css3 flexbox布局

<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>css3flexbox布局</title>
		<style type="text/css">
			*{margin:0;padding:0;}
			header{width:80%;margin:100px auto;height:300px;display:flex;/*采取的是flexbox布局模式*/
			flex-flow:row;/*row行，column：列*/}
			section:first-child{height:100%;background: red;flex:2;}
			section:nth-child(2){height:100%;background:green;flex:2;}
			section:last-child{height:100%;background: blue; flex:2;}
		</style>
	</head>
	<body>
		<header>
			<section></section>
			<section></section>
			<section></section>
		</header>
	</body>
</html>