html, body, div, span,
h1, h2, h3, p, 
 em, img, 
i,a,
ul, li,
header
 {
    margin:0;
    padding:0;
    border:0;
    outline:0;
    font-size:100%;
    vertical-align:baseline;
    background:transparent;
}
html {
  font-family: "Arial","Microsoft YaHei","黑体","宋体",sans-serif; /* 1 */
  -ms-text-size-adjust: 100%; /* 3 */ /*防止iphone下浏览器由竖屏转向横屏时字体放大的效果*/
  -webkit-text-size-adjust: 100%; /* 3 */
}
header{ 
    display:block;
}

 ul {
    list-style:none;
}