console 命令行工具 X clear

console

<div class="div1">层1</div>
<div class="div2">层2</div>

.div1{
background-color:#FF0000;
width:2000px;
height:2000px;
}
 
.div2{
background-color:#33FF66;
width:100px;
height:100px;
position:fixed;
left:50px;
top:50px;