CSS3-Mdeia Query
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<link rel="stylesheet" href="./link.css" type="text/css" media="only screen and (max-width:480px)" /><!-- 当浏览器窗口小于480px时候使用外部链接 -->
<style>
@media screen and(min-width: 480px){
body{background: black;}
}
</style>
</head>
<body>
</body>
</html>
这样设置了，当浏览器窗口大于480px时没反应
