方案一
var pageSize = 6.4;
document.documentElement.style.fontSize=document.documentElement.clientWidth/pageSize+'px';
window.addEventListener("resize",function(){
document.documentElement.style.fontSize=document.documentElement.clientWidth/pageSize+'px';
},false);
方案二
var h = window.screen.width - $(window).height();
var remBase = Math.min($(window).width(),$(window).height()+h)/16;
if(remBase==0){remBase='20px';}
$('html').css('font-size',remBase);
