手机端自适应单位rem
<script>
(function (win,doc){
if (!win.addEventListener) alert('b2');
var html=document.documentElement;
function setFont()
{
var cliWidth=html.clientWidth;
html.style.fontSize=100*(cliWidth/750)+'px';
}
win.addEventListener('resize',setFont,false);
setFont();
})(window,document);
</script>以750宽度为一个标准
7.5rem = 750px