HTML5 浏覽器支援（h5的浏覽器相容性）

<!--[if lt IE 9]>
    <script src="http://cdn.static.runoob.com/libs/html5shiv/3.7/html5shiv.min.js"></script>
<![endif]-->      

/*html5*/
article,aside,dialog,footer,header,section,nav,figure,menu{display:block}