<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
<style>
#main {
400px;
height: 150px;
border: 1px solid #c3c3c3;
display: flex;
justify-content: center;
align-items: center;
}
#main div {
70px;
height: 70px;
}
</style>
</head>
<body>
<div id="main">
<div style="background-color:coral;"></div>
</div>
<p><b>注意:</b> Internet Explorer 10 及更早版本浏览器不支持 justify-content 属性。</p>
<p><b>注意:</b> Safari 6.1 及更新版本通过 -webkit-justify-content 属性支持该属性。</p>
</body>
</html>
原文地址：http://www.runoob.com/try/try.php?filename=trycss3_justify-content