diff --git a/app/layouts/default.vue b/app/layouts/default.vue
index 2287753..69ff625 100644
--- a/app/layouts/default.vue
+++ b/app/layouts/default.vue
@@ -1,12 +1,12 @@
 <template>
   <el-container class="layout-container">
-    <el-aside :width="collapsed ? '64px' : '200px'" class="sidebar desktop-only">
+    <el-aside :width="collapsed ? '64px' : '200px'" class="sidebar desktop-only transition-base">
       <div class="logo">
-        <h2 v-if="!collapsed">运动会记分板</h2>
-        <el-icon v-else :size="24"><Trophy /></el-icon>
+        <h2 v-if="!collapsed" class="slide-down-enter">运动会记分板</h2>
+        <el-icon v-else :size="24" class="slide-down-enter"><Trophy /></el-icon>
       </div>
       <div class="sidebar-toggle">
-        <el-button text @click="toggleCollapse" size="small">
+        <el-button text @click="toggleCollapse" size="small" class="rotate-icon">
           <el-icon>
             <ArrowLeft v-if="!collapsed" />
             <ArrowRight v-else />
@@ -19,15 +19,37 @@
         :collapse="collapsed"
         :collapse-transition="false"
       >
-        <el-menu-item
-          v-for="item in menuItems"
-          :key="item.path"
-          :index="item.path"
-          @click="onMenuClick(item.path)"
-        >
-          <el-icon><component :is="item.icon" /></el-icon>
-          <span>{{ item.label }}</span>
-        </el-menu-item>
+        <template v-for="item in menuItems" :key="item.path || item.label">
+          <!-- Regular menu item -->
+          <el-menu-item
+            v-if="!item.children"
+            :index="item.path"
+            @click="onMenuClick(item.path)"
+          >
+            <el-icon><component :is="item.icon" /></el-icon>
+            <span>{{ item.label }}</span>
+          </el-menu-item>
+          
+          <!-- Submenu with children -->
+          <el-sub-menu
+            v-else
+            :index="item.label"
+          >
+            <template #title>
+              <el-icon><component :is="item.icon" /></el-icon>
+              <span>{{ item.label }}</span>
+            </template>
+            <el-menu-item
+              v-for="child in item.children"
+              :key="child.path"
+              :index="child.path"
+              @click="onMenuClick(child.path)"
+            >
+              <el-icon><component :is="child.icon" /></el-icon>
+              <span>{{ child.label }}</span>
+            </el-menu-item>
+          </el-sub-menu>
+        </template>
 
         <el-sub-menu v-if="hasAdminMenu" index="admin">
           <template #title>
@@ -54,6 +76,12 @@
           <h3>运动会管理系统</h3>
         </div>
         <div class="header-right">
+          <el-button text @click="toggleDark()" class="theme-toggle-btn">
+            <el-icon>
+              <Sunny v-if="isDark" />
+              <Moon v-else />
+            </el-icon>
+          </el-button>
           <el-dropdown v-if="currentUser" @command="handleUserCommand">
             <span class="user-info">
               <el-avatar :size="32">
@@ -86,7 +114,7 @@
     direction="ltr"
     size="70%"
     :with-header="false"
-    class="mobile-only"
+    class="mobile-only drawer-transition"
   >
     <div class="drawer-logo">
       <h2>运动会记分板</h2>
@@ -95,15 +123,37 @@
       :default-active="activeMenu"
       class="drawer-menu"
     >
-      <el-menu-item
-        v-for="item in menuItems"
-        :key="item.path"
-        :index="item.path"
-        @click="onMenuClick(item.path, true)"
-      >
-        <el-icon><component :is="item.icon" /></el-icon>
-        <span>{{ item.label }}</span>
-      </el-menu-item>
+      <template v-for="item in menuItems" :key="item.path || item.label">
+        <!-- Regular menu item -->
+        <el-menu-item
+          v-if="!item.children"
+          :index="item.path"
+          @click="onMenuClick(item.path, true)"
+        >
+          <el-icon><component :is="item.icon" /></el-icon>
+          <span>{{ item.label }}</span>
+        </el-menu-item>
+        
+        <!-- Submenu with children -->
+        <el-sub-menu
+          v-else
+          :index="item.label"
+        >
+          <template #title>
+            <el-icon><component :is="item.icon" /></el-icon>
+            <span>{{ item.label }}</span>
+          </template>
+          <el-menu-item
+            v-for="child in item.children"
+            :key="child.path"
+            :index="child.path"
+            @click="onMenuClick(child.path, true)"
+          >
+            <el-icon><component :is="child.icon" /></el-icon>
+            <span>{{ child.label }}</span>
+          </el-menu-item>
+        </el-sub-menu>
+      </template>
 
       <el-sub-menu v-if="hasAdminMenu" index="admin">
         <template #title>
@@ -122,7 +172,7 @@
     </el-menu>
   </el-drawer>
 
-  <el-dialog v-model="showLoginDialog" title="登录" width="400px">
+  <el-dialog v-model="showLoginDialog" title="登录" width="400px" class="dialog-zoom">
     <el-form :model="loginForm" :rules="loginRules" ref="loginFormRef">
       <el-form-item prop="username">
         <el-input 
@@ -150,7 +200,9 @@
 </template>
 
 <script setup lang="ts">
-import { HomeFilled, Trophy, UserFilled, Edit, DataLine, Menu, Setting, Key, ArrowLeft, ArrowRight, ArrowDown } from '@element-plus/icons-vue'
+import { HomeFilled, Trophy, UserFilled, Edit, DataLine, Menu, Setting, Key, ArrowLeft, ArrowRight, ArrowDown, LocationFilled, Sunny, Moon } from '@element-plus/icons-vue'
+import { useDark, useToggle } from '@vueuse/core'
+import { ref, onMounted, computed } from 'vue'
 
 const route = useRoute()
 const activeMenu = computed(() => route.path)
@@ -159,6 +211,22 @@ const showLoginDialog = ref(false)
 const logging = ref(false)
 const loginFormRef = ref()
 
+// 使用 VueUse 的 useDark 管理暗色模式 - SSR safe
+const isDark = ref(false)
+const toggleDark = ref(() => {})
+
+onMounted(() => {
+  const dark = useDark({
+    selector: 'html',
+    attribute: 'class',
+    valueDark: 'dark',
+    valueLight: '',
+    storageKey: 'theme',
+  })
+  isDark.value = dark
+  toggleDark.value = useToggle(dark)
+})
+
 const collapsed = ref(false)
 const currentUser = ref<any>(null)
 const hasAdminMenu = computed(() => currentUser.value?.role === 'admin')
@@ -175,10 +243,17 @@ const loginRules = {
 
 const menuItems = [
   { path: '/', label: '首页', icon: HomeFilled },
-  { path: '/events', label: '比赛项目', icon: Trophy },
-  { path: '/teams', label: '队伍管理', icon: UserFilled },
-  { path: '/results', label: '成绩录入', icon: Edit },
-  { path: '/scoreboard', label: '记分板', icon: DataLine }
+  {
+    label: '比赛管理',
+    icon: Trophy,
+    children: [
+      { path: '/events', label: '比赛项目', icon: Trophy },
+      { path: '/teams', label: '队伍管理', icon: UserFilled },
+      { path: '/results', label: '成绩录入', icon: Edit },
+      { path: '/scoreboard', label: '记分板', icon: DataLine }
+    ]
+  },
+  { path: '/checkins', label: '机位打卡', icon: LocationFilled }
 ]
 
 const toggleCollapse = () => {
@@ -243,9 +318,12 @@ onMounted(() => {
   if (savedUser) {
     currentUser.value = JSON.parse(savedUser)
   }
+  // 主题切换由 VueUse useDark 自动处理
 })
 </script>
 
+
+
 <style scoped>
 .layout-container {
   height: 100vh;
@@ -256,73 +334,213 @@ onMounted(() => {
   overflow-y: auto;
 }
 
+/* 侧边栏 - 始终使用深色背景 */
 .sidebar {
-  background-color: #304156;
-  color: #fff;
-  transition: width 0.3s;
+  background: linear-gradient(180deg, var(--sidebar-bg) 0%, var(--sidebar-header-bg) 100%);
+  color: var(--sidebar-text);
+  transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
   overflow: hidden;
   height: 100%;
+  box-shadow: 2px 0 8px rgba(0, 0, 0, 0.1);
 }
 
 .logo {
-  height: 56px;
+  height: 60px;
   display: flex;
   align-items: center;
   justify-content: center;
-  background-color: #2b3a4a;
+  background-color: var(--sidebar-header-bg);
+  border-bottom: 1px rgba(255, 255, 255, 0.05);
+  overflow: hidden;
 }
 
 .logo h2 {
   color: #fff;
-  font-size: 16px;
+  font-size: 18px;
+  font-weight: 600;
   margin: 0;
   white-space: nowrap;
+  letter-spacing: 0.5px;
+  transition: opacity 0.2s ease;
 }
 
 .sidebar-toggle {
   display: flex;
   justify-content: flex-end;
-  padding: 4px 8px;
-  border-bottom: 1px solid #263445;
+  padding: 8px 12px;
+  border-bottom: 1px rgba(255, 255, 255, 0.05);
 }
 
+.rotate-icon {
+  transition: transform 0.3s ease;
+}
+
+.rotate-icon:hover {
+  transform: rotate(180deg);
+}
+
+/* 菜单样式 */
 .sidebar-menu {
   border-right: none;
-  background-color: #304156;
+  background-color: transparent;
 }
 
 .sidebar-menu:not(.el-menu--collapse) {
-  width: 200px;
+  width: 100%;
 }
 
 .sidebar-menu .el-menu-item,
 .sidebar-menu .el-sub-menu__title {
-  color: #bfcbd9;
+  color: var(--sidebar-text);
+  height: 48px;
+  line-height: 48px;
+  margin: 4px 8px;
+  border-radius: 8px;
+  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
 }
 
 .sidebar-menu .el-menu-item:hover,
-.sidebar-menu .el-sub-menu__title:hover,
+.sidebar-menu .el-sub-menu__title:hover {
+  background-color: var(--sidebar-hover-bg);
+  color: #fff;
+}
+
 .sidebar-menu .el-menu-item.is-active,
 .sidebar-menu .el-sub-menu .el-menu-item.is-active {
-  background-color: #263445;
-  color: #409eff;
+  background-color: var(--sidebar-active-bg);
+  color: var(--sidebar-active-text);
+  font-weight: 500;
+}
+
+.sidebar-menu .el-menu-item.is-active::before {
+  content: '';
+  position: absolute;
+  left: 0;
+  top: 50%;
+  transform: translateY(-50%);
+  width: 3px;
+  height: 24px;
+  background-color: #fff;
+  border-radius: 0 3px 3px 0;
+}
+
+/* 子菜单样式 */
+.sidebar-menu .el-sub-menu .el-menu-item {
+  padding-left: 20px !important;
+  margin: 2px 8px;
+}
+
+/* 菜单图标 */
+.sidebar-menu .el-icon {
+  margin-right: 8px;
+  font-size: 18px;
+}
+
+/* Staggered animation for menu items */
+.sidebar-menu .el-menu-item:nth-child(1),
+.sidebar-menu .el-sub-menu:nth-child(1) {
+  animation-delay: 0.05s;
+}
+
+.sidebar-menu .el-menu-item:nth-child(2),
+.sidebar-menu .el-sub-menu:nth-child(2) {
+  animation-delay: 0.1s;
+}
+
+.sidebar-menu .el-menu-item:nth-child(3),
+.sidebar-menu .el-sub-menu:nth-child(3) {
+  animation-delay: 0.15s;
+}
+
+.sidebar-menu .el-menu-item:nth-child(4),
+.sidebar-menu .el-sub-menu:nth-child(4) {
+  animation-delay: 0.2s;
+}
+
+.sidebar-menu .el-menu-item:nth-child(5),
+.sidebar-menu .el-sub-menu:nth-child(5) {
+  animation-delay: 0.25s;
+}
+
+@keyframes slide-in-left {
+  0% {
+    opacity: 0;
+    transform: translateX(-20px);
+  }
+  100% {
+    opacity: 1;
+    transform: translateX(0);
+  }
+}
+
+.sidebar-menu .el-menu-item:hover,
+.sidebar-menu .el-sub-menu__title:hover {
+  background-color: var(--sidebar-hover-bg);
+  color: #fff;
+  transform: translateX(5px);
+}
+
+.sidebar-menu .el-menu-item.is-active,
+.sidebar-menu .el-sub-menu .el-menu-item.is-active {
+  background-color: var(--sidebar-active-bg);
+  color: var(--sidebar-active-text);
+  font-weight: 500;
+  transform: translateX(5px);
+}
+
+.sidebar-menu .el-menu-item.is-active::before {
+  content: '';
+  position: absolute;
+  left: 0;
+  top: 50%;
+  transform: translateY(-50%);
+  width: 3px;
+  height: 24px;
+  background-color: #fff;
+  border-radius: 0 3px 3px 0;
+}
+
+/* 子菜单样式 */
+.sidebar-menu .el-sub-menu .el-menu-item {
+  padding-left: 20px !important;
+  margin: 2px 8px;
+  display: flex;
+  align-items: center;
+}
+
+/* 菜单图标 - 确保垂直居中 */
+.sidebar-menu .el-icon {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  margin-right: 8px;
+  font-size: 18px;
+  flex-shrink: 0;
+}
+
+/* 子菜单箭头对齐 */
+.sidebar-menu .el-sub-menu__title .el-sub-menu__icon-arrow {
+  margin-left: auto;
+  display: flex;
+  align-items: center;
 }
 
 .header {
-  background-color: #fff;
-  border-bottom: 1px solid #e6e6e6;
+  background-color: var(--header-bg);
+  border-bottom: 1px solid var(--header-border);
   display: flex;
   align-items: center;
   justify-content: space-between;
-  padding: 0 20px;
-  height: 56px;
+  padding: 0 24px;
+  height: 60px;
   flex-shrink: 0;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
 }
 
 .header-left {
   display: flex;
   align-items: center;
-  gap: 8px;
+  gap: 12px;
 }
 
 .header-right {
@@ -332,7 +550,9 @@ onMounted(() => {
 
 .header h3 {
   margin: 0;
-  color: #303133;
+  color: var(--header-text);
+  font-size: 18px;
+  font-weight: 600;
 }
 
 .user-info {
@@ -340,37 +560,78 @@ onMounted(() => {
   align-items: center;
   gap: 8px;
   cursor: pointer;
+  padding: 6px 12px;
+  border-radius: 8px;
+  transition: all 0.3s ease;
+}
+
+.user-info:hover {
+  background-color: var(--sidebar-hover-bg);
+  transform: translateY(-2px);
 }
 
 .username {
-  color: #303133;
+  color: var(--header-text);
+  font-weight: 500;
+}
+
+.theme-toggle-btn {
+  margin-right: 12px;
+  color: var(--header-text);
+  border-radius: 8px;
+  padding: 8px;
+  transition: all 0.3s ease;
+}
+
+.theme-toggle-btn:hover {
+  background-color: var(--sidebar-hover-bg) !important;
+  color: #fff;
+  transform: rotate(30deg);
 }
 
 .main-content {
-  background-color: #f0f2f5;
-  padding: 20px;
+  background-color: var(--main-bg);
+  padding: 24px;
   height: 100%;
   box-sizing: border-box;
   overflow-y: auto;
+  animation: fade-in 0.4s ease-out;
 }
 
+/* 移动端抽屉 */
 .drawer-logo {
-  height: 56px;
+  height: 60px;
   display: flex;
   align-items: center;
   justify-content: center;
-  background-color: #2b3a4a;
-  color: #fff;
+  background: linear-gradient(180deg, var(--sidebar-bg) 0%, var(--sidebar-header-bg) 100%);
+  border-bottom: 1px rgba(255, 255, 255, 0.05);
 }
 
 .drawer-logo h2 {
   margin: 0;
   font-size: 18px;
+  font-weight: 600;
   color: #fff;
 }
 
 .drawer-menu {
   border-right: none;
+  background-color: var(--sidebar-bg);
+}
+
+.drawer-menu .el-menu-item,
+.drawer-menu .el-sub-menu__title,
+.drawer-menu .el-sub-menu .el-menu-item {
+  color: var(--sidebar-text);
+}
+
+.drawer-menu .el-menu-item:hover,
+.drawer-menu .el-sub-menu__title:hover,
+.drawer-menu .el-menu-item.is-active,
+.drawer-menu .el-sub-menu .el-menu-item.is-active {
+  background-color: var(--sidebar-hover-bg);
+  color: #fff;
 }
 
 .desktop-only {
@@ -385,7 +646,7 @@ onMounted(() => {
   display: none;
 }
 
-@media (max-width: 900px) {
+@media (max-width: 768px) {
   .desktop-only {
     display: none;
   }
@@ -399,17 +660,17 @@ onMounted(() => {
   }
 
   .header {
-    padding: 0 12px;
+    padding: 0 16px;
   }
 
   .main-content {
-    padding: 12px;
+    padding: 16px;
   }
 }
 
 .footer {
-  background-color: #fff;
-  border-top: 1px solid #e6e6e6;
+  background-color: var(--footer-bg);
+  border-top: 1px solid var(--footer-border);
   display: flex;
   align-items: center;
   justify-content: center;
@@ -420,7 +681,7 @@ onMounted(() => {
 
 .footer p {
   margin: 0;
-  color: #909399;
-  font-size: 12px;
+  color: var(--footer-text);
+  font-size: 13px;
 }
 </style>