diff --git a/biji-qianduan/src/components/home/SidebarMenu.vue b/biji-qianduan/src/components/home/SidebarMenu.vue
index 8fa4b45..1602273 100644
--- a/biji-qianduan/src/components/home/SidebarMenu.vue
+++ b/biji-qianduan/src/components/home/SidebarMenu.vue
@@ -29,6 +29,7 @@
           :collapse="isCollapsed && !isMobile"
           popper-effect="light"
           :collapse-transition="true"
+          @select="handleMenuSelect"
       >
         <div class="menu-section" v-if="isMobile">
           <div v-if="userStore.isLoggedIn" class="user-info">
@@ -107,6 +108,24 @@ const goToTrash = () => router.push({ name: 'Trash' });
 const goToLogin = () => router.push('/login');
 const goToRegister = () => router.push('/register');
 
+const handleMenuSelect = (index) => {
+  if (index.startsWith('group-')) {
+    const id = index.replace('group-', '');
+    const findItem = (items) => {
+      for (let item of items) {
+        if (String(item.id) === id) return item;
+        if (item.children) {
+          const found = findItem(item.children);
+          if (found) return found;
+        }
+      }
+      return null;
+    };
+    const item = findItem(props.categoryTree);
+    if (item) emit('select-file', item);
+  }
+};
+
 const handleDeleteGroup = (group) => {
   ElMessageBox.confirm(
       `确定要删除分类 “${group.grouping}” 吗？这将同时删除该分类下的所有子分类和笔记。`,
@@ -145,18 +164,19 @@ const renderMenu = (item) => {
   if (item.children && item.children.length > 0) {
     return h(ElSubMenu, {
       index: `group-${item.id}`,
-      popperClass: props.isCollapsed ? 'hide-popper' : ''
+      popperClass: props.isCollapsed ? 'hide-popper' : '',
+      class: { 'is-active': props.activeMenu === `group-${item.id}` },
+      disabled: false
     }, {
       title: () => h('div', {
         class: 'submenu-title-wrapper',
-        onClick: () => emit('select-file', item),
         style: 'width: 100%; display: flex; align-items: center;'
       }, [ wrappedContent() ]),
       default: () => item.children.map(child => renderMenu(child))
     });
   }
 
-  return h(ElMenuItem, { index: `group-${item.id}`, onClick: () => emit('select-file', item) }, {
+  return h(ElMenuItem, { index: `group-${item.id}` }, {
     default: wrappedContent
   });
 };
@@ -349,6 +369,30 @@ const renderMenu = (item) => {
   background: #fff;
 }
 
+/* 移除嵌套 SubMenu 的 active 样式 */
+:deep(.el-menu--inline .el-sub-menu.is-active > .el-sub-menu__title) {
+  background: transparent !important;
+  color: var(--text-color-secondary) !important;
+  box-shadow: none !important;
+}
+
+:deep(.el-menu--inline .el-sub-menu.is-active > .el-sub-menu__title::before) {
+  height: 0 !important;
+}
+
+/* 只有顶级 SubMenu 被直接选中时才显示 active 样式 */
+:deep(.el-menu > .el-sub-menu.is-active > .el-sub-menu__title) {
+  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-color-light) 100%) !important;
+  color: #fff !important;
+  font-weight: 600 !important;
+  box-shadow: 0 4px 12px rgba(64, 158, 255, 0.35) !important;
+}
+
+:deep(.el-menu > .el-sub-menu.is-active > .el-sub-menu__title::before) {
+  height: 24px !important;
+  background: #fff !important;
+}
+
 :deep(.el-menu-item:hover), :deep(.el-sub-menu__title:hover) {
   background-color: rgba(64, 158, 255, 0.08);
   color: var(--primary-color);