feat: 支持跟随系统深色/浅色模式（darkmode + theme.json + 主题检测）

src/app.config.ts

@@ -1,4 +1,6 @@
 export default defineAppConfig({
+  darkmode: true,
+  themeLocation: 'theme.json',
   pages: [
     'pages/index/index',
     'pages/shop/index',

src/theme.json

@@ -0,0 +1,26 @@
+{
+  "light": {
+    "navBgColor": "#ffffff",
+    "navTxtStyle": "black",
+    "bgColor": "#ffffff",
+    "bgTxtStyle": "dark",
+    "bgColorTop": "#ffffff",
+    "bgColorBottom": "#ffffff",
+    "tabBarColor": "#b08d8d",
+    "tabBarSelectedColor": "#ff9a9e",
+    "tabBarBgColor": "#ffffff",
+    "tabBarBorderStyle": "black"
+  },
+  "dark": {
+    "navBgColor": "#1e1e2f",
+    "navTxtStyle": "white",
+    "bgColor": "#1e1e2f",
+    "bgTxtStyle": "light",
+    "bgColorTop": "#1e1e2f",
+    "bgColorBottom": "#1e1e2f",
+    "tabBarColor": "#a0a0c0",
+    "tabBarSelectedColor": "#ff7eb3",
+    "tabBarBgColor": "#1e1e2f",
+    "tabBarBorderStyle": "white"
+  }
+}

src/utils/store.ts

@@ -262,8 +262,14 @@ export function setTheme(theme: ThemeMode) {
 /** 根据自动模式解析实际生效主题 */
 export function resolveTheme(mode: ThemeMode): 'light' | 'dark' {
   if (mode === 'auto') {
-    const info = Taro.getSystemInfoSync()
-    return info.theme === 'dark' ? 'dark' : 'light'
+    // 需 app.json 开启 darkmode 后 theme 字段才有效；getSystemInfoSync 已废弃，改用 getAppBaseInfo
+    try {
+      const info = Taro.getAppBaseInfo()
+      return info.theme === 'dark' ? 'dark' : 'light'
+    } catch {
+      const info = Taro.getSystemInfoSync()
+      return info.theme === 'dark' ? 'dark' : 'light'
+    }
   }
   return mode
 }