diff --git a/404.html b/404.html
index 51984c7..89beee2 100644
--- a/404.html
+++ b/404.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -8,7 +8,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -33,15 +33,17 @@
 
         <!-- MathJax -->
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
@@ -63,19 +65,16 @@
             var theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var body = document.querySelector('body');
             var sidebar = null;
             var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
@@ -85,45 +84,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
             </div>
         </nav>
 
-        <!-- Track and set sidebar scroll position -->
-        <script>
-            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
-            sidebarScrollbox.addEventListener('click', function(e) {
-                if (e.target.tagName === 'A') {
-                    sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
-                }
-            }, { passive: true });
-            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
-            sessionStorage.removeItem('sidebar-scroll');
-            if (sidebarScrollTop) {
-                // preserve sidebar scroll position when navigating via links within sidebar
-                sidebarScrollbox.scrollTop = sidebarScrollTop;
-            } else {
-                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
-                var activeSection = document.querySelector('#sidebar .active');
-                if (activeSection) {
-                    activeSection.scrollIntoView({ block: 'center' });
-                }
-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/book.js b/book.js
index aa12e7e..178f1e9 100644
--- a/book.js
+++ b/book.js
@@ -225,7 +225,7 @@ function playground_text(playground, hidden = true) {
                 }
 
                 var clipButton = document.createElement('button');
-                clipButton.className = 'fa fa-copy clip-button';
+                clipButton.className = 'clip-button';
                 clipButton.title = 'Copy to clipboard';
                 clipButton.setAttribute('aria-label', clipButton.title);
                 clipButton.innerHTML = '<i class=\"tooltiptext\"></i>';
@@ -258,7 +258,7 @@ function playground_text(playground, hidden = true) {
 
         if (window.playground_copyable) {
             var copyCodeClipboardButton = document.createElement('button');
-            copyCodeClipboardButton.className = 'fa fa-copy clip-button';
+            copyCodeClipboardButton.className = 'clip-button';
             copyCodeClipboardButton.innerHTML = '<i class="tooltiptext"></i>';
             copyCodeClipboardButton.title = 'Copy to clipboard';
             copyCodeClipboardButton.setAttribute('aria-label', copyCodeClipboardButton.title);
@@ -289,6 +289,10 @@ function playground_text(playground, hidden = true) {
     var themeToggleButton = document.getElementById('theme-toggle');
     var themePopup = document.getElementById('theme-list');
     var themeColorMetaTag = document.querySelector('meta[name="theme-color"]');
+    var themeIds = [];
+    themePopup.querySelectorAll('button.theme').forEach(function (el) {
+        themeIds.push(el.id);
+    });
     var stylesheets = {
         ayuHighlight: document.querySelector("[href$='ayu-highlight.css']"),
         tomorrowNight: document.querySelector("[href$='tomorrow-night.css']"),
@@ -317,7 +321,7 @@ function playground_text(playground, hidden = true) {
     function get_theme() {
         var theme;
         try { theme = localStorage.getItem('mdbook-theme'); } catch (e) { }
-        if (theme === null || theme === undefined) {
+        if (theme === null || theme === undefined || !themeIds.includes(theme)) {
             return default_theme;
         } else {
             return theme;
@@ -459,17 +463,6 @@ function playground_text(playground, hidden = true) {
         try { localStorage.setItem('mdbook-sidebar', 'visible'); } catch (e) { }
     }
 
-
-    var sidebarAnchorToggles = document.querySelectorAll('#sidebar a.toggle');
-
-    function toggleSection(ev) {
-        ev.currentTarget.parentElement.classList.toggle('expanded');
-    }
-
-    Array.from(sidebarAnchorToggles).forEach(function (el) {
-        el.addEventListener('click', toggleSection);
-    });
-
     function hideSidebar() {
         body.classList.remove('sidebar-visible')
         body.classList.add('sidebar-hidden');
@@ -597,12 +590,12 @@ function playground_text(playground, hidden = true) {
 
     function hideTooltip(elem) {
         elem.firstChild.innerText = "";
-        elem.className = 'fa fa-copy clip-button';
+        elem.className = 'clip-button';
     }
 
     function showTooltip(elem, msg) {
         elem.firstChild.innerText = msg;
-        elem.className = 'fa fa-copy tooltipped';
+        elem.className = 'clip-button tooltipped';
     }
 
     var clipboardSnippets = new ClipboardJS('.clip-button', {
diff --git a/css/chrome.css b/css/chrome.css
index 83b7969..4cd7308 100644
--- a/css/chrome.css
+++ b/css/chrome.css
@@ -40,9 +40,9 @@ a > .hljs {
     border-block-end-style: solid;
 }
 #menu-bar.sticky,
-.js #menu-bar-hover-placeholder:hover + #menu-bar,
-.js #menu-bar:hover,
-.js.sidebar-visible #menu-bar {
+#menu-bar-hover-placeholder:hover + #menu-bar,
+#menu-bar:hover,
+html.sidebar-visible #menu-bar {
     position: -webkit-sticky;
     position: sticky;
     top: 0 !important;
@@ -91,7 +91,7 @@ a > .hljs {
     display: flex;
     margin: 0 5px;
 }
-.no-js .left-buttons button {
+html:not(.js) .left-buttons button {
     display: none;
 }
 
@@ -107,7 +107,7 @@ a > .hljs {
     overflow: hidden;
     text-overflow: ellipsis;
 }
-.js .menu-title {
+.menu-title {
     cursor: pointer;
 }
 
@@ -250,8 +250,8 @@ pre > .buttons i {
 pre > .buttons button {
     cursor: inherit;
     margin: 0px 5px;
-    padding: 3px 5px;
-    font-size: 14px;
+    padding: 4px 4px 3px 5px;
+    font-size: 23px;
 
     border-style: solid;
     border-width: 1px;
@@ -262,6 +262,27 @@ pre > .buttons button {
     transition-property: color,border-color,background-color;
     color: var(--icons);
 }
+
+pre > .buttons button.clip-button {
+    padding: 2px 4px 0px 6px;
+}
+pre > .buttons button.clip-button::before {
+    /* clipboard image from octicons (https://github.com/primer/octicons/tree/v2.0.0) MIT license
+     */
+    content: url('data:image/svg+xml,<svg width="21" height="20" viewBox="0 0 24 25" \
+xmlns="http://www.w3.org/2000/svg" aria-label="Copy to clipboard">\
+<path d="M18 20h2v3c0 1-1 2-2 2H2c-.998 0-2-1-2-2V5c0-.911.755-1.667 1.667-1.667h5A3.323 3.323 0 \
+0110 0a3.323 3.323 0 013.333 3.333h5C19.245 3.333 20 4.09 20 5v8.333h-2V9H2v14h16v-3zM3 \
+7h14c0-.911-.793-1.667-1.75-1.667H13.5c-.957 0-1.75-.755-1.75-1.666C11.75 2.755 10.957 2 10 \
+2s-1.75.755-1.75 1.667c0 .911-.793 1.666-1.75 1.666H4.75C3.793 5.333 3 6.09 3 7z"/>\
+<path d="M4 19h6v2H4zM12 11H4v2h8zM4 17h4v-2H4zM15 15v-3l-4.5 4.5L15 21v-3l8.027-.032L23 15z"/>\
+</svg>');
+    filter: var(--copy-button-filter);
+}
+pre > .buttons button.clip-button:hover::before {
+    filter: var(--copy-button-filter-hover);
+}
+
 @media (pointer: coarse) {
     pre > .buttons button {
         /* On mobile, make it easier to tap buttons. */
@@ -399,6 +420,22 @@ ul#searchresults span.teaser em {
     background-color: var(--sidebar-bg);
     color: var(--sidebar-fg);
 }
+.sidebar-iframe-inner {
+    background-color: var(--sidebar-bg);
+    color: var(--sidebar-fg);
+    padding: 10px 10px;
+    margin: 0;
+    font-size: 1.4rem;
+}
+.sidebar-iframe-outer {
+    border: none;
+    height: 100%;
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+}
 [dir=rtl] .sidebar { left: unset; right: 0; }
 .sidebar-resizing {
     -moz-user-select: none;
@@ -406,8 +443,7 @@ ul#searchresults span.teaser em {
     -ms-user-select: none;
     user-select: none;
 }
-.no-js .sidebar,
-.js:not(.sidebar-resizing) .sidebar {
+html:not(.sidebar-resizing) .sidebar {
     transition: transform 0.3s; /* Animation: slide away */
 }
 .sidebar code {
diff --git a/css/general.css b/css/general.css
index 7670b08..0862b51 100644
--- a/css/general.css
+++ b/css/general.css
@@ -190,6 +190,16 @@ kbd {
     vertical-align: middle;
 }
 
+sup {
+    /* Set the line-height for superscript and footnote references so that there
+       isn't an awkward space appearing above lines that contain the footnote.
+
+       See https://github.com/rust-lang/mdBook/pull/2443#discussion_r1813773583
+       for an explanation.
+    */
+    line-height: 0;
+}
+
 :not(.footnote-definition) + .footnote-definition,
 .footnote-definition + :not(.footnote-definition) {
     margin-block-start: 2em;
diff --git a/css/variables.css b/css/variables.css
index 0da55e8..12d1db7 100644
--- a/css/variables.css
+++ b/css/variables.css
@@ -56,6 +56,11 @@
     --search-mark-bg: #e3b171;
 
     --color-scheme: dark;
+
+    /* Same as `--icons` */
+    --copy-button-filter: invert(45%) sepia(6%) saturate(621%) hue-rotate(198deg) brightness(99%) contrast(85%);
+    /* Same as `--sidebar-active` */
+    --copy-button-filter-hover: invert(68%) sepia(55%) saturate(531%) hue-rotate(341deg) brightness(104%) contrast(101%);
 }
 
 .coal {
@@ -100,9 +105,14 @@
     --search-mark-bg: #355c7d;
 
     --color-scheme: dark;
+
+    /* Same as `--icons` */
+    --copy-button-filter: invert(26%) sepia(8%) saturate(575%) hue-rotate(169deg) brightness(87%) contrast(82%);
+    /* Same as `--sidebar-active` */
+    --copy-button-filter-hover: invert(36%) sepia(70%) saturate(503%) hue-rotate(167deg) brightness(98%) contrast(89%);
 }
 
-.light {
+.light, html:not(.js) {
     --bg: hsl(0, 0%, 100%);
     --fg: hsl(0, 0%, 0%);
 
@@ -144,6 +154,11 @@
     --search-mark-bg: #a2cff5;
 
     --color-scheme: light;
+
+    /* Same as `--icons` */
+    --copy-button-filter: invert(45.49%);
+    /* Same as `--sidebar-active` */
+    --copy-button-filter-hover: invert(14%) sepia(93%) saturate(4250%) hue-rotate(243deg) brightness(99%) contrast(130%);
 }
 
 .navy {
@@ -188,6 +203,11 @@
     --search-mark-bg: #a2cff5;
 
     --color-scheme: dark;
+
+    /* Same as `--icons` */
+    --copy-button-filter: invert(51%) sepia(10%) saturate(393%) hue-rotate(198deg) brightness(86%) contrast(87%);
+    /* Same as `--sidebar-active` */
+    --copy-button-filter-hover: invert(46%) sepia(20%) saturate(1537%) hue-rotate(156deg) brightness(85%) contrast(90%);
 }
 
 .rust {
@@ -231,11 +251,14 @@
     --searchresults-li-bg: #dec2a2;
     --search-mark-bg: #e69f67;
 
-    --color-scheme: light;
+    /* Same as `--icons` */
+    --copy-button-filter: invert(51%) sepia(10%) saturate(393%) hue-rotate(198deg) brightness(86%) contrast(87%);
+    /* Same as `--sidebar-active` */
+    --copy-button-filter-hover: invert(77%) sepia(16%) saturate(1798%) hue-rotate(328deg) brightness(98%) contrast(83%);
 }
 
 @media (prefers-color-scheme: dark) {
-    .light.no-js {
+    html:not(.js) {
         --bg: hsl(200, 7%, 8%);
         --fg: #98a3ad;
 
@@ -275,5 +298,12 @@
         --searchresults-border-color: #98a3ad;
         --searchresults-li-bg: #2b2b2f;
         --search-mark-bg: #355c7d;
+
+        --color-scheme: dark;
+
+        /* Same as `--icons` */
+        --copy-button-filter: invert(26%) sepia(8%) saturate(575%) hue-rotate(169deg) brightness(87%) contrast(82%);
+        /* Same as `--sidebar-active` */
+        --copy-button-filter-hover: invert(36%) sepia(70%) saturate(503%) hue-rotate(167deg) brightness(98%) contrast(89%);
     }
 }
diff --git a/functions.html b/functions.html
index 332d140..6384753 100644
--- a/functions.html
+++ b/functions.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -7,7 +7,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -32,15 +32,17 @@
 
         <!-- MathJax -->
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
@@ -62,19 +64,16 @@
             var theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var body = document.querySelector('body');
             var sidebar = null;
             var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
@@ -84,45 +83,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html" class="active"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
             </div>
         </nav>
 
-        <!-- Track and set sidebar scroll position -->
-        <script>
-            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
-            sidebarScrollbox.addEventListener('click', function(e) {
-                if (e.target.tagName === 'A') {
-                    sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
-                }
-            }, { passive: true });
-            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
-            sessionStorage.removeItem('sidebar-scroll');
-            if (sidebarScrollTop) {
-                // preserve sidebar scroll position when navigating via links within sidebar
-                sidebarScrollbox.scrollTop = sidebarScrollTop;
-            } else {
-                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
-                var activeSection = document.querySelector('#sidebar .active');
-                if (activeSection) {
-                    activeSection.scrollIntoView({ block: 'center' });
-                }
-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/highlight.css b/highlight.css
index ba57b82..352c79b 100644
--- a/highlight.css
+++ b/highlight.css
@@ -16,6 +16,7 @@
 .hljs-variable,
 .hljs-template-variable,
 .hljs-attribute,
+.hljs-attr,
 .hljs-tag,
 .hljs-name,
 .hljs-regexp,
diff --git a/index.html b/index.html
index 992ef4d..dc35166 100644
--- a/index.html
+++ b/index.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -7,7 +7,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -32,15 +32,17 @@
 
         <!-- MathJax -->
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
@@ -62,19 +64,16 @@
             var theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var body = document.querySelector('body');
             var sidebar = null;
             var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
@@ -84,45 +83,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
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+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
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             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/inputs_outputs.html b/inputs_outputs.html
index b96ff22..2b0ac98 100644
--- a/inputs_outputs.html
+++ b/inputs_outputs.html
@@ -1,5 +1,5 @@
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-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -7,7 +7,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
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         <meta name="viewport" content="width=device-width, initial-scale=1">
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@@ -32,15 +32,17 @@
 
         <!-- MathJax -->
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-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
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@@ -62,19 +64,16 @@
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             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
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-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
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         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
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-            var body = document.querySelector('body');
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@@ -84,45 +83,25 @@
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             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html" class="active"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
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-        <!-- Track and set sidebar scroll position -->
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-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/introduction.html b/introduction.html
index 992ef4d..dc35166 100644
--- a/introduction.html
+++ b/introduction.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -7,7 +7,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -32,15 +32,17 @@
 
         <!-- MathJax -->
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-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
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@@ -62,19 +64,16 @@
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             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
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-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
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-            var body = document.querySelector('body');
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@@ -84,45 +83,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html" class="active"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
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         </nav>
 
-        <!-- Track and set sidebar scroll position -->
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-            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
-            sidebarScrollbox.addEventListener('click', function(e) {
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-                sidebarScrollbox.scrollTop = sidebarScrollTop;
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-                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
-                var activeSection = document.querySelector('#sidebar .active');
-                if (activeSection) {
-                    activeSection.scrollIntoView({ block: 'center' });
-                }
-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/odes.html b/odes.html
index 126575a..ae02da9 100644
--- a/odes.html
+++ b/odes.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -7,7 +7,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -32,15 +32,17 @@
 
         <!-- MathJax -->
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
@@ -62,19 +64,16 @@
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             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var body = document.querySelector('body');
             var sidebar = null;
             var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
@@ -84,45 +83,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html" class="active"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
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         </nav>
 
-        <!-- Track and set sidebar scroll position -->
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-            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
-            sidebarScrollbox.addEventListener('click', function(e) {
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-                // preserve sidebar scroll position when navigating via links within sidebar
-                sidebarScrollbox.scrollTop = sidebarScrollTop;
-            } else {
-                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
-                var activeSection = document.querySelector('#sidebar .active');
-                if (activeSection) {
-                    activeSection.scrollIntoView({ block: 'center' });
-                }
-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/operations.html b/operations.html
index 47f1128..9de6b32 100644
--- a/operations.html
+++ b/operations.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -7,7 +7,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -32,15 +32,17 @@
 
         <!-- MathJax -->
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
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@@ -62,19 +64,16 @@
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             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var body = document.querySelector('body');
             var sidebar = null;
             var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
@@ -84,45 +83,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html" class="active"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
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         </nav>
 
-        <!-- Track and set sidebar scroll position -->
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-            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
-            sidebarScrollbox.addEventListener('click', function(e) {
-                if (e.target.tagName === 'A') {
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-                }
-            }, { passive: true });
-            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
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-                // preserve sidebar scroll position when navigating via links within sidebar
-                sidebarScrollbox.scrollTop = sidebarScrollTop;
-            } else {
-                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
-                var activeSection = document.querySelector('#sidebar .active');
-                if (activeSection) {
-                    activeSection.scrollIntoView({ block: 'center' });
-                }
-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/print.html b/print.html
index 9595a80..478d018 100644
--- a/print.html
+++ b/print.html
@@ -1,5 +1,5 @@
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-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -8,7 +8,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -33,15 +33,17 @@
 
         <!-- MathJax -->
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
@@ -63,19 +65,16 @@
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             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var body = document.querySelector('body');
             var sidebar = null;
             var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
@@ -85,45 +84,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
             </div>
         </nav>
 
-        <!-- Track and set sidebar scroll position -->
-        <script>
-            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
-            sidebarScrollbox.addEventListener('click', function(e) {
-                if (e.target.tagName === 'A') {
-                    sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
-                }
-            }, { passive: true });
-            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
-            sessionStorage.removeItem('sidebar-scroll');
-            if (sidebarScrollTop) {
-                // preserve sidebar scroll position when navigating via links within sidebar
-                sidebarScrollbox.scrollTop = sidebarScrollTop;
-            } else {
-                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
-                var activeSection = document.querySelector('#sidebar .active');
-                if (activeSection) {
-                    activeSection.scrollIntoView({ block: 'center' });
-                }
-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/tensors.html b/tensors.html
index e4f262c..f3413c4 100644
--- a/tensors.html
+++ b/tensors.html
@@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html lang="en" class="light" dir="ltr">
+<html lang="en" class="light sidebar-visible" dir="ltr">
     <head>
         <!-- Book generated using mdBook -->
         <meta charset="UTF-8">
@@ -7,7 +7,7 @@
 
 
         <!-- Custom HTML head -->
-        
+
         <meta name="description" content="">
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff">
@@ -32,15 +32,17 @@
 
         <!-- MathJax -->
         <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
-    </head>
-    <body class="sidebar-visible no-js">
-    <div id="body-container">
+
         <!-- Provide site root to javascript -->
         <script>
             var path_to_root = "";
             var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
         </script>
-
+        <!-- Start loading toc.js asap -->
+        <script src="toc.js"></script>
+    </head>
+    <body>
+    <div id="body-container">
         <!-- Work around some values being stored in localStorage wrapped in quotes -->
         <script>
             try {
@@ -62,19 +64,16 @@
             var theme;
             try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
             if (theme === null || theme === undefined) { theme = default_theme; }
-            var html = document.querySelector('html');
+            const html = document.documentElement;
             html.classList.remove('light')
             html.classList.add(theme);
-            var body = document.querySelector('body');
-            body.classList.remove('no-js')
-            body.classList.add('js');
+            html.classList.add("js");
         </script>
 
         <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
 
         <!-- Hide / unhide sidebar before it is displayed -->
         <script>
-            var body = document.querySelector('body');
             var sidebar = null;
             var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
             if (document.body.clientWidth >= 1080) {
@@ -84,45 +83,25 @@
                 sidebar = 'hidden';
             }
             sidebar_toggle.checked = sidebar === 'visible';
-            body.classList.remove('sidebar-visible');
-            body.classList.add("sidebar-" + sidebar);
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
-                <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html" class="active"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
-            </div>
+            <!-- populated by js -->
+            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
+            <noscript>
+                <iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
+            </noscript>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                 <div class="sidebar-resize-indicator"></div>
             </div>
         </nav>
 
-        <!-- Track and set sidebar scroll position -->
-        <script>
-            var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
-            sidebarScrollbox.addEventListener('click', function(e) {
-                if (e.target.tagName === 'A') {
-                    sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
-                }
-            }, { passive: true });
-            var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
-            sessionStorage.removeItem('sidebar-scroll');
-            if (sidebarScrollTop) {
-                // preserve sidebar scroll position when navigating via links within sidebar
-                sidebarScrollbox.scrollTop = sidebarScrollTop;
-            } else {
-                // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
-                var activeSection = document.querySelector('#sidebar .active');
-                if (activeSection) {
-                    activeSection.scrollIntoView({ block: 'center' });
-                }
-            }
-        </script>
-
         <div id="page-wrapper" class="page-wrapper">
 
             <div class="page">
-                                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar-hover-placeholder"></div>
                 <div id="menu-bar" class="menu-bar sticky">
                     <div class="left-buttons">
                         <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
diff --git a/toc.html b/toc.html
new file mode 100644
index 0000000..c066ff6
--- /dev/null
+++ b/toc.html
@@ -0,0 +1,32 @@
+<!DOCTYPE HTML>
+<html lang="en" class="light" dir="ltr">
+    <head>
+        <!-- sidebar iframe generated using mdBook
+
+        This is a frame, and not included directly in the page, to control the total size of the
+        book. The TOC contains an entry for each page, so if each page includes a copy of the TOC,
+        the total size of the page becomes O(n**2).
+
+        The frame is only used as a fallback when JS is turned off. When it's on, the sidebar is
+        instead added to the main page by `toc.js` instead. The JavaScript mode is better
+        because, when running in a `file:///` URL, the iframed page would not be Same-Origin as
+        the rest of the page, so the sidebar and the main page theme would fall out of sync.
+        -->
+        <meta charset="UTF-8">
+        <meta name="robots" content="noindex">
+        <!-- Custom HTML head -->
+        <meta name="viewport" content="width=device-width, initial-scale=1">
+        <meta name="theme-color" content="#ffffff">
+        <link rel="stylesheet" href="css/variables.css">
+        <link rel="stylesheet" href="css/general.css">
+        <link rel="stylesheet" href="css/chrome.css">
+        <link rel="stylesheet" href="css/print.css" media="print">
+        <!-- Fonts -->
+        <link rel="stylesheet" href="FontAwesome/css/font-awesome.css">
+        <link rel="stylesheet" href="fonts/fonts.css">
+        <!-- Custom theme stylesheets -->
+    </head>
+    <body class="sidebar-iframe-inner">
+        <ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html" target="_parent"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html" target="_parent"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html" target="_parent"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html" target="_parent"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html" target="_parent"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html" target="_parent"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>
+    </body>
+</html>
diff --git a/toc.js b/toc.js
new file mode 100644
index 0000000..dc77b8e
--- /dev/null
+++ b/toc.js
@@ -0,0 +1,70 @@
+// Populate the sidebar
+//
+// This is a script, and not included directly in the page, to control the total size of the book.
+// The TOC contains an entry for each page, so if each page includes a copy of the TOC,
+// the total size of the page becomes O(n**2).
+class MDBookSidebarScrollbox extends HTMLElement {
+    constructor() {
+        super();
+    }
+    connectedCallback() {
+        this.innerHTML = '<ol class="chapter"><li class="chapter-item expanded "><a href="introduction.html"><strong aria-hidden="true">1.</strong> DiffSL Language</a></li><li class="chapter-item expanded "><a href="tensors.html"><strong aria-hidden="true">2.</strong> Tensor Variables</a></li><li class="chapter-item expanded "><a href="operations.html"><strong aria-hidden="true">3.</strong> Tensor Operations</a></li><li class="chapter-item expanded "><a href="odes.html"><strong aria-hidden="true">4.</strong> Defining ODEs</a></li><li class="chapter-item expanded "><a href="inputs_outputs.html"><strong aria-hidden="true">5.</strong> Inputs and Outputs</a></li><li class="chapter-item expanded "><a href="functions.html"><strong aria-hidden="true">6.</strong> Predefined functions</a></li></ol>';
+        // Set the current, active page, and reveal it if it's hidden
+        let current_page = document.location.href.toString();
+        if (current_page.endsWith("/")) {
+            current_page += "index.html";
+        }
+        var links = Array.prototype.slice.call(this.querySelectorAll("a"));
+        var l = links.length;
+        for (var i = 0; i < l; ++i) {
+            var link = links[i];
+            var href = link.getAttribute("href");
+            if (href && !href.startsWith("#") && !/^(?:[a-z+]+:)?\/\//.test(href)) {
+                link.href = path_to_root + href;
+            }
+            // The "index" page is supposed to alias the first chapter in the book.
+            if (link.href === current_page || (i === 0 && path_to_root === "" && current_page.endsWith("/index.html"))) {
+                link.classList.add("active");
+                var parent = link.parentElement;
+                if (parent && parent.classList.contains("chapter-item")) {
+                    parent.classList.add("expanded");
+                }
+                while (parent) {
+                    if (parent.tagName === "LI" && parent.previousElementSibling) {
+                        if (parent.previousElementSibling.classList.contains("chapter-item")) {
+                            parent.previousElementSibling.classList.add("expanded");
+                        }
+                    }
+                    parent = parent.parentElement;
+                }
+            }
+        }
+        // Track and set sidebar scroll position
+        this.addEventListener('click', function(e) {
+            if (e.target.tagName === 'A') {
+                sessionStorage.setItem('sidebar-scroll', this.scrollTop);
+            }
+        }, { passive: true });
+        var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
+        sessionStorage.removeItem('sidebar-scroll');
+        if (sidebarScrollTop) {
+            // preserve sidebar scroll position when navigating via links within sidebar
+            this.scrollTop = sidebarScrollTop;
+        } else {
+            // scroll sidebar to current active section when navigating via "next/previous chapter" buttons
+            var activeSection = document.querySelector('#sidebar .active');
+            if (activeSection) {
+                activeSection.scrollIntoView({ block: 'center' });
+            }
+        }
+        // Toggle buttons
+        var sidebarAnchorToggles = document.querySelectorAll('#sidebar a.toggle');
+        function toggleSection(ev) {
+            ev.currentTarget.parentElement.classList.toggle('expanded');
+        }
+        Array.from(sidebarAnchorToggles).forEach(function (el) {
+            el.addEventListener('click', toggleSection);
+        });
+    }
+}
+window.customElements.define("mdbook-sidebar-scrollbox", MDBookSidebarScrollbox);
diff --git a/tomorrow-night.css b/tomorrow-night.css
index 81fe276..11752b8 100644
--- a/tomorrow-night.css
+++ b/tomorrow-night.css
@@ -11,6 +11,7 @@
 /* Tomorrow Red */
 .hljs-variable,
 .hljs-attribute,
+.hljs-attr,
 .hljs-tag,
 .hljs-regexp,
 .ruby .hljs-constant,
@@ -54,6 +55,7 @@
 
 /* Tomorrow Aqua */
 .hljs-title,
+.hljs-section,
 .css .hljs-hexcolor {
   color: #8abeb7;
 }
