diff --git a/reader.html b/reader.html
index 18d6b5b..33e7cc5 100644
--- a/reader.html
+++ b/reader.html
@@ -1,58 +1,61 @@
-<!DOCTYPE html>
-<meta charset="utf-8">
-<meta name="color-scheme" content="light dark">
-<meta name="viewport" content="width=device-width, initial-scale=1">
-<meta http-equiv="Content-Security-Policy" content="default-src 'self' blob:; script-src 'self'; style-src 'self' blob: 'unsafe-inline'; img-src 'self' blob: data:; connect-src 'self' blob: data: *; frame-src blob: data:; object-src blob: data:; form-action 'none';">
+<!doctype html>
+<meta charset="utf-8" />
+<meta name="color-scheme" content="light dark" />
+<meta name="viewport" content="width=device-width, initial-scale=1" />
+<meta
+  http-equiv="Content-Security-Policy"
+  content="default-src 'self' blob:; script-src 'self' 'unsafe-eval'; style-src 'self' blob: 'unsafe-inline'; img-src 'self' blob: data:; connect-src 'self' blob: data: *; frame-src blob: data:; object-src blob: data:; form-action 'none';"
+/>
 <title>E-Book Reader</title>
 <style>
-:root {
-    --active-bg: rgba(0, 0, 0, .05);
-}
-@supports (color-scheme: light dark) {
+  :root {
+    --active-bg: rgba(0, 0, 0, 0.05);
+  }
+  @supports (color-scheme: light dark) {
     @media (prefers-color-scheme: dark) {
-        :root {
-            --active-bg: rgba(255, 255, 255, .1);
-        }
+      :root {
+        --active-bg: rgba(255, 255, 255, 0.1);
+      }
     }
-}
-html {
+  }
+  html {
     height: 100%;
-}
-body {
+  }
+  body {
     margin: 0 auto;
     height: 100%;
     font: menu;
     font-family: system-ui, sans-serif;
-}
-#drop-target {
+  }
+  #drop-target {
     height: 100vh;
     display: flex;
     align-items: center;
     justify-content: center;
     text-align: center;
     visibility: hidden;
-}
-#drop-target h1 {
+  }
+  #drop-target h1 {
     font-weight: 900;
-}
-#file-button {
+  }
+  #file-button {
     font: inherit;
     background: none;
     border: 0;
     padding: 0;
     text-decoration: underline;
     cursor: pointer;
-}
-.icon {
+  }
+  .icon {
     display: block;
     fill: none;
     stroke: currentcolor;
     stroke-width: 2px;
-}
-.empty-state-icon {
+  }
+  .empty-state-icon {
     margin: auto;
-}
-.toolbar {
+  }
+  .toolbar {
     box-sizing: border-box;
     position: absolute;
     z-index: 1;
@@ -64,30 +67,30 @@ body {
     padding: 6px;
     transition: opacity 250ms ease;
     visibility: hidden;
-}
-.toolbar button {
+  }
+  .toolbar button {
     padding: 3px;
     border-radius: 6px;
     background: none;
     border: 0;
     color: GrayText;
-}
-.toolbar button:hover {
-    background: rgba(0, 0, 0, .1);
+  }
+  .toolbar button:hover {
+    background: rgba(0, 0, 0, 0.1);
     color: currentcolor;
-}
-#header-bar {
+  }
+  #header-bar {
     top: 0;
-}
-#nav-bar {
+  }
+  #nav-bar {
     bottom: 0;
-}
-#progress-slider {
+  }
+  #progress-slider {
     flex-grow: 1;
     margin: 0 12px;
     visibility: hidden;
-}
-#side-bar {
+  }
+  #side-bar {
     visibility: hidden;
     box-sizing: border-box;
     position: absolute;
@@ -101,15 +104,19 @@ body {
     flex-direction: column;
     background: Canvas;
     color: CanvasText;
-    box-shadow: 0 0 0 1px rgba(0, 0, 0, .2), 0 0 40px rgba(0, 0, 0, .2);
-    transition: visibility 0s linear 300ms, transform 300ms ease;
-}
-#side-bar.show {
+    box-shadow:
+      0 0 0 1px rgba(0, 0, 0, 0.2),
+      0 0 40px rgba(0, 0, 0, 0.2);
+    transition:
+      visibility 0s linear 300ms,
+      transform 300ms ease;
+  }
+  #side-bar.show {
     visibility: visible;
     transform: translateX(0);
     transition-delay: 0s;
-}
-#dimming-overlay {
+  }
+  #dimming-overlay {
     visibility: hidden;
     position: fixed;
     z-index: 2;
@@ -117,188 +124,216 @@ body {
     left: 0;
     width: 100%;
     height: 100%;
-    background: rgba(0, 0, 0, .2);
+    background: rgba(0, 0, 0, 0.2);
     opacity: 0;
-    transition: visibility 0s linear 300ms, opacity 300ms ease;
-}
-#dimming-overlay.show {
+    transition:
+      visibility 0s linear 300ms,
+      opacity 300ms ease;
+  }
+  #dimming-overlay.show {
     visibility: visible;
     opacity: 1;
     transition-delay: 0s;
-}
-#side-bar-header {
+  }
+  #side-bar-header {
     padding: 1rem;
     display: flex;
-    border-bottom: 1px solid rgba(0, 0, 0, .1);
+    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
     align-items: center;
-}
-#side-bar-cover {
+  }
+  #side-bar-cover {
     height: 10vh;
     min-height: 60px;
     max-height: 180px;
     border-radius: 3px;
     border: 0;
     background: lightgray;
-    box-shadow: 0 0 1px rgba(0, 0, 0, .1), 0 0 16px rgba(0, 0, 0, .1);
+    box-shadow:
+      0 0 1px rgba(0, 0, 0, 0.1),
+      0 0 16px rgba(0, 0, 0, 0.1);
     margin-inline-end: 1rem;
-}
-#side-bar-cover:not([src]) {
+  }
+  #side-bar-cover:not([src]) {
     display: none;
-}
-#side-bar-title {
-    margin: .5rem 0;
+  }
+  #side-bar-title {
+    margin: 0.5rem 0;
     font-size: inherit;
-}
-#side-bar-author {
-    margin: .5rem 0;
+  }
+  #side-bar-author {
+    margin: 0.5rem 0;
     font-size: small;
     color: GrayText;
-}
-#toc-view {
-    padding: .5rem;
+  }
+  #toc-view {
+    padding: 0.5rem;
     overflow-y: scroll;
-}
-#toc-view li, #toc-view ol {
+  }
+  #toc-view li,
+  #toc-view ol {
     margin: 0;
     padding: 0;
     list-style: none;
-}
-#toc-view a, #toc-view span {
+  }
+  #toc-view a,
+  #toc-view span {
     display: block;
     border-radius: 6px;
     padding: 8px;
     margin: 2px 0;
-}
-#toc-view a {
+  }
+  #toc-view a {
     color: CanvasText;
     text-decoration: none;
-}
-#toc-view a:hover {
+  }
+  #toc-view a:hover {
     background: var(--active-bg);
-}
-#toc-view span {
+  }
+  #toc-view span {
     color: GrayText;
-}
-#toc-view svg {
+  }
+  #toc-view svg {
     margin-inline-start: -24px;
     padding-inline-start: 5px;
     padding-inline-end: 6px;
     fill: CanvasText;
     cursor: default;
-    transition: transform .2s ease;
-    opacity: .5;
-}
-#toc-view svg:hover {
+    transition: transform 0.2s ease;
+    opacity: 0.5;
+  }
+  #toc-view svg:hover {
     opacity: 1;
-}
-#toc-view [aria-current] {
+  }
+  #toc-view [aria-current] {
     font-weight: bold;
     background: var(--active-bg);
-}
-#toc-view [aria-expanded="false"] svg {
+  }
+  #toc-view [aria-expanded="false"] svg {
     transform: rotate(-90deg);
-}
-#toc-view [aria-expanded="false"] + [role="group"] {
+  }
+  #toc-view [aria-expanded="false"] + [role="group"] {
     display: none;
-}
-.menu-container {
+  }
+  .menu-container {
     position: relative;
-}
-.menu, .menu ul {
+  }
+  .menu,
+  .menu ul {
     list-style: none;
     padding: 0;
     margin: 0;
-}
-.menu {
+  }
+  .menu {
     visibility: hidden;
     position: absolute;
     right: 0;
     background: Canvas;
     color: CanvasText;
     border-radius: 6px;
-    box-shadow: 0 0 0 1px rgba(0, 0, 0, .2), 0 0 16px rgba(0, 0, 0, .1);
+    box-shadow:
+      0 0 0 1px rgba(0, 0, 0, 0.2),
+      0 0 16px rgba(0, 0, 0, 0.1);
     padding: 6px;
     cursor: default;
-}
-.menu.show {
+  }
+  .menu.show {
     visibility: visible;
-}
-.menu li {
+  }
+  .menu li {
     padding: 6px 12px;
     padding-left: 24px;
     border-radius: 6px;
-}
-.menu li:hover {
+  }
+  .menu li:hover {
     background: var(--active-bg);
-}
-.menu li[aria-checked="true"] {
+  }
+  .menu li[aria-checked="true"] {
     background-position: center left;
     background-repeat: no-repeat;
-    background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2224%22%20height%3D%2224%22%3E%3Ccircle%20cx%3D%2212%22%20cy%3D%2212%22%20r%3D%223%22%2F%3E%3C%2Fsvg%3E');
-}
-.popover {
+    background-image: url("data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2224%22%20height%3D%2224%22%3E%3Ccircle%20cx%3D%2212%22%20cy%3D%2212%22%20r%3D%223%22%2F%3E%3C%2Fsvg%3E");
+  }
+  .popover {
     background: Canvas;
     color: CanvasText;
     border-radius: 6px;
-    box-shadow: 0 0 0 1px rgba(0, 0, 0, .2), 0 0 16px rgba(0, 0, 0, .1), 0 0 32px rgba(0, 0, 0, .1);
-}
-.popover-arrow-down {
+    box-shadow:
+      0 0 0 1px rgba(0, 0, 0, 0.2),
+      0 0 16px rgba(0, 0, 0, 0.1),
+      0 0 32px rgba(0, 0, 0, 0.1);
+  }
+  .popover-arrow-down {
     fill: Canvas;
-    filter: drop-shadow(0 -1px 0 rgba(0, 0, 0, .2));
-}
-.popover-arrow-up {
+    filter: drop-shadow(0 -1px 0 rgba(0, 0, 0, 0.2));
+  }
+  .popover-arrow-up {
     fill: Canvas;
-    filter: drop-shadow(0 1px 0 rgba(0, 0, 0, .2));
-}
+    filter: drop-shadow(0 1px 0 rgba(0, 0, 0, 0.2));
+  }
 </style>
-<input type="file" id="file-input" hidden>
+<input type="file" id="file-input" hidden />
 <div id="drop-target" class="filter">
-    <div>
-        <svg class="icon empty-state-icon" width="72" height="72" aria-hidden="true">
-            <path d="M36 18s-6-6-12-6-15 6-15 6v42s9-6 15-6 12 6 12 6c4-4 8-6 12-6s12 2 15 6V18c-6-4-12-6-15-6-4 0-8 2-12 6m0 0v42"/>
-        </svg>
-        <h1>Drop a book here!</h1>
-        <p>Or <button id="file-button">choose a file</button> to open it.</p>
-    </div>
+  <div>
+    <svg
+      class="icon empty-state-icon"
+      width="72"
+      height="72"
+      aria-hidden="true"
+    >
+      <path
+        d="M36 18s-6-6-12-6-15 6-15 6v42s9-6 15-6 12 6 12 6c4-4 8-6 12-6s12 2 15 6V18c-6-4-12-6-15-6-4 0-8 2-12 6m0 0v42"
+      />
+    </svg>
+    <h1>Drop a book here!</h1>
+    <p>Or <button id="file-button">choose a file</button> to open it.</p>
+  </div>
 </div>
 <div id="dimming-overlay" aria-hidden="true"></div>
 <div id="side-bar">
-    <div id="side-bar-header">
-        <img id="side-bar-cover">
-        <div>
-            <h1 id="side-bar-title"></h1>
-            <p id="side-bar-author"></p>
-        </div>
+  <div id="side-bar-header">
+    <img id="side-bar-cover" />
+    <div>
+      <h1 id="side-bar-title"></h1>
+      <p id="side-bar-author"></p>
     </div>
-    <div id="toc-view"></div>
+  </div>
+  <div id="toc-view"></div>
 </div>
 <div id="header-bar" class="toolbar">
-    <button id="side-bar-button" aria-label="Show sidebar">
-        <svg class="icon" width="24" height="24" aria-hidden="true">
-            <path d="M 4 6 h 16 M 4 12 h 16 M 4 18 h 16"/>
-        </svg>
+  <button id="side-bar-button" aria-label="Show sidebar">
+    <svg class="icon" width="24" height="24" aria-hidden="true">
+      <path d="M 4 6 h 16 M 4 12 h 16 M 4 18 h 16" />
+    </svg>
+  </button>
+  <div id="menu-button" class="menu-container">
+    <button aria-label="Show settings" aria-haspopup="true">
+      <svg class="icon" width="24" height="24" aria-hidden="true">
+        <path
+          d="M5 12.7a7 7 0 0 1 0-1.4l-1.8-2 2-3.5 2.7.5a7 7 0 0 1 1.2-.7L10 3h4l.9 2.6 1.2.7 2.7-.5 2 3.4-1.8 2a7 7 0 0 1 0 1.5l1.8 2-2 3.5-2.7-.5a7 7 0 0 1-1.2.7L14 21h-4l-.9-2.6a7 7 0 0 1-1.2-.7l-2.7.5-2-3.4 1.8-2Z"
+        />
+        <circle cx="12" cy="12" r="3" />
+      </svg>
     </button>
-    <div id="menu-button" class="menu-container">
-        <button aria-label="Show settings" aria-haspopup="true">
-            <svg class="icon" width="24" height="24" aria-hidden="true">
-                <path d="M5 12.7a7 7 0 0 1 0-1.4l-1.8-2 2-3.5 2.7.5a7 7 0 0 1 1.2-.7L10 3h4l.9 2.6 1.2.7 2.7-.5 2 3.4-1.8 2a7 7 0 0 1 0 1.5l1.8 2-2 3.5-2.7-.5a7 7 0 0 1-1.2.7L14 21h-4l-.9-2.6a7 7 0 0 1-1.2-.7l-2.7.5-2-3.4 1.8-2Z"/>
-                <circle cx="12" cy="12" r="3"/>
-            </svg>
-        </button>
-    </div>
+  </div>
 </div>
 <div id="nav-bar" class="toolbar">
-    <button id="left-button" aria-label="Go left">
-        <svg class="icon" width="24" height="24" aria-hidden="true">
-            <path d="M 15 6 L 9 12 L 15 18"/>
-        </svg>
-    </button>
-    <input id="progress-slider" type="range" min="0" max="1" step="any" list="tick-marks">
-    <datalist id="tick-marks"></datalist>
-    <button id="right-button" aria-label="Go right">
-        <svg class="icon" width="24" height="24" aria-hidden="true">
-            <path d="M 9 6 L 15 12 L 9 18"/>
-        </svg>
-    </button>
+  <button id="left-button" aria-label="Go left">
+    <svg class="icon" width="24" height="24" aria-hidden="true">
+      <path d="M 15 6 L 9 12 L 15 18" />
+    </svg>
+  </button>
+  <input
+    id="progress-slider"
+    type="range"
+    min="0"
+    max="1"
+    step="any"
+    list="tick-marks"
+  />
+  <datalist id="tick-marks"></datalist>
+  <button id="right-button" aria-label="Go right">
+    <svg class="icon" width="24" height="24" aria-hidden="true">
+      <path d="M 9 6 L 15 12 L 9 18" />
+    </svg>
+  </button>
 </div>
 <script src="reader.js" type="module"></script>
