diff --git a/src/App.vue b/src/App.vue
index 6b44b0f..262c44e 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -1,5 +1,9 @@
 <template>
-  <n-config-provider :locale="zhCN" :data-locale="dateZhCN">
+  <n-config-provider
+    :locale="zhCN"
+    :data-locale="dateZhCN"
+    :theme="isDark ? darkTheme : null"
+  >
     <n-message-provider>
       <n-notification-provider>
         <n-dialog-provider>
@@ -12,12 +16,36 @@
 </template>
 
 <script setup lang="ts">
-import { zhCN, dateZhCN } from "naive-ui"
+import { zhCN, dateZhCN, darkTheme } from "naive-ui"
 import GlobalLoading from "@/components/GlobalLoading.vue"
 import { checkAndUpdate } from "@/utils/updater"
+import { useSettingStore } from "@/stores/setting"
+
+const settingStore = useSettingStore()
+
+const media = window.matchMedia("(prefers-color-scheme: dark)")
+const systemDark = ref(media.matches)
+
+const themeMode = computed(() => settingStore.appearance.theme)
+const isDark = computed(() => {
+  return themeMode.value === "dark" || (themeMode.value === "system" && systemDark.value)
+})
+
+watchEffect(() => {
+  document.documentElement.setAttribute("data-theme", isDark.value ? "dark" : "light")
+})
+
+const onSystemThemeChange = (e: MediaQueryListEvent) => {
+  systemDark.value = e.matches
+}
 
 onMounted(() => {
   checkAndUpdate()
+  media.addEventListener("change", onSystemThemeChange)
+})
+
+onUnmounted(() => {
+  media.removeEventListener("change", onSystemThemeChange)
 })
 </script>
 
diff --git a/src/assets/global.css b/src/assets/global.css
index d84c341..7aec021 100644
--- a/src/assets/global.css
+++ b/src/assets/global.css
@@ -31,4 +31,21 @@
 
   --set-item-title-size: 14px;
   --set-item-desc-size: 12px;
+}
+
+/* 深色主题：通过根节点 data-theme="dark" 覆盖同名变量 */
+:root[data-theme="dark"] {
+  --color-window-bg: #1b1c20;
+  --color-surface: #26272e;
+  --color-surface-hover: #30323b;
+
+  --color-text-primary: #f0f1f5;
+  --color-text-secondary: #9aa0ab;
+  --color-text-invert: #1d1d1f;
+
+  --color-border: rgba(255, 255, 255, 0.08);
+  --color-border-hover: rgba(102, 126, 234, 0.5);
+  --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.35);
+  --shadow-card-hover: 0 10px 28px rgba(0, 0, 0, 0.5);
+  --shadow-focus: 0 4px 16px rgba(102, 126, 234, 0.3);
 }
\ No newline at end of file
diff --git a/src/layout/MainLayout.vue b/src/layout/MainLayout.vue
index 92650f0..61c7a3f 100644
--- a/src/layout/MainLayout.vue
+++ b/src/layout/MainLayout.vue
@@ -23,9 +23,13 @@ const isMacos = navigator.userAgent.includes("Mac OS X")
 .container {
   width: 100vw;
   height: 100vh;
-  background: rgba(255, 255, 255, 1);
+  background: var(--color-window-bg);
   backdrop-filter: blur(20px);
-  border: 1px solid rgba(255, 255, 255, 0.2);
+  border: 1px solid var(--color-border);
+
+  :deep(.n-layout) {
+    background: transparent;
+  }
 }
 
 .header {
@@ -35,6 +39,6 @@ const isMacos = navigator.userAgent.includes("Mac OS X")
 
 .content {
   background: transparent;
-  height: calc(100vh - 40px);
+  height: calc(100vh - var(--titlebar-height));
 }
 </style>
diff --git a/src/views/setting/Appearance.vue b/src/views/setting/Appearance.vue
index b60680b..828a854 100644
--- a/src/views/setting/Appearance.vue
+++ b/src/views/setting/Appearance.vue
@@ -38,6 +38,10 @@ const settingStore = useSettingStore()
 const theme = ref(settingStore.appearance.theme)
 const showShadow = ref(settingStore.appearance.showShadow)
 
+watch(theme, (newVal) => {
+  settingStore.appearance.theme = newVal
+})
+
 watch(showShadow, (newVal) => {
   settingStore.appearance.showShadow = newVal
   getCurrentWindow().setShadow(newVal)