feat: add dark/light theme

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)