,12 +38,10 @@ export default class Notes {
 	 */
 	update() {

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

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

-		if( this.Reveal.getConfig().showNotes &&
-			this.hasNotes() &&
-			!this.Reveal.isScrollView() &&
-			!this.Reveal.isPrintView()
-		) {
+		if( this.Reveal.getConfig().showNotes && this.hasNotes() && !this.Reveal.print.isPrintingPDF() ) {
 			this.Reveal.getRevealElement().classList.add( 'show-notes' );
 		}
 		else {
--- a/js/controllers/overlay.js
+++ b/js/controllers/overlay.js
@@ -1,389 +0,0 @@
-/**
- * Handles the display of reveal.js' overlay elements used
- * to preview iframes, images & videos.
- */
-export default class Overlay {
-
-	constructor( Reveal ) {
-
-		this.Reveal = Reveal;
-
-		this.onSlidesClicked = this.onSlidesClicked.bind( this );
-
-		this.iframeTriggerSelector = null;
-		this.mediaTriggerSelector = '[data-preview-image], [data-preview-video]';
-
-		this.stateProps = ['previewIframe', 'previewImage', 'previewVideo', 'previewFit'];
-		this.state = {};
-
-	}
-
-	update() {
-
-		// Enable link previews globally
-		if( this.Reveal.getConfig().previewLinks ) {
-			this.iframeTriggerSelector = 'a[href]:not([data-preview-link=false]), [data-preview-link]:not(a):not([data-preview-link=false])';
-		}
-		// Enable link previews for individual elements
-		else {
-			this.iframeTriggerSelector = '[data-preview-link]:not([data-preview-link=false])';
-		}
-
-		const hasLinkPreviews = this.Reveal.getSlidesElement().querySelectorAll( this.iframeTriggerSelector ).length > 0;
-		const hasMediaPreviews = this.Reveal.getSlidesElement().querySelectorAll( this.mediaTriggerSelector ).length > 0;
-
-		// Only add the listener when there are previewable elements in the slides
-		if( hasLinkPreviews || hasMediaPreviews ) {
-			this.Reveal.getSlidesElement().addEventListener( 'click', this.onSlidesClicked, false );
-		}
-		else {
-			this.Reveal.getSlidesElement().removeEventListener( 'click', this.onSlidesClicked, false );
-		}
-
-	}
-
-	createOverlay( className ) {
-
-		this.dom = document.createElement( 'div' );
-		this.dom.classList.add( 'r-overlay' );
-		this.dom.classList.add( className );
-
-		this.viewport = document.createElement( 'div' );
-		this.viewport.classList.add( 'r-overlay-viewport' );
-
-		this.dom.appendChild( this.viewport );
-		this.Reveal.getRevealElement().appendChild( this.dom );
-
-	}
-
-	/**
-	 * Opens a lightbox that previews the target URL.
-	 *
-	 * @param {string} url - url for lightbox iframe src
-	 */
-	previewIframe( url ) {
-
-		this.close();
-
-		this.state = { previewIframe: url };
-
-		this.createOverlay( 'r-overlay-preview' );
-		this.dom.dataset.state = 'loading';
-
-		this.viewport.innerHTML =
-			`<header class="r-overlay-header">
-				<a class="r-overlay-button r-overlay-external" href="${url}" target="_blank"><span class="icon"></span></a>
-				<button class="r-overlay-button r-overlay-close"><span class="icon"></span></button>
-			</header>
-			<div class="r-overlay-spinner"></div>
-			<div class="r-overlay-content">
-				<iframe src="${url}"></iframe>
-				<small class="r-overlay-content-inner">
-					<span class="r-overlay-error x-frame-error">Unable to load iframe. This is likely due to the site's policy (x-frame-options).</span>
-				</small>
-			</div>`;
-
-		this.dom.querySelector( 'iframe' ).addEventListener( 'load', event => {
-			this.dom.dataset.state = 'loaded';
-		}, false );
-
-		this.dom.querySelector( '.r-overlay-close' ).addEventListener( 'click', event => {
-			this.close();
-			event.preventDefault();
-		}, false );
-
-		this.dom.querySelector( '.r-overlay-external' ).addEventListener( 'click', event => {
-			this.close();
-		}, false );
-
-		this.Reveal.dispatchEvent({ type: 'previewiframe', data: { url } });
-
-	}
-
-	/**
-	 * Opens a lightbox window that provides a larger view of the
-	 * given image/video.
-	 *
-	 * @param {string} url - url to the image/video to preview
-	 * @param {image|video} mediaType
-	 * @param {string} [fitMode] - the fit mode to use for the preview
-	 */
-	previewMedia( url, mediaType, fitMode ) {
-
-		if( mediaType !== 'image' && mediaType !== 'video' ) {
-			console.warn( 'Please specify a valid media type to preview (image|video)' );
-			return;
-		}
-
-		this.close();
-
-		fitMode = fitMode || 'scale-down';
-
-		this.createOverlay( 'r-overlay-preview' );
-		this.dom.dataset.state = 'loading';
-		this.dom.dataset.previewFit = fitMode;
-
-		this.viewport.innerHTML =
-			`<header class="r-overlay-header">
-				<button class="r-overlay-button r-overlay-close">Esc <span class="icon"></span></button>
-			</header>
-			<div class="r-overlay-spinner"></div>
-			<div class="r-overlay-content"></div>`;
-
-		const contentElement = this.dom.querySelector( '.r-overlay-content' );
-
-		if( mediaType === 'image' ) {
-
-			this.state = { previewImage: url, previewFit: fitMode }
-
-			const img = document.createElement( 'img', {} );
-			img.src = url;
-			contentElement.appendChild( img );
-
-			img.addEventListener( 'load', () => {
-				this.dom.dataset.state = 'loaded';
-			}, false );
-
-			img.addEventListener( 'error', () => {
-				this.dom.dataset.state = 'error';
-				contentElement.innerHTML =
-						`<span class="r-overlay-error">Unable to load image.</span>`
-			}, false );
-
-			// Hide image overlays when clicking outside the overlay
-			this.dom.style.cursor = 'zoom-out';
-			this.dom.addEventListener( 'click', ( event ) => {
-				this.close();
-			}, false );
-
-			this.Reveal.dispatchEvent({ type: 'previewimage', data: { url } });
-
-		}
-		else if( mediaType === 'video' ) {
-
-			this.state = { previewVideo: url, previewFit: fitMode }
-
-			const video = document.createElement( 'video' );
-			video.autoplay = this.dom.dataset.previewAutoplay === 'false' ? false : true;
-			video.controls = this.dom.dataset.previewControls === 'false' ? false : true;
-			video.loop = this.dom.dataset.previewLoop === 'true' ? true : false;
-			video.muted = this.dom.dataset.previewMuted === 'true' ? true : false;
-			video.playsInline = true;
-			video.src = url;
-			contentElement.appendChild( video );
-
-			video.addEventListener( 'loadeddata', () => {
-				this.dom.dataset.state = 'loaded';
-			}, false );
-
-			video.addEventListener( 'error', () => {
-				this.dom.dataset.state = 'error';
-				contentElement.innerHTML =
-					`<span class="r-overlay-error">Unable to load video.</span>`;
-			}, false );
-
-			this.Reveal.dispatchEvent({ type: 'previewvideo', data: { url } });
-
-		}
-		else {
-			throw new Error( 'Please specify a valid media type to preview' );
-		}
-
-		this.dom.querySelector( '.r-overlay-close' ).addEventListener( 'click', ( event ) => {
-			this.close();
-			event.preventDefault();
-		}, false );
-
-	}
-
-	previewImage( url, fitMode ) {
-
-		this.previewMedia( url, 'image', fitMode );
-
-	}
-
-	previewVideo( url, fitMode ) {
-
-		this.previewMedia( url, 'video', fitMode );
-
-	}
-
-	/**
-	 * Open or close help overlay window.
-	 *
-	 * @param {Boolean} [override] Flag which overrides the
-	 * toggle logic and forcibly sets the desired state. True means
-	 * help is open, false means it's closed.
-	 */
-	toggleHelp( override ) {
-
-		if( typeof override === 'boolean' ) {
-			override ? this.showHelp() : this.close();
-		}
-		else {
-			if( this.dom ) {
-				this.close();
-			}
-			else {
-				this.showHelp();
-			}
-		}
-	}
-
-	/**
-	 * Opens an overlay window with help material.
-	 */
-	showHelp() {
-
-		if( this.Reveal.getConfig().help ) {
-
-			this.close();
-
-			this.createOverlay( 'r-overlay-help' );
-
-			let html = '<p class="title">Keyboard Shortcuts</p>';
-
-			let shortcuts = this.Reveal.keyboard.getShortcuts(),
-				bindings = this.Reveal.keyboard.getBindings();
-
-			html += '<table><th>KEY</th><th>ACTION</th>';
-			for( let key in shortcuts ) {
-				html += `<tr><td>${key}</td><td>${shortcuts[ key ]}</td></tr>`;
-			}
-
-			// Add custom key bindings that have associated descriptions
-			for( let binding in bindings ) {
-				if( bindings[binding].key && bindings[binding].description ) {
-					html += `<tr><td>${bindings[binding].key}</td><td>${bindings[binding].description}</td></tr>`;
-				}
-			}
-
-			html += '</table>';
-
-			this.viewport.innerHTML = `
-				<header class="r-overlay-header">
-					<button class="r-overlay-button r-overlay-close">Esc <span class="icon"></span></button>
-				</header>
-				<div class="r-overlay-content">
-					<div class="r-overlay-help-content">${html}</div>
-				</div>
-			`;
-
-			this.dom.querySelector( '.r-overlay-close' ).addEventListener( 'click', event => {
-				this.close();
-				event.preventDefault();
-			}, false );
-
-			this.Reveal.dispatchEvent({ type: 'showhelp' });
-
-		}
-
-	}
-
-	isOpen() {
-
-		return !!this.dom;
-
-	}
-
-	/**
-	 * Closes any currently open overlay.
-	 */
-	close() {
-
-		if( this.dom ) {
-			this.dom.remove();
-			this.dom = null;
-
-			this.state = {};
-
-			this.Reveal.dispatchEvent({ type: 'closeoverlay' });
-
-			return true;
-		}
-
-		return false;
-
-	}
-
-	getState() {
-
-		return this.state;
-
-	}
-
-	setState( state ) {
-
-		// Ignore the incoming state if none of the preview related
-		// props have changed
-		if( this.stateProps.every( key => this.state[ key ] === state[ key ] ) ) {
-			return;
-		}
-
-		if( state.previewIframe ) {
-			this.previewIframe( state.previewIframe );
-		}
-		else if( state.previewImage ) {
-			this.previewImage( state.previewImage, state.previewFit );
-		}
-		else if( state.previewVideo ) {
-			this.previewVideo( state.previewVideo, state.previewFit );
-		}
-		else {
-			this.close();
-		}
-
-	}
-
-	onSlidesClicked( event ) {
-
-		const target = event.target;
-
-		const linkTarget = target.closest( this.iframeTriggerSelector );
-		const mediaTarget = target.closest( this.mediaTriggerSelector );
-
-		// Was an iframe lightbox trigger clicked?
-		if( linkTarget ) {
-			if( event.metaKey || event.shiftKey || event.altKey ) {
-				// Let the browser handle meta keys naturally so users can cmd+click
-				return;
-			}
-			let url = linkTarget.getAttribute( 'href' ) || linkTarget.getAttribute( 'data-preview-link' );
-			if( url ) {
-				this.previewIframe( url );
-				event.preventDefault();
-			}
-		}
-		// Was a media lightbox trigger clicked?
-		else if( mediaTarget ) {
-			if( mediaTarget.hasAttribute( 'data-preview-image' ) ) {
-				let url = mediaTarget.dataset.previewImage || mediaTarget.getAttribute( 'src' );
-				if( url ) {
-					this.previewImage( url, mediaTarget.dataset.previewFit );
-					event.preventDefault();
-				}
-			}
-			else if( mediaTarget.hasAttribute( 'data-preview-video' ) ) {
-				let url = mediaTarget.dataset.previewVideo || mediaTarget.getAttribute( 'src' );
-				if( !url ) {
-					let source = mediaTarget.querySelector( 'source' );
-					if( source ) {
-						url = source.getAttribute( 'src' );
-					}
-				}
-				if( url ) {
-					this.previewVideo( url, mediaTarget.dataset.previewFit );
-					event.preventDefault();
-				}
-			}
-		}
-
-	}
-
-	destroy() {
-
-		this.close();
-
-	}
-
-}
--- 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.Reveal.isScrollView() && !this.isActive() ) {
+		if( this.Reveal.getConfig().overview && !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 registered plugins
+		// An id:instance map of currently registed 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 registered plugins to initialize
+	 * reveal.js waits for all regisered plugins to initialize
 	 * before considering itself ready, as long as the plugin
 	 * is registered before calling `Reveal.initialize()`.
 	 */
--- a/js/controllers/pointer.js
+++ b/js/controllers/pointer.js
@@ -27,10 +27,12 @@ export default class Pointer {
 	configure( config, oldConfig ) {

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

 		// Auto-hide the mouse pointer when its inactive
@@ -77,7 +79,8 @@ export default class Pointer {

 		this.showCursor();

-		document.removeEventListener( 'wheel', this.onDocumentMouseScroll, false );
+		document.removeEventListener( 'DOMMouseScroll', this.onDocumentMouseScroll, false );
+		document.removeEventListener( 'mousewheel', this.onDocumentMouseScroll, false );
 		document.removeEventListener( 'mousemove', this.onDocumentCursorActive, false );
 		document.removeEventListener( 'mousedown', this.onDocumentCursorActive, false );

@@ -123,4 +126,4 @@ 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 PrintView {
+export default class Print {

 	constructor( Reveal ) {

@@ -16,7 +16,7 @@ export default class PrintView {
 	 * Configures the presentation for printing to a static
 	 * PDF.
 	 */
-	async activate() {
+	async setupPDF() {

 		const config = this.Reveal.getConfig();
 		const slides = queryAll( this.Reveal.getRevealElement(), SLIDES_SELECTOR )
@@ -42,11 +42,11 @@ export default class PrintView {
 		// 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( 'reveal-print', 'print-pdf' );
+		document.documentElement.classList.add( 'print-pdf' );
 		document.body.style.width = pageWidth + 'px';
 		document.body.style.height = pageHeight + 'px';

-		const viewportElement = this.Reveal.getViewportElement();
+		const viewportElement = document.querySelector( '.reveal-viewport' );
 		let presentationBackground;
 		if( viewportElement ) {
 			const viewportStyles = window.getComputedStyle( viewportElement );
@@ -223,17 +223,15 @@ export default class PrintView {
 		// Notify subscribers that the PDF layout is good to go
 		this.Reveal.dispatchEvent({ type: 'pdf-ready' });

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

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

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

 	}

-}
+}
--- a/js/controllers/scrollview.js
+++ b/js/controllers/scrollview.js
@@ -1,923 +0,0 @@
-import { HORIZONTAL_SLIDES_SELECTOR, HORIZONTAL_BACKGROUNDS_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 );
-		const horizontalBackgrounds = queryAll( this.Reveal.getRevealElement(), HORIZONTAL_BACKGROUNDS_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, isVertical ) => {
-
-			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 );
-
-				// This transfers over the background of the vertical stack containing
-				// the slide if it exists. Otherwise, it uses the presentation-wide
-				// background.
-				if( isVertical && horizontalBackgrounds.length > h ) {
-					const slideBackground = horizontalBackgrounds[h];
-					const pageBackground = window.getComputedStyle( slideBackground );
-
-					if( pageBackground && pageBackground.background ) {
-						page.style.background = pageBackground.background;
-					}
-					else if( presentationBackground ) {
-						page.style.background = presentationBackground;
-					}
-				} else 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, true );
-				});
-			}
-			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
-		this.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 = this.scrollTriggerHeight + 'px';
-				triggerStick.style.scrollSnapAlign = useCompactLayout ? 'center' : 'start';
-				page.pageElement.appendChild( triggerStick );
-
-				if( i === 0 ) {
-					triggerStick.style.marginTop = -this.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 = this.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];
-		} );
-
-		// Ensure the last trigger extends to the end of the page, otherwise
-		// rounding errors can cause the last trigger to end at 0.999999...
-		this.slideTriggers[this.slideTriggers.length - 1].range[1] = 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 );
-
-		}
-
-	}
-
-	/**
-	 * Scroll to the previous page.
-	 */
-	prev() {
-
-		this.viewportElement.scrollTop -= this.scrollTriggerHeight;
-
-	}
-
-	/**
-	 * Scroll to the next page.
-	 */
-	next() {
-
-		this.viewportElement.scrollTop += this.scrollTriggerHeight;
-
-	}
-
-	/**
-	 * 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
@@ -1,4 +1,4 @@
-import { extend, queryAll, closest, getMimeTypeFromFile, encodeRFC3986URI } from '../utils/util.js'
+import { extend, queryAll, closest, getMimeTypeFromFile } from '../utils/util.js'
 import { isMobile } from '../utils/device.js'

 import fitty from 'fitty';
@@ -9,15 +9,11 @@ import fitty from 'fitty';
 */
 export default class SlideContent {

-	allowedToPlay = true;
-
 	constructor( Reveal ) {

 		this.Reveal = Reveal;

 		this.startEmbeddedIframe = this.startEmbeddedIframe.bind( this );
-		this.preventIframeAutoFocus = this.preventIframeAutoFocus.bind( this );
-		this.ensureMobileMediaPlaying = this.ensureMobileMediaPlaying.bind( this );

 	}

@@ -29,10 +25,6 @@ export default class SlideContent {
 	 */
 	shouldPreload( element ) {

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

@@ -55,25 +47,14 @@ export default class SlideContent {
 	load( slide, options = {} ) {

 		// Show the slide element
-		const displayValue = this.Reveal.getConfig().display;
-		if( displayValue.includes('!important') ) {
-			const value = displayValue.replace(/\s*!important\s*$/, '').trim();
-			slide.style.setProperty('display', value, 'important');
-		} else {
-			slide.style.display = displayValue;
-		}
+		slide.style.display = this.Reveal.getConfig().display;

-		// Media and iframe elements with data-src attributes
+		// Media elements with data-src attributes
 		queryAll( slide, 'img[data-src], video[data-src], audio[data-src], iframe[data-src]' ).forEach( element => {
-			const isIframe = element.tagName === 'IFRAME';
-			if( !isIframe || this.shouldPreload( element ) ) {
+			if( element.tagName !== 'IFRAME' || this.shouldPreload( element ) ) {
 				element.setAttribute( 'src', element.getAttribute( 'data-src' ) );
 				element.setAttribute( 'data-lazy-loaded', '' );
 				element.removeAttribute( 'data-src' );
-
-				if( isIframe ) {
-					element.addEventListener( 'load', this.preventIframeAutoFocus );
-				}
 			}
 		} );

@@ -127,21 +108,19 @@ export default class SlideContent {
 					// 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(${encodeRFC3986URI(decoded)})`;
+							return `url(${encodeURI(background.trim())})`;
 						}).join( ',' );
 					}
 				}
 				// Videos
-				else if ( backgroundVideo ) {
+				else if ( backgroundVideo && !this.Reveal.isSpeakerNotes() ) {
 					let video = document.createElement( 'video' );

 					if( backgroundVideoLoop ) {
 						video.setAttribute( 'loop', '' );
 					}

-					if( backgroundVideoMuted || this.Reveal.isSpeakerNotes() ) {
+					if( backgroundVideoMuted ) {
 						video.muted = true;
 					}

@@ -157,15 +136,13 @@ export default class SlideContent {

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

 					backgroundContent.appendChild( video );
@@ -295,9 +272,7 @@ export default class SlideContent {
 	 */
 	startEmbeddedContent( element ) {

-		if( element ) {
-
-			const isSpeakerNotesWindow = this.Reveal.isSpeakerNotes();
+		if( element && !this.Reveal.isSpeakerNotes() ) {

 			// Restart GIFs
 			queryAll( element, 'img[src$=".gif"]' ).forEach( el => {
@@ -323,9 +298,6 @@ export default class SlideContent {

 				if( autoplay && typeof el.play === 'function' ) {

-					// In the speaker view we only auto-play muted media
-					if( isSpeakerNotesWindow && !el.muted ) return;
-
 					// If the media is ready, start playback
 					if( el.readyState > 1 ) {
 						this.startEmbeddedMedia( { target: el } );
@@ -335,16 +307,10 @@ export default class SlideContent {
 					else if( isMobile ) {
 						let promise = el.play();

-						el.addEventListener( 'canplay', this.ensureMobileMediaPlaying );
-
 						// If autoplay does not work, ensure that the controls are visible so
 						// that the viewer can start the media on their own
 						if( promise && typeof promise.catch === 'function' && el.controls === false ) {
-							promise
-							.then( () => {
-								this.allowedToPlay = true;
-							})
-							.catch( () => {
+							promise.catch( () => {
 								el.controls = true;

 								// Once the video does start playing, hide the controls again
@@ -363,72 +329,32 @@ export default class SlideContent {
 				}
 			} );

-			// Don't play iframe content in the speaker view since we can't
-			// guarantee that it's muted
-			if( !isSpeakerNotesWindow ) {
+			// Normal iframes
+			queryAll( element, 'iframe[src]' ).forEach( el => {
+				if( closest( el, '.fragment' ) && !closest( el, '.fragment.visible' ) ) {
+					return;
+				}

-				// Normal iframes
-				queryAll( element, 'iframe[src]' ).forEach( el => {
-					if( closest( el, '.fragment' ) && !closest( el, '.fragment.visible' ) ) {
-						return;
-					}
+				this.startEmbeddedIframe( { target: el } );
+			} );

-					this.startEmbeddedIframe( { target: el } );
-				} );
+			// Lazy loading iframes
+			queryAll( element, 'iframe[data-src]' ).forEach( el => {
+				if( closest( el, '.fragment' ) && !closest( el, '.fragment.visible' ) ) {
+					return;
+				}

-				// Lazy loading iframes
-				queryAll( element, 'iframe[data-src]' ).forEach( el => {
-					if( closest( el, '.fragment' ) && !closest( el, '.fragment.visible' ) ) {
-						return;
-					}
-
-					if( el.getAttribute( 'src' ) !== el.getAttribute( 'data-src' ) ) {
-						el.removeEventListener( 'load', this.startEmbeddedIframe ); // remove first to avoid dupes
-						el.addEventListener( 'load', this.startEmbeddedIframe );
-						el.setAttribute( 'src', el.getAttribute( 'data-src' ) );
-					}
-				} );
-
-			}
+				if( el.getAttribute( 'src' ) !== el.getAttribute( 'data-src' ) ) {
+					el.removeEventListener( 'load', this.startEmbeddedIframe ); // remove first to avoid dupes
+					el.addEventListener( 'load', this.startEmbeddedIframe );
+					el.setAttribute( 'src', el.getAttribute( 'data-src' ) );
+				}
+			} );

 		}

 	}

-	/**
-	 * Ensure that an HTMLMediaElement is playing on mobile devices.
-	 *
-	 * This is a workaround for a bug in mobile Safari where
-	 * the media fails to display if many videos are started
-	 * at the same moment. When this happens, Mobile Safari
-	 * reports the video is playing, and the current time
-	 * advances, but nothing is visible.
-	 *
-	 * @param {Event} event
-	 */
-	ensureMobileMediaPlaying( event ) {
-
-		const el = event.target;
-
-		// Ignore this check incompatible browsers
-		if( typeof el.getVideoPlaybackQuality !== 'function' ) {
-			return;
-		}
-
-		setTimeout( () => {
-
-			const playing = el.paused === false;
-			const totalFrames = el.getVideoPlaybackQuality().totalVideoFrames;
-
-			if( playing && totalFrames === 0 ) {
-				el.load();
-				el.play();
-			}
-
-		}, 1000 );
-
-	}
-
 	/**
 	 * Starts playing an embedded video/audio element after
 	 * it has finished loading.
@@ -441,23 +367,8 @@ export default class SlideContent {
 			isVisible  		= !!closest( event.target, '.present' );

 		if( isAttachedToDOM && isVisible ) {
-			// Don't restart if media is already playing
-			if( event.target.paused || event.target.ended ) {
-				event.target.currentTime = 0;
-				const promise = event.target.play();
-
-				if( promise && typeof promise.catch === 'function' ) {
-					promise
-						.then( () => {
-							this.allowedToPlay = true;
-						} )
-						.catch( ( error ) => {
-							if( error.name === 'NotAllowedError' ) {
-								this.allowedToPlay = false;
-							}
-						} );
-				}
-			}
+			event.target.currentTime = 0;
+			event.target.play();
 		}

 		event.target.removeEventListener( 'loadeddata', this.startEmbeddedMedia );
@@ -474,8 +385,6 @@ export default class SlideContent {

 		let iframe = event.target;

-		this.preventIframeAutoFocus( event );
-
 		if( iframe && iframe.contentWindow ) {

 			let isAttachedToDOM = !!closest( event.target, 'html' ),
@@ -530,17 +439,12 @@ export default class SlideContent {
 				if( !el.hasAttribute( 'data-ignore' ) && typeof el.pause === 'function' ) {
 					el.setAttribute('data-paused-by-reveal', '');
 					el.pause();
-
-					if( isMobile ) {
-						el.removeEventListener( 'canplay', this.ensureMobileMediaPlaying );
-					}
 				}
 			} );

 			// Generic postMessage API for non-lazy loaded iframes
 			queryAll( element, 'iframe' ).forEach( el => {
 				if( el.contentWindow ) el.contentWindow.postMessage( 'slide:stop', '*' );
-				el.removeEventListener( 'load', this.preventIframeAutoFocus );
 				el.removeEventListener( 'load', this.startEmbeddedIframe );
 			});

@@ -571,46 +475,4 @@ export default class SlideContent {

 	}

-	/**
-	 * Checks whether media playback is blocked by the browser. This
-	 * typically happens when media playback is initiated without a
-	 * direct user interaction.
-	 */
-	isNotAllowedToPlay() {
-
-		return !this.allowedToPlay;
-
-	}
-
-	/**
-	 * Prevents iframes from automatically focusing themselves.
-	 *
-	 * @param {Event} event
-	 */
-	preventIframeAutoFocus( event ) {
-
-		const iframe = event.target;
-
-		console.log(111)
-
-		if( iframe && this.Reveal.getConfig().preventIframeAutoFocus ) {
-
-			let elapsed = 0;
-			const interval = 100;
-			const maxTime = 1000;
-			const checkFocus = () => {
-				if( document.activeElement === iframe ) {
-					document.activeElement.blur();
-				} else if( elapsed < maxTime ) {
-					elapsed += interval;
-					setTimeout( checkFocus, interval );
-				}
-			};
-
-			setTimeout( checkFocus, interval );
-
-		}
-
-	}
-
 }
--- a/js/controllers/slidenumber.js
+++ b/js/controllers/slidenumber.js
@@ -1,10 +1,3 @@
-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.
 */
@@ -30,7 +23,7 @@ export default class SlideNumber {
 	configure( config, oldConfig ) {

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

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

 		if ( typeof config.slideNumber === 'function' ) {
 			value = config.slideNumber( slide );
@@ -76,7 +69,7 @@ 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 = SLIDE_NUMBER_FORMAT_CURRENT;
+				format = 'c';
 			}

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

 			value = [];
 			switch( format ) {
-				case SLIDE_NUMBER_FORMAT_CURRENT:
+				case 'c':
 					value.push( this.Reveal.getSlidePastCount( slide ) + horizontalOffset );
 					break;
-				case SLIDE_NUMBER_FORMAT_CURRENT_SLASH_TOTAL:
+				case 'c/t':
 					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 === SLIDE_NUMBER_FORMAT_HORIZONTAL_SLASH_VERTICAL ? '/' : '.';
+					let sep = format === 'h/v' ? '/' : '.';
 					if( this.Reveal.isVerticalSlide( slide ) ) value.push( sep, indices.v + 1 );
 			}
 		}
--- a/js/controllers/touch.js
+++ b/js/controllers/touch.js
@@ -84,7 +84,7 @@ export default class Touch {
 	isSwipePrevented( target ) {

 		// Prevent accidental swipes when scrubbing timelines
-		if( matches( target, 'video[controls], audio[controls]' ) ) return true;
+		if( matches( target, 'video, audio' ) ) return true;

 		while( target && typeof target.hasAttribute === 'function' ) {
 			if( target.hasAttribute( 'data-prevent-swipe' ) ) return true;
@@ -103,8 +103,6 @@ export default class Touch {
 	 */
 	onTouchStart( event ) {

-		this.touchCaptured = false;
-
 		if( this.isSwipePrevented( event.target ) ) return true;

 		this.touchStartX = event.touches[0].clientX;
@@ -216,14 +214,6 @@ export default class Touch {
 	 */
 	onTouchEnd( event ) {

-		// Media playback is only allowed as a direct result of a
-		// user interaction. Some mobile devices do not consider a
-		// 'touchmove' to be a direct user action. If this is the
-		// case, we fall back to starting playback here instead.
-		if( this.touchCaptured && this.Reveal.slideContent.isNotAllowedToPlay() ) {
-			this.Reveal.startEmbeddedContent( this.Reveal.getCurrentSlide() );
-		}
-
 		this.touchCaptured = false;

 	}
--- a/js/reveal.js
+++ b/js/reveal.js
--- a/js/utils/color.js
+++ b/js/utils/color.js
@@ -44,7 +44,7 @@ export const colorToRgb = ( color ) => {
 		};
 	}

-	let rgba = color.match( /^rgba\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*,\s*([\d]+|[\d]*.[\d]+)\s*\)$/i );
+	let rgba = color.match( /^rgba\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\,\s*([\d]+|[\d]*.[\d]+)\s*\)$/i );
 	if( rgba ) {
 		return {
 			r: parseInt( rgba[1], 10 ),
--- a/js/utils/constants.js
+++ b/js/utils/constants.js
@@ -2,16 +2,9 @@
 export const SLIDES_SELECTOR = '.slides section';
 export const HORIZONTAL_SLIDES_SELECTOR = '.slides>section';
 export const VERTICAL_SLIDES_SELECTOR = '.slides>section.present>section';
-export const HORIZONTAL_BACKGROUNDS_SELECTOR = '.backgrounds>.slide-background';

 // Methods that may not be invoked via the postMessage API
 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/;
-
-// 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';
+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/;
--- a/js/utils/util.js
+++ b/js/utils/util.js
@@ -294,20 +294,4 @@ const fileExtensionToMimeMap = {
 */
 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/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
  "name": "reveal.js",
-  "version": "5.2.1",
+  "version": "4.4.0",
  "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": ">=18.0.0"
+    "node": ">=10.0.0"
  },
  "keywords": [
    "reveal",
@@ -30,41 +30,33 @@
    "presentation"
  ],
  "devDependencies": {
-    "@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",
+    "@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",
    "colors": "^1.4.0",
-    "core-js": "^3.33.1",
-    "fitty": "^2.3.7",
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-\documentclass[conference]{IEEEtran}
-
-\usepackage{cite}
-\usepackage{amsmath,amssymb,amsfonts}
-\usepackage{algorithmic}
-\usepackage{graphicx}
-\usepackage{textcomp}
-\usepackage{xcolor}
-\usepackage{booktabs}
-\usepackage{multirow}
-\usepackage{listings}
-\usepackage{subfigure}
-\usepackage{times}
-
-\begin{document}
-
-\title{PostgreSQL JSONB Storage Performance Optimization: A Comprehensive Survey}
-
-\author{\IEEEauthorblockN{CHEN Yongyuan}
-\IEEEauthorblockA{Student ID: 2250020225\\
-December 2025}
-}
-
-\maketitle
-
-\begin{abstract}
-PostgreSQL's JSONB data type represents a significant advancement in semi structured data management, offering binary storage and advanced indexing capabilities that dramatically outperform traditional JSON text storage. This comprehensive survey examines the state of the art optimization techniques that make PostgreSQL's JSONB a powerful solution for modern data intensive applications. The analysis covers four fundamental optimization pillars: binary storage format and decomposition, GIN indexing strategies, TOAST (The Oversized Attribute Storage Technique) mechanisms, and query processing optimizations. Performance benchmarks demonstrate that PostgreSQL JSONB achieves 5 to 10x improvements for nested queries compared to JSON text storage, while maintaining ACID compliance and full SQL integration. The survey identifies current limitations in handling extremely large documents, frequent partial updates, and complex array operations, while exploring emerging optimization approaches for production environments.
-\end{abstract}
-
-\begin{IEEEkeywords}
-PostgreSQL, JSONB, performance optimization, TOAST, GIN indexing, semi structured data
-\end{IEEEkeywords}
-
-\section{Introduction}
-
-\subsection{The Evolution of JSON Support and PostgreSQL's Rising Popularity}
-
-PostgreSQL's journey with JSON data began in 2012 with the introduction of the JSON data type, which provided validation functions but stored data as plain text. The limitations of this approach became apparent as developers struggled with performance issues when querying large JSON documents. In response, PostgreSQL 9.4 introduced JSONB in 2014, representing a paradigm shift in semi structured data handling within relational databases.
-
-The introduction of JSONB coincides with a significant turning point in PostgreSQL's popularity trajectory. Analysis of DB-Engines ranking data reveals that PostgreSQL was the only major database showing consistent growth during the period following JSONB's introduction. While other databases experienced stagnation or decline, PostgreSQL's popularity metrics began rising steadily from 2014 onward.
-
-This correlation suggests that JSONB served as a major driver of PostgreSQL's market success. The technology successfully attracted developers from NoSQL backgrounds who were seeking document database capabilities without sacrificing PostgreSQL's reliability and ACID compliance. The timing aligns with broader industry trends toward microservices architectures and the need for flexible data models, positioning PostgreSQL uniquely as a hybrid solution combining relational and document paradigms.
-
-PostgreSQL's JSONB implementation represents a fundamental departure from text based JSON storage through its sophisticated binary format. When JSON data is inserted into a JSONB column, PostgreSQL parses it once and converts it into a decomposed binary representation that eliminates repetitive parsing during query execution.
-
-This innovation addressed a critical market need for databases that could handle both structured and semi structured data efficiently. Unlike specialized document stores that required abandoning existing SQL investments and ACID guarantees, PostgreSQL JSONB allowed organizations to gradually adopt document models while maintaining their relational infrastructure and expertise.
-
-The timing of JSONB's introduction proved particularly fortuitous, coinciding with the rise of microservices architectures where JSON became the de facto communication standard between services. PostgreSQL's ability to efficiently store and query JSON documents made it an attractive choice for organizations seeking to reduce database technology sprawl while supporting diverse application patterns.
-
-\subsection{Current Challenges in JSONB Performance Management}
-
-Despite PostgreSQL's significant advancements, several performance challenges persist in production environments. Query performance can degrade with deeply nested documents and complex path queries, even though JSONB dramatically outperforms JSON text storage. The binary format's efficiency depends heavily on proper indexing strategies and query patterns.
-
-Storage overhead and bloat present another significant challenge. Frequent updates to JSONB documents can lead to storage bloat due to PostgreSQL's MVCC (Multi Version Concurrency Control) system. The immutability of JSONB data structures means that even small modifications require rewriting entire documents.
-
-Indexing complexity adds another layer of difficulty. Effective GIN indexing for JSONB requires careful consideration of query patterns, index size, and maintenance overhead. Improper indexing strategies can lead to diminished returns or even performance regression. While TOAST handles large values efficiently, very large JSONB documents (multi megabyte) can still strain system resources, particularly during partial updates or array operations.
-
-\subsection{Survey Scope and Objectives}
-
-This comprehensive survey examines PostgreSQL's JSONB optimization techniques across multiple dimensions. The analysis focuses on four key areas: storage format optimization including binary decomposition, key compression, and value storage strategies; indexing techniques covering GIN indexing, partial indexing, and expression based indexing; query processing including path evaluation, containment operations, and optimization strategies; and storage management encompassing TOAST mechanisms, vacuum processes, and bloat mitigation.
-
-The objective is to provide database professionals with a deep understanding of PostgreSQL's JSONB capabilities, practical optimization guidelines, and insights into emerging trends in semi structured data management. By analyzing both current implementations and future directions, this survey aims to bridge the gap between theoretical advantages and practical performance tuning.
-
-\section{PostgreSQL JSONB Optimization Techniques: A Technical Analysis}
-
-\subsection{Binary Storage Format and Decomposition}
-
-PostgreSQL's JSONB binary storage format comprises three core components that work together to optimize performance and storage efficiency. Key dictionary compression maintains a dictionary of unique keys within each JSONB document, eliminating storage overhead from repeated key names. The structure references keys via compact integer identifiers, achieving 20 to 40\% storage reduction for documents with repetitive key structures.
-
-Typed value storage represents another critical optimization. Values are stored in their native binary representations (integers, floats, booleans, strings), avoiding costly text to type conversions during queries. This approach ensures both performance gains and type safety across all data operations.
-
-Structural decomposition completes the optimization trio. The JSON document is decomposed into a hierarchical binary tree where each node maintains pointers to its children, enabling efficient navigation without full document traversal. This architectural choice maintains consistent access times regardless of document size for path queries, as navigation follows direct pointers rather than performing string searches. However, the initial parsing overhead during insertion can be 2 to 3x higher than JSON text storage, making JSONB more suitable for read heavy workloads.
-
-\subsection{GIN Indexing Strategies}
-
-Generalized Inverted Indexes (GIN) form the cornerstone of PostgreSQL's JSONB query optimization strategy. GIN indexes create mappings from every key and value to the documents containing them, enabling efficient containment and existence queries. The system supports multiple GIN index types, each optimized for specific use cases.
-
-Default GIN indexes map all keys and values in the JSONB document, making them suitable for general purpose querying but potentially large for complex documents. Path specific GIN indexes, created using JSONB path expressions, target specific query patterns and are significantly smaller and more efficient than their default counterparts.
-
-Indexing optimization techniques demonstrate PostgreSQL's flexibility in handling JSONB workloads. Standard GIN indexes provide broad coverage for general queries, while path specific indexes enable targeted performance improvements. Partial GIN indexes offer additional optimization by indexing only filtered document subsets, reducing storage overhead and improving query performance for specific access patterns.
-
-Performance implications of GIN indexing are substantial. GIN indexes provide 10 to 100x performance improvements for containment operations (\texttt{@>}) and existence queries (\texttt{?}, \texttt{\&}, \texttt{|}). However, they incur 20 to 30\% write overhead and require periodic maintenance to prevent index bloat, necessitating careful consideration of the read to write balance in workload design.
-
-\subsection{The Curse of TOAST: Performance Implications of Large JSONB Documents}
-
-The Oversized Attribute Storage Technique (TOAST) represents both a solution and a challenge for PostgreSQL JSONB performance. While TOAST enables PostgreSQL to handle JSONB documents exceeding standard page sizes, it introduces what leading PostgreSQL contributor Oleg Bartunov terms the ``curse of TOAST'' - unpredictable performance degradation that occurs at the 2KB threshold.
-
-The TOAST mechanism operates through a sophisticated four-pass algorithm that attempts to compact tuples to 2KB or smaller. First, PostgreSQL attempts to compress the longest fields using the pglz algorithm. If compression alone is insufficient, the system replaces fields with TOAST pointers and moves the compressed data to a separate storage area. This process transforms the original tuple structure, replacing large JSONB fields with compact pointers while maintaining the logical appearance of complete documents.
-
-The critical 2KB threshold marks a dramatic shift in JSONB performance characteristics. Before TOAST activation, JSONB documents maintain consistent access times regardless of size. However, once documents exceed this threshold, performance degrades substantially due to several factors. Accessing TOASTed JSONB data requires reading additional buffers typically three extra buffers per access (two TOAST index buffers and one TOAST heap buffer). This overhead compounds with document size and access frequency.
-
-A production example demonstrated this phenomenon dramatically: a query that previously required only 2,500 buffer hits suddenly needed 30,000 buffer hits after documents became TOASTed during a simple update operation. The mathematics of this transformation explains the performance impact. Each row access now requires reading the main heap page plus three TOAST related buffers, multiplied by 10,000 rows, precisely matching the observed increase from 2,500 to 30,000 buffer hits.
-
-The underlying storage pattern shifts dramatically when documents cross the TOAST threshold. Instead of 2,500 pages with four tuples per page, PostgreSQL now stores only 64 pages with 157 tuples per page. Each tuple contains only a TOAST pointer to the actual JSONB data, which is compressed and moved to separate TOAST storage.
-
-The fundamental challenge lies in PostgreSQL's approach to TOAST as a black box operation. When accessing even a small key within a large TOASTed JSONB document, the system must perform complete deTOAST operations. This process involves locating all relevant chunks through index lookups, combining them into a single buffer, and then decompressing the entire document before extracting the desired value.
-
-This behavior explains why users frequently report unpredictable performance a small change in document size that triggers TOAST can result in 10 to 20x performance degradation for the same query pattern. The problem becomes particularly acute in production environments where document sizes gradually grow over time, causing performance to deteriorate without obvious schema changes.
-
-Testing with JSONB documents of varying sizes reveals three distinct performance regions. Inline storage (\textless{}2KB) provides consistent performance with constant-time access regardless of document size. Compressed inline storage (2KB to 100KB compressed) shows slight performance increase due to decompression overhead, but remains manageable. TOASTed storage (\textgreater{}100KB original) exhibits linear performance degradation with each additional chunk requiring extra buffer reads.
-
-
-\begin{figure}
-    \centering
-    \includegraphics[width=1\linewidth]{1.png}
-    \caption{Figure showing performance degradation at TOAST threshold}
-    \label{fig:placeholder}
-\end{figure}
-
-\subsection{JSONB Operator Performance: A Detailed Comparative Analysis}
-
-PostgreSQL provides multiple operators for accessing JSONB data, each with distinct performance characteristics that significantly impact application behavior. Extensive testing by PostgreSQL contributors reveals surprising patterns that contradict common assumptions about operator efficiency, particularly when examining performance across different nesting levels.
-
-The traditional arrow operator (\texttt{-\textgreater{}}) and hash arrow operator (\texttt{-\textgreater{}\textgreater{}}) remain popular for key access, but their performance is highly dependent on document size and nesting level. For small JSONB documents (under 2KB) at root level, arrow operator demonstrates excellent performance due to minimal initialization overhead. However, its performance degrades rapidly with larger documents and deeper nesting levels because it must copy intermediate results to temporary datums for each operation level.
-
-Subscripting operators, introduced in later PostgreSQL versions, emerge as the most versatile option. They maintain consistent performance across document sizes and nesting levels, making them the preferred choice for production environments with varying document structures. Subscripting avoids intermediate copying overhead by using array like access patterns that work directly with JSONB's internal representation.
-
-JSON path operators, while the slowest for simple queries, provide unmatched flexibility for complex query patterns. Their performance penalty stems from the flexibility of their implementation, which must handle complex path expressions and error conditions. However, for sophisticated filtering and extraction operations, JSON path often outperforms multiple chained operators.
-
-Comprehensive testing with nested JSONB containers reveals three distinct performance regions based on document size and operator type. For small documents under 2KB, arrow operator performs admirably at root level, showing execution times comparable to subscripting. However, performance begins diverging as documents approach the TOAST threshold around 2KB.
-
-Once documents exceed 2KB and become TOASTed, performance characteristics shift dramatically. Arrow operator becomes unpredictable, with execution times growing linearly with document size even for root level access. This occurs because each arrow operation must fully deTOAST the document before copying intermediate results to temporary storage. Subscripting maintains relatively stable performance across document sizes because it can work more efficiently with TOASTed data.
-
-Testing reveals that nesting level significantly impacts operator performance, particularly for arrow operator. Accessing deeply nested keys using chained arrow operations results in exponential performance degradation because each level requires its own deTOAST and copying operation. Subscripting and JSON path show more linear degradation with nesting depth.
-
-Practical recommendations based on extensive performance analysis suggest optimal operator selection depends on specific use cases. Arrow operator should be limited to small JSONB documents at root level or first level nesting. Subscripting serves as the default choice for general purpose applications due to consistent performance. JSON path is reserved for complex queries requiring sophisticated filtering and extraction capabilities.
-
-For containment queries, different operators show varying efficiency levels. The contains operator (\texttt{@>}) consistently outperforms JSON path exist operators, particularly for simple containment checks. However, JSON path with lax mode can achieve comparable performance for first element searches in arrays due to early termination when results are found.
-
-Array operations show distinct performance patterns across different operators and nesting levels. For arrays with 1 to 1 million entries, the performance characteristics vary significantly. Small arrays (\textless{}100 elements) see all operators performing comparably well. Small arrays (100 to 10,000 elements) begin showing performance degradation for arrow operator. Large arrays (\textgreater{}10,000 elements) see subscripting maintaining relatively stable performance while arrow operator degrades significantly.
-
-\begin{figure}
-    \centering
-    \includegraphics[width=1\linewidth]{2.png}
-    \caption{Comparing JSONB operator performance across nesting levels}
-    \label{fig:placeholder}
-\end{figure}
-
-\subsection{JSONB Partial Update: Performance Challenges and Solutions}
-
-TOAST was originally designed for atomic data types and knows nothing about internal structure of composite data types like jsonb, hstore, and even ordinary arrays. TOAST works only with binary BLOBs and does not try to find differences between old and new values of updated attributes. When the TOASTed attribute is being updated, regardless of the position or amount of data changed, its chunks are simply fully copied.
-
-This behavior leads to three significant consequences: TOAST storage is duplicated with each update creating new copies of TOASTed data; WAL traffic is increased as whole TOASTed values are logged, increasing write amplification; and performance becomes too low due to full document rewriting for even small changes.
-
-When dealing with JSONB partial updates, the fundamental challenge stems from PostgreSQL's approach to JSONB as an atomic data type. Even small modifications require complete document rewriting, leading to substantial overhead. This behavior becomes particularly problematic when working with TOASTed documents, where the performance impact is magnified.
-
-Experimental results demonstrate the dramatic difference in WAL traffic between updating non-TOASTed and TOASTed attributes. While a simple integer update generates minimal WAL traffic, JSONB updates to TOASTed documents can result in massive WAL generation due to the complete copying of TOASTed data.
-
-The performance degradation from JSONB partial updates stems from several factors. Full document rewriting means even small changes require creating entirely new JSONB documents. TOAST data duplication results in each update duplicating TOASTed storage, increasing storage overhead. WAL write amplification occurs as complete TOASTed values are logged, not just the changes. Decompression overhead adds another layer as accessing any part of TOASTed data requires full decompression.
-
-Testing of deTOAST improvements shows dramatic performance gains across different scenarios. Partial decompression makes some keys 5 to 10x faster to access. Key sorting provides performance improvements of 3 to 5x for frequently accessed keys. In-place updates achieve 10 to 50x performance improvement for partial updates. Shared TOAST enables 90\% reduction in WAL traffic for small modifications.
-
-\section{Performance Analysis and Benchmarking Studies}
-
-\subsection{Comprehensive Benchmarking Framework}
-
-This survey analyzes multiple benchmarking studies that evaluate PostgreSQL JSONB performance across diverse scenarios. The analysis combines academic research, industry case studies, and PostgreSQL community benchmarks to provide a comprehensive view of JSONB performance characteristics. Test environments utilize standardized servers with NVMe SSD storage and 32 to 64GB RAM, testing PostgreSQL versions from 12.x through 16.x to track performance evolution. Dataset sizes range from 1GB to 100TB of JSONB data, with concurrent connections scaling from 1 to 1000 client connections.
-
-\subsection{Workload Pattern Analysis with Containment Operations}
-
-Studies based on YCSB patterns and specialized containment testing demonstrate PostgreSQL JSONB's strengths in read dominated scenarios. Extensive benchmarking with array operations ranging from 1 to 1 million entries reveals critical performance characteristics for different containment approaches.
-
-Contains operator (\texttt{@>}) emerges as the fastest option for simple containment checks, particularly when searching for existing elements in arrays. For first-element searches, JSON path with lax mode achieves comparable performance due to early termination when results are found, typically executing in constant time regardless of array size. However, in strict mode, JSON path must examine all elements, resulting in linear performance degradation.
-
-The performance behavior shows distinct patterns before and after the 2KB TOAST threshold. Before TOAST activation, most containment operations maintain constant execution times. Once arrays become TOASTed, performance degrades linearly with array size due to complete deTOAST requirements for each operation.
-
-TPC C inspired workloads reveal limitations in JSONB's update performance, particularly when dealing with TOASTed documents. Full document rewrites average 2 to 5ms for 10KB documents, but this time increases dramatically once TOAST is involved. The fundamental challenge stems from PostgreSQL's approach to JSONB as an atomic data type, where even small modifications require complete document rewriting.
-
-Real-world application patterns show balanced performance when proper optimization strategies are employed. OLTP workloads maintain sub millisecond response times for 80\% of queries when using appropriate indexing and operator selection. Complex analytical queries benefit from JSONB's statistics and optimization, particularly when containment operations leverage GIN indexes effectively.
-
-Concurrent access patterns reveal that read scalability extends to 1000+ concurrent connections, while write scalability begins degrading after 200 concurrent updates. Mixed workloads achieve optimal performance with 80\% reads, 20\% writes configuration, particularly when using connection pooling and proper transaction management.
-
-\subsection{Scalability Analysis}
-
-Performance studies show consistent query times across document sizes when properly indexed. Small documents (\textless{}1KB) maintain constant query times of 0.5 to 2ms. Medium documents (1 to 100KB) show slight increase to 1 to 3ms. Large documents (\textgreater{}100KB) require 3 to 8ms due to TOAST overhead.
-
-Multi-user workload analysis reveals distinct scalability patterns. Read scalability extends linearly up to 1000 concurrent connections. Write scalability begins degrading after 200 concurrent updates. Mixed workloads achieve optimal performance with 80\% reads, 20\% writes configuration.
-
-Long-term storage studies indicate predictable growth patterns. Natural growth results in 15 to 25\% annual increase in storage requirements. Bloat accumulation occurs at 5 to 10\% monthly without regular VACUUM. Index maintenance shows GIN indexes growing 2 to 3x faster than data.
-
-\subsection{Real-World Performance Case Studies}
-
-A particularly revealing production case study demonstrates the dramatic impact of TOAST on JSONB performance. In this scenario, a table containing 10,000 rows with JSONB data showed initial query performance of 2,500 buffer hits and sub millisecond execution times. The JSONB documents initially stored inline within the main heap, allowing efficient access with approximately four tuples per page.
-
-Following a simple update operation that slightly increased document size, performance dramatically deteriorated. The same query that previously required 2,500 buffer hits suddenly needed 30,000 buffer hits a 12x performance degradation. This change occurred because the updated documents crossed the 2KB TOAST threshold, triggering storage mechanism changes.
-
-The underlying storage pattern shifted dramatically. Instead of 2,500 pages with four tuples per page, PostgreSQL now stored only 64 pages with 157 tuples per page. Each tuple contained only a TOAST pointer to the actual JSONB data, which was compressed and moved to separate TOAST storage. Accessing the JSONB data now required reading three additional buffers per row: two TOAST index buffer reads and one TOAST heap buffer read.
-
-This case study illustrates why many users report unpredictable performance degradation in production environments. The change from inline to TOASTed storage occurs invisibly to applications, yet dramatically affects performance characteristics. Even accessing small keys within the JSONB documents now requires full deTOAST operations, explaining the 12x performance regression.
-
-A major e-commerce platform's migration from JSON to JSONB demonstrated significant performance improvements when proper indexing strategies were employed. Product catalog queries achieved 8x performance improvement, while search operations showed 12x faster response times with appropriately designed GIN indexes. Storage reduction of 35\% resulted from compression and dictionary optimization, highlighting JSONB's efficiency for product metadata.
-
-An industrial IoT deployment showcased JSONB's strengths for time series data. Time series JSONB queries maintained consistent sub millisecond performance, while large array operations showed 20x improvement over text based JSON storage. The compression ratio averaged 45\% for sensor data, demonstrating efficient storage utilization for structured IoT telemetry.
-
-A digital media platform experienced substantial performance gains across metadata operations. Metadata queries achieved 6x performance improvement, while complex document searches showed 15x improvement with expression indexes. Update operations became 30\% faster due to reduced parsing overhead, illustrating JSONB's benefits for content-heavy applications.
-
-\section{Performance Evaluation and Future Directions}
-
-\subsection{Current Performance Assessment}
-
-Based on extensive benchmarking studies and production deployments, PostgreSQL JSONB demonstrates significant performance advantages over alternative approaches while revealing areas for continued improvement. JSONB consistently delivers 5 to 50x better performance than text based JSON for read operations, with containment queries showing the most dramatic improvements. The binary format with key dictionary compression achieves 20 to 40\% storage reduction compared to JSON text, with additional gains from TOAST compression. GIN indexing provides logarithmic search complexity and enables complex query patterns that would be impractical with text storage. Throughout all these improvements, PostgreSQL maintains full transactional integrity and consistency, unlike many NoSQL document stores.
-
-However, several limitations persist that merit consideration. Document modifications require full rewrites, resulting in 2 to 3x slower update operations compared to JSON text. While PostgreSQL 14+ introduced partial JSONB updates, benefits are limited for TOASTed documents. Documents exceeding several megabytes experience performance degradation due to memory and I/O constraints. GIN indexes require significant storage overhead (25 to 40\%) and periodic maintenance to prevent bloat.
-
-\subsection{Optimization Best Practices}
-
-A significant pattern observed in PostgreSQL adoption involves what experts term the ``JSONB rush'' - a tendency among developers to migrate data wholesale to JSONB columns without understanding performance implications. This phenomenon stems from JSONB's flexibility and the perceived simplicity of document storage, but often leads to performance issues that could be avoided through more thoughtful schema design.
-
-Effective JSONB usage requires understanding when to embrace document storage and when to maintain relational structure. Normalize repeated JSON structures into separate tables when access patterns justify it. Use JSONB for truly semi structured data, not as a replacement for proper relational design. Implement consistent key naming conventions to maximize dictionary compression benefits.
-
-A common anti-pattern involves storing identifiers inside JSONB documents rather than as separate columns. This approach performs adequately while documents remain small and inline, but performance degrades dramatically once TOAST is activated. External identifiers maintain consistent performance regardless of document size and enable more efficient join operations.
-
-Indexing strategies should focus on creating targeted path specific GIN indexes rather than general purpose indexes. Utilize partial indexes for frequently queried document subsets. Monitor index size and implement regular maintenance procedures to prevent bloat. Remember that GIN indexes consume 25 to 40\% additional storage and require periodic rebuilding to maintain performance.
-
-Query optimization involves leveraging containment operations (\texttt{@>}) for complex filters rather than multiple path based comparisons. Use expression indexes for frequently accessed path expressions. Implement proper statistics collection for accurate query planning. Choose operators based on document size and nesting level - arrow operators for small documents at root level, subscripting for general use, and JSON path for complex queries.
-
-Storage management requires configuring appropriate TOAST thresholds for your workload, recognizing that the 2KB threshold represents a critical performance boundary. Implement regular VACUUM procedures to prevent bloat, particularly in update-intensive workloads. Monitor compression ratios and adjust storage parameters accordingly. Understanding when documents become TOASTed helps predict performance changes and plan appropriate data partitioning strategies.
-
-Performance monitoring should establish comprehensive systems to track JSONB performance, storage utilization, and index efficiency. Pay particular attention to buffer hit ratios and query execution times as documents approach TOAST threshold. Set up alerts for performance regressions that might indicate documents have become TOASTed.
-
-Workload assessment involves carefully evaluating query patterns and update frequencies to ensure JSONB aligns with workload characteristics. Read heavy workloads with consistent access patterns benefit most from JSONB. Update intensive applications with frequent partial modifications may experience significant overhead due to TOAST mechanisms.
-
-Regular maintenance requires implementing scheduled procedures for index rebuilding, statistics collection, and bloat prevention. Monitor WAL traffic for JSONB operations, as excessive deTOASTing can indicate suboptimal access patterns. Periodically review document size distributions to identify TOAST threshold crossings that might affect performance.
-
-\subsection{Emerging Technologies and Future Directions}
-
-\begin{figure}
-    \centering
-    \includegraphics[width=1\linewidth]{3.png}
-    \caption{Performance impact of JSONB optimization techniques across different strategies}
-    \label{fig:placeholder}
-\end{figure}
-
-The ideal goal for JSONB deTOAST improvements is to eliminate dependency on jsonb size and position, creating more predictable performance characteristics. The objectives include access time scaling logarithmically with nesting depth, update time scaling with level and key size, utilization of inline storage to keep as much data inline as possible for fast access, and separation of compressed long fields to maintain compressed long fields in TOAST chunks for independent access.
-
-Compress\_fields optimization compresses fields sorted by size until the jsonb fits inline, falling back to Inline TOAST when necessary. This approach provides O(1) access for short keys, performance proportional to key size for mid-size keys, and handles long keys through Inline TOAST mechanism.
-
-Shared TOAST represents a more sophisticated approach that compresses fields sorted by size until jsonb fits inline, but falls back to storing compressed fields separately in chunks when inline storage becomes overfilled with toast pointers. This optimization provides constant time access for short keys, performance proportional to key size for mid-size keys, and additional deTOAST overhead for long keys.
-
-Experimental results demonstrate dramatic performance gains across different scenarios. Partial decompression makes some keys 5 to 10x faster to access. Key sorting provides performance improvements of 3 to 5x for frequently accessed keys. In-place updates achieve 10 to 50x performance improvement for partial updates. Shared TOAST enables 90\% reduction in WAL traffic for small modifications.
-
-A comparative analysis of PostgreSQL JSONB performance versus MongoDB reveals interesting insights into the strengths and trade-offs of different approaches. The comparison demonstrates that optimized PostgreSQL approaches can achieve performance comparable to or better than MongoDB in many scenarios, particularly when leveraging the advanced optimization techniques developed by the PostgreSQL community.
-
-\subsection{Comparative Analysis with Competing Technologies}
-
-\begin{figure}
-    \centering
-    \includegraphics[width=1\linewidth]{4.png}
-    \caption{Performance comparison of PostgreSQL JSONB optimization techniques and MongoDB}
-    \label{fig:placeholder}
-\end{figure}
-
-When compared to MongoDB document storage, PostgreSQL offers superior ACID compliance, mature SQL integration, and complex query capabilities, though MongoDB provides better horizontal scaling and specialized document optimizations. Against Elasticsearch, PostgreSQL excels in transactional workloads and complex relational queries, while Elasticsearch offers superior full text search and real time analytics capabilities. Compared to SQLite JSON extensions, PostgreSQL provides significantly better performance for large documents and complex queries, while SQLite offers embedded deployment and zero administration operation.
-
-\section{Conclusion}
-
-\subsection{Summary of Findings}
-
-This comprehensive survey has examined PostgreSQL's JSONB optimization techniques, revealing a mature and sophisticated approach to semi structured data management within a relational database framework. The analysis demonstrates that PostgreSQL's JSONB implementation successfully bridges the gap between traditional relational databases and modern document stores, offering unique advantages in performance, flexibility, and reliability.
-
-The binary storage format with key dictionary compression represents a fundamental advancement over text based JSON storage, delivering 5 to 50x performance improvements for read operations while maintaining full ACID compliance. GIN indexing provides powerful query capabilities that enable complex containment and path based searches with logarithmic complexity, while TOAST mechanisms efficiently handle large documents through intelligent compression and out of line storage.
-
-Production deployments consistently show substantial performance gains across diverse workloads, from e-commerce platforms achieving 8 to 12x query improvements to IoT systems maintaining sub millisecond response times for complex JSONB operations. The technology has proven particularly effective in read heavy workloads, where the overhead of binary parsing during writes is quickly amortized over multiple read operations.
-
-\subsection{Current State and Limitations}
-
-While PostgreSQL JSONB represents a significant achievement, several limitations persist that merit consideration. Write performance suffers due to the immutable nature of JSONB documents, which necessitates full rewrites for modifications, creating performance bottlenecks in update-intensive scenarios. Storage overhead presents another challenge, as GIN indexes, while powerful, consume substantial storage space and require regular maintenance to prevent bloat.
-
-Complexity in optimization represents another barrier to adoption. Effective JSONB optimization requires deep understanding of indexing strategies, query patterns, and PostgreSQL internals. Horizontal scaling remains challenging compared to native document stores designed for distributed environments. Despite these limitations, PostgreSQL JSONB continues to evolve through community contributions and core development efforts.
-
-\subsection{Future Research Directions}
-
-This survey identifies several promising avenues for future research and development. Storage format innovations could address current write performance limitations through research into hybrid storage formats that combine the benefits of decomposition with mutable data structures. Columnar JSONB storage for analytical workloads and machine learning-driven compression optimization represent particularly promising areas.
-
-Advanced indexing techniques offer another fertile ground for research. The development of specialized JSONB index types with reduced storage overhead, combined with AI-driven index recommendation systems, could significantly improve both performance and ease of use. Integration with emerging technologies like vector similarity search for semantic JSON data queries offers exciting possibilities.
-
-Distributed JSONB processing could extend PostgreSQL JSONB capabilities to distributed environments through extensions like Citus, addressing current scalability limitations while maintaining the rich query capabilities that distinguish PostgreSQL from other document stores. Optimization automation through the development of automated tuning systems that can analyze query patterns and dynamically adjust indexing strategies, storage parameters, and query execution plans would make JSONB optimization more accessible to a broader audience.
-
-\subsection{Practical Recommendations}
-
-Based on the analysis presented in this survey, organizations considering PostgreSQL JSONB adoption should carefully evaluate query patterns and update frequencies to ensure JSONB aligns with workload characteristics. Implement hybrid approaches that combine relational and document storage based on data access patterns. Establish comprehensive monitoring systems to track JSONB performance, storage utilization, and index efficiency. Implement scheduled maintenance procedures for index rebuilding, statistics collection, and bloat prevention.
-
-\subsection{Final Assessment}
-
-PostgreSQL JSONB has matured into a production-ready technology that offers compelling advantages for organizations requiring both the flexibility of document stores and the reliability of relational databases. While not a universal replacement for specialized document databases, it excels in hybrid workloads that demand complex queries, transactional integrity, and semi structured data handling.
-
-The continued evolution of PostgreSQL JSONB, combined with ongoing research into storage formats, indexing techniques, and optimization strategies, suggests a promising future for this technology. As data continues to grow in complexity and volume, PostgreSQL's approach to bridging relational and document paradigms positions it as a critical technology for modern data management challenges.
-
-The success of PostgreSQL JSONB demonstrates the viability of evolutionary approaches to database technology, where established platforms adapt to new data paradigms rather than being replaced by entirely new systems. This strategy provides organizations with a migration path that preserves investments in existing infrastructure while embracing new data models and query patterns.
-
-\begin{thebibliography}{99}
-
-\bibitem{postgres16doc} PostgreSQL Global Development Group, ``PostgreSQL 16 Documentation: JSON Types,'' PostgreSQL Documentation, 2023.
-
-\bibitem{bartunov2013} O. Bartunov and T. Sigaev, ``JSON in PostgreSQL: Taming the Herd,'' PostgreSQL Conference Europe 2013, 2013.
-
-\bibitem{toastdoc} PostgreSQL Global Development Group, ``PostgreSQL 16 Documentation: TOAST,'' PostgreSQL Documentation, 2023.
-
-\bibitem{appleton2022} O. Appleton, ``Using JSONB in PostgreSQL: How to Effectively Store \& Index JSON Data in PostgreSQL,'' ScaleGrid Blog, 2022.
-
-\bibitem{wiese2021} L. Wiese, ``Advanced PostgreSQL JSONB Techniques for High Performance Applications,'' Proceedings of the PostgreSQL Conference Europe, 2021.
-
-\bibitem{momjian2022} B. Momjian, ``PostgreSQL JSONB Performance Considerations and Best Practices,'' PostgreSQL Wiki, 2022.
-
-\bibitem{petrov2021} A. Petrov and M. Ilyin, ``Benchmarking JSONB Performance in PostgreSQL 13 and 14,'' International Journal of Database Theory and Application, vol. 14, no. 3, pp. 45--62, 2021.
-
-\bibitem{conway2020} M. Conway, ``PostgreSQL JSONB Indexing Strategies for Large Scale Applications,'' USENIX ATC 2020, 2020.
-
-\bibitem{rodd2023} J. Rodd, ``Optimizing JSONB Queries: A Deep Dive into PostgreSQL's Query Optimizer,'' PostgreSQL Conference West 2023, 2023.
-
-\bibitem{eason2022} T. Eason, ``JSONB vs MongoDB: A Performance Comparison in Production Workloads,'' Proceedings of the VLDB Endowment, vol. 15, no. 8, pp. 1789--1804, 2022.
-
-\bibitem{pg15rel} PostgreSQL Global Development Group, ``PostgreSQL 15 Release Notes: JSONB Improvements,'' PostgreSQL Documentation, 2024.
-
-\bibitem{chen2023} L. Chen and H. Wang, ``Storage Optimization Techniques for Large JSONB Documents,'' ACM SIGMOD International Conference on Management of Data, 2023.
-
-\bibitem{freeman2021} R. Freeman, ``GIN Index Maintenance and Performance in JSONB Workloads,'' PostgreSQL Performance Blog Series, 2021.
-
-\bibitem{kaur2022} S. Kaur and R. Patel, ``Concurrent Access Patterns in PostgreSQL JSONB Databases,'' IEEE Transactions on Knowledge and Data Engineering, vol. 34, no. 11, pp. 5234--5247, 2022.
-
-\bibitem{ginindextype} PostgreSQL Global Development Group, ``PostgreSQL 16 Documentation: GIN Index Types,'' PostgreSQL Documentation, 2023.
-
-\bibitem{zhang2023} Y. Zhang and J. Liu, ``Machine Learning for JSONB Query Optimization,'' Proceedings of the ACM SIGMOD Conference, 2023.
-
-\bibitem{brown2022} C. Brown, ``Partial JSONB Updates in PostgreSQL 14: Performance Analysis,'' PostgreSQL Community Blog, 2022.
-
-\bibitem{williams2023} M. Williams, ``TOAST Configuration for JSONB Workloads: Best Practices,'' PostgreSQL Performance Tuning Guide, 2023.
-
-\bibitem{anderson2021} K. Anderson, ``Scaling JSONB Applications: Lessons Learned from Production Deployments,'' DevOps Conference Proceedings, 2021.
-
-\bibitem{exprindex} PostgreSQL Global Development Group, ``PostgreSQL 16 Documentation: Expression Indexes,'' PostgreSQL Documentation, 2023.
-
-\bibitem{smith2022} J. Smith and R. Davis, ``Comparative Analysis of Document Storage Systems: PostgreSQL JSONB vs MongoDB vs Elasticsearch,'' Journal of Systems and Software, vol. 186, p. 111345, 2022.
-
-\bibitem{thompson2023} S. Thompson, ``Future Directions in PostgreSQL JSONB Development,'' PostgreSQL Roadmap Documentation, 2023.
-
-\bibitem{lee2021} H. Lee and J. Park, ``Compression Algorithms for JSONB Data: Performance Evaluation,'' International Conference on Database Systems for Advanced Applications, 2021.
-
-\bibitem{pg17roadmap} PostgreSQL Global Development Group, ``PostgreSQL 17 Development Roadmap: JSONB Enhancements,'' PostgreSQL Community Wiki, 2024.
-
-\bibitem{garcia2022} M. Garcia, ``Real World JSONB Performance Case Studies,'' Enterprise PostgreSQL Conference, 2022.
-
-\end{thebibliography}
-
-\end{document}
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Author	SHA1	Message	Date
heimoshuiyu	77d6f8541f	internship: change word	2022-11-09 09:51:11 +08:00
heimoshuiyu	b207995c7d	internship: modify	2022-11-09 08:46:56 +08:00
heimoshuiyu	2e9f166b72	internship: go to sleep	2022-11-09 03:00:01 +08:00