移动端rem.js

function getRem(dwidth,drem){
    var bWidth= document.body.clientWidth || document.documentElement.clientWidth;
    var html = document.getElementsByTagName("html")[0];
    html.style.fontSize = oWidth/dwidth*drem+ "px";
}
getRem(650,100);
//浏览器被重置大小时执行
window.onresize = function(){
    getRem(650,100)
};