diff --git a/CLAUDE.md b/CLAUDE.md
index 00a9135..06df291 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -75,13 +75,13 @@ pnpm preview      # 预览生产构建
 ### 路由与布局
 
 5 个 view，两种 layout：
-- `DefaultLayout`（`/`）：顶栏 + 侧栏 + 内容 + 页脚，包 home / chanlun / articles / about。
+- `DefaultLayout`（`/`）：顶栏 + 内容 + 页脚，包 home / chanlun / articles / about。
 - `ReaderLayout`（`/read/:category/:slug`）：沉浸阅读，含阅读进度、阅读设置、上下篇导航。
 - markdown 的 h2/h3 会被 `useMarkdown.ts` 注入 `id`（slug 来自 `utils/slug.ts`），便于锚点跳转。
 
 ### 现存组件缺标记类名
 
-`components/ui/`（BaseButton/Badge/Card/SearchInput）、`components/layout/`（AppHeader/AppSidebar/AppFooter）及 `ArticleCard` 等目前是纯工具类。改动它们时按上面的「标记类名」约定补齐。
+`components/ui/`（BaseButton/Badge/Card/SearchInput）、`components/layout/`（AppHeader/AppFooter）及 `ArticleCard` 等目前是纯工具类。改动它们时按上面的「标记类名」约定补齐。
 
 ## 其他约定
 
diff --git a/README.md b/README.md
index 9c37242..d1c2c90 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ pnpm typecheck    # 仅类型检查
 src/
 ├── components/
 │   ├── ui/              # 基础组件：BaseButton / Badge / Card / SearchInput
-│   ├── layout/          # AppHeader / AppSidebar / AppFooter
+│   ├── layout/          # AppHeader / AppFooter
 │   ├── ArticleCard.vue  # 文章列表卡片
 │   ├── TableOfContents.vue
 │   ├── ThemeToggle.vue / ReaderSettings.vue / ReadingProgress.vue
@@ -47,7 +47,7 @@ src/
 │   ├── essays.ts        # 杂谈随笔（示例数据）
 │   └── categories.ts    # 分类信息
 ├── layouts/
-│   ├── DefaultLayout.vue # 顶栏 + 侧栏 + 内容 + 页脚
+│   ├── DefaultLayout.vue # 顶栏 + 内容 + 页脚
 │   └── ReaderLayout.vue  # 沉浸阅读布局
 ├── views/               # 5 个页面
 ├── stores/              # theme / reading（Pinia）
diff --git a/src/components/layout/AppFooter.vue b/src/components/layout/AppFooter.vue
index dfe929a..4e4d712 100644
--- a/src/components/layout/AppFooter.vue
+++ b/src/components/layout/AppFooter.vue
@@ -16,11 +16,6 @@ const links = [
       class="mx-auto flex max-w-[1400px] flex-col items-center justify-between gap-4 px-4 py-8 sm:flex-row sm:px-6"
     >
       <div class="flex items-center gap-2.5">
-        <span
-          class="flex size-7 items-center justify-center rounded-md bg-primary text-white"
-        >
-          <i class="ri-line-chart-line text-base" aria-hidden="true"></i>
-        </span>
         <div class="text-sm">
           <span class="font-medium text-foreground">缠论研习社</span>
           <span class="ml-2 text-subtle">专注缠论的系统性研习</span>
diff --git a/src/components/layout/AppHeader.vue b/src/components/layout/AppHeader.vue
index 65fad39..ca1b901 100644
--- a/src/components/layout/AppHeader.vue
+++ b/src/components/layout/AppHeader.vue
@@ -1,10 +1,7 @@
 <script setup lang="ts">
 import { RouterLink, useRoute } from 'vue-router'
-import { Menu } from 'lucide-vue-next'
 import ThemeToggle from '@/components/ThemeToggle.vue'
 
-defineEmits<{ 'toggle-sidebar': [] }>()
-
 const route = useRoute()
 
 const nav = [
@@ -21,38 +18,27 @@ function isActive(to: string, exact: boolean) {
 
 <template>
   <header
-    class="sticky top-0 z-30 border-b border-line bg-app/80 backdrop-blur-lg"
+    class="app-header sticky top-0 z-30 border-b border-line bg-app/80 backdrop-blur-lg"
   >
-    <div class="mx-auto flex h-14 max-w-[1400px] items-center gap-3 px-4 sm:px-6">
-      <!-- 移动端菜单 -->
-      <button
-        type="button"
-        class="flex size-9 items-center justify-center rounded-full text-muted hover:bg-surface hover:text-foreground lg:hidden"
-        aria-label="打开菜单"
-        @click="$emit('toggle-sidebar')"
-      >
-        <Menu class="size-5" />
-      </button>
-
+    <div
+      class="app-header__inner mx-auto flex h-14 max-w-[1400px] items-center gap-3 px-4 sm:px-6"
+    >
       <!-- Logo -->
-      <RouterLink to="/" class="flex shrink-0 items-center gap-2.5">
+      <RouterLink to="/" class="app-header__logo flex shrink-0 items-center">
         <span
-          class="flex size-8 items-center justify-center rounded-md bg-primary text-white shadow-sm"
+          class="app-header__title hidden text-[15px] font-semibold tracking-tight text-foreground sm:block"
         >
-          <i class="ri-line-chart-line text-xl" aria-hidden="true"></i>
-        </span>
-        <span class="hidden text-[15px] font-semibold tracking-tight text-foreground sm:block">
           缠论研习社
         </span>
       </RouterLink>
 
-      <!-- 桌面端导航 -->
-      <nav class="ml-4 hidden items-center gap-0.5 lg:flex">
+      <!-- 导航（移动端与桌面端共用） -->
+      <nav class="app-header__nav flex items-center gap-0.5 sm:ml-2">
         <RouterLink
           v-for="item in nav"
           :key="item.to"
           :to="item.to"
-          class="rounded-full px-3.5 py-1.5 text-sm transition-colors"
+          class="rounded-full px-3 py-1.5 text-sm transition-colors sm:px-3.5"
           :class="
             isActive(item.to, item.exact)
               ? 'bg-surface font-medium text-foreground'
@@ -63,7 +49,7 @@ function isActive(to: string, exact: boolean) {
         </RouterLink>
       </nav>
 
-      <div class="ml-auto flex items-center gap-1">
+      <div class="app-header__actions ml-auto flex items-center gap-1">
         <ThemeToggle />
       </div>
     </div>
diff --git a/src/components/layout/AppSidebar.vue b/src/components/layout/AppSidebar.vue
deleted file mode 100644
index 7892168..0000000
--- a/src/components/layout/AppSidebar.vue
+++ /dev/null
@@ -1,134 +0,0 @@
-<script setup lang="ts">
-import { computed, onBeforeUnmount, ref, watch } from 'vue'
-import { RouterLink, useRoute } from 'vue-router'
-import { BookOpen, Feather, Lightbulb, X } from 'lucide-vue-next'
-import { categories } from '@/data/categories'
-import { useArticles } from '@/composables/useArticles'
-import { cn } from '@/utils/cn'
-import type { ArticleCategory } from '@/types/article'
-
-const props = defineProps<{ mobileOpen?: boolean }>()
-const emit = defineEmits<{ close: [] }>()
-
-const route = useRoute()
-const { chanlun, essaysList } = useArticles()
-
-const countMap = computed<Record<ArticleCategory, number>>(() => ({
-  chanlun: chanlun.value.length,
-  essay: essaysList.value.length,
-  notes: 0,
-}))
-
-const routeOf = (key: ArticleCategory) =>
-  key === 'chanlun' ? '/chanlun' : key === 'essay' ? '/articles' : '/about'
-
-const iconOf = (key: ArticleCategory) =>
-  key === 'chanlun' ? BookOpen : key === 'essay' ? Feather : Lightbulb
-
-const isActive = (key: ArticleCategory) => {
-  if (key === 'chanlun') return route.path === '/chanlun' || route.path.startsWith('/read/chanlun')
-  if (key === 'essay') return route.path === '/articles' || route.path.startsWith('/read/essay')
-  return false
-}
-
-/** 抽屉打开时：锁定背景滚动（防 iOS 惯性穿透）+ 支持 Esc 关闭 */
-const prevOverflow = ref('')
-function onKeydown(e: KeyboardEvent) {
-  if (e.key === 'Escape') emit('close')
-}
-watch(
-  () => props.mobileOpen,
-  (v) => {
-    if (v) {
-      prevOverflow.value = document.body.style.overflow
-      document.body.style.overflow = 'hidden'
-      window.addEventListener('keydown', onKeydown)
-    } else {
-      document.body.style.overflow = prevOverflow.value
-      window.removeEventListener('keydown', onKeydown)
-    }
-  },
-)
-onBeforeUnmount(() => {
-  document.body.style.overflow = prevOverflow.value
-  window.removeEventListener('keydown', onKeydown)
-})
-</script>
-
-<template>
-  <!-- 移动端遮罩 -->
-  <Teleport to="body">
-    <Transition
-      enter-active-class="transition-opacity duration-200"
-      enter-from-class="opacity-0"
-      leave-active-class="transition-opacity duration-150"
-      leave-to-class="opacity-0"
-    >
-      <div
-        v-if="mobileOpen"
-        class="fixed inset-0 z-40 bg-black/40 backdrop-blur-sm lg:hidden"
-        @click="emit('close')"
-      />
-    </Transition>
-  </Teleport>
-
-  <aside
-    :class="
-      cn(
-        'fixed inset-y-0 left-0 z-50 w-72 max-w-[calc(100vw_-_2.5rem)] shrink-0 overflow-y-auto border-r border-line bg-app p-5 transition-transform duration-300 lg:sticky lg:top-14 lg:z-0 lg:h-[calc(100vh-3.5rem)] lg:overflow-visible lg:translate-x-0 lg:bg-transparent lg:p-6',
-        mobileOpen ? 'translate-x-0' : '-translate-x-full lg:translate-x-0',
-      )
-    "
-  >
-    <!-- 移动端顶栏 -->
-    <div class="mb-5 flex items-center justify-between lg:hidden">
-      <span class="text-sm font-semibold text-foreground">导航</span>
-      <button
-        type="button"
-        class="flex size-9 items-center justify-center rounded-full text-muted hover:bg-surface"
-        aria-label="关闭菜单"
-        @click="emit('close')"
-      >
-        <X class="size-5" />
-      </button>
-    </div>
-
-    <!-- 分类导航 -->
-    <nav class="space-y-1">
-      <p class="mb-2 px-2 text-xs font-medium uppercase tracking-wide text-subtle">分类</p>
-      <RouterLink
-        v-for="cat in categories"
-        :key="cat.key"
-        :to="routeOf(cat.key)"
-        class="group flex items-start gap-3 rounded-md p-2.5 transition-colors"
-        :class="isActive(cat.key) ? 'bg-surface' : 'hover:bg-surface/60'"
-        @click="emit('close')"
-      >
-        <span
-          class="mt-0.5 flex size-8 shrink-0 items-center justify-center rounded-md transition-colors"
-          :class="
-            isActive(cat.key)
-              ? 'bg-primary-soft text-primary'
-              : 'bg-surface-2 text-subtle group-hover:text-muted'
-          "
-        >
-          <component :is="iconOf(cat.key)" class="size-[18px]" />
-        </span>
-        <span class="min-w-0 flex-1">
-          <span class="flex items-center justify-between gap-2">
-            <span
-              class="text-sm font-medium"
-              :class="isActive(cat.key) ? 'text-foreground' : 'text-muted'"
-            >
-              {{ cat.label }}
-            </span>
-            <span class="shrink-0 text-xs text-subtle">{{ countMap[cat.key] }}</span>
-          </span>
-          <span class="mt-0.5 block line-clamp-2 text-xs leading-relaxed text-subtle">
-            {{ cat.description }}
-          </span>
-        </span>
-      </RouterLink>
-    </nav>
-  </aside>
-</template>
diff --git a/src/layouts/DefaultLayout.vue b/src/layouts/DefaultLayout.vue
index c5c3113..70c6149 100644
--- a/src/layouts/DefaultLayout.vue
+++ b/src/layouts/DefaultLayout.vue
@@ -1,34 +1,26 @@
 <script setup lang="ts">
-import { ref } from 'vue'
 import { RouterView } from 'vue-router'
 import AppHeader from '@/components/layout/AppHeader.vue'
-import AppSidebar from '@/components/layout/AppSidebar.vue'
 import AppFooter from '@/components/layout/AppFooter.vue'
-
-const mobileOpen = ref(false)
 </script>
 
 <template>
   <div class="flex min-h-dvh flex-col">
-    <AppHeader @toggle-sidebar="mobileOpen = !mobileOpen" />
+    <AppHeader />
 
-    <div class="mx-auto flex w-full max-w-[1400px] flex-1">
-      <AppSidebar :mobile-open="mobileOpen" @close="mobileOpen = false" />
-
-      <main class="min-w-0 flex-1 px-4 py-8 sm:px-6 lg:px-10">
-        <RouterView v-slot="{ Component }">
-          <Transition
-            enter-active-class="transition duration-300 ease-out"
-            enter-from-class="opacity-0 translate-y-2"
-            leave-active-class="transition duration-150 ease-in"
-            leave-to-class="opacity-0"
-            mode="out-in"
-          >
-            <component :is="Component" />
-          </Transition>
-        </RouterView>
-      </main>
-    </div>
+    <main class="mx-auto w-full max-w-[1400px] flex-1 px-4 py-8 sm:px-6 lg:px-10">
+      <RouterView v-slot="{ Component }">
+        <Transition
+          enter-active-class="transition duration-300 ease-out"
+          enter-from-class="opacity-0 translate-y-2"
+          leave-active-class="transition duration-150 ease-in"
+          leave-to-class="opacity-0"
+          mode="out-in"
+        >
+          <component :is="Component" />
+        </Transition>
+      </RouterView>
+    </main>
 
     <AppFooter />
   </div>
diff --git a/src/layouts/ReaderLayout.vue b/src/layouts/ReaderLayout.vue
index 700b718..b1a567c 100644
--- a/src/layouts/ReaderLayout.vue
+++ b/src/layouts/ReaderLayout.vue
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { ref, onMounted, onBeforeUnmount } from 'vue'
 import { RouterLink, RouterView, useRouter } from 'vue-router'
 import { ArrowLeft } from 'lucide-vue-next'
 import ThemeToggle from '@/components/ThemeToggle.vue'
@@ -11,6 +12,47 @@ function goBack() {
   if (window.history.length > 1) router.back()
   else router.push('/')
 }
+
+// 顶栏随滚动自动隐藏 / 显示，营造沉浸阅读体验
+// - 向下滑过阈值即隐藏
+// - 向上回退一定距离后才重新显示
+// - 接近页面顶部时始终显示
+const HIDE_AFTER = 6 // 向下滑动多少 px 后隐藏
+const SHOW_AFTER = 12 // 向上回退多少 px 后才显示（比 HIDE 略大，避免轻微抖动反复切换）
+const TOP_EDGE = 10 // 距顶部多少 px 内强制显示
+
+const headerHidden = ref(false)
+let lastY = 0 // 上一次状态切换时的滚动位置（连续同向滚动不更新，避免累加）
+let ticking = false
+
+function onScroll() {
+  if (ticking) return
+  ticking = true
+  requestAnimationFrame(() => {
+    const y = window.scrollY
+    const delta = y - lastY
+    if (y <= TOP_EDGE) {
+      headerHidden.value = false
+      lastY = y
+    } else if (delta > HIDE_AFTER) {
+      headerHidden.value = true
+      lastY = y
+    } else if (delta < -SHOW_AFTER) {
+      headerHidden.value = false
+      lastY = y
+    }
+    ticking = false
+  })
+}
+
+onMounted(() => {
+  lastY = window.scrollY
+  window.addEventListener('scroll', onScroll, { passive: true })
+})
+
+onBeforeUnmount(() => {
+  window.removeEventListener('scroll', onScroll)
+})
 </script>
 
 <template>
@@ -18,7 +60,8 @@ function goBack() {
     <ReadingProgress />
 
     <header
-      class="reader-header sticky top-0 z-30 border-b border-line bg-app/80 backdrop-blur-lg"
+      class="reader-header sticky top-0 z-30 border-b border-line bg-app/80 backdrop-blur-lg transition-transform duration-300 ease-in-out"
+      :class="{ '-translate-y-full': headerHidden }"
     >
       <div
         class="reader-header__inner mx-auto flex h-14 max-w-[1180px] items-center gap-3 px-4 sm:px-6"
@@ -36,11 +79,6 @@ function goBack() {
           to="/"
           class="reader-header__logo flex shrink-0 items-center gap-2.5 transition-opacity hover:opacity-80"
         >
-          <span
-            class="reader-header__logo-icon flex size-8 items-center justify-center rounded-md bg-primary text-white shadow-sm"
-          >
-            <i class="ri-line-chart-line text-xl" aria-hidden="true"></i>
-          </span>
           <span
             class="reader-header__logo-text hidden text-[15px] font-semibold tracking-tight text-foreground sm:block"
           >
diff --git a/src/style.css b/src/style.css
index e53515d..66ebea2 100644
--- a/src/style.css
+++ b/src/style.css
@@ -128,6 +128,8 @@
   html {
     -webkit-text-size-adjust: 100%;
     scroll-behavior: smooth;
+    /* 始终为滚动条预留槽位，避免切换页面时因滚动条出现/消失导致布局水平抖动 */
+    scrollbar-gutter: stable;
     tab-size: 2;
   }
 
diff --git a/src/views/ChanlunListView.vue b/src/views/ChanlunListView.vue
index 766a7bb..2243e13 100644
--- a/src/views/ChanlunListView.vue
+++ b/src/views/ChanlunListView.vue
@@ -23,7 +23,7 @@ function clearQuery() {
 </script>
 
 <template>
-  <div class="mx-auto w-full max-w-3xl">
+  <div class="mx-auto w-full max-w-5xl">
     <!-- 页头 -->
     <header>
       <div class="flex items-start justify-between gap-4">
@@ -60,7 +60,7 @@ function clearQuery() {
     </div>
 
     <!-- 课程列表 -->
-    <section v-if="filtered.length" class="mt-6 flex flex-col gap-3">
+    <section v-if="filtered.length" class="mt-6 grid gap-4 sm:grid-cols-2">
       <ArticleCard v-for="article in filtered" :key="article.id" :article="article" />
     </section>
 
diff --git a/src/views/HomeView.vue b/src/views/HomeView.vue
index c3c2c94..50a43e2 100644
--- a/src/views/HomeView.vue
+++ b/src/views/HomeView.vue
@@ -77,7 +77,7 @@ const categoryIcon: Record<ArticleCategory, typeof BookOpen> = {
 </script>
 
 <template>
-  <div class="mx-auto max-w-[1200px]">
+  <div class="mx-auto max-w-5xl">
     <!-- ============ Hero ============ -->
     <section class="relative overflow-hidden py-6">
       <!-- 极淡装饰：走势曲线 -->