Multilevel scrollable menu

问题

I want to make a multilevel scrollable menu. How can I do it? Here is the FIDDLE I make for testing:

.nav ul {
position: absolute;
margin: 0;
padding: 0;
list-style: none;
display: block;
overflow: scroll;
max-height: 100px;
}

I have tried out to set the max-height, and add the overflow: scroll. But it doesnt display what I want. I want it to be eg: level 2 scrollable, meanwhile level 3, level 4 still stay side by side when i mouse over it. Thank you guys!

回答1:

Is this better ?

http://jsfiddle.net/jq1zrkwo/4/

just removed this :

max-height:100px;
overflow:scroll;

来源：https://stackoverflow.com/questions/28804878/multilevel-scrollable-menu