.onlineBox{width:80px;height:35px;border:1px solid #ccc;position:relative}li,ul{padding:0;margin:0;list-style:none}.ul-css{width:400px;height:500px;border:1px solid #ccc;margin:0;overflow:scroll}.ul-css li{text-align:left;padding-left:10px;height:30px;line-height:30px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.ul-css>li:hover{background:#ccc}.onlineBox1{float:left;width:70%;position:absolute;top:50%;transform:translateY(-50%)}.onlineBox2{position:absolute;top:0;right:0;width:30px;height:100%}