feat(admin): convert sidebar to multi-level menu structure

admin/src/layout/index.vue

@@ -1,26 +1,39 @@
 <template>
   <el-container style="min-height: 100vh">
-    <el-aside width="200px" style="background: #304156">
+    <el-aside width="220px" style="background: #304156">
       <div class="logo">笑话管理后台</div>
       <el-menu
         :default-active="$route.path"
+        :unique-opened="true"
         background-color="#304156"
         text-color="#bfcbd9"
         active-text-color="#409EFF"
         router
       >
-        <el-menu-item index="/dashboard">
-          <span>仪表盘</span>
-        </el-menu-item>
-        <el-menu-item index="/jokes">
-          <span>笑话管理</span>
-        </el-menu-item>
-        <el-menu-item index="/category/type">
-          <span>类型管理</span>
-        </el-menu-item>
-        <el-menu-item index="/category/crowd">
-          <span>人群管理</span>
-        </el-menu-item>
+        <el-sub-menu index="/dashboard">
+          <template #title>
+            <span>首页</span>
+          </template>
+          <el-menu-item index="/dashboard">仪表盘</el-menu-item>
+        </el-sub-menu>
+
+        <el-sub-menu index="/content">
+          <template #title>
+            <span>内容管理</span>
+          </template>
+          <el-menu-item index="/jokes">笑话管理</el-menu-item>
+          <el-menu-item index="/category/type">类型管理</el-menu-item>
+          <el-menu-item index="/category/crowd">人群管理</el-menu-item>
+        </el-sub-menu>
+
+        <el-sub-menu index="/system">
+          <template #title>
+            <span>系统管理</span>
+          </template>
+          <el-menu-item index="/settings">AI 配置</el-menu-item>
+          <el-menu-item index="/links">友链管理</el-menu-item>
+          <el-menu-item index="/feedbacks">反馈管理</el-menu-item>
+        </el-sub-menu>
       </el-menu>
     </el-aside>
     <el-container>
@@ -56,8 +69,26 @@ const handleLogout = () => {
   font-size: 18px;
   font-weight: bold;
   background: #2b3a4a;
+  letter-spacing: 2px;
 }
 .el-aside {
   background: #304156;
 }
+/* 多级菜单样式 */
+:deep(.el-sub-menu__title) {
+  font-size: 14px;
+  font-weight: 600;
+}
+:deep(.el-menu-item) {
+  font-size: 13px;
+  padding-left: 54px !important;
+}
+:deep(.el-menu-item.is-active) {
+  background-color: #263445 !important;
+}
+:deep(.el-sub-menu .el-menu-item) {
+  min-width: 0;
+  height: 44px;
+  line-height: 44px;
+}
 </style>