.tree .dv{width:120px;height:40px;border: 1px solid #ccc;display: inline-block;font-size: 16px;position: relative;}

.tree ul{overflow: hidden;padding-top: 20px;position: relative;}

.tree li{float: left;text-align: center;position: relative;padding: 20px 5px 0 5px;font-size: 0;}

.tree li:only-child{padding: 0;}

.tree ul ul::before{content: "";position: absolute;left: 50%;top: 0;width: 0;height: 20px;border-left: 1px solid #ccc;}

.tree li::before{content: "";position: absolute;right: 50%;top: 0;width: 50%;height: 20px;border-top: 1px solid #ccc;}

.tree li::after{content: "";position: absolute;right: 50%;top: 0;width: 50%;height: 20px;border-top: 1px solid #ccc;}

.tree li::after{left: 50%;top: 0;right: 0;
    border-left: 1px solid #ccc;
}

.tree li:first-child::after{border-radius: 5px 0 0 0;}

.treeul li:first-child::before,.treeul li:last-child::after{border:none}

.treeul li:last-child::before{border-right:1px solid #ccc;border-radius: 0px 5px 0 0;}

.treeul li:only-child::before{border: none;}