console 命令行工具 X clear

console

<div class="demo"></div>

 .demo {
   width: 100px;
   height: 100px;
   background-color: #0acb17;
   transition: 1s 1s height,1s width;
 }

 .demo:hover {
   width: 200px;
   height: 200px;
 }