ul {
margin:0;
padding:0;
list-style:none;
}
li {
white-space:nowrap;
}
a {
color:#000;
text-decoration:none;
text-align:center;
font-size:20px;
line-height:30px;
}
a:hover {
color:#000;
text-decoration:none;
}
.panel-level-1 > li {
padding:0 20px;
border:1px solid black;
border-radius:5px;
width:250px;
overflow:hidden;
margin-bottom:10px;
}
.panel-level-2 > li {
padding-left:20px;
border:1px solid black;
border-radius:5px;
margin-bottom:10px;
}
.panel-level-3 > li {
padding-left:20px;
}
↑上面代码改变，会自动显示代码结果 jQuery调用版本：2.1.1
