CSS—绝对定位元素后恢复正常文档流

div{
  width:100%;
  text-align:center;
  font-size:20px;
}
#div_1{
  position:absolute;
  height:50px;
  background-color:#F00;
}
#div_2{
  height:100px;
  background-color:#0F0;
}
  

<div id="div_1">Div that should appear on top</div>
<div id="div_2">Div that should appear below</div>

div{
  width:100%;
  text-align:center;
  font-size:20px;
}
#div_1{
  height:50px;
  background-color:#F00;
}
#div_2{
  height:100px;
  background-color:#0F0;
}

<<div id=“div\u 2”>应显示在下面的div</div>