function setRem(){
var ui_w = 375;
var client_w =
document.documentElement.clientWidth||document.body.clientWidth;
client_w = client_w > 650 ? 650 : client_w;
client_w = client_w < 250 ? 250 : client_w;
var html_=document.getElementsByTagName('html')[0];
html_.style.fontSize=(client_w/ui_w)*10+'px';
}
var timer=null;
window.onresize=function(){
clearTimeout(timer);
timer=setTimeout(setRem,100);
}
// 页面加载fontsize直接10px
window.onload=setRem;