rem.js

var winWidth;
//获取屏幕宽度
if(window.innerWidth) {
winWidth = window.innerWidth;
} else if((document.body) && (document.body.clientWidth)) {
winWidth = document.body.clientWidth;
}
window.onload = function(){
/1rem=100px/
getRem(winWidth,100)
};
window.onresize = function(){
getRem(winWidth,100)
};
function getRem(pwidth,prem){
var html = document.getElementsByTagName(“html”)[0];
var oWidth = document.body.clientWidth || document.documentElement.clientWidth;
html.style.fontSize = oWidth/pwidth*prem + “px”;
}