因为我们选择让边栏浮动，所以当浏览器窗口的宽度太窄时，边栏会出现在主内容区域下面。

Because we chose to float the sidebar, there comes a point when the sidebar will flip under the main content area when the width of the viewport is too narrow.

youdao

因为我们选择让边栏浮动，所以当浏览器窗口的宽度太窄时，边栏会出现在主内容区域下面。

Because we chose to float the sidebar, there comes a point when the sidebar will flip under the main content area when the width of the viewport is too narrow.

youdao