diff --git a/src/components/layout/AppSidebar.vue b/src/components/layout/AppSidebar.vue
index 982b3b2..7860f1d 100644
--- a/src/components/layout/AppSidebar.vue
+++ b/src/components/layout/AppSidebar.vue
@@ -1,5 +1,5 @@
 <template>
-  <aside class="df-sidebar">
+  <aside class="df-sidebar" :class="{ 'df-sidebar--collapsed': collapsed }">
     <!-- Logo -->
     <div class="sidebar-brand">
       <div class="brand-mark">
@@ -10,74 +10,118 @@
           </linearGradient></defs>
         </svg>
       </div>
-      <span class="brand-text">DevFlow</span>
-      <span class="brand-version">v0.1</span>
+      <span v-if="!collapsed" class="brand-text">DevFlow</span>
+      <span v-if="!collapsed" class="brand-version">v0.1</span>
+      <button v-if="!collapsed" class="collapse-btn" @click="toggleCollapsed" :title="$t('nav.collapse')">
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="15 18 9 12 15 6"/></svg>
+      </button>
     </div>
 
+    <!-- 收缩态展开按钮(底部固定位置,仅在 collapsed 时显示) -->
+    <button v-if="collapsed" class="expand-btn" @click="toggleCollapsed" :title="$t('nav.expand')">
+      <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="9 18 15 12 9 6"/></svg>
+    </button>
+
     <!-- Navigation -->
     <nav class="sidebar-nav">
       <div class="nav-group">
-        <span class="nav-group-label">{{ $t('nav.workspace') }}</span>
+        <span v-if="!collapsed" class="nav-group-label">{{ $t('nav.workspace') }}</span>
         <router-link
           v-for="item in primaryNav" :key="item.path"
           :to="item.path"
           class="nav-link"
           active-class="nav-link--active"
+          :title="collapsed ? $t(item.label) : undefined"
         >
           <span class="nav-link-icon" v-html="item.svg"></span>
-          <span class="nav-link-text">{{ $t(item.label) }}</span>
-          <span v-if="item.badge" class="nav-link-badge">{{ item.badge }}</span>
+          <span v-if="!collapsed" class="nav-link-text">{{ $t(item.label) }}</span>
+          <span v-if="!collapsed && item.badge" class="nav-link-badge">{{ item.badge }}</span>
         </router-link>
       </div>
 
       <div class="nav-divider"></div>
 
       <div class="nav-group">
-        <span class="nav-group-label">{{ $t('nav.traceability') }}</span>
+        <span v-if="!collapsed" class="nav-group-label">{{ $t('nav.traceability') }}</span>
         <router-link
           v-for="item in secondaryNav" :key="item.path"
           :to="item.path"
           class="nav-link"
           active-class="nav-link--active"
+          :title="collapsed ? $t(item.label) : undefined"
         >
           <span class="nav-link-icon" v-html="item.svg"></span>
-          <span class="nav-link-text">{{ $t(item.label) }}</span>
-          <span v-if="item.path === '/knowledge' && candidateCount > 0" class="nav-link-badge">{{ candidateCount }}</span>
+          <span v-if="!collapsed" class="nav-link-text">{{ $t(item.label) }}</span>
+          <span v-if="!collapsed && item.path === '/knowledge' && candidateCount > 0" class="nav-link-badge">{{ candidateCount }}</span>
         </router-link>
       </div>
     </nav>
 
     <!-- Footer -->
     <div class="sidebar-footer">
-      <div class="sidebar-status">
+      <div v-if="!collapsed" class="sidebar-status">
         <span class="status-dot"></span>
         <span class="status-text">{{ $t('nav.systemReady') }}</span>
       </div>
       <!-- AI 面板切换按钮 -->
-      <button class="nav-link ai-toggle-btn" :class="{ 'ai-toggle-btn--active': aiStore.state.panelOpen }" @click="aiStore.togglePanel()">
+      <button class="nav-link ai-toggle-btn" :class="{ 'ai-toggle-btn--active': aiStore.state.panelOpen }" @click="aiStore.togglePanel()" :title="collapsed ? $t('nav.aiPanel') : undefined">
         <span class="nav-link-icon">
           <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round"><path d="M12 2a7 7 0 014 12.74V17a1 1 0 01-1 1H9a1 1 0 01-1-1v-2.26A7 7 0 0112 2z"/><line x1="9" y1="21" x2="15" y2="21"/></svg>
         </span>
-        <span class="nav-link-text">{{ $t('nav.aiPanel') }}</span>
-        <span class="ai-toggle-shortcut">⌘I</span>
+        <span v-if="!collapsed" class="nav-link-text">{{ $t('nav.aiPanel') }}</span>
+        <span v-if="!collapsed" class="ai-toggle-shortcut">⌘I</span>
       </button>
-      <router-link to="/settings" class="nav-link" active-class="nav-link--active">
+      <router-link to="/settings" class="nav-link" active-class="nav-link--active" :title="collapsed ? $t('nav.settings') : undefined">
         <span class="nav-link-icon">
           <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="3"/><path d="M19.4 15a1.65 1.65 0 00.33 1.82l.06.06a2 2 0 010 2.83 2 2 0 01-2.83 0l-.06-.06a1.65 1.65 0 00-1.82-.33 1.65 1.65 0 00-1 1.51V21a2 2 0 01-4 0v-.09A1.65 1.65 0 009 19.4a1.65 1.65 0 00-1.82.33l-.06.06a2 2 0 01-2.83-2.83l.06-.06A1.65 1.65 0 004.68 15a1.65 1.65 0 00-1.51-1H3a2 2 0 010-4h.09A1.65 1.65 0 004.6 9a1.65 1.65 0 00-.33-1.82l-.06-.06a2 2 0 012.83-2.83l.06.06A1.65 1.65 0 009 4.68a1.65 1.65 0 001-1.51V3a2 2 0 014 0v.09a1.65 1.65 0 001 1.51 1.65 1.65 0 001.82-.33l.06-.06a2 2 0 012.83 2.83l-.06.06A1.65 1.65 0 0019.4 9a1.65 1.65 0 001.51 1H21a2 2 0 010 4h-.09a1.65 1.65 0 00-1.51 1z"/></svg>
         </span>
-        <span class="nav-link-text">{{ $t('nav.settings') }}</span>
+        <span v-if="!collapsed" class="nav-link-text">{{ $t('nav.settings') }}</span>
       </router-link>
     </div>
   </aside>
 </template>
 
 <script setup lang="ts">
-import { computed } from 'vue'
+import { computed, ref, onMounted, onBeforeUnmount } from 'vue'
 import { useAiStore } from '@/stores/ai'
 import { useKnowledgeStore } from '@/stores/knowledge'
+import { useAppSettingsStore } from '@/stores/appSettings'
 
 const aiStore = useAiStore()
 const knowledgeStore = useKnowledgeStore()
+const appSettings = useAppSettingsStore()
+
+// ── 侧边栏收缩状态(持久化到 appSettings,小窗口自动收缩) ──
+// 展开 192px(文字+图标) / 收缩 56px(仅图标,hover tooltip 显示文字)
+// 优先级:用户手动设置 > 小窗口自动收缩(≤768px)
+const COLLAPSE_THRESHOLD = 768
+const userCollapsed = ref(false)  // 用户手动设置的收缩状态
+const isNarrowWindow = ref(false) // 小窗口自动收缩标记
+
+const collapsed = computed(() => userCollapsed.value || isNarrowWindow.value)
+
+// 持久化用户手动收缩状态
+function toggleCollapsed() {
+  userCollapsed.value = !userCollapsed.value
+  void appSettings.set('df-sidebar-collapsed', userCollapsed.value)
+}
+
+// 监听窗口宽度:小窗口自动收缩(但不改变用户偏好)
+function checkWindowWidth() {
+  isNarrowWindow.value = window.innerWidth < COLLAPSE_THRESHOLD
+}
+
+onMounted(async () => {
+  // 恢复用户偏好(默认展开)
+  userCollapsed.value = appSettings.get('df-sidebar-collapsed', false)
+  // 检查当前窗口宽度
+  checkWindowWidth()
+  window.addEventListener('resize', checkWindowWidth)
+})
+
+onBeforeUnmount(() => {
+  window.removeEventListener('resize', checkWindowWidth)
+})
 
 // 知识库候选数量(侧栏 badge)— 解包 computed 取值保持响应式
 const candidateCount = computed(() => knowledgeStore.candidateCount)
@@ -111,6 +155,13 @@ const secondaryNav = [
   flex-direction: column;
   position: relative;
   user-select: none;
+  transition: width 0.2s var(--df-ease), min-width 0.2s var(--df-ease);
+}
+
+/* 收缩态 */
+.df-sidebar--collapsed {
+  width: 56px;
+  min-width: 56px;
 }
 
 /* — Logo — */
@@ -121,12 +172,18 @@ const secondaryNav = [
   padding: 14px 16px 12px;
   border-bottom: 0.5px solid var(--df-border);
 }
+.df-sidebar--collapsed .sidebar-brand {
+  padding: 12px 10px 10px;
+  justify-content: center;
+}
 .brand-mark {
   width: 28px; height: 28px;
   display: flex; align-items: center; justify-content: center;
   background: var(--df-accent-bg);
   border: 0.5px solid var(--df-border);
+  flex-shrink: 0;
 }
+.df-sidebar--collapsed .brand-mark { width: 32px; height: 32px; }
 .brand-text {
   font-size: 15px;
   font-weight: 500;
@@ -140,11 +197,48 @@ const secondaryNav = [
   background: rgba(255,255,255,0.04);
   padding: 1px 6px;
   border-radius: var(--df-radius-xs);
+}
+
+/* 收缩按钮(展开态 brand 区右侧) */
+.collapse-btn {
   margin-left: auto;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 22px; height: 22px;
+  border: none;
+  border-radius: var(--df-radius-sm);
+  background: transparent;
+  color: var(--df-text-dim);
+  cursor: pointer;
+  transition: all 0.15s var(--df-ease);
+}
+.collapse-btn:hover {
+  background: var(--df-sidebar-hover);
+  color: var(--df-text);
+}
+
+/* 展开按钮(收缩态 brand 区下方) */
+.expand-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 100%;
+  padding: 6px 0;
+  border: none;
+  background: transparent;
+  color: var(--df-text-dim);
+  cursor: pointer;
+  transition: all 0.15s var(--df-ease);
+}
+.expand-btn:hover {
+  background: var(--df-sidebar-hover);
+  color: var(--df-text);
 }
 
 /* — Nav — */
 .sidebar-nav { flex: 1; overflow-y: auto; padding: 8px 8px; }
+.df-sidebar--collapsed .sidebar-nav { padding: 8px 6px; }
 
 .nav-group { margin-bottom: 2px; }
 .nav-group-label {
@@ -162,6 +256,7 @@ const secondaryNav = [
   background: var(--df-border);
   margin: 6px 12px;
 }
+.df-sidebar--collapsed .nav-divider { margin: 4px 8px; }
 
 .nav-link {
   display: flex;
@@ -177,6 +272,10 @@ const secondaryNav = [
   transition: all 0.18s var(--df-ease);
   position: relative;
 }
+.df-sidebar--collapsed .nav-link {
+  justify-content: center;
+  padding: 8px 0;
+}
 
 .nav-link:hover {
   background: var(--df-sidebar-hover);
@@ -198,6 +297,8 @@ const secondaryNav = [
   background: var(--df-accent);
   border-radius: 0 3px 3px 0;
 }
+/* 收缩态隐藏左边高亮线(居中布局无空间) */
+.df-sidebar--collapsed .nav-link--active::before { display: none; }
 
 .nav-link-icon {
   display: flex;
@@ -276,14 +377,6 @@ const secondaryNav = [
 }
 
 /* ═══ Responsive ═══ */
-@media (max-width: 768px) {
-  .df-sidebar { width: 56px; min-width: 56px; }
-  .brand-text, .brand-version, .nav-group-label, .nav-link-text,
-  .nav-link-badge, .sidebar-status, .status-text, .ai-toggle-shortcut { display: none; }
-  .sidebar-brand { padding: 12px 10px 10px; justify-content: center; }
-  .brand-mark { width: 32px; height: 32px; }
-  .nav-link { justify-content: center; padding: 8px 0; }
-  .nav-divider { margin: 4px 8px; }
-  .nav-link--active::before { display: none; }
-}
+/* 小窗口自动收缩由 JS resize listener 驱动(isNarrowWindow),无需 media query。
+   原 768px media query 已删除,收缩逻辑统一走 collapsed class 控制。 */
 </style>
diff --git a/src/i18n/en/nav.ts b/src/i18n/en/nav.ts
index d0137ca..31d4a6a 100644
--- a/src/i18n/en/nav.ts
+++ b/src/i18n/en/nav.ts
@@ -11,5 +11,7 @@ export default {
     traceability: 'Traceability',
     systemReady: 'System Ready',
     aiPanel: 'AI Panel',
+    collapse: 'Collapse sidebar',
+    expand: 'Expand sidebar',
   },
 }
diff --git a/src/i18n/zh-CN/nav.ts b/src/i18n/zh-CN/nav.ts
index cb79c23..f3f2bf3 100644
--- a/src/i18n/zh-CN/nav.ts
+++ b/src/i18n/zh-CN/nav.ts
@@ -11,5 +11,7 @@ export default {
     traceability: '追溯',
     systemReady: '系统就绪',
     aiPanel: 'AI 面板',
+    collapse: '收起侧边栏',
+    expand: '展开侧边栏',
   },
 }