Like WeChat session list, it does not take up the position of other elements.
Can it be realized only with CSS?
If not, what should be done?
You mean the vertical scroll bar, and the scroll bar comes according to the screen size, the output height is larger than the screen, the scroll bar comes out.
The good layout is OK, CSS can be realized
Fixed height, and then overflow-y:scroll
Define the scroll bar
The key is not to occupy the location of other elements, so you can only use plug-ins, such as this.