console 命令行工具 X clear

console

<div>
  <div class="animate">
    <div class="a1">1</div>
    <div class="a2">2</div>
  </div>
</div>

.animete {
  width: 100%;
  height:100%;
  background-color:#efefef;
  .a1 {
    width: 200px;
    height: 200px;
    background-color:#ccc;
  }
  .a2 {
    width: 200px;
    height: 200px;
    background-color:#999;
  }
}