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console 命令行工具 X clear

                    
>
console
<div class="wrapper">
  <div class="middle">
    <div class = "inside">middle</div>
  </div>
  <div class="left">left</div>
  <div class="right">right</div>
</div>
.inside{
  margin:0 100px 0 100px
}
.middle{
  background-color:lightblue;
  width:100%;
  float:left;
  
}
.left{
  width:100px;
  background-color:lightpink;
  float:left;
  margin-left:-100%;
}
.right{
  width:100px;
  background-color:lightgreen;
  float:left;
  margin-left:-100px
}