🐛[BUG] ProLayout在小屏幕设备上menu折叠后手工展开, 此时如果content有滚动条, 下滑看到menu drawer下方都是透明的.

### 🐛 bug 描述
ProLayout在小屏幕设备上menu折叠后手工展开, 此时如果content有滚动条, 下滑看到menu drawer下方都是透明的.

### 📷 复现步骤
见复现代码

### 🏞 期望结果
和2.6.x一样展开menu后不可滚动

### 💻 复现代码
[复现代码](https://codesandbox.io/p/sandbox/procomponent-v2-7-1-issue-68fr86)
[官方给出的DEMO没有问题, 版本升级到2.7.1后可复现](https://codesandbox.io/s/f56qlz)

### © 版本信息
- ProComponents 版本: 2.7.1

Start with the ProLayout implementation and the linked CodeSandbox reproduction, using the reported ProComponents 2.7.1 behavior on a small-screen device as the baseline. Verify the menu drawer after manual expansion while the content can scroll, and compare the result with the expected 2.6.x behavior: the drawer should remain opaque below and the page should not scroll.

Written by the indexing model from the issue text.