根据不同的屏幕宽度引入不同的css文件

<link rel="stylesheet" href="css/jl_public.css?v=11"/>
<link rel="stylesheet" media="screen and (min-width:800px) and (max-device-width:1200px)" href="css/c1.css"/>
<link rel="stylesheet" media="screen and (max-width:800px)" href="css/c2.css"/>
<!--[if lt IE 9]>
<script src="css3-mediaqueries.js" type="text/javascript"></script>

<![endif]-->
<meta name="viewport" content="width=device-width,initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0,user-scalable=no">
<meta content="yes" name="apple-mobile-web-app-capable">
<meta content="black" name="apple-mobile-web-app-status-bar-style">
<meta content="telephone=no" name="format-detection">