*{margin:0;padding:0}
ul,li{list-style:none}
ul{margin:50px}
ul li{float:left;width:80px;height:30px;line-height:30px;text-align:center;background:#000;border-right:1px solid #fff;color:#fff;    position: relative;cursor: pointer;}
div{position: absolute;width:200px;height:200px;background:#333;top:30px;left:0;display:none}
li:hover div{display:block}