diff --git a/client/lib/main.dart b/client/lib/main.dart
index 39b83b5..b03f2c5 100644
--- a/client/lib/main.dart
+++ b/client/lib/main.dart
@@ -5,6 +5,7 @@ import 'dart:ui' as ui;
 
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:window_manager/window_manager.dart';
 
 import 'bridge/vpn_bridge_provider.dart';
 import 'pangolin_theme.dart';
@@ -25,6 +26,11 @@ Future<void> main() async {
       exit(0); // 已有实例在跑(已唤起其窗口),本进程退出。
     }
     await TrayService.instance.init();
+    // 桌面窗口尺寸：默认 920×640；最小宽 720（低于 form_factor 的 680 阈值会
+    // 掉进 MobileShell，侧栏消失）。init() 内已 windowManager.ensureInitialized()。
+    await windowManager.setMinimumSize(const Size(720, 560));
+    await windowManager.setSize(const Size(920, 640));
+    await windowManager.center();
   }
   runApp(const ProviderScope(child: PangolinApp()));
 }