diff --git a/frontend/src/components/common/MarkdownContent.vue b/frontend/src/components/common/MarkdownContent.vue
index 3e3f173..6580f2e 100644
--- a/frontend/src/components/common/MarkdownContent.vue
+++ b/frontend/src/components/common/MarkdownContent.vue
@@ -24,19 +24,26 @@ watch(() => props.source, async (source) => {
 .markdown-content :deep(ul) { padding-left: 1.5em; list-style: disc; }
 .markdown-content :deep(ol) { padding-left: 1.5em; list-style: decimal; }
 .markdown-content :deep(li::marker) { color: var(--color-markdown-marker); font-weight: 700; }
-.markdown-content :deep(.shiki) { overflow: auto; padding: var(--space-md); border: 1px solid var(--color-border-subtle); border-radius: var(--radius-md); }
+.markdown-content :deep(.shiki) { overflow: auto; margin: .85em 0; padding: 16px; border: 1px solid var(--color-code-border); border-radius: 6px; background: var(--color-code-background) !important; color: var(--color-code-text); font-family: var(--font-ui-mono); font-size: .875em; line-height: 1.45; tab-size: 4; }
 .markdown-content :deep(code) { padding: .1em .3em; border-radius: var(--radius-sm); background: var(--color-background-tertiary); font-family: var(--font-ui-mono); }
-.markdown-content :deep(pre code) { padding: 0; background: transparent; }
+.markdown-content :deep(.shiki code) { display: block; min-width: max-content; padding: 0; background: transparent; font: inherit; }
+.markdown-content :deep(.shiki .line) { display: block; min-height: 1.45em; }
 .markdown-content :deep(blockquote) { padding-left: 1em; border-left: 3px solid var(--color-accent-primary); color: var(--color-text-secondary); }
 .markdown-content :deep(table) { width: 100%; margin: .65em 0; border-collapse: collapse; }
 .markdown-content :deep(th), .markdown-content :deep(td) { padding: .45em .65em; border: 1px solid var(--color-markdown-grid); text-align: left; }
 .markdown-content :deep(th) { background: var(--color-markdown-table-header); font-weight: 700; }
 .markdown-content :deep(img) { max-width: 100%; }
 .markdown-content :deep(hr) { margin: 1em 0; border: 0; border-top: 1px solid var(--color-border-default); }
-:global([data-theme='dark']) .markdown-content :deep(.shiki),
-:global([data-theme='dark']) .markdown-content :deep(.shiki span) {
+:global([data-code-theme='github-light']) .markdown-content :deep(.shiki),
+:global([data-code-theme='github-light']) .markdown-content :deep(.shiki span) {
+  color: var(--shiki-light) !important;
+  font-style: var(--shiki-light-font-style) !important;
+  font-weight: var(--shiki-light-font-weight) !important;
+  text-decoration: var(--shiki-light-text-decoration) !important;
+}
+:global([data-code-theme='github-dark']) .markdown-content :deep(.shiki),
+:global([data-code-theme='github-dark']) .markdown-content :deep(.shiki span) {
   color: var(--shiki-dark) !important;
-  background-color: var(--shiki-dark-bg) !important;
   font-style: var(--shiki-dark-font-style) !important;
   font-weight: var(--shiki-dark-font-weight) !important;
   text-decoration: var(--shiki-dark-text-decoration) !important;
diff --git a/frontend/src/contracts/index.ts b/frontend/src/contracts/index.ts
index 2a3d973..237fa4f 100644
--- a/frontend/src/contracts/index.ts
+++ b/frontend/src/contracts/index.ts
@@ -329,6 +329,7 @@ export interface ThemeConfig {
   is_dark: boolean
   author?: string
   builtin: boolean
+  code_theme?: 'github-light' | 'github-dark'
 }
 
 // ============ Index ============
diff --git a/frontend/src/features/editor/EditorPane.vue b/frontend/src/features/editor/EditorPane.vue
index 2e64f78..2767e6a 100644
--- a/frontend/src/features/editor/EditorPane.vue
+++ b/frontend/src/features/editor/EditorPane.vue
@@ -1,10 +1,12 @@
 <script setup lang="ts">
 import { useEditorStore } from '@/stores/editor'
 import { useSettingsStore } from '@/stores/settings'
+import { useThemeStore } from '@/stores/theme'
 import VisualMarkdownEditor from './VisualMarkdownEditor.vue'
 
 const editorStore = useEditorStore()
 const settingsStore = useSettingsStore()
+const themeStore = useThemeStore()
 function updateContent(event: Event) {
   editorStore.updateContent((event.target as HTMLTextAreaElement).value)
   editorStore.scheduleAutoSave(settingsStore.autoSaveInterval)
@@ -12,7 +14,7 @@ function updateContent(event: Event) {
 </script>
 
 <template>
-  <VisualMarkdownEditor v-if="editorStore.mode === 'wysiwyg'" :key="editorStore.currentFilePath ?? 'empty'"
+  <VisualMarkdownEditor v-if="editorStore.mode === 'wysiwyg'" :key="`${editorStore.currentFilePath ?? 'empty'}:${themeStore.resolvedCodeBlockTheme}`"
     :initial-content="editorStore.content" />
   <textarea v-else class="editor-pane source" :value="editorStore.content" :spellcheck="false"
     aria-label="Markdown 源码编辑器" @input="updateContent" />
diff --git a/frontend/src/features/editor/VisualMarkdownEditor.vue b/frontend/src/features/editor/VisualMarkdownEditor.vue
index a339f4a..6a37edc 100644
--- a/frontend/src/features/editor/VisualMarkdownEditor.vue
+++ b/frontend/src/features/editor/VisualMarkdownEditor.vue
@@ -2,6 +2,7 @@
 import { onBeforeUnmount, onMounted, ref } from 'vue'
 import { Link } from '@element-plus/icons-vue'
 import { Crepe } from '@milkdown/crepe'
+import { oneDark } from '@codemirror/theme-one-dark'
 import {
   createCodeBlockCommand,
   toggleEmphasisCommand,
@@ -19,6 +20,7 @@ import { callCommand } from '@milkdown/kit/utils'
 import AppIcon from '@/components/common/AppIcon.vue'
 import { useEditorStore } from '@/stores/editor'
 import { useSettingsStore } from '@/stores/settings'
+import { useThemeStore } from '@/stores/theme'
 import { applyMarkdownFontSize, fontSizeMarkdownPlugin } from './fontSizeMarkdown'
 import '@milkdown/crepe/theme/common/style.css'
 import '@milkdown/crepe/theme/frame.css'
@@ -26,6 +28,7 @@ import '@milkdown/crepe/theme/frame.css'
 const props = defineProps<{ initialContent: string }>()
 const editorStore = useEditorStore()
 const settingsStore = useSettingsStore()
+const themeStore = useThemeStore()
 const editorRoot = ref<HTMLElement | null>(null)
 const loading = ref(true)
 const fontSizeInput = ref(16)
@@ -104,6 +107,7 @@ onMounted(async () => {
     featureConfigs: {
       [Crepe.Feature.Placeholder]: { text: '开始记录你的想法…' },
       [Crepe.Feature.CodeMirror]: {
+        theme: themeStore.resolvedCodeBlockTheme === 'github-dark' ? oneDark : [],
         previewOnlyByDefault: false,
         searchPlaceholder: '搜索语言',
         noResultText: '没有匹配的语言',
@@ -269,6 +273,12 @@ defineExpose({ getEditor: () => crepe?.editor })
 .milkdown-host :deep(.ProseMirror p) { font-weight: 400; }
 .milkdown-host :deep(.ProseMirror h1), .milkdown-host :deep(.ProseMirror h2), .milkdown-host :deep(.ProseMirror h3), .milkdown-host :deep(.ProseMirror h4), .milkdown-host :deep(.ProseMirror h5), .milkdown-host :deep(.ProseMirror h6) { font-weight: 700; }
 .milkdown-host :deep(.font-size-marker) { display: none; }
+.milkdown-host :deep(.milkdown-code-block) { overflow: hidden; border: 1px solid var(--color-code-border); border-radius: 6px; background: var(--color-code-background); color: var(--color-code-text); }
+.milkdown-host :deep(.milkdown-code-block .cm-editor),
+.milkdown-host :deep(.milkdown-code-block .cm-gutters),
+.milkdown-host :deep(.milkdown-code-block .cm-panel) { background: var(--color-code-background); }
+.milkdown-host :deep(.milkdown-code-block .cm-content) { caret-color: var(--color-code-text); font-family: var(--font-editor-mono); }
+.milkdown-host :deep(.milkdown-code-block .language-button) { color: var(--color-code-muted); }
 :global(.milkdown-toolbar) { border: 1px solid var(--color-border-default) !important; background: var(--color-surface-elevated) !important; box-shadow: var(--shadow-md) !important; }
 :global(.milkdown-toolbar .toolbar-item svg), :global(.milkdown-toolbar .toolbar-item.active svg) { color: var(--color-text-primary) !important; fill: var(--color-text-primary) !important; opacity: 1 !important; }
 :global(.milkdown-toolbar .toolbar-item:hover svg), :global(.milkdown-toolbar .toolbar-item.active svg) { color: var(--color-accent-primary) !important; fill: var(--color-accent-primary) !important; }
diff --git a/frontend/src/features/themes/ThemesView.vue b/frontend/src/features/themes/ThemesView.vue
index 35ec448..1a93a5d 100644
--- a/frontend/src/features/themes/ThemesView.vue
+++ b/frontend/src/features/themes/ThemesView.vue
@@ -13,7 +13,7 @@ const themeStore = useThemeStore()
         <p class="subtle">v{{ theme.version }} · {{ theme.builtin ? '内置主题' : theme.author }}</p>
       </button>
     </div>
-    <div class="panel preference-panel"><h2 class="panel-title">编辑器外观</h2><div class="form-grid"><div class="field"><label>字号：{{ themeStore.fontEditorSize }}px</label><input v-model.number="themeStore.fontEditorSize" type="range" min="12" max="24" /></div><div class="field"><label>行高：{{ themeStore.lineHeight }}</label><input v-model.number="themeStore.lineHeight" type="range" min="1.2" max="2.2" step="0.1" /></div><div class="field"><label>字体</label><select v-model="themeStore.fontEditorFamily" class="select"><option value="system-ui">系统字体</option><option value="serif">衬线字体</option><option value="var(--font-ui-mono)">等宽字体</option></select></div></div><div class="editor-preview" :style="{ fontSize: `${themeStore.fontEditorSize}px`, lineHeight: themeStore.lineHeight, fontFamily: themeStore.fontEditorFamily }"><h3>主题预览</h3><p>知识的价值不只在于保存，更在于被重新发现和使用。</p><code>const notes = await search('本地优先')</code></div></div>
+    <div class="panel preference-panel"><h2 class="panel-title">编辑器外观</h2><div class="form-grid"><div class="field"><label>字号：{{ themeStore.fontEditorSize }}px</label><input v-model.number="themeStore.fontEditorSize" type="range" min="12" max="24" /></div><div class="field"><label>行高：{{ themeStore.lineHeight }}</label><input v-model.number="themeStore.lineHeight" type="range" min="1.2" max="2.2" step="0.1" /></div><div class="field"><label>字体</label><select v-model="themeStore.fontEditorFamily" class="select"><option value="system-ui">系统字体</option><option value="serif">衬线字体</option><option value="var(--font-ui-mono)">等宽字体</option></select></div><div class="field"><label>代码块样式</label><select v-model="themeStore.codeBlockTheme" class="select"><option value="auto">跟随主题</option><option value="github-light">GitHub Light</option><option value="github-dark">GitHub Dark</option></select><small>Markdown 渲染使用对应的 Shiki GitHub 主题</small></div></div><div class="editor-preview" :style="{ fontSize: `${themeStore.fontEditorSize}px`, lineHeight: themeStore.lineHeight, fontFamily: themeStore.fontEditorFamily }"><h3>主题预览</h3><p>知识的价值不只在于保存，更在于被重新发现和使用。</p><pre class="code-preview"><code><span class="code-keyword">const</span> <span class="code-variable">notes</span> = <span class="code-keyword">await</span> <span class="code-function">search</span>(<span class="code-string">'本地优先'</span>)</code></pre></div></div>
   </section>
 </template>
 
@@ -28,5 +28,15 @@ const themeStore = useThemeStore()
 .theme-info { display: flex; justify-content: space-between; gap: var(--space-md); }
 .preference-panel { display: grid; gap: var(--space-xl); }
 .editor-preview { padding: var(--space-xl); border: 1px solid var(--color-border-default); border-radius: var(--radius-md); background: var(--color-background-secondary); }
-.editor-preview p { margin: var(--space-sm) 0; }.editor-preview code { color: var(--color-accent-primary); }
+.editor-preview p { margin: var(--space-sm) 0; }
+.field small { color: var(--color-text-tertiary); }
+.code-preview { overflow: auto; margin-top: var(--space-md); padding: 16px; border: 1px solid var(--color-code-border); border-radius: 6px; background: var(--color-code-background); color: var(--color-code-text); font: 13px/1.45 var(--font-ui-mono); }
+:global([data-code-theme='github-light']) .code-keyword { color: #cf222e; }
+:global([data-code-theme='github-light']) .code-variable { color: #24292f; }
+:global([data-code-theme='github-light']) .code-function { color: #8250df; }
+:global([data-code-theme='github-light']) .code-string { color: #0a3069; }
+:global([data-code-theme='github-dark']) .code-keyword { color: #ff7b72; }
+:global([data-code-theme='github-dark']) .code-variable { color: #c9d1d9; }
+:global([data-code-theme='github-dark']) .code-function { color: #d2a8ff; }
+:global([data-code-theme='github-dark']) .code-string { color: #a5d6ff; }
 </style>
diff --git a/frontend/src/stores/theme.spec.ts b/frontend/src/stores/theme.spec.ts
new file mode 100644
index 0000000..9d1d0cc
--- /dev/null
+++ b/frontend/src/stores/theme.spec.ts
@@ -0,0 +1,47 @@
+// @vitest-environment happy-dom
+import { beforeEach, describe, expect, it } from 'vitest'
+import { createPinia, setActivePinia } from 'pinia'
+import { nextTick } from 'vue'
+import { useThemeStore } from './theme'
+
+beforeEach(() => {
+  localStorage.clear()
+  document.documentElement.removeAttribute('data-theme')
+  document.documentElement.removeAttribute('data-code-theme')
+  setActivePinia(createPinia())
+  Object.defineProperty(window, 'matchMedia', {
+    configurable: true,
+    value: () => ({ matches: false }),
+  })
+})
+
+describe('代码块主题偏好', () => {
+  it('跟随应用主题选择对应的 GitHub 代码主题', async () => {
+    const store = useThemeStore()
+    store.applyTheme('dark')
+    await nextTick()
+
+    expect(store.resolvedCodeBlockTheme).toBe('github-dark')
+    expect(document.documentElement.dataset.codeTheme).toBe('github-dark')
+  })
+
+  it('允许代码块主题独立于应用主题', async () => {
+    const store = useThemeStore()
+    store.applyTheme('dark')
+    store.codeBlockTheme = 'github-light'
+    await nextTick()
+
+    expect(store.resolvedCodeBlockTheme).toBe('github-light')
+    expect(document.documentElement.dataset.codeTheme).toBe('github-light')
+  })
+
+  it('恢复持久化的代码块主题偏好', async () => {
+    localStorage.setItem('editor-appearance', JSON.stringify({ codeBlockTheme: 'github-dark' }))
+    const store = useThemeStore()
+    store.initTheme()
+    await nextTick()
+
+    expect(store.codeBlockTheme).toBe('github-dark')
+    expect(document.documentElement.dataset.codeTheme).toBe('github-dark')
+  })
+})
diff --git a/frontend/src/stores/theme.ts b/frontend/src/stores/theme.ts
index 5b591f6..ffd0f23 100644
--- a/frontend/src/stores/theme.ts
+++ b/frontend/src/stores/theme.ts
@@ -3,17 +3,24 @@ import { ref, computed, watch } from 'vue'
 import type { ThemeConfig } from '@/contracts'
 
 const builtinThemes: ThemeConfig[] = [
-  { theme_id: 'light', name: '浅色', version: '1.0.0', description: '默认浅色主题', is_dark: false, builtin: true },
-  { theme_id: 'dark', name: '深色', version: '1.0.0', description: '默认深色主题', is_dark: true, builtin: true },
-  { theme_id: 'sepia', name: '护眼', version: '1.0.0', description: '护眼暖色调', is_dark: false, builtin: true },
+  { theme_id: 'light', name: '浅色', version: '1.0.0', description: '默认浅色主题', is_dark: false, builtin: true, code_theme: 'github-light' },
+  { theme_id: 'dark', name: '深色', version: '1.0.0', description: '默认深色主题', is_dark: true, builtin: true, code_theme: 'github-dark' },
+  { theme_id: 'sepia', name: '护眼', version: '1.0.0', description: '护眼暖色调', is_dark: false, builtin: true, code_theme: 'github-light' },
 ]
 
+export type CodeBlockThemePreference = 'auto' | 'github-light' | 'github-dark'
+
+function isCodeBlockThemePreference(value: unknown): value is CodeBlockThemePreference {
+  return value === 'auto' || value === 'github-light' || value === 'github-dark'
+}
+
 export const useThemeStore = defineStore('theme', () => {
   const themes = ref<ThemeConfig[]>(builtinThemes)
   const currentThemeId = ref<string>('light')
   const fontEditorSize = ref(15)
   const fontEditorFamily = ref('system-ui')
   const lineHeight = ref(1.7)
+  const codeBlockTheme = ref<CodeBlockThemePreference>('auto')
   let appearanceHydrated = false
 
   const currentTheme = computed(() =>
@@ -21,6 +28,10 @@ export const useThemeStore = defineStore('theme', () => {
   )
 
   const isDark = computed(() => currentTheme.value?.is_dark || false)
+  const resolvedCodeBlockTheme = computed<'github-light' | 'github-dark'>(() => {
+    if (codeBlockTheme.value !== 'auto') return codeBlockTheme.value
+    return currentTheme.value?.code_theme ?? (isDark.value ? 'github-dark' : 'github-light')
+  })
 
   function applyTheme(themeId: string) {
     const theme = themes.value.find((t) => t.theme_id === themeId)
@@ -41,10 +52,11 @@ export const useThemeStore = defineStore('theme', () => {
     const savedAppearance = localStorage.getItem('editor-appearance')
     if (savedAppearance) {
       try {
-        const value = JSON.parse(savedAppearance) as { size?: number; family?: string; lineHeight?: number }
+        const value = JSON.parse(savedAppearance) as { size?: number; family?: string; lineHeight?: number; codeBlockTheme?: unknown }
         if (value.size) fontEditorSize.value = value.size
         if (value.family) fontEditorFamily.value = value.family
         if (value.lineHeight) lineHeight.value = value.lineHeight
+        if (isCodeBlockThemePreference(value.codeBlockTheme)) codeBlockTheme.value = value.codeBlockTheme
       } catch { localStorage.removeItem('editor-appearance') }
     }
     const saved = localStorage.getItem('theme')
@@ -67,12 +79,20 @@ export const useThemeStore = defineStore('theme', () => {
     fontEditorSize.value = 15
     fontEditorFamily.value = 'system-ui'
     lineHeight.value = 1.7
+    codeBlockTheme.value = 'auto'
   }
 
   const persistAppearance = () => localStorage.setItem('editor-appearance', JSON.stringify({
-    size: fontEditorSize.value, family: fontEditorFamily.value, lineHeight: lineHeight.value,
+    size: fontEditorSize.value,
+    family: fontEditorFamily.value,
+    lineHeight: lineHeight.value,
+    codeBlockTheme: codeBlockTheme.value,
   }))
 
+  watch(resolvedCodeBlockTheme, (theme) => {
+    document.documentElement.setAttribute('data-code-theme', theme)
+  }, { immediate: true })
+
   watch(fontEditorSize, (v) => {
     document.documentElement.style.setProperty('--font-editor-size', `${v}px`)
     if (appearanceHydrated) persistAppearance()
@@ -88,6 +108,10 @@ export const useThemeStore = defineStore('theme', () => {
     if (appearanceHydrated) persistAppearance()
   }, { immediate: true })
 
+  watch(codeBlockTheme, () => {
+    if (appearanceHydrated) persistAppearance()
+  })
+
   return {
     themes,
     currentThemeId,
@@ -96,6 +120,8 @@ export const useThemeStore = defineStore('theme', () => {
     fontEditorSize,
     fontEditorFamily,
     lineHeight,
+    codeBlockTheme,
+    resolvedCodeBlockTheme,
     applyTheme,
     initTheme,
     toggleTheme,
diff --git a/frontend/src/styles/tokens.css b/frontend/src/styles/tokens.css
index a13cbfc..b4109a2 100644
--- a/frontend/src/styles/tokens.css
+++ b/frontend/src/styles/tokens.css
@@ -190,6 +190,20 @@
   --color-text-link: #7b512e;
 }
 
+[data-code-theme='github-light'] {
+  --color-code-background: #f6f8fa;
+  --color-code-border: #d0d7de;
+  --color-code-text: #24292f;
+  --color-code-muted: #57606a;
+}
+
+[data-code-theme='github-dark'] {
+  --color-code-background: #161b22;
+  --color-code-border: #30363d;
+  --color-code-text: #c9d1d9;
+  --color-code-muted: #8b949e;
+}
+
 * {
   box-sizing: border-box;
   margin: 0;
diff --git a/frontend/src/utils/markdown.spec.ts b/frontend/src/utils/markdown.spec.ts
new file mode 100644
index 0000000..11b2b33
--- /dev/null
+++ b/frontend/src/utils/markdown.spec.ts
@@ -0,0 +1,13 @@
+import { describe, expect, it } from 'vitest'
+import { highlightCode } from './markdown'
+
+describe('Shiki GitHub 双主题', () => {
+  it('一次渲染同时生成 GitHub Light 和 GitHub Dark 颜色变量', async () => {
+    const html = await highlightCode('const answer = 42', 'typescript')
+
+    expect(html).toContain('github-light')
+    expect(html).toContain('github-dark')
+    expect(html).toContain('--shiki-light')
+    expect(html).toContain('--shiki-dark')
+  })
+})