From e51d2a8c4922caf2619183c97d11c2e69337680e Mon Sep 17 00:00:00 2001
From: Kia King Ishii <kia.king.08@gmail.com>
Date: Sun, 22 May 2022 16:27:51 +0900
Subject: [PATCH] feat: add custom container stylings

---
 docs/.vitepress/config.ts                     |   6 +-
 docs/config/frontmatter-configs.md            |  24 +
 docs/guide/frontmatter.md                     |  38 ++
 docs/guide/markdown-extensions.md             | 413 ++++++++++++++++++
 docs/snippets/snippet-with-region.js          |   7 +
 docs/snippets/snippet.js                      |   3 +
 src/client/theme-default/index.ts             |   5 +-
 .../styles/components/custom-block.css        |  66 +++
 .../styles/{ => components}/vp-doc.css        |  43 +-
 .../styles/{ => components}/vp-sponsor.css    |   0
 src/client/theme-default/styles/vars.css      | 112 +++--
 src/node/markdown/plugins/containers.ts       |   4 +-
 12 files changed, 673 insertions(+), 48 deletions(-)
 create mode 100644 docs/guide/frontmatter.md
 create mode 100644 docs/guide/markdown-extensions.md
 create mode 100644 docs/snippets/snippet-with-region.js
 create mode 100644 docs/snippets/snippet.js
 create mode 100644 src/client/theme-default/styles/components/custom-block.css
 rename src/client/theme-default/styles/{ => components}/vp-doc.css (93%)
 rename src/client/theme-default/styles/{ => components}/vp-sponsor.css (100%)

diff --git a/docs/.vitepress/config.ts b/docs/.vitepress/config.ts
index e2aa7800..09f2a04b 100644
--- a/docs/.vitepress/config.ts
+++ b/docs/.vitepress/config.ts
@@ -52,7 +52,11 @@ function sidebarGuide() {
   return [
     {
       text: 'Introduction',
-      items: [{ text: 'What is VitePress?', link: '/guide/what-is-vitepress' }]
+      items: [
+        { text: 'What is VitePress?', link: '/guide/what-is-vitepress' },
+        { text: 'Markdown Extensions', link: '/guide/markdown-extensions' },
+        { text: 'Frontmatter', link: '/guide/frontmatter' }
+      ]
     },
     {
       text: 'Migrations',
diff --git a/docs/config/frontmatter-configs.md b/docs/config/frontmatter-configs.md
index ed1f5f09..b11a5cf2 100644
--- a/docs/config/frontmatter-configs.md
+++ b/docs/config/frontmatter-configs.md
@@ -52,6 +52,30 @@ description: VitePress
 ---
 ```
 
+### head
+
+- Type: `Head[]`
+
+Specify extra head tags to be injected:
+
+```yaml
+---
+head:
+  - - meta
+    - name: description
+      content: hello
+  - - meta
+    - name: keywords
+      content: super duper SEO
+---
+```
+
+```ts
+type Head =
+  | [string, Record<string, string>]
+  | [string, Record<string, string>, string]
+```
+
 ## layout
 
 - Type: `doc | home | page`
diff --git a/docs/guide/frontmatter.md b/docs/guide/frontmatter.md
new file mode 100644
index 00000000..4f25ac96
--- /dev/null
+++ b/docs/guide/frontmatter.md
@@ -0,0 +1,38 @@
+# Frontmatter
+
+Any Markdown file that contains a YAML frontmatter block will be processed by [gray-matter](https://github.com/jonschlinkert/gray-matter). The frontmatter must be at the top of the Markdown file, and must take the form of valid YAML set between triple-dashed lines. Example:
+
+```md
+---
+title: Docs with VitePress
+editLink: true
+---
+```
+
+Between the triple-dashed lines, you can set [predefined variables](../config/frontmatter-configs), or even create custom ones of your own. These variables can be used via the special <code>$frontmatter</code> variable.
+
+Here’s an example of how you could use it in your Markdown file:
+
+```md
+---
+title: Docs with VitePress
+editLink: true
+---
+
+# {{ $frontmatter.title }}
+
+Guide content
+```
+
+## Alternative frontmatter Formats
+
+VitePress also supports JSON frontmatter syntax, starting and ending in curly braces:
+
+```json
+---
+{
+  "title": "Blogging Like a Hacker",
+  "editLink": true
+}
+---
+```
diff --git a/docs/guide/markdown-extensions.md b/docs/guide/markdown-extensions.md
new file mode 100644
index 00000000..dbeefe11
--- /dev/null
+++ b/docs/guide/markdown-extensions.md
@@ -0,0 +1,413 @@
+# Markdown Extensions
+
+VitePress comes with built in Markdown Extensions.
+
+## Header Anchors
+
+Headers automatically get anchor links applied. Rendering of anchors can be configured using the `markdown.anchor` option.
+
+## Links
+
+Both internal and external links gets special treatments.
+
+### Internal Links
+
+Internal links are converted to router link for SPA navigation. Also, every `index.md` contained in each sub-directory will automatically be converted to `index.html`, with corresponding URL `/`.
+
+For example, given the following directory structure:
+
+```
+.
+├─ index.md
+├─ foo
+│  ├─ index.md
+│  ├─ one.md
+│  └─ two.md
+└─ bar
+   ├─ index.md
+   ├─ three.md
+   └─ four.md
+```
+
+And providing you are in `foo/one.md`:
+
+```md
+[Home](/) <!-- sends the user to the root index.md -->
+[foo](/foo/) <!-- sends the user to index.html of directory foo -->
+[foo heading](./#heading) <!-- anchors user to a heading in the foo index file -->
+[bar - three](../bar/three) <!-- you can omit extention -->
+[bar - three](../bar/three.md) <!-- you can append .md -->
+[bar - four](../bar/four.html) <!-- or you can append .html -->
+```
+
+### Page Suffix
+
+Pages and internal links get generated with the `.html` suffix by default.
+
+### External Links
+
+Outbound links automatically get `target="_blank" rel="noopener noreferrer"`:
+
+- [vuejs.org](https://vuejs.org)
+- [VitePress on GitHub](https://github.com/vuejs/vitepress)
+
+## Frontmatter
+
+[YAML frontmatter](https://jekyllrb.com/docs/front-matter/) is supported out of the box:
+
+```yaml
+---
+title: Blogging Like a Hacker
+lang: en-US
+---
+```
+
+This data will be available to the rest of the page, along with all custom and theming components.
+
+For more details, see [Frontmatter](./frontmatter).
+
+## GitHub-Style Tables
+
+**Input**
+
+```
+| Tables        | Are           | Cool  |
+| ------------- |:-------------:| -----:|
+| col 3 is      | right-aligned | $1600 |
+| col 2 is      | centered      |   $12 |
+| zebra stripes | are neat      |    $1 |
+```
+
+**Output**
+
+| Tables        |      Are      |   Cool |
+| ------------- | :-----------: | -----: |
+| col 3 is      | right-aligned | \$1600 |
+| col 2 is      |   centered    |   \$12 |
+| zebra stripes |   are neat    |    \$1 |
+
+## Emoji :tada:
+
+**Input**
+
+```
+:tada: :100:
+```
+
+**Output**
+
+:tada: :100:
+
+A [list of all emojis](https://github.com/markdown-it/markdown-it-emoji/blob/master/lib/data/full.json) is available.
+
+## Table of Contents
+
+**Input**
+
+```
+[[toc]]
+```
+
+**Output**
+
+[[toc]]
+
+Rendering of the TOC can be configured using the `markdown.toc` option.
+
+## Custom Containers
+
+Custom containers can be defined by their types, titles, and contents.
+
+### Default Title
+
+**Input**
+
+```md
+::: info
+This is an info box.
+:::
+
+::: tip
+This is a tip.
+:::
+
+::: warning
+This is a warning.
+:::
+
+::: danger
+This is a dangerous warning.
+:::
+
+::: details
+This is a details block.
+:::
+```
+
+**Output**
+
+::: info
+This is an info box.
+:::
+
+::: tip
+This is a tip.
+:::
+
+::: warning
+This is a dangerous warning.
+:::
+
+::: danger
+This is a dangerous warning.
+:::
+
+::: details
+This is a details block.
+:::
+
+### Custom Title
+
+You may set custom title by appending the text right after the "type" of the container.
+
+**Input**
+
+````md
+::: danger STOP
+Danger zone, do not proceed
+:::
+
+::: details Click me to view the code
+```js
+console.log('Hello, VitePress!')
+```
+:::
+````
+
+**Output**
+
+::: danger STOP
+Danger zone, do not proceed
+:::
+
+::: details Click me to view the code
+```js
+console.log('Hello, VitePress!')
+```
+:::
+
+## Syntax Highlighting in Code Blocks
+
+VitePress uses [Prism](https://prismjs.com) to highlight language syntax in Markdown code blocks, using coloured text. Prism supports a wide variety of programming languages. All you need to do is append a valid language alias to the beginning backticks for the code block:
+
+**Input**
+
+````
+```js
+export default {
+  name: 'MyComponent',
+  // ...
+}
+```
+````
+
+**Output**
+
+```js
+export default {
+  name: 'MyComponent'
+  // ...
+}
+```
+
+**Input**
+
+````
+```html
+<ul>
+  <li v-for="todo in todos" :key="todo.id">
+    {{ todo.text }}
+  </li>
+</ul>
+```
+````
+
+**Output**
+
+```html
+<ul>
+  <li v-for="todo in todos" :key="todo.id">{{ todo.text }}</li>
+</ul>
+```
+
+A [list of valid languages](https://prismjs.com/#languages-list) is available on Prism’s site.
+
+## Line Highlighting in Code Blocks
+
+**Input**
+
+````
+```js{4}
+export default {
+  data () {
+    return {
+      msg: 'Highlighted!'
+    }
+  }
+}
+```
+````
+
+**Output**
+
+```js{4}
+export default {
+  data () {
+    return {
+      msg: 'Highlighted!'
+    }
+  }
+}
+```
+
+In addition to a single line, you can also specify multiple single lines, ranges, or both:
+
+- Line ranges: for example `{5-8}`, `{3-10}`, `{10-17}`
+- Multiple single lines: for example `{4,7,9}`
+- Line ranges and single lines: for example `{4,7-13,16,23-27,40}`
+
+**Input**
+
+````
+```js{1,4,6-7}
+export default { // Highlighted
+  data () {
+    return {
+      msg: `Highlighted!
+      This line isn't highlighted,
+      but this and the next 2 are.`,
+      motd: 'VitePress is awesome',
+      lorem: 'ipsum',
+    }
+  }
+}
+```
+````
+
+**Output**
+
+```js{1,4,6-8}
+export default { // Highlighted
+  data () {
+    return {
+      msg: `Highlighted!
+      This line isn't highlighted,
+      but this and the next 2 are.`,
+      motd: 'VitePress is awesome',
+      lorem: 'ipsum',
+    }
+  }
+}
+```
+
+## Line Numbers
+
+You can enable line numbers for each code blocks via config:
+
+```js
+module.exports = {
+  markdown: {
+    lineNumbers: true
+  }
+}
+```
+
+## Import Code Snippets
+
+You can import code snippets from existing files via following syntax:
+
+```md
+<<< @/filepath
+```
+
+It also supports [line highlighting](#line-highlighting-in-code-blocks):
+
+```md
+<<< @/filepath{highlightLines}
+```
+
+**Input**
+
+```md
+<<< @/snippets/snippet.js{2}
+```
+
+**Code file**
+
+<!--lint disable strong-marker-->
+
+<<< @/snippets/snippet.js
+
+<!--lint enable strong-marker-->
+
+**Output**
+
+<!--lint disable strong-marker-->
+
+<<< @/snippets/snippet.js{2}
+
+<!--lint enable strong-marker-->
+
+::: tip
+The value of `@` corresponds to the source root. By default it's the VitePress project root, unless `srcDir` is configured.
+:::
+
+You can also use a [VS Code region](https://code.visualstudio.com/docs/editor/codebasics#_folding) to only include the corresponding part of the code file. You can provide a custom region name after a `#` following the filepath (`snippet` by default):
+
+**Input**
+
+```md
+<<< @/snippets/snippet-with-region.js{1}
+```
+
+**Code file**
+
+<!--lint disable strong-marker-->
+
+<<< @/snippets/snippet-with-region.js
+
+<!--lint enable strong-marker-->
+
+**Output**
+
+<!--lint disable strong-marker-->
+
+<<< @/snippets/snippet-with-region.js#snippet{1}
+
+<!--lint enable strong-marker-->
+
+## Advanced Configuration
+
+VitePress uses [markdown-it](https://github.com/markdown-it/markdown-it) as the Markdown renderer. A lot of the extensions above are implemented via custom plugins. You can further customize the `markdown-it` instance using the `markdown` option in `.vitepress/config.js`:
+
+```js
+const anchor = require('markdown-it-anchor')
+
+module.exports = {
+  markdown: {
+    // options for markdown-it-anchor
+    // https://github.com/valeriangalliat/markdown-it-anchor#permalinks
+    anchor: {
+      permalink: anchor.permalink.headerLink()
+    },
+
+    // options for markdown-it-table-of-contents
+    toc: { includeLevel: [1, 2] },
+
+    config: (md) => {
+      // use more markdown-it plugins!
+      md.use(require('markdown-it-xxx'))
+    }
+  }
+}
+```
diff --git a/docs/snippets/snippet-with-region.js b/docs/snippets/snippet-with-region.js
new file mode 100644
index 00000000..9c7faaeb
--- /dev/null
+++ b/docs/snippets/snippet-with-region.js
@@ -0,0 +1,7 @@
+// #region snippet
+function foo() {
+  // ..
+}
+// #endregion snippet
+
+export default foo
diff --git a/docs/snippets/snippet.js b/docs/snippets/snippet.js
new file mode 100644
index 00000000..575039d1
--- /dev/null
+++ b/docs/snippets/snippet.js
@@ -0,0 +1,3 @@
+export default function () {
+  // ..
+}
diff --git a/src/client/theme-default/index.ts b/src/client/theme-default/index.ts
index ca744086..712f89bb 100644
--- a/src/client/theme-default/index.ts
+++ b/src/client/theme-default/index.ts
@@ -2,8 +2,9 @@ import './styles/fonts.css'
 import './styles/vars.css'
 import './styles/base.css'
 import './styles/utils.css'
-import './styles/vp-doc.css'
-import './styles/vp-sponsor.css'
+import './styles/components/custom-block.css'
+import './styles/components/vp-doc.css'
+import './styles/components/vp-sponsor.css'
 
 import { Theme } from 'vitepress'
 import Layout from './Layout.vue'
diff --git a/src/client/theme-default/styles/components/custom-block.css b/src/client/theme-default/styles/components/custom-block.css
new file mode 100644
index 00000000..0239b2b5
--- /dev/null
+++ b/src/client/theme-default/styles/components/custom-block.css
@@ -0,0 +1,66 @@
+.custom-block {
+  border: 1px solid transparent;
+  border-radius: 8px;
+  padding: 16px 16px 8px;
+  line-height: 20px;
+  font-size: 14px;
+  color: var(--vp-c-text-2);
+}
+
+.custom-block.info {
+  border-color: var(--vp-custom-block-info-border);
+  color: var(--vp-custom-block-info-text);
+  background-color: var(--vp-custom-block-info-bg);
+}
+
+.custom-block.tip {
+  border-color: var(--vp-custom-block-tip-border);
+  color: var(--vp-custom-block-tip-text);
+  background-color: var(--vp-custom-block-tip-bg);
+}
+
+.custom-block.warning {
+  border-color: var(--vp-custom-block-warning-border);
+  color: var(--vp-custom-block-warning-text);
+  background-color: var(--vp-custom-block-warning-bg);
+}
+
+.custom-block.danger {
+  border-color: var(--vp-custom-block-danger-border);
+  color: var(--vp-custom-block-danger-text);
+  background-color: var(--vp-custom-block-danger-bg);
+}
+
+.custom-block.details {
+  border-color: var(--vp-custom-block-details-border);
+  color: var(--vp-custom-block-details-text);
+  background-color: var(--vp-custom-block-details-bg);
+}
+
+.custom-block-title {
+  font-weight: 700;
+}
+
+.custom-block p + p {
+  margin: 8px 0;
+}
+
+.custom-block.details summary {
+  margin: 0 0 8px;
+  font-weight: 700;
+}
+
+.custom-block.details summary + p {
+  margin: 8px 0;
+}
+
+.custom-block a {
+  color: inherit;
+  font-weight: 600;
+  text-decoration: underline;
+  transition: opacity .25s;
+}
+
+.custom-block a:hover {
+  opacity: 0.6;
+}
diff --git a/src/client/theme-default/styles/vp-doc.css b/src/client/theme-default/styles/components/vp-doc.css
similarity index 93%
rename from src/client/theme-default/styles/vp-doc.css
rename to src/client/theme-default/styles/components/vp-doc.css
index e664afbc..644def57 100644
--- a/src/client/theme-default/styles/vp-doc.css
+++ b/src/client/theme-default/styles/components/vp-doc.css
@@ -115,18 +115,27 @@
 
 .vp-doc ul,
 .vp-doc ol {
+  padding-left: 1.25rem;
   margin: 16px 0;
 }
 
 .vp-doc ul {
-  padding-left: 1.25rem;
   list-style: disc;
 }
 
+.vp-doc ol {
+  list-style: decimal;
+}
+
 .vp-doc li + li {
   margin-top: 8px;
 }
 
+.vp-doc li > ol,
+.vp-doc li > ul {
+  margin: 8px 0 0;
+}
+
 /**
  * Table
  * -------------------------------------------------------------------------- */
@@ -177,6 +186,38 @@
   border-top: 1px solid var(--vp-c-divider-light);
 }
 
+/**
+ * Custom Block
+ * -------------------------------------------------------------------------- */
+
+.vp-doc .custom-block {
+  margin: 16px 0;
+}
+
+.vp-doc .custom-block p {
+  margin: 8px 0;
+  line-height: 24px;
+}
+
+.vp-doc .custom-block p:first-child {
+  margin: 0;
+}
+
+.vp-doc .custom-block a {
+  color: inherit;
+  font-weight: 600;
+  text-decoration: underline;
+  transition: opacity .25s;
+}
+
+.vp-doc .custom-block a:hover {
+  opacity: 0.6;
+}
+
+.vp-doc .custom-block div[class*='language-'] {
+  margin: 8px 0;
+}
+
 /**
  * Code
  * -------------------------------------------------------------------------- */
diff --git a/src/client/theme-default/styles/vp-sponsor.css b/src/client/theme-default/styles/components/vp-sponsor.css
similarity index 100%
rename from src/client/theme-default/styles/vp-sponsor.css
rename to src/client/theme-default/styles/components/vp-sponsor.css
diff --git a/src/client/theme-default/styles/vars.css b/src/client/theme-default/styles/vars.css
index 0ec0581d..0fa023e4 100644
--- a/src/client/theme-default/styles/vars.css
+++ b/src/client/theme-default/styles/vars.css
@@ -43,12 +43,6 @@
   --vp-c-text-dark-3: rgba(235, 235, 235, 0.38);
   --vp-c-text-dark-4: rgba(235, 235, 235, 0.18);
 
-  --vp-c-green: #42b883;
-  --vp-c-green-light: #42d392;
-  --vp-c-green-lighter: #35eb9a;
-  --vp-c-green-dark: #33a06f;
-  --vp-c-green-darker: #155f3e;
-
   --vp-c-indigo: #213547;
   --vp-c-indigo-soft: #476582;
   --vp-c-indigo-light: #aac8e4;
@@ -56,29 +50,26 @@
   --vp-c-indigo-dark: #1d2f3f;
   --vp-c-indigo-darker: #14212e;
 
-  --vp-c-blue: #3b8eed;
-  --vp-c-blue-light: #549ced;
-  --vp-c-blue-lighter: #50a2ff;
-  --vp-c-blue-dark: #3468a3;
-  --vp-c-blue-darker: #255489;
+  --vp-c-green: #42b883;
+  --vp-c-green-light: #42d392;
+  --vp-c-green-lighter: #35eb9a;
+  --vp-c-green-dark: #33a06f;
+  --vp-c-green-darker: #155f3e;
+  --vp-c-green-dimm: rgba(66, 184, 131, 0.08);
 
   --vp-c-yellow: #ffc517;
   --vp-c-yellow-light: #ffe417;
   --vp-c-yellow-lighter: #ffff17;
   --vp-c-yellow-dark: #e0ad15;
-  --vp-c-yellow-darker: #bc9112;
+  --vp-c-yellow-darker: #ad850e;
+  --vp-c-yellow-dimm: rgba(255, 197, 23, 0.08);
 
   --vp-c-red: #ed3c50;
   --vp-c-red-light: #f43771;
   --vp-c-red-lighter: #fd1d7c;
   --vp-c-red-dark: #cd2d3f;
   --vp-c-red-darker: #ab2131;
-
-  --vp-c-purple: #de41e0;
-  --vp-c-purple-light: #e936eb;
-  --vp-c-purple-lighter: #f616f8;
-  --vp-c-purple-dark: #823c83;
-  --vp-c-purple-darker: #602960;
+  --vp-c-red-dimm: rgba(237, 60, 80, 0.08);
 }
 
 /**
@@ -188,30 +179,6 @@
   --vp-layout-max-width: 1376px;
 }
 
-/**
- * Component: Nav
- * -------------------------------------------------------------------------- */
-
-:root {
-  --vp-nav-height: var(--vp-nav-height-mobile);
-  --vp-nav-height-mobile: 56px;
-  --vp-nav-height-desktop: 72px;
-}
-
-@media (min-width: 960px) {
-  :root {
-    --vp-nav-height: var(--vp-nav-height-desktop);
-  }
-}
-
-/**
- * Component: Sidebar
- * -------------------------------------------------------------------------- */
-
-:root {
-  --vp-sidebar-width: 272px;
-}
-
 /**
  * Component: Code
  * -------------------------------------------------------------------------- */
@@ -289,6 +256,67 @@
   --vp-button-sponsor-text: var(--vp-c-text-dark-2);
 }
 
+/**
+ * Component: Custom Block
+ * -------------------------------------------------------------------------- */
+
+:root {
+  --vp-custom-block-info-border: var(--vp-c-divider-light);
+  --vp-custom-block-info-text: var(--vp-c-text-2);
+  --vp-custom-block-info-bg: var(--vp-c-white-soft);
+
+  --vp-custom-block-tip-border: var(--vp-c-green);
+  --vp-custom-block-tip-text: var(--vp-c-green-darker);
+  --vp-custom-block-tip-bg: var(--vp-c-green-dimm);
+
+  --vp-custom-block-warning-border: var(--vp-c-yellow);
+  --vp-custom-block-warning-text: var(--vp-c-yellow-darker);
+  --vp-custom-block-warning-bg: var(--vp-c-yellow-dimm);
+
+  --vp-custom-block-danger-border: var(--vp-c-red);
+  --vp-custom-block-danger-text: var(--vp-c-red-darker);
+  --vp-custom-block-danger-bg: var(--vp-c-red-dimm);
+
+  --vp-custom-block-details-border: var(--vp-custom-block-info-border);
+  --vp-custom-block-details-text: var(--vp-custom-block-info-text);
+  --vp-custom-block-details-bg: var(--vp-custom-block-info-bg);
+}
+
+.dark {
+  --vp-custom-block-info-border: var(--vp-c-divider-light);
+  --vp-custom-block-info-bg: var(--vp-c-black-mute);
+
+  --vp-custom-block-tip-text: var(--vp-c-green);
+
+  --vp-custom-block-warning-text: var(--vp-c-yellow);
+
+  --vp-custom-block-danger-text: var(--vp-c-red);
+}
+
+/**
+ * Component: Nav
+ * -------------------------------------------------------------------------- */
+
+:root {
+  --vp-nav-height: var(--vp-nav-height-mobile);
+  --vp-nav-height-mobile: 56px;
+  --vp-nav-height-desktop: 72px;
+}
+
+@media (min-width: 960px) {
+  :root {
+    --vp-nav-height: var(--vp-nav-height-desktop);
+  }
+}
+
+/**
+ * Component: Sidebar
+ * -------------------------------------------------------------------------- */
+
+:root {
+  --vp-sidebar-width: 272px;
+}
+
 /**
  * Component: Home
  * -------------------------------------------------------------------------- */
diff --git a/src/node/markdown/plugins/containers.ts b/src/node/markdown/plugins/containers.ts
index 9e3caa23..def665b2 100644
--- a/src/node/markdown/plugins/containers.ts
+++ b/src/node/markdown/plugins/containers.ts
@@ -6,7 +6,7 @@ export const containerPlugin = (md: MarkdownIt) => {
   md.use(...createContainer('tip', 'TIP'))
     .use(...createContainer('info', 'INFO'))
     .use(...createContainer('warning', 'WARNING'))
-    .use(...createContainer('danger', 'WARNING'))
+    .use(...createContainer('danger', 'DANGER'))
     .use(...createContainer('details', 'Details'))
     // explicitly escape Vue syntax
     .use(container, 'v-pre', {
@@ -34,7 +34,7 @@ function createContainer(klass: string, defaultTitle: string): ContainerArgs {
         if (token.nesting === 1) {
           if (klass === 'details') {
             return `<details class="${klass} custom-block">${
-              info ? `<summary>${info}</summary>` : ''
+              info ? `<summary>${info}</summary>` : `<summary>Details</summary>`
             }\n`
           }
           return `<div class="${klass} custom-block"><p class="custom-block-title">${