diff --git a/package.json b/package.json
index 18ee8f8..ad34633 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,6 @@
     "rehype-katex": "^7.0.1",
     "rehype-slug": "^6.0.0",
     "remark-math": "^6.0.0",
-    "remark-toc": "^9.0.0",
     "sanitize-html": "^2.15.0"
   },
   "devDependencies": {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8ff6a36..dd8589c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -59,9 +59,6 @@ importers:
       remark-math:
         specifier: ^6.0.0
         version: 6.0.0
-      remark-toc:
-        specifier: ^9.0.0
-        version: 9.0.0
       sanitize-html:
         specifier: ^2.15.0
         version: 2.15.0
@@ -925,9 +922,6 @@ packages:
   '@types/sax@1.2.7':
     resolution: {integrity: sha512-rO73L89PJxeYM3s3pPPjiPgVVcymqU490g0YO5n5By0k2Erzj6tay/4lr1CHAAU4JyOWd1rpQ8bCf6cZfHU96A==}
 
-  '@types/ungap__structured-clone@1.2.0':
-    resolution: {integrity: sha512-ZoaihZNLeZSxESbk9PUAPZOlSpcKx81I1+4emtULDVmBLkYutTcMlCj2K9VNlf9EWODxdO6gkAqEaLorXwZQVA==}
-
   '@types/unist@2.0.11':
     resolution: {integrity: sha512-CmBKiL6NNo/OqgmMn95Fk9Whlp2mtvIv+KNpQKN2F4SjvrEesubTRWGYSg+BnWZOnlCaSTU1sMpsBOzgbYhnsA==}
 
@@ -1691,8 +1685,8 @@ packages:
   duplexer@0.1.2:
     resolution: {integrity: sha512-jtD6YG370ZCIi/9GTaJKQxWTZD045+4R4hTk/x1UyoqadyJ9x9CgSi1RlVDQF8U2sxLLSnFkCaMihqljHIWgMg==}
 
-  electron-to-chromium@1.5.126:
-    resolution: {integrity: sha512-AtH1uLcTC72LA4vfYcEJJkrMk/MY/X0ub8Hv7QGAePW2JkeUFHEL/QfS4J77R6M87Sss8O0OcqReSaN1bpyA+Q==}
+  electron-to-chromium@1.5.127:
+    resolution: {integrity: sha512-Ke5OggqOtEqzCzcUyV+9jgO6L6sv1gQVKGtSExXHjD/FK0p4qzPZbrDsrCdy0DptcQprD0V80RCBYSWLMhTTgQ==}
 
   emmet@2.4.11:
     resolution: {integrity: sha512-23QPJB3moh/U9sT4rQzGgeyyGIrcM+GH5uVYg2C6wZIxAIJq7Ng3QLT79tl8FUwDXhyq9SusfknOrofAKqvgyQ==}
@@ -2553,9 +2547,6 @@ packages:
   mdast-util-to-string@4.0.0:
     resolution: {integrity: sha512-0H44vDimn51F0YwvxSJSm0eCDOJTRlmN0R1yBh4HLj9wiV1Dn0QoXGbvFAWj2hSItVTlCmBF1hqKlIyUBVFLPg==}
 
-  mdast-util-toc@7.1.0:
-    resolution: {integrity: sha512-2TVKotOQzqdY7THOdn2gGzS9d1Sdd66bvxUyw3aNpWfcPXCLYSJCCgfPy30sEtuzkDraJgqF35dzgmz6xlvH/w==}
-
   mdn-data@2.0.28:
     resolution: {integrity: sha512-aylIc7Z9y4yzHYAJNuESG3hfhC+0Ibp/MAMiaOZgNv4pmEdFyfZhhhny4MNiAfWdBQ1RQ2mfDWmM1x8SvGyp8g==}
 
@@ -3071,9 +3062,6 @@ packages:
   remark-stringify@11.0.0:
     resolution: {integrity: sha512-1OSmLd3awB/t8qdoEOMazZkNsfVTeY4fTsgzcQFdXNq8ToTN4ZGwrMnlda4K6smTFKD+GRV6O48i6Z4iKgPPpw==}
 
-  remark-toc@9.0.0:
-    resolution: {integrity: sha512-KJ9txbo33GjDAV1baHFze7ij4G8c7SGYoY8Kzsm2gzFpbhL/bSoVpMMzGa3vrNDSWASNd/3ppAqL7cP2zD6JIA==}
-
   request-light@0.5.8:
     resolution: {integrity: sha512-3Zjgh+8b5fhRJBQZoy+zbVKpAQGLyka0MPgW3zruTF4dFFJ8Fqcfu9YsAvi/rvdcaTeWG3MkbZv4WKxAn/84Lg==}
 
@@ -4610,8 +4598,6 @@ snapshots:
     dependencies:
       '@types/node': 22.13.14
 
-  '@types/ungap__structured-clone@1.2.0': {}
-
   '@types/unist@2.0.11': {}
 
   '@types/unist@3.0.3': {}
@@ -5330,7 +5316,7 @@ snapshots:
   browserslist@4.24.4:
     dependencies:
       caniuse-lite: 1.0.30001707
-      electron-to-chromium: 1.5.126
+      electron-to-chromium: 1.5.127
       node-releases: 2.0.19
       update-browserslist-db: 1.1.3(browserslist@4.24.4)
 
@@ -5589,7 +5575,7 @@ snapshots:
 
   duplexer@0.1.2: {}
 
-  electron-to-chromium@1.5.126: {}
+  electron-to-chromium@1.5.127: {}
 
   emmet@2.4.11:
     dependencies:
@@ -6754,16 +6740,6 @@ snapshots:
     dependencies:
       '@types/mdast': 4.0.4
 
-  mdast-util-toc@7.1.0:
-    dependencies:
-      '@types/mdast': 4.0.4
-      '@types/ungap__structured-clone': 1.2.0
-      '@ungap/structured-clone': 1.3.0
-      github-slugger: 2.0.0
-      mdast-util-to-string: 4.0.0
-      unist-util-is: 6.0.0
-      unist-util-visit: 5.0.0
-
   mdn-data@2.0.28: {}
 
   mdn-data@2.0.30: {}
@@ -7518,11 +7494,6 @@ snapshots:
       mdast-util-to-markdown: 2.1.2
       unified: 11.0.5
 
-  remark-toc@9.0.0:
-    dependencies:
-      '@types/mdast': 4.0.4
-      mdast-util-toc: 7.1.0
-
   request-light@0.5.8: {}
 
   request-light@0.7.0: {}
diff --git a/src/components/Navbar.astro b/src/components/Navbar.astro
index fc78a37..e03d83d 100644
--- a/src/components/Navbar.astro
+++ b/src/components/Navbar.astro
@@ -33,6 +33,7 @@ const navItems = [
 ---
 
 <nav
+  aria-label="Site Navigation"
   class:list={[
     isPost ? 'hidden lg:block' : '',
     'mb-10.5 text-3.6 font-semibold leading-8.75 font-navbar',
diff --git a/src/components/Widgets/Scrollbar.astro b/src/components/Widgets/Scrollbar.astro
index e0e6284..69c4100 100644
--- a/src/components/Widgets/Scrollbar.astro
+++ b/src/components/Widgets/Scrollbar.astro
@@ -2,6 +2,7 @@
 import { OverlayScrollbars } from 'overlayscrollbars'
 
 function setupScrollbar() {
+  // Add scrollbar to body
   const bodyElement = document.body
   if (!bodyElement.hasAttribute('data-scrollbar-initialized')) {
     OverlayScrollbars({
@@ -20,6 +21,7 @@ function setupScrollbar() {
     bodyElement.setAttribute('data-scrollbar-initialized', 'true')
   }
 
+  // Add scrollbar to code blocks
   const preElements = document.querySelectorAll('pre')
   preElements.forEach((pre) => {
     if (!pre.hasAttribute('data-scrollbar-initialized')) {
@@ -30,7 +32,7 @@ function setupScrollbar() {
         },
       }, {
         scrollbars: {
-          theme: 'scrollbar-code',
+          theme: 'scrollbar-widget',
           autoHide: 'leave',
           autoHideDelay: 500,
         },
@@ -39,6 +41,25 @@ function setupScrollbar() {
       pre.setAttribute('data-scrollbar-initialized', 'true')
     }
   })
+
+  // Add scrollbar to TOC content
+  const tocElement = document.getElementById('toc-content')
+  if (tocElement && !tocElement.hasAttribute('data-scrollbar-initialized')) {
+    OverlayScrollbars({
+      target: tocElement,
+      cancel: {
+        nativeScrollbarsOverlaid: true,
+      },
+    }, {
+      scrollbars: {
+        theme: 'scrollbar-widget',
+        autoHide: 'leave',
+        autoHideDelay: 500,
+      },
+    })
+
+    tocElement.setAttribute('data-scrollbar-initialized', 'true')
+  }
 }
 
 setupScrollbar()
@@ -64,7 +85,7 @@ document.addEventListener('astro:after-swap', setupScrollbar)
   --os-handle-min-size: 12%;
 }
 
-.scrollbar-code {
+.scrollbar-widget {
   --os-size: 0.6rem;
   --os-padding-perpendicular: 0.1rem;
   --os-padding-axis: 0.2rem;
@@ -80,7 +101,7 @@ document.addEventListener('astro:after-swap', setupScrollbar)
 }
 
 @media (max-width: 1023px) {
-  .os-scrollbar {
+  .os-scrollbar.scrollbar-body {
     display: none !important;
   }
 }
diff --git a/src/components/Widgets/TOC.astro b/src/components/Widgets/TOC.astro
new file mode 100644
index 0000000..52d278a
--- /dev/null
+++ b/src/components/Widgets/TOC.astro
@@ -0,0 +1,112 @@
+---
+import type { MarkdownHeading } from 'astro'
+import { ui } from '@/i18n/ui'
+import { getPageInfo } from '@/utils/page'
+
+interface Props {
+  headings: MarkdownHeading[]
+}
+
+const { currentLang } = getPageInfo(Astro.url.pathname)
+const currentUI = ui[currentLang as keyof typeof ui]
+
+const { headings = [] } = Astro.props
+const filteredHeadings = headings.filter(heading =>
+  heading.depth >= 2
+  && heading.depth <= 4
+  && heading.text !== 'Footnotes',
+)
+---
+
+{filteredHeadings.length > 0 && (
+  <div
+    class="relative mb-6 bg-secondary/5"
+    border="~ secondary/5 rounded solid"
+    transition="~ duration-300 ease-in-out"
+  >
+    {/* Accordion toggle for expandable TOC */}
+    <input
+      type="checkbox"
+      id="toc-toggle"
+      class="accordion-toggle"
+      hidden
+    />
+    <label
+      for="toc-toggle"
+      class="absolute inset-0 z-99 cursor-pointer"
+    ></label>
+
+    {/* TOC title bar */}
+    <div class="h-12 w-full flex items-center bg-secondary/0">
+      <span class="toc-title">
+        {currentUI.toc}
+      </span>
+    </div>
+
+    {/* Expandable content wrapper */}
+    <div class="accordion-wrapper">
+      <nav
+        id="toc-content"
+        class="accordion-content"
+        aria-label="Table of Contents"
+      >
+        <ul class="toc-list">
+          {filteredHeadings.map(heading => (
+            <li
+              class:list={{
+                'ml-0': heading.depth === 2,
+                'ml-4': heading.depth === 3,
+                'ml-8': heading.depth === 4,
+              }}
+            >
+              <a
+                href={`#${heading.slug}`}
+                class:list={[
+                  { 'toc-link-h2': heading.depth === 2 },
+                  { 'toc-link-h3': heading.depth === 3 },
+                  { 'toc-link-h4': heading.depth === 4 },
+                ]}
+              >
+                {heading.text}
+              </a>
+            </li>
+          ))}
+        </ul>
+      </nav>
+    </div>
+  </div>
+)}
+
+<!-- Override heti default styles -->
+<style>
+.toc-title {
+  --at-apply: 'font-semibold pl-4 px-4 py-3';
+}
+.toc-list {
+  --at-apply: 'list-none pl-0 space-y-2 mt-1 mb-4';
+}
+.toc-link-h2 {
+  --at-apply: 'text-sm no-underline font-semibold';
+}
+.toc-link-h3 {
+  --at-apply: 'text-sm no-underline font-normal';
+}
+.toc-link-h4 {
+  --at-apply: 'text-sm no-underline font-normal';
+}
+/* Initial collapsed state with zero height grid row */
+.accordion-wrapper {
+  --at-apply: 'grid rows-[0fr] duration-300 ease-in-out';
+}
+.accordion-content {
+    --at-apply: 'overflow-hidden max-h-66 lg:max-h-82 z-99 pl-4';
+  }
+
+/* When toggle is checked, expand the wrapper to show content */
+.accordion-toggle:checked ~ .accordion-wrapper {
+  grid-template-rows: 1fr;
+}
+.accordion-toggle:checked ~ .accordion-wrapper .accordion-content {
+    --at-apply: 'overflow-y-auto';
+  }
+</style>
diff --git a/src/content/config.ts b/src/content/config.ts
index 9509f33..3cf25c3 100644
--- a/src/content/config.ts
+++ b/src/content/config.ts
@@ -14,7 +14,7 @@ const postsCollection = defineCollection({
     // Advanced
     draft: z.boolean().optional().default(false),
     pin: z.number().int().min(0).max(99).optional().default(0),
-    toc: z.boolean().optional().default(false),
+    toc: z.boolean().optional().default(true),
     lang: z.enum(['', ...allLocales]).optional().default(''),
     abbrlink: z.string().optional().default('').refine(
       abbrlink => !abbrlink || /^[a-z0-9\-]*$/.test(abbrlink),
diff --git a/src/content/posts/Markdown Style Guide-en.md b/src/content/posts/guides/Markdown Style Guide-en.md
similarity index 100%
rename from src/content/posts/Markdown Style Guide-en.md
rename to src/content/posts/guides/Markdown Style Guide-en.md
diff --git a/src/content/posts/Markdown Style Guide-es.md b/src/content/posts/guides/Markdown Style Guide-es.md
similarity index 100%
rename from src/content/posts/Markdown Style Guide-es.md
rename to src/content/posts/guides/Markdown Style Guide-es.md
diff --git a/src/content/posts/Markdown Style Guide-ja.md b/src/content/posts/guides/Markdown Style Guide-ja.md
similarity index 100%
rename from src/content/posts/Markdown Style Guide-ja.md
rename to src/content/posts/guides/Markdown Style Guide-ja.md
diff --git a/src/content/posts/Markdown Style Guide-ru.md b/src/content/posts/guides/Markdown Style Guide-ru.md
similarity index 100%
rename from src/content/posts/Markdown Style Guide-ru.md
rename to src/content/posts/guides/Markdown Style Guide-ru.md
diff --git a/src/content/posts/Markdown Style Guide-zh-tw.md b/src/content/posts/guides/Markdown Style Guide-zh-tw.md
similarity index 100%
rename from src/content/posts/Markdown Style Guide-zh-tw.md
rename to src/content/posts/guides/Markdown Style Guide-zh-tw.md
diff --git a/src/content/posts/Markdown Style Guide-zh.md b/src/content/posts/guides/Markdown Style Guide-zh.md
similarity index 100%
rename from src/content/posts/Markdown Style Guide-zh.md
rename to src/content/posts/guides/Markdown Style Guide-zh.md
diff --git a/src/content/posts/Theme Guide-en.md b/src/content/posts/guides/Theme Guide-en.md
similarity index 93%
rename from src/content/posts/Theme Guide-en.md
rename to src/content/posts/guides/Theme Guide-en.md
index fc8b523..32fb104 100644
--- a/src/content/posts/Theme Guide-en.md	
+++ b/src/content/posts/guides/Theme Guide-en.md	
@@ -231,7 +231,7 @@ Pins the article to the top. The higher the number, the higher the priority of t
 
 #### toc
 
-Enables the table of contents. This feature is not yet implemented.
+Generate table of contents. Set to false to disable automatic generation. Default is true.
 
 #### lang
 
@@ -243,15 +243,15 @@ Specifies the article language. Only one language can be specified. If not speci
 # moreLocales: ['es', 'ru']
 
 # lang: ''
-src/content/posts/apple.md    -> example.com/posts/apple/
-                              -> example.com/es/posts/apple/
-                              -> example.com/ru/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
+                             -> example.com/es/posts/apple/
+                             -> example.com/ru/posts/apple/
 # lang: en
-src/content/posts/apple.md    -> example.com/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
 # lang: es
-src/content/posts/banana.md   -> example.com/es/posts/banana/
+src/content/posts/apple.md   -> example.com/es/posts/apple/
 # lang: ru
-src/content/posts/orange.md   -> example.com/ru/posts/orange/
+src/content/posts/apple.md   -> example.com/ru/posts/apple/
 ```
 
 #### abbrlink
diff --git a/src/content/posts/Theme Guide-es.md b/src/content/posts/guides/Theme Guide-es.md
similarity index 94%
rename from src/content/posts/Theme Guide-es.md
rename to src/content/posts/guides/Theme Guide-es.md
index a10b484..8522a0c 100644
--- a/src/content/posts/Theme Guide-es.md	
+++ b/src/content/posts/guides/Theme Guide-es.md	
@@ -231,7 +231,7 @@ Fija el artículo en la parte superior. Cuanto mayor sea el número, mayor será
 
 #### toc
 
-Habilita la tabla de contenidos. Esta función aún no está implementada.
+¿Generar índice? Si se establece en false, se desactiva la generación automática. Valor predeterminado: true.
 
 #### lang
 
@@ -243,15 +243,15 @@ Especifica el idioma del artículo. Solo se puede especificar un idioma. Si no s
 # moreLocales: ['es', 'ru']
 
 # lang: ''
-src/content/posts/apple.md    -> example.com/posts/apple/
-                              -> example.com/es/posts/apple/
-                              -> example.com/ru/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
+                             -> example.com/es/posts/apple/
+                             -> example.com/ru/posts/apple/
 # lang: en
-src/content/posts/apple.md    -> example.com/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
 # lang: es
-src/content/posts/banana.md   -> example.com/es/posts/banana/
+src/content/posts/apple.md   -> example.com/es/posts/apple/
 # lang: ru
-src/content/posts/orange.md   -> example.com/ru/posts/orange/
+src/content/posts/apple.md   -> example.com/ru/posts/apple/
 ```
 
 #### abbrlink
diff --git a/src/content/posts/Theme Guide-ja.md b/src/content/posts/guides/Theme Guide-ja.md
similarity index 94%
rename from src/content/posts/Theme Guide-ja.md
rename to src/content/posts/guides/Theme Guide-ja.md
index a6e0e6a..2526900 100644
--- a/src/content/posts/Theme Guide-ja.md	
+++ b/src/content/posts/guides/Theme Guide-ja.md	
@@ -231,7 +231,7 @@ abbrlink: theme-guide
 
 #### toc
 
-目次を有効にします。この機能はまだ実装されていません。
+目次を自動生成するかどうか。false に設定すると自動生成が無効になり、デフォルトは true。
 
 #### lang
 
@@ -243,15 +243,15 @@ abbrlink: theme-guide
 # moreLocales: ['es', 'ru']
 
 # lang: ''
-src/content/posts/apple.md    -> example.com/posts/apple/
-                              -> example.com/es/posts/apple/
-                              -> example.com/ru/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
+                             -> example.com/es/posts/apple/
+                             -> example.com/ru/posts/apple/
 # lang: en
-src/content/posts/apple.md    -> example.com/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
 # lang: es
-src/content/posts/banana.md   -> example.com/es/posts/banana/
+src/content/posts/apple.md   -> example.com/es/posts/apple/
 # lang: ru
-src/content/posts/orange.md   -> example.com/ru/posts/orange/
+src/content/posts/apple.md   -> example.com/ru/posts/apple/
 ```
 
 #### abbrlink
diff --git a/src/content/posts/Theme Guide-ru.md b/src/content/posts/guides/Theme Guide-ru.md
similarity index 94%
rename from src/content/posts/Theme Guide-ru.md
rename to src/content/posts/guides/Theme Guide-ru.md
index bbafe31..ccd2c99 100644
--- a/src/content/posts/Theme Guide-ru.md	
+++ b/src/content/posts/guides/Theme Guide-ru.md	
@@ -231,7 +231,7 @@ abbrlink: theme-guide
 
 #### toc
 
-Включает оглавление. Эта функция еще не реализована.
+Генерировать оглавление. При значении false автоматическая генерация отключается. По умолчанию: true.
 
 #### lang
 
@@ -243,15 +243,15 @@ abbrlink: theme-guide
 # moreLocales: ['es', 'ru']
 
 # lang: ''
-src/content/posts/apple.md    -> example.com/posts/apple/
-                              -> example.com/es/posts/apple/
-                              -> example.com/ru/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
+                             -> example.com/es/posts/apple/
+                             -> example.com/ru/posts/apple/
 # lang: en
-src/content/posts/apple.md    -> example.com/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
 # lang: es
-src/content/posts/banana.md   -> example.com/es/posts/banana/
+src/content/posts/apple.md   -> example.com/es/posts/apple/
 # lang: ru
-src/content/posts/orange.md   -> example.com/ru/posts/orange/
+src/content/posts/apple.md   -> example.com/ru/posts/apple/
 ```
 
 #### abbrlink
diff --git a/src/content/posts/Theme Guide-zh-tw.md b/src/content/posts/guides/Theme Guide-zh-tw.md
similarity index 93%
rename from src/content/posts/Theme Guide-zh-tw.md
rename to src/content/posts/guides/Theme Guide-zh-tw.md
index b19b2e6..ae6c644 100644
--- a/src/content/posts/Theme Guide-zh-tw.md	
+++ b/src/content/posts/guides/Theme Guide-zh-tw.md	
@@ -231,7 +231,7 @@ abbrlink: theme-guide
 
 #### toc
 
-是否開啟目錄。尚未實現該功能。
+是否生成目錄。設為 false 時停用自動生成，預設為 true。
 
 #### lang
 
@@ -243,15 +243,15 @@ abbrlink: theme-guide
 # moreLocales: ['es', 'ru']
 
 # lang: ''
-src/content/posts/apple.md    -> example.com/posts/apple/
-                              -> example.com/es/posts/apple/
-                              -> example.com/ru/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
+                             -> example.com/es/posts/apple/
+                             -> example.com/ru/posts/apple/
 # lang: en
-src/content/posts/apple.md    -> example.com/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
 # lang: es
-src/content/posts/banana.md   -> example.com/es/posts/banana/
+src/content/posts/apple.md   -> example.com/es/posts/apple/
 # lang: ru
-src/content/posts/orange.md   -> example.com/ru/posts/orange/
+src/content/posts/apple.md   -> example.com/ru/posts/apple/
 ```
 
 #### abbrlink
diff --git a/src/content/posts/Theme Guide-zh.md b/src/content/posts/guides/Theme Guide-zh.md
similarity index 93%
rename from src/content/posts/Theme Guide-zh.md
rename to src/content/posts/guides/Theme Guide-zh.md
index 6f2820d..bd437b2 100644
--- a/src/content/posts/Theme Guide-zh.md	
+++ b/src/content/posts/guides/Theme Guide-zh.md	
@@ -231,7 +231,7 @@ abbrlink: theme-guide
 
 #### toc
 
-是否开启目录。尚未实现该功能。
+是否生成目录。设为 false 时关闭自动生成，默认为 true。
 
 #### lang
 
@@ -243,15 +243,15 @@ abbrlink: theme-guide
 # moreLocales: ['es', 'ru']
 
 # lang: ''
-src/content/posts/apple.md    -> example.com/posts/apple/
-                              -> example.com/es/posts/apple/
-                              -> example.com/ru/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
+                             -> example.com/es/posts/apple/
+                             -> example.com/ru/posts/apple/
 # lang: en
-src/content/posts/apple.md    -> example.com/posts/apple/
+src/content/posts/apple.md   -> example.com/posts/apple/
 # lang: es
-src/content/posts/banana.md   -> example.com/es/posts/banana/
+src/content/posts/apple.md   -> example.com/es/posts/apple/
 # lang: ru
-src/content/posts/orange.md   -> example.com/ru/posts/orange/
+src/content/posts/apple.md   -> example.com/ru/posts/apple/
 ```
 
 #### abbrlink
diff --git a/src/i18n/ui.ts b/src/i18n/ui.ts
index 49a70de..4252bf7 100644
--- a/src/i18n/ui.ts
+++ b/src/i18n/ui.ts
@@ -6,6 +6,7 @@ export const ui = {
     posts: '文章',
     tags: '标签',
     about: '关于',
+    toc: '目录',
   },
   'zh-tw': {
     title: '重新編排',
@@ -14,6 +15,7 @@ export const ui = {
     posts: '文章',
     tags: '標籤',
     about: '關於',
+    toc: '目錄',
   },
   'ja': {
     title: '再組版',
@@ -22,6 +24,7 @@ export const ui = {
     posts: '記事',
     tags: 'タグ',
     about: '概要',
+    toc: '目次',
   },
   'en': {
     title: 'Retypeset',
@@ -30,6 +33,7 @@ export const ui = {
     posts: 'Posts',
     tags: 'Tags',
     about: 'About',
+    toc: 'Table of Contents',
   },
   'es': {
     title: 'Retipografía',
@@ -38,6 +42,7 @@ export const ui = {
     posts: 'Artículos',
     tags: 'Etiquetas',
     about: 'Sobre',
+    toc: 'Índice',
   },
   'ru': {
     title: 'Переверстка',
@@ -46,5 +51,6 @@ export const ui = {
     posts: 'Посты',
     tags: 'Теги',
     about: 'О себе',
+    toc: 'Оглавление',
   },
 }
diff --git a/src/pages/[...posts_slug].astro b/src/pages/[...posts_slug].astro
index 579ac3a..9ecd3bc 100644
--- a/src/pages/[...posts_slug].astro
+++ b/src/pages/[...posts_slug].astro
@@ -3,6 +3,7 @@ import type { CollectionEntry } from 'astro:content'
 import Comments from '@/components/Comments/index.astro'
 import PostDate from '@/components/PostDate.astro'
 import GoBack from '@/components/Widgets/GoBack.astro'
+import TOC from '@/components/Widgets/TOC.astro'
 import { allLocales, defaultLocale, moreLocales } from '@/config'
 import { getTagPath } from '@/i18n/path'
 import Layout from '@/layouts/Layout.astro'
@@ -96,7 +97,7 @@ export async function getStaticPaths() {
 
 const { post, lang, supportedLangs } = Astro.props
 const description = generateDescription(post, 'meta')
-const { Content, remarkPluginFrontmatter } = await post.render()
+const { Content, headings, remarkPluginFrontmatter } = await post.render()
 ---
 
 <Layout
@@ -132,6 +133,8 @@ const { Content, remarkPluginFrontmatter } = await post.render()
         minutes={remarkPluginFrontmatter.minutes}
       />
     </div>
+    <!-- TOC -->
+    {post.data.toc && <TOC headings={headings} />}
     <!-- Content -->
     <Content />
   </article>
diff --git a/src/styles/global.css b/src/styles/global.css
index 8c3d3dc..3818399 100644
--- a/src/styles/global.css
+++ b/src/styles/global.css
@@ -5,7 +5,7 @@
 }
 
 html {
-  --at-apply: 'bg-background c-secondary antialiased scrollbar-hidden';
+  --at-apply: 'bg-background c-secondary antialiased scrollbar-hidden scroll-smooth';
 }
 
 html::-webkit-scrollbar {
diff --git a/src/styles/heti.css b/src/styles/heti.css
index 5bcd59b..f0ff921 100644
--- a/src/styles/heti.css
+++ b/src/styles/heti.css
@@ -18,165 +18,165 @@
 }
 
 /* Links */
-.heti a {
+.heti :where(a) {
   --at-apply: 'underline decoration-secondary/40 underline-0.075em underline-offset-0.2em lg:underline-0.1em';
   --at-apply: 'font-medium transition-colors tracking-0 hover:(c-primary decoration-secondary/80) ';
 }
 
 /* Paragraphs */
-.heti p {
+.heti :where(p) {
   --at-apply: 'mt-3 mb-4 text-justify';
 }
-.heti p:not(:lang(zh)):not(:lang(ja)):not(:lang(ko)) {
+.heti :where(p:not(:lang(zh)):not(:lang(ja)):not(:lang(ko))) {
   --at-apply: 'text-start';
 }
 
 /* Headings */
-.heti h1,
-.heti h2,
-.heti h3,
-.heti h4,
-.heti h5,
-.heti h6 {
+.heti :where(h1),
+.heti :where(h2),
+.heti :where(h3),
+.heti :where(h4),
+.heti :where(h5),
+.heti :where(h6) {
   --at-apply: 'mt-6 mb-3 font-semibold';
 }
-.heti h1 {
+.heti :where(h1) {
   --at-apply: 'text-8 leading-12';
 }
-.heti h2 {
+.heti :where(h2) {
   --at-apply: 'text-6 leading-9';
 }
-.heti h3 {
+.heti :where(h3) {
   --at-apply: 'text-5 leading-9';
 }
-.heti h4 {
+.heti :where(h4) {
   --at-apply: 'text-4.5 leading-6';
 }
-.heti h5 {
+.heti :where(h5) {
   --at-apply: 'text-4 leading-6';
 }
-.heti h6 {
+.heti :where(h6) {
   --at-apply: 'text-3.5 leading-6';
 }
-.heti h1,
-.heti h2,
-.heti h3 {
+.heti :where(h1),
+.heti :where(h2),
+.heti :where(h3) {
   --at-apply: 'tracking-0.05em';
 }
-.heti h1:not(:lang(zh)):not(:lang(ja)):not(:lang(ko)),
-.heti h2:not(:lang(zh)):not(:lang(ja)):not(:lang(ko)),
-.heti h3:not(:lang(zh)):not(:lang(ja)):not(:lang(ko)) {
+.heti :where(h1:not(:lang(zh)):not(:lang(ja)):not(:lang(ko))),
+.heti :where(h2:not(:lang(zh)):not(:lang(ja)):not(:lang(ko))),
+.heti :where(h3:not(:lang(zh)):not(:lang(ja)):not(:lang(ko))) {
   --at-apply: 'tracking-0';
 }
-.heti h1 + h2,
-.heti h2 + h3,
-.heti h3 + h4,
-.heti h4 + h5,
-.heti h5 + h6 {
+.heti :where(h1 + h2),
+.heti :where(h2 + h3),
+.heti :where(h3 + h4),
+.heti :where(h4 + h5),
+.heti :where(h5 + h6) {
   --at-apply: 'mt-3';
 }
 
 /* Blockquotes */
-.heti blockquote {
+.heti :where(blockquote) {
   --at-apply: 'mt-3 mb-6 px-4 py-3 rounded';
   --at-apply: 'border-l-4 border-solid border-secondary/25 bg-secondary/5';
 }
-.heti blockquote blockquote {
+.heti blockquote :where(blockquote) {
   --at-apply: 'my-3';
 }
-.heti blockquote p {
+.heti blockquote :where(p) {
   --at-apply: 'my-2';
 }
 
 /* Code Blocks */
-.heti pre {
-  --at-apply: 'mt-3 mb-4 px-4 py-3 rounded bg-secondary/5! border border-solid border-secondary/7';
+.heti :where(pre) {
+  --at-apply: 'mt-3 mb-4 px-4 py-3 rounded bg-secondary/5! border border-solid border-secondary/5';
   --at-apply: 'overflow-auto whitespace-pre scrollbar-hidden';
 }
-.heti pre code {
+.heti pre :where(code) {
   --at-apply: 'p-0 bg-secondary/0 tracking-0 border-none';
 }
-html.dark .heti pre span {
+html.dark .heti pre :where(span) {
   --at-apply: 'text-[var(--shiki-dark)]!';
 }
 
 /* Inline Code */
-.heti code {
-  --at-apply: 'p-0.5 bg-secondary/5 rounded text-0.85em border border-solid border-secondary/7';
+.heti :where(code) {
+  --at-apply: 'p-0.5 bg-secondary/5 rounded text-0.85em border border-solid border-secondary/5';
 }
 
 /* Horizontal Rules */
-.heti hr {
+.heti :where(hr) {
   --at-apply: 'border-secondary/25';
 }
 
 /* Lists */
-.heti ul,
-.heti ol,
-.heti dl {
+.heti :where(ul),
+.heti :where(ol),
+.heti :where(dl) {
   --at-apply: 'mt-3 mb-6';
 }
-.heti ul,
-.heti ol {
+.heti :where(ul),
+.heti :where(ol) {
   --at-apply: 'pl-8';
 }
-.heti ul ul,
-.heti ul ol,
-.heti ol ul,
-.heti ol ol {
+.heti ul :where(ul),
+.heti ul :where(ol),
+.heti ol :where(ul),
+.heti ol :where(ol) {
   --at-apply: 'my-0';
 }
-.heti ul {
+.heti :where(ul) {
   --at-apply: 'list-disc';
 }
-.heti ol {
+.heti :where(ol) {
   --at-apply: 'list-decimal';
 }
-.heti ul ul,
-.heti ol ul {
+.heti ul :where(ul),
+.heti ol :where(ul) {
   --at-apply: 'list-circle';
 }
-.heti ul ul ul,
-.heti ul ol ul,
-.heti ol ul ul,
-.heti ol ol ul {
+.heti ul ul :where(ul),
+.heti ul ol :where(ul),
+.heti ol ul :where(ul),
+.heti ol ol :where(ul) {
   --at-apply: 'list-square';
 }
-.heti li {
+.heti :where(li) {
   --at-apply: 'list-unset';
 }
 
 /* Tables */
-.heti table {
+.heti :where(table) {
   --at-apply: 'box-border table-fixed mt-3 mb-6 rounded-md break-words';
   --at-apply: 'border border-solid border-secondary/25 border-collapse';
 }
-.heti th,
-.heti td {
+.heti :where(th),
+.heti :where(td) {
   --at-apply: 'px-3 py-1.5 border border-solid border-secondary/40';
 }
 
 /* Abbreviations */
-.heti abbr {
+.heti :where(abbr) {
   --at-apply: 'tracking-0';
 }
-.heti abbr[title] {
+.heti :where(abbr[title]) {
   --at-apply: 'mx-0.25 pb-0.25 border-dotted border-secondary border-b-1 no-underline cursor-help';
 }
 
 /* Superscript and Subscript */
-.heti sub,
-.heti sup {
+.heti :where(sub),
+.heti :where(sup) {
   --at-apply: 'mx-0.15em relative text-0.75em leading-1 align-baseline';
 }
-.heti sub {
+.heti :where(sub) {
   --at-apply: 'bottom--0.25em';
 }
-.heti sup {
+.heti :where(sup) {
   --at-apply: 'top--0.5em';
 }
-.heti sub a,
-.heti sup a {
+.heti sub :where(a),
+.heti sup :where(a) {
   --at-apply: 'no-underline';
 }
 .heti sup:target,
@@ -189,16 +189,16 @@ html.dark .heti sup a:target {
 }
 
 /* Keyboard Input */
-.heti kbd {
+.heti :where(kbd) {
   --at-apply: 'rounded border border-solid border-secondary/40 text-secondary';
   --at-apply: 'inline-block text-0.85em font-bold leading-none px-1 py-0.75 whitespace-nowrap';
 }
 
 /* Highlighted Text */
-.heti mark {
+.heti :where(mark) {
   --at-apply: 'mx-0.25 px-0.25 py-0.5 text-inherit bg-#ff0';
 }
-html.dark .heti mark {
+html.dark .heti :where(mark) {
   --at-apply: 'bg-#4d4a00e0';
 }
 
@@ -231,68 +231,68 @@ html.dark .heti mark {
   content: "Сноски";
   --at-apply: 'block text-5 font-semibold mt-6 mb-3';
 }
-.heti .data-footnote-backref {
+.heti :where(.data-footnote-backref) {
   --at-apply: 'no-underline';
 }
 
 /* Bold */
-.heti b,
-.heti strong {
+.heti :where(b),
+.heti :where(strong) {
   --at-apply: 'font-semibold';
 }
 
 /* Italic */
-.heti i {
+.heti :where(i) {
   --at-apply: 'font-italic';
 }
 
 /* Emphasized */
-.heti em {
+.heti :where(em) {
   --at-apply: 'italic';
 }
 
 /* Quotes */
-.heti q {
+.heti :where(q) {
   quotes: "「" "」" "『" "』";
 }
-.heti q:not(:lang(zh)):not(:lang(ja)):not(:lang(ko)) {
+.heti :where(q:not(:lang(zh)):not(:lang(ja)):not(:lang(ko))) {
   quotes: initial;
   quotes: auto;
 }
 
 /* Wavy Underline */
-.heti u {
+.heti :where(u) {
   --at-apply: 'mx-0.25 underline decoration-wavy decoration-red underline-offset-4';
 }
-html.dark .heti u {
+html.dark .heti :where(u) {
   --at-apply: 'decoration-#A14F50';
 }
 
 /* Strikethrough */
-.heti del,
-.heti s {
+.heti :where(del),
+.heti :where(s) {
   --at-apply: 'mx-0.25';
 }
 
 /* Images */
-.heti figure {
+.heti :where(figure) {
   --at-apply: 'my-6';
 }
-.heti figure > figcaption {
+.heti figure > :where(figcaption) {
   --at-apply: 'text-center text-sm mt-3 text-secondary/75';
 }
 
 /* Markdown Extensions Style >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> */
-.heti details {
+.heti :where(details) {
   --at-apply: 'my-4 px-4 py-3 border border-solid border-secondary/25 rounded cursor-pointer';
 }
-.heti details summary {
+.heti details :where(summary) {
   --at-apply: 'cursor-pointer';
 }
-.heti details[open] summary {
+.heti details[open] :where(summary) {
   --at-apply: 'border-b border-solid border-secondary/25 mb-3 pb-3';
 }
-/* .heti details summary {
+/* .heti details :where(summary) {
   list-style: none;
 }
 .heti details summary::-webkit-details-marker {