diff --git a/web/src/components/Index.vue b/web/src/components/Index.vue
index a9c9d4c..d7ff290 100644
--- a/web/src/components/Index.vue
+++ b/web/src/components/Index.vue
@@ -25,6 +25,34 @@ const isUserMenuOpen = ref(false)
 const userAccount = ref('管理员')
 const siteConfig = ref<any>({})
 
+// 主题：明暗模式
+const getInitialTheme = (): 'light' | 'dark' => {
+  try {
+    const stored = localStorage.getItem('theme') as 'light' | 'dark' | null
+    if (stored === 'light' || stored === 'dark') return stored
+    const systemDark = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches
+    return systemDark ? 'dark' : 'light'
+  } catch {
+    return 'light'
+  }
+}
+
+const theme = ref<'light' | 'dark'>(getInitialTheme())
+
+const applyTheme = (next: 'light' | 'dark') => {
+  theme.value = next
+  if (next === 'dark') {
+    document.documentElement.classList.add('dark')
+  } else {
+    document.documentElement.classList.remove('dark')
+  }
+  try { localStorage.setItem('theme', next) } catch {}
+}
+
+const toggleTheme = () => {
+  applyTheme(theme.value === 'dark' ? 'light' : 'dark')
+}
+
 // 从JWT中解析用户名
 const parseJwtUsername = (token: string): string => {
   try {
@@ -255,14 +283,14 @@ const siteTitle = computed(() => {
 <template>
   <router-view v-if="!isAuthenticated || route.path == '/login' || route.path == 'login'"></router-view>
 
-  <div class="min-h-screen bg-gray-50" v-else>
+  <div class="min-h-screen bg-background" v-else>
     <!-- 顶部导航栏 -->
-    <nav class="bg-white shadow-sm border-b border-gray-200">
+    <nav class="bg-background shadow-sm border-b border-border">
       <div class="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
         <div class="flex justify-between items-center h-16">
           <!-- Logo/品牌名称 -->
           <div class="flex items-center">
-            <h1 class="text-lg sm:text-xl font-bold text-gray-900">{{ siteTitle }}</h1>
+            <h1 class="text-lg sm:text-xl font-bold text-foreground">{{ siteTitle }}</h1>
           </div>
 
           <!-- 桌面端导航 -->
@@ -270,8 +298,8 @@ const siteTitle = computed(() => {
             <button v-for="tab in tabRoutes" :key="tab.name" @click="handleTabClick(tab)" :class="[
               'relative py-2 px-3 text-sm font-medium transition-all duration-200 rounded-md whitespace-nowrap',
               activeTab === tab.name
-                ? 'text-blue-600 bg-blue-50'
-                : 'text-gray-600 hover:text-blue-600 hover:bg-gray-50'
+                ? 'text-blue-600 bg-blue-50 dark:text-blue-400 dark:bg-blue-400/10'
+                : 'text-gray-600 hover:text-blue-600 hover:bg-gray-50 dark:text-gray-300 dark:hover:text-blue-400 dark:hover:bg-white/5'
             ]">
               {{ tab.name }}
               <!-- 活动状态指示器 -->
@@ -282,27 +310,65 @@ const siteTitle = computed(() => {
 
           <!-- 右侧区域 -->
           <div class="flex items-center space-x-4">
+            <!-- 主题切换（仅桌面显示） -->
+            <button @click="toggleTheme" class="hidden md:inline-flex p-2 rounded-md text-gray-600 hover:text-blue-600 hover:bg-gray-50 transition-colors dark:text-gray-300 dark:hover:text-blue-400 dark:hover:bg-white/5" :title="theme === 'dark' ? '切换到浅色' : '切换到深色'">
+              <svg v-if="theme === 'dark'" class="w-5 h-5" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z"/>
+              </svg>
+              <svg v-else class="w-5 h-5" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                <circle cx="12" cy="12" r="5"/>
+                <line x1="12" y1="1" x2="12" y2="3"/>
+                <line x1="12" y1="21" x2="12" y2="23"/>
+                <line x1="4.22" y1="4.22" x2="5.64" y2="5.64"/>
+                <line x1="18.36" y1="18.36" x2="19.78" y2="19.78"/>
+                <line x1="1" y1="12" x2="3" y2="12"/>
+                <line x1="21" y1="12" x2="23" y2="12"/>
+                <line x1="4.22" y1="19.78" x2="5.64" y2="18.36"/>
+                <line x1="18.36" y1="5.64" x2="19.78" y2="4.22"/>
+              </svg>
+            </button>
             <!-- 用户账号下拉菜单 -->
             <div class="relative user-menu-container">
-              <button @click="toggleUserMenu" class="flex items-center space-x-2 p-2 rounded-md hover:bg-gray-50 transition-colors">
+              <button @click="toggleUserMenu" class="flex items-center space-x-2 p-2 rounded-md hover:bg-muted transition-colors dark:hover:bg-white/5">
                 <div class="w-8 h-8 bg-blue-100 rounded-full flex items-center justify-center">
                   <svg class="w-4 h-4 text-blue-600" fill="currentColor" viewBox="0 0 20 20">
                     <path fill-rule="evenodd" d="M10 9a3 3 0 100-6 3 3 0 000 6zm-7 9a7 7 0 1114 0H3z" clip-rule="evenodd" />
                   </svg>
                 </div>
-                <span class="hidden sm:block text-sm font-medium text-gray-700">{{ userAccount }}</span>
+                <span class="hidden sm:block text-sm font-medium text-foreground">{{ userAccount }}</span>
                 <svg class="w-4 h-4 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                   <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7" />
                 </svg>
               </button>
               
               <!-- 下拉菜单 -->
-              <div v-if="isUserMenuOpen" class="absolute right-0 mt-2 w-48 bg-white rounded-md shadow-lg border border-gray-200 z-50">
+              <div v-if="isUserMenuOpen" class="absolute right-0 mt-2 w-52 bg-card text-foreground rounded-md shadow-lg border border-border z-50">
                 <div class="py-1">
-                  <div class="px-4 py-2 text-sm text-gray-500 border-b border-gray-100">
-                    <div class="font-medium text-gray-900">{{ userAccount }}</div>
+                  <div class="px-4 py-2 text-sm text-muted-foreground border-b border-border">
+                    <div class="font-medium text-foreground">{{ userAccount }}</div>
                     <!-- <div class="text-xs">当前登录账号</div> -->
                   </div>
+                  <!-- 移动端主题切换入口 -->
+                  <button @click="toggleTheme" class="md:hidden w-full text-left px-4 py-2 text-sm hover:bg-muted dark:hover:bg-white/5 flex items-center justify-between">
+                    <span>外观</span>
+                    <span class="inline-flex items-center gap-2">
+                      <svg v-if="theme === 'dark'" class="w-4 h-4" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z"/>
+                      </svg>
+                      <svg v-else class="w-4 h-4" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+                        <circle cx="12" cy="12" r="5"/>
+                        <line x1="12" y1="1" x2="12" y2="3"/>
+                        <line x1="12" y1="21" x2="12" y2="23"/>
+                        <line x1="4.22" y1="4.22" x2="5.64" y2="5.64"/>
+                        <line x1="18.36" y1="18.36" x2="19.78" y2="19.78"/>
+                        <line x1="1" y1="12" x2="3" y2="12"/>
+                        <line x1="21" y1="12" x2="23" y2="12"/>
+                        <line x1="4.22" y1="19.78" x2="5.64" y2="18.36"/>
+                        <line x1="18.36" y1="5.64" x2="19.78" y2="4.22"/>
+                      </svg>
+                      <span class="text-xs text-muted-foreground">{{ theme === 'dark' ? '深色' : '浅色' }}</span>
+                    </span>
+                  </button>
                   <button @click="logout" class="w-full text-left px-4 py-2 text-sm text-red-600 hover:bg-red-50 transition-colors">
                     <div class="flex items-center space-x-2">
                       <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -328,14 +394,14 @@ const siteTitle = computed(() => {
         </div>
 
         <!-- 移动端菜单 -->
-        <div v-if="isMobileMenuOpen" class="md:hidden border-t border-gray-200 py-2">
+        <div v-if="isMobileMenuOpen" class="md:hidden border-t border-border py-2">
           <div class="flex flex-col space-y-1">
             <button v-for="tab in tabRoutes" :key="tab.name" @click="handleTabClick(tab); isMobileMenuOpen = false"
               :class="[
                 'text-left py-3 px-4 text-sm font-medium transition-all duration-200 rounded-md',
                 activeTab === tab.name
-                  ? 'text-blue-600 bg-blue-50'
-                  : 'text-gray-600 hover:text-blue-600 hover:bg-gray-50'
+                  ? 'text-blue-600 bg-blue-50 dark:text-blue-400 dark:bg-blue-400/10'
+                  : 'text-muted-foreground hover:text-blue-600 hover:bg-muted dark:hover:bg-white/5'
               ]">
               {{ tab.name }}
             </button>
diff --git a/web/src/components/pages/cronMessages/CronMessages.vue b/web/src/components/pages/cronMessages/CronMessages.vue
index 6f229a0..e6795b2 100644
--- a/web/src/components/pages/cronMessages/CronMessages.vue
+++ b/web/src/components/pages/cronMessages/CronMessages.vue
@@ -161,7 +161,7 @@ onMounted(async () => {
       <div class="flex-shrink-0">
         <Dialog v-model:open="isAddCronMessageDialogOpen">
           <DialogTrigger as-child>
-            <Button variant="default" class="w-full sm:w-auto bg-gray-800 hover:bg-gray-900">
+            <Button variant="default" class="w-full sm:w-auto">
               <svg class="w-4 h-4 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                 <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 4v16m8-8H4" />
               </svg>
@@ -212,7 +212,9 @@ onMounted(async () => {
           <TableCell class="max-w-32 truncate" :title="cronMessage.title">{{ cronMessage.title }}</TableCell>
           <TableCell class="max-w-32 truncate" :title="cronMessage.content">{{ cronMessage.content }}</TableCell>
           <TableCell>
-            <code class="bg-gray-100 px-2 py-1 rounded text-sm">{{ cronMessage.cron }}</code>
+            <code class="px-2 py-1 rounded text-sm font-mono bg-muted text-foreground border border-border">
+              {{ cronMessage.cron }}
+            </code>
           </TableCell>
           <TableCell class="max-w-24 truncate" :title="cronMessage.task_id">{{ cronMessage.task_id }}</TableCell>
           <TableCell class="max-w-32 truncate" :title="cronMessage.next_time || '-'">{{ cronMessage.next_time || '-' }}
diff --git a/web/src/components/pages/dashboard/Dashboard.vue b/web/src/components/pages/dashboard/Dashboard.vue
index 591f068..c8d6288 100644
--- a/web/src/components/pages/dashboard/Dashboard.vue
+++ b/web/src/components/pages/dashboard/Dashboard.vue
@@ -256,7 +256,7 @@ const renderLineChart = () => {
       enabled: true,
       shared: true,
       intersect: false,
-      theme: 'light',
+      theme: document.documentElement.classList.contains('dark') ? 'dark' : 'light',
       style: {
         fontSize: '12px',
         fontFamily: 'Inter, sans-serif'
@@ -279,28 +279,33 @@ const renderLineChart = () => {
         const total = successCount + failedCount;
         const successRate = total > 0 ? ((successCount / total) * 100).toFixed(1) : '0.0';
 
+        const containerCls = 'bg-card text-foreground p-3 rounded-lg shadow-lg border border-border';
+        const labelMutedCls = 'text-sm text-muted-foreground';
+        const valueStrongCls = 'text-sm font-medium text-foreground';
+        const successRateCls = 'text-sm font-medium';
+
         return `
-          <div class="bg-white p-3 rounded-lg shadow-lg border">
-            <div class="font-medium text-gray-900 mb-2">${w.globals.categoryLabels[dataPointIndex]}</div>
+          <div class="${containerCls}">
+            <div class="font-medium mb-2">${w.globals.categoryLabels[dataPointIndex]}</div>
             <div class="space-y-1">
               <div class="flex items-center justify-between">
                 <span class="flex items-center">
                   <span class="w-2 h-2 bg-green-500 rounded-full mr-2"></span>
-                  <span class="text-sm text-gray-600">成功:</span>
+                  <span class="${labelMutedCls}">成功:</span>
                 </span>
-                <span class="text-sm font-medium text-gray-900">${successCount} 条</span>
+                <span class="${valueStrongCls}">${successCount} 条</span>
               </div>
               <div class="flex items-center justify-between">
                 <span class="flex items-center">
                   <span class="w-2 h-2 bg-red-500 rounded-full mr-2"></span>
-                  <span class="text-sm text-gray-600">失败:</span>
+                  <span class="${labelMutedCls}">失败:</span>
                 </span>
-                <span class="text-sm font-medium text-gray-900">${failedCount} 条</span>
+                <span class="${valueStrongCls}">${failedCount} 条</span>
               </div>
-              <div class="border-t pt-1 mt-2">
+              <div class="border-t border-border pt-1 mt-2">
                 <div class="flex items-center justify-between">
-                  <span class="text-sm text-gray-600">成功率:</span>
-                  <span class="text-sm font-medium text-green-600">${successRate}%</span>
+                  <span class="${labelMutedCls}">成功率:</span>
+                  <span class="${successRateCls}">${successRate}%</span>
                 </div>
               </div>
             </div>
diff --git a/web/src/components/pages/hostedMessage/HostedMessage.vue b/web/src/components/pages/hostedMessage/HostedMessage.vue
index 9c6c199..d1aab65 100644
--- a/web/src/components/pages/hostedMessage/HostedMessage.vue
+++ b/web/src/components/pages/hostedMessage/HostedMessage.vue
@@ -165,8 +165,8 @@ onMounted(async () => {
           <SheetTitle>{{ selectedTaskName }} - 托管消息详情</SheetTitle>
         </SheetHeader>
         <div class="mt-4">
-          <div class="bg-gray-50 p-4 rounded-lg max-h-[82vh] overflow-y-auto break-words">
-            <pre class="whitespace-pre-wrap text-sm font-mono">{{ selectedLog }}</pre>
+          <div class="bg-card p-4 rounded-lg border border-border max-h-[82vh] overflow-y-auto break-words">
+            <pre class="whitespace-pre-wrap text-sm font-mono text-foreground">{{ selectedLog }}</pre>
           </div>
         </div>
       </SheetContent>
diff --git a/web/src/components/pages/sendLogs/SendLogs.vue b/web/src/components/pages/sendLogs/SendLogs.vue
index cfb58f9..1a06122 100644
--- a/web/src/components/pages/sendLogs/SendLogs.vue
+++ b/web/src/components/pages/sendLogs/SendLogs.vue
@@ -240,8 +240,8 @@ onMounted(async () => {
           <SheetTitle>{{ selectedTaskName }} - 发信日志详情</SheetTitle>
         </SheetHeader>
         <div class="mt-4">
-          <div class="bg-gray-50 p-4 rounded-lg max-h-[82vh] overflow-y-auto break-words">
-            <pre class="whitespace-pre-wrap text-sm font-mono">{{ selectedLog }}</pre>
+          <div class="bg-card p-4 rounded-lg border border-border max-h-[82vh] overflow-y-auto break-words">
+            <pre class="whitespace-pre-wrap text-sm font-mono text-foreground">{{ selectedLog }}</pre>
           </div>
         </div>
       </SheetContent>
diff --git a/web/src/components/pages/sendTasks/SendTasks.vue b/web/src/components/pages/sendTasks/SendTasks.vue
index 5711538..45d67dc 100644
--- a/web/src/components/pages/sendTasks/SendTasks.vue
+++ b/web/src/components/pages/sendTasks/SendTasks.vue
@@ -177,7 +177,7 @@ onMounted(async () => {
       <div class="flex-shrink-0">
         <Dialog v-model:open="isAddChannelDrawerOpen">
           <DialogTrigger as-child>
-            <Button variant="default" class="w-full sm:w-auto bg-gray-800 hover:bg-gray-900">
+            <Button variant="default" class="w-full sm:w-auto">
               <svg class="w-4 h-4 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                 <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 4v16m8-8H4" />
               </svg>
@@ -265,8 +265,8 @@ onMounted(async () => {
           <SheetTitle>{{ selectedChannelName }} - 发信方式配置详情</SheetTitle>
         </SheetHeader>
         <div class="mt-6">
-          <div class="bg-gray-50 p-4 rounded-lg">
-            <pre class="whitespace-pre-wrap text-sm font-mono">{{ selectedConfig }}</pre>
+          <div class="bg-card p-4 rounded-lg border border-border">
+            <pre class="whitespace-pre-wrap text-sm font-mono text-foreground">{{ selectedConfig }}</pre>
           </div>
         </div>
       </SheetContent>
diff --git a/web/src/components/pages/sendWays/SendWays.vue b/web/src/components/pages/sendWays/SendWays.vue
index 7c5141b..e13c298 100644
--- a/web/src/components/pages/sendWays/SendWays.vue
+++ b/web/src/components/pages/sendWays/SendWays.vue
@@ -186,7 +186,7 @@ onMounted(async () => {
       <div class="flex-shrink-0">
         <Drawer v-model:open="isAddChannelDrawerOpen">
           <DrawerTrigger as-child>
-            <Button variant="default" class="w-full sm:w-auto bg-gray-800 hover:bg-gray-900">
+            <Button variant="default" class="w-full sm:w-auto">
               <svg class="w-4 h-4 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                 <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 4v16m8-8H4" />
               </svg>
@@ -275,8 +275,8 @@ onMounted(async () => {
           <SheetTitle>{{ selectedChannelName }} - 发信方式配置详情</SheetTitle>
         </SheetHeader>
         <div class="mt-6">
-          <div class="bg-gray-50 p-4 rounded-lg">
-            <pre class="whitespace-pre-wrap text-sm font-mono">{{ selectedConfig }}</pre>
+          <div class="bg-card p-4 rounded-lg border border-border">
+            <pre class="whitespace-pre-wrap text-sm font-mono text-foreground">{{ selectedConfig }}</pre>
           </div>
         </div>
       </SheetContent>
diff --git a/web/src/components/pages/settings/SettingsSidebar.vue b/web/src/components/pages/settings/SettingsSidebar.vue
index 0b733a5..166fbc3 100644
--- a/web/src/components/pages/settings/SettingsSidebar.vue
+++ b/web/src/components/pages/settings/SettingsSidebar.vue
@@ -44,10 +44,10 @@ export default {
             :key="item.id"
             @click="$emit('update:activeTab', item.id)"
             :class="[
-              'w-full flex items-center px-4 py-3 text-left text-sm font-medium transition-colors',
+              'w-full flex items-center px-4 py-3 text-left text-sm font-medium transition-colors rounded-md',
               activeTab === item.id
-                ? 'bg-blue-50 text-blue-700 border-r-2 border-blue-700'
-                : 'text-gray-600 hover:bg-gray-50 hover:text-gray-900'
+                ? 'bg-accent text-accent-foreground border-r-2 border-primary dark:bg-accent/40'
+                : 'text-muted-foreground hover:bg-muted hover:text-foreground dark:hover:bg-white/5'
             ]"
           >
             <component :is="item.icon" class="mr-3 w-5 h-5" />
diff --git a/web/src/components/pages/settings/SiteSettings.vue b/web/src/components/pages/settings/SiteSettings.vue
index bafcd90..0515bf4 100644
--- a/web/src/components/pages/settings/SiteSettings.vue
+++ b/web/src/components/pages/settings/SiteSettings.vue
@@ -111,9 +111,9 @@ export default {
             <label class="text-sm font-medium text-gray-700">站点图标(只支持svg文本)</label>
             <Input v-model="state.logo" placeholder="请输入自定义的网站logo（svg文本）" />
             <!-- SVG预览 -->
-            <div v-if="state.logo" class="mt-2 p-3 border border-gray-200 rounded-md bg-gray-50">
-              <div class="text-xs text-gray-500 mb-2">预览效果：</div>
-              <div class="flex items-center justify-center w-16 h-16 bg-white border border-gray-300 rounded"
+            <div v-if="state.logo" class="mt-2 p-3 border border-border rounded-md bg-card">
+              <div class="text-xs text-muted-foreground mb-2">预览效果：</div>
+              <div class="flex items-center justify-center w-16 h-16 bg-white dark:bg-white border border-border rounded"
                 v-html="state.logo"></div>
             </div>
           </div>
diff --git a/web/src/index.css b/web/src/index.css
index 0a61557..c594492 100644
--- a/web/src/index.css
+++ b/web/src/index.css
@@ -79,38 +79,38 @@
 }
 
 .dark {
-  --background: oklch(0.145 0 0);
+  --background: oklch(0.18 0 0);
   --foreground: oklch(0.985 0 0);
-  --card: oklch(0.145 0 0);
+  --card: oklch(0.19 0 0);
   --card-foreground: oklch(0.985 0 0);
-  --popover: oklch(0.145 0 0);
+  --popover: oklch(0.19 0 0);
   --popover-foreground: oklch(0.985 0 0);
   --primary: oklch(0.985 0 0);
   --primary-foreground: oklch(0.205 0 0);
-  --secondary: oklch(0.269 0 0);
+  --secondary: oklch(0.30 0 0);
   --secondary-foreground: oklch(0.985 0 0);
-  --muted: oklch(0.269 0 0);
-  --muted-foreground: oklch(0.708 0 0);
-  --accent: oklch(0.269 0 0);
+  --muted: oklch(0.24 0 0);
+  --muted-foreground: oklch(0.72 0 0);
+  --accent: oklch(0.30 0 0);
   --accent-foreground: oklch(0.985 0 0);
   --destructive: oklch(0.396 0.141 25.723);
   --destructive-foreground: oklch(0.637 0.237 25.331);
-  --border: oklch(0.269 0 0);
-  --input: oklch(0.269 0 0);
-  --ring: oklch(0.439 0 0);
+  --border: oklch(0.34 0 0);
+  --input: oklch(0.34 0 0);
+  --ring: oklch(0.5 0 0);
   --chart-1: oklch(0.488 0.243 264.376);
   --chart-2: oklch(0.696 0.17 162.48);
   --chart-3: oklch(0.769 0.188 70.08);
   --chart-4: oklch(0.627 0.265 303.9);
   --chart-5: oklch(0.645 0.246 16.439);
-  --sidebar: oklch(0.205 0 0);
+  --sidebar: oklch(0.20 0 0);
   --sidebar-foreground: oklch(0.985 0 0);
-  --sidebar-primary: oklch(0.488 0.243 264.376);
+  --sidebar-primary: oklch(0.52 0.24 264.376);
   --sidebar-primary-foreground: oklch(0.985 0 0);
-  --sidebar-accent: oklch(0.269 0 0);
+  --sidebar-accent: oklch(0.30 0 0);
   --sidebar-accent-foreground: oklch(0.985 0 0);
-  --sidebar-border: oklch(0.269 0 0);
-  --sidebar-ring: oklch(0.439 0 0);
+  --sidebar-border: oklch(0.34 0 0);
+  --sidebar-ring: oklch(0.5 0 0);
 }
 
 @layer base {
@@ -120,4 +120,35 @@
   body {
     @apply bg-background text-foreground;
   }
+  /* 全局文本元素在暗色/亮色下均使用前景色，避免灰度类在暗色不可读 */
+  h1, h2, h3, h4, h5, h6,
+  p, label, span, small, strong, em, b, i,
+  li, dt, dd, th, td {
+    @apply text-foreground;
+  }
+}
+
+/* 在暗色模式下，覆盖常见的灰度文字类为前景色，提升可读性 */
+@layer utilities {
+  .dark .text-black,
+  .dark .text-gray-900,
+  .dark .text-gray-800,
+  .dark .text-gray-700,
+  .dark .text-gray-600,
+  .dark .text-gray-500 {
+    color: var(--foreground) !important;
+  }
+
+  /* ApexCharts tooltip 容器透明，交由自定义HTML内部控制视觉，避免圆角黑边 */
+  .apexcharts-tooltip {
+    background: transparent !important;
+    border: none !important;
+    box-shadow: none !important;
+    border-radius: 0 !important;
+    padding: 0 !important;
+  }
+  .apexcharts-tooltip-title {
+    background: transparent !important;
+    border: none !important;
+  }
 }
\ No newline at end of file
diff --git a/web/src/main.ts b/web/src/main.ts
index 5d7ea2c..a25c0ce 100644
--- a/web/src/main.ts
+++ b/web/src/main.ts
@@ -5,6 +5,21 @@ import pinia from './store';
 //@ts-ignore
 import router from './router';
 
+// 初始化主题：优先本地存储，其次系统偏好
+(() => {
+  try {
+    const storageKey = 'theme';
+    const stored = localStorage.getItem(storageKey);
+    const systemPrefersDark = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches;
+    const theme = stored || (systemPrefersDark ? 'dark' : 'light');
+    if (theme === 'dark') {
+      document.documentElement.classList.add('dark');
+    } else {
+      document.documentElement.classList.remove('dark');
+    }
+  } catch (_) {}
+})();
+
 const app = createApp(App)
 app.use(router)
 app.use(pinia)