<html>
<head>
<style>
#main {
width: 400px;
height: 150px;
border: 1px solid #c3c3c3;
display: flex;
}
#main div {
width: 70px;
height: 70px;
}
div#myRedDIV {order:2;}
div#myBlueDIV {order:4;}
div#myGreenDIV {order:3;}
div#myPinkDIV {order:1;}
</style>
</head>
<body>
<div id="main">
<div style="background-color:coral;" id="myRedDIV"></div>
<div style="background-color:lightblue;" id="myBlueDIV"></div>
<div style="background-color:lightgreen;" id="myGreenDIV"></div>
<div style="background-color:pink;" id="myPinkDIV"></div>
</div>
<p><b>注意：</b>Internet Explorer 和 Safari 不支持 order 属性。</p>
</body>
</html>