diff --git a/repo/emoji-sets/client.mjs b/repo/emoji-sets/client.mjs
index b67fb26..9093ec2 100644
--- a/repo/emoji-sets/client.mjs
+++ b/repo/emoji-sets/client.mjs
@@ -19,6 +19,7 @@ export default async function ({ web, env }, db) {
   const unsupportedEmojis = [],
     emojiReqs = new Map(),
     getEmoji = async (emoji) => {
+      emoji = encodeURIComponent(emoji);
       if (unsupportedEmojis.includes(emoji)) return undefined;
       try {
         if (!emojiReqs.get(emoji)) {
@@ -37,16 +38,14 @@ export default async function ({ web, env }, db) {
     const updateEmojis = async () => {
       const $emojis = document.querySelectorAll(nativeEmojiSelector);
       for (const $emoji of $emojis) {
-        const emojiBg = await getEmoji($emoji.ariaLabel);
-        if (emojiBg) {
-          $emoji.style.background = emojiBg;
+        const emojiSrc = await getEmoji($emoji.ariaLabel);
+        if (emojiSrc) {
+          $emoji.style.background = emojiSrc;
           $emoji.style.width = '1em';
           $emoji.style.height = '1em';
           $emoji.style.display = 'inline-block';
           $emoji.innerText = '';
-        } else {
-          $emoji.dataset.emojiSetsUnsupported = true;
-        }
+        } else $emoji.dataset.emojiSetsUnsupported = true;
       }
     };
     web.addDocumentObserver(updateEmojis, [nativeEmojiSelector]);
@@ -56,16 +55,14 @@ export default async function ({ web, env }, db) {
     const updateEmojis = async () => {
       const $emojis = document.querySelectorAll(imgEmojiSelector);
       for (const $emoji of $emojis) {
-        const emojiBg = await getEmoji($emoji.ariaLabel);
-        if (emojiBg) {
-          $emoji.style.background = emojiBg;
+        const emojiSrc = await getEmoji($emoji.ariaLabel);
+        if (emojiSrc) {
+          $emoji.style.background = emojiSrc;
           $emoji.style.opacity = 1;
           if ($emoji.nextElementSibling?.matches?.(imgEmojiOverlaySelector)) {
             $emoji.nextElementSibling.style.opacity = 0;
           }
-        } else {
-          $emoji.dataset.emojiSetsUnsupported = true;
-        }
+        } else $emoji.dataset.emojiSetsUnsupported = true;
       }
     };
     updateEmojis();
diff --git a/repo/indentation-lines/client.css b/repo/indentation-lines/client.css
index 8acd6b6..aaef3d0 100644
--- a/repo/indentation-lines/client.css
+++ b/repo/indentation-lines/client.css
@@ -5,6 +5,41 @@
  * (https://notion-enhancer.github.io/) under the MIT license
  */
 
+.notion-page-content .notion-bulleted_list-block > div > div:last-child,
+.notion-page-content .notion-numbered_list-block > div > div:last-child,
+.notion-page-content .notion-to_do-block > div > div:last-child,
+.notion-page-content .notion-toggle-block > div > div:last-child,
+.notion-page-content .notion-table_of_contents-block > div > div > a > div > div {
+  position: relative;
+}
+
+.notion-page-content .notion-bulleted_list-block > div > div:last-child::before,
+.notion-page-content .notion-numbered_list-block > div > div:last-child::before,
+.notion-page-content .notion-to_do-block > div > div:last-child::before,
+.notion-page-content .notion-toggle-block > div > div:last-child::before {
+  content: '';
+  position: absolute;
+  height: calc(100% - 2em);
+  top: 2em;
+  left: -14.48px;
+}
+
+.notion-page-content
+  .notion-table_of_contents-block
+  > div
+  > div
+  > a
+  > div
+  > div:not([style*='margin-left: 0px'])
+  > div::before {
+  content: '';
+  position: absolute;
+  height: 100%;
+  top: 0;
+  left: -14.48px;
+}
+
+/* add background to block dragger */
 .notion-frame
   > [style*='position: absolute; top: 0px; left: 0px;']
   [style*='position: absolute; top: 3px; left: -20px; width: 18px; height: 24px; pointer-events: auto; cursor: -webkit-grab;']
@@ -57,37 +92,3 @@
   > .plus:hover {
   background: rgba(255, 255, 255, 0.1) !important;
 }
-
-.notion-page-content .notion-bulleted_list-block > div > div:last-child,
-.notion-page-content .notion-numbered_list-block > div > div:last-child,
-.notion-page-content .notion-to_do-block > div > div:last-child,
-.notion-page-content .notion-toggle-block > div > div:last-child,
-.notion-page-content .notion-table_of_contents-block > div > div > a > div > div {
-  position: relative;
-}
-
-.notion-page-content .notion-bulleted_list-block > div > div:last-child::before,
-.notion-page-content .notion-numbered_list-block > div > div:last-child::before,
-.notion-page-content .notion-to_do-block > div > div:last-child::before,
-.notion-page-content .notion-toggle-block > div > div:last-child::before {
-  content: '';
-  position: absolute;
-  height: calc(100% - 2em);
-  top: 2em;
-  left: -14.48px;
-}
-
-.notion-page-content
-  .notion-table_of_contents-block
-  > div
-  > div
-  > a
-  > div
-  > div:not([style*='margin-left: 0px'])
-  > div::before {
-  content: '';
-  position: absolute;
-  height: 100%;
-  top: 0;
-  left: -14.48px;
-}
diff --git a/repo/indentation-lines/client.mjs b/repo/indentation-lines/client.mjs
index ad0300f..35137a9 100644
--- a/repo/indentation-lines/client.mjs
+++ b/repo/indentation-lines/client.mjs
@@ -58,13 +58,32 @@ export default async function ({ web }, db) {
       }`;
 
     if (rainbow) {
-      for (let i = 0; i < colors.length; i++) {
-        css += `
-          .notion-page-content ${`.notion-table_of_contents-block `.repeat(i + 1)}
-            > div > div > a > div > div:not([style*='margin-left: 0px']) > div::before {
-            --indentation_lines--color: var(--theme--text_${colors[i]});
-          }`;
-      }
+      css += `
+        .notion-page-content .notion-table_of_contents-block > div > div > a > div
+          > div[style*='margin-left: 24px'] > div::before {
+          --indentation_lines--color: var(--theme--text_${colors[0]});
+        }
+        .notion-page-content .notion-table_of_contents-block > div > div > a > div
+          > div[style*='margin-left: 48px'] > div::before {
+          --indentation_lines--color: var(--theme--text_${colors[1]});
+        }`;
+    }
+  }
+
+  if (db.get(['outliner'])) {
+    css += `
+      .outliner--header:not([style='--outliner--indent:0px;'])::before {
+        border-left: 1px ${style} var(--indentation_lines--color, currentColor);
+        opacity: ${opacity};
+      }`;
+    if (rainbow) {
+      css += `
+        .outliner--header[style='--outliner--indent:18px;']::before {
+          --indentation_lines--color: var(--theme--text_${colors[0]});
+        }
+        .outliner--header[style='--outliner--indent:36px;']::before {
+          --indentation_lines--color: var(--theme--text_${colors[1]});
+        }`;
     }
   }
 
diff --git a/repo/indentation-lines/mod.json b/repo/indentation-lines/mod.json
index 67576ff..d73c754 100644
--- a/repo/indentation-lines/mod.json
+++ b/repo/indentation-lines/mod.json
@@ -54,6 +54,12 @@
       "key": "table_of_contents",
       "label": "tables of contents",
       "value": true
+    },
+    {
+      "type": "toggle",
+      "key": "outliner",
+      "label": "outliner (panel extension)",
+      "value": true
     }
   ]
 }
diff --git a/repo/outliner/client.css b/repo/outliner/client.css
new file mode 100644
index 0000000..f01768e
--- /dev/null
+++ b/repo/outliner/client.css
@@ -0,0 +1,47 @@
+/*
+ * notion-enhancer: outliner
+ * (c) 2020 CloudHill <rl.cloudhill@gmail.com> (https://github.com/CloudHill)
+ * (c) 2021 dragonwocky <thedragonring.bod@gmail.com> (https://dragonwocky.me/)
+ * (https://notion-enhancer.github.io/) under the MIT license
+ */
+
+#outliner--notice {
+  color: var(--theme--text_secondary);
+  font-size: 14px;
+  margin-top: 0;
+  margin-bottom: 1rem;
+}
+
+.outliner--header {
+  position: relative;
+  margin: 0 -1rem;
+  padding: 0 1rem;
+  display: block;
+  font-size: 14px;
+  line-height: 2.2;
+  white-space: nowrap;
+  overflow: hidden;
+  user-select: none;
+  text-overflow: ellipsis;
+  text-decoration: none;
+  text-indent: var(--outliner--indent);
+  color: inherit;
+  cursor: pointer !important;
+  transition: background 20ms ease-in;
+}
+.outliner--header:hover {
+  background: var(--theme--ui_interactive-hover);
+}
+
+.outliner--header:empty::after {
+  color: var(--theme--text_secondary);
+  content: attr(placeholder);
+}
+
+/* indentation lines */
+.outliner--header:not([style='--outliner--indent:0px;'])::before {
+  content: '';
+  height: 100%;
+  position: absolute;
+  left: calc((1rem + var(--outliner--indent)) - 11px);
+}
diff --git a/repo/outliner/client.mjs b/repo/outliner/client.mjs
new file mode 100644
index 0000000..6f3899d
--- /dev/null
+++ b/repo/outliner/client.mjs
@@ -0,0 +1,91 @@
+/*
+ * notion-enhancer: outliner
+ * (c) 2020 CloudHill <rl.cloudhill@gmail.com> (https://github.com/CloudHill)
+ * (c) 2021 dragonwocky <thedragonring.bod@gmail.com> (https://dragonwocky.me/)
+ * (https://notion-enhancer.github.io/) under the MIT license
+ */
+
+export default async function ({ web, components }, db) {
+  const dbNoticeText = 'Open a page to see its table of contents.',
+    pageNoticeText = 'Click on a heading to jump to it.',
+    $notice = web.html`<p id="outliner--notice">${dbNoticeText}</p>`;
+
+  const $headingList = web.html`<div></div>`;
+
+  let viewFocused = false;
+  await components.addPanelView({
+    id: '87e077cc-5402-451c-ac70-27cc4ae65546',
+    icon: web.html`<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
+      <circle cx="5" cy="7" r="2.8"/>
+      <circle cx="5" cy="17" r="2.79"/>
+      <path d="M21,5.95H11c-0.55,0-1-0.45-1-1v0c0-0.55,0.45-1,1-1h10c0.55,0,1,0.45,1,1v0C22,5.5,21.55,5.95,21,5.95z"/>
+      <path d="M17,10.05h-6c-0.55,0-1-0.45-1-1v0c0-0.55,0.45-1,1-1h6c0.55,0,1,0.45,1,1v0C18,9.6,17.55,10.05,17,10.05z"/>
+      <path d="M21,15.95H11c-0.55,0-1-0.45-1-1v0c0-0.55,0.45-1,1-1h10c0.55,0,1,0.45,1,1v0C22,15.5,21.55,15.95,21,15.95z" />
+      <path d="M17,20.05h-6c-0.55,0-1-0.45-1-1v0c0-0.55,0.45-1,1-1h6c0.55,0,1,0.45,1,1v0C18,19.6,17.55,20.05,17,20.05z"/>
+    </svg>`,
+    title: 'Outliner',
+    $content: web.render(web.html`<div></div>`, $notice, $headingList),
+    onFocus: () => {
+      viewFocused = true;
+    },
+    onBlur: () => {
+      viewFocused = false;
+    },
+  });
+  await web.whenReady();
+
+  let $page;
+  const updateHeadings = () => {
+      if (!$page) return;
+      const $headerBlocks = $page.querySelectorAll(
+          '[class^="notion-"][class*="header-block"]'
+        ),
+        $fragment = web.html`<div></div>`;
+      let depth = 0,
+        indent = 0;
+      for (const $header of $headerBlocks) {
+        const id = $header.dataset.blockId.replace(/-/g, ''),
+          placeholder = $header.querySelector('[placeholder]').getAttribute('placeholder'),
+          headerDepth = +placeholder.at(-1);
+        if (depth && depth < headerDepth) {
+          indent += 18;
+        } else if (depth > headerDepth) {
+          indent = Math.max(indent - 18, 0);
+        }
+        depth = headerDepth;
+        const $outlineHeader = web.render(
+          web.html`<a href="#${id}" class="outliner--header"
+              placeholder="${web.escape(placeholder)}"
+              style="--outliner--indent:${indent}px;"></a>`,
+          $header.innerText
+        );
+        $fragment.append($outlineHeader);
+      }
+      if ($fragment.innerHTML !== $headingList.innerHTML) {
+        web.render(web.empty($headingList), ...$fragment.children);
+      }
+    },
+    pageObserver = () => {
+      if (!viewFocused) return;
+      if (document.contains($page)) {
+        updateHeadings();
+      } else {
+        $page = document.getElementsByClassName('notion-page-content')[0];
+        if ($page) {
+          $notice.innerText = pageNoticeText;
+          $headingList.style.display = '';
+          updateHeadings();
+        } else {
+          $notice.innerText = dbNoticeText;
+          $headingList.style.display = 'none';
+        }
+      }
+    };
+  web.addDocumentObserver(pageObserver, [
+    '.notion-header-block',
+    '.notion-sub_header-block',
+    '.notion-sub_sub_header-block',
+    '.notion-collection_view_page-block',
+  ]);
+  pageObserver();
+}
diff --git a/repo/outliner/mod.json b/repo/outliner/mod.json
new file mode 100644
index 0000000..12a83ba
--- /dev/null
+++ b/repo/outliner/mod.json
@@ -0,0 +1,22 @@
+{
+  "name": "outliner",
+  "id": "87e077cc-5402-451c-ac70-27cc4ae65546",
+  "version": "0.4.0",
+  "description": "adds a table of contents to the side panel.",
+  "tags": ["extension", "panel"],
+  "authors": [
+    {
+      "name": "CloudHill",
+      "email": "rh.cloudhill@gmail.com",
+      "homepage": "https://github.com/CloudHill",
+      "avatar": "https://avatars.githubusercontent.com/u/54142180"
+    }
+  ],
+  "js": {
+    "client": ["client.mjs"]
+  },
+  "css": {
+    "client": ["client.css"]
+  },
+  "options": []
+}
diff --git a/repo/registry.json b/repo/registry.json
index 96b6ef4..7365710 100644
--- a/repo/registry.json
+++ b/repo/registry.json
@@ -17,14 +17,15 @@
   "playful-purple",
   "pinky-boom",
 
-  "bypass-preview",
   "font-chooser",
+  "outliner",
   "scroll-to-top",
+  "indentation-lines",
+  "emoji-sets",
+  "bypass-preview",
+  "topbar-icons",
+  "word-counter",
   "calendar-scroll",
   "collapse-properties",
-  "indentation-lines",
-  "focus-mode",
-  "word-counter",
-  "emoji-sets",
-  "topbar-icons"
+  "focus-mode"
 ]
diff --git a/repo/word-counter/client.css b/repo/word-counter/client.css
index 5bd4fb3..614e70b 100644
--- a/repo/word-counter/client.css
+++ b/repo/word-counter/client.css
@@ -7,6 +7,7 @@
 #word-counter--notice {
   color: var(--theme--text_secondary);
   font-size: 14px;
+  margin-top: 0;
 }
 
 .word-counter--stat {
diff --git a/repo/word-counter/client.mjs b/repo/word-counter/client.mjs
index 44fe96d..1c15f95 100644
--- a/repo/word-counter/client.mjs
+++ b/repo/word-counter/client.mjs
@@ -35,9 +35,9 @@ const copyToClipboard = async (str) => {
   };
 
 export default async function ({ web, components }, db) {
-  const dbNoticeText = 'Open a normal page to see word count.',
+  const dbNoticeText = 'Open a page to see its word count.',
     pageNoticeText = 'Click a stat to copy it.',
-    $notice = web.html`<span id="word-counter--notice">${dbNoticeText}</span>`;
+    $notice = web.html`<p id="word-counter--notice">${dbNoticeText}</p>`;
 
   const $wordCount = web.html`<b>12</b>`,
     $characterCount = web.html`<b>12</b>`,
@@ -47,7 +47,7 @@ export default async function ({ web, components }, db) {
     $readingTooltip = web.html`${await components.feather('info')}`,
     $speakingTime = web.html`<b>18 secs</b>`,
     $speakingTooltip = web.html`${await components.feather('info')}`,
-    $statContainer = web.render(
+    $statList = web.render(
       web.html`<div></div>`,
       web.render(web.html`<p class="word-counter--stat"></p>`, $wordCount, ' words'),
       web.render(web.html`<p class="word-counter--stat"></p>`, $characterCount, ' characters'),
@@ -66,15 +66,24 @@ export default async function ({ web, components }, db) {
         ' speaking time'
       )
     );
-  $statContainer.querySelectorAll('.word-counter--stat').forEach(($stat) => {
+  $statList.querySelectorAll('.word-counter--stat').forEach(($stat) => {
     $stat.addEventListener('click', () => copyToClipboard($stat.innerText));
   });
   components.setTooltip($readingTooltip, '**~ 275 wpm**');
   components.setTooltip($speakingTooltip, '**~ 180 wpm**');
+
+  let viewFocused = false;
   await components.addPanelView({
+    id: 'b99deb52-6955-43d2-a53b-a31540cd19a5',
     icon: await components.feather('type'),
     title: 'Word Counter',
-    $content: web.render(web.html`<div></div>`, $notice, $statContainer),
+    $content: web.render(web.html`<div></div>`, $notice, $statList),
+    onFocus: () => {
+      viewFocused = true;
+    },
+    onBlur: () => {
+      viewFocused = false;
+    },
   });
 
   let $page;
@@ -89,17 +98,18 @@ export default async function ({ web, components }, db) {
       $speakingTime.innerText = humanTime(words / 180);
     },
     pageObserver = () => {
+      if (!viewFocused) return;
       if (document.contains($page)) {
         updateStats();
       } else {
         $page = document.getElementsByClassName('notion-page-content')[0];
         if ($page) {
           $notice.innerText = pageNoticeText;
-          $statContainer.style.display = '';
+          $statList.style.display = '';
           updateStats();
         } else {
           $notice.innerText = dbNoticeText;
-          $statContainer.style.display = 'none';
+          $statList.style.display = 'none';
         }
       }
     };