.tree-node{flex:1;position:relative;display:flex;align-items:center;justify-content:space-between;font-size:13px;padding-right:5px}.tree-node.available:hover{border:1px dashed #ff8c00}.tree-node.available:hover:after{display:block;content:"单击添加";position:absolute;top:0;left:0;width:100%;height:100%;text-align:center;background-color:hsla(0,0%,39.2%,.8);color:#fff}