//设置 rem 函数
function setRem () {

    // 320 默认大小16px; 320px = 20rem ;每个元素px基础上/16
    // 1024 默认大小16px; 1024px = 64rem ;每个元素px基础上/16
    let htmlWidth = document.documentElement.clientWidth || document.body.clientWidth;
//得到html的Dom元素
    let htmlDom = document.getElementsByTagName('html')[0];
//设置根元素字体大小
    htmlDom.style.fontSize= Math.max(htmlWidth/64,12)  + 'px';
    // console.log('size='+htmlWidth/60)

    let htmlHeight = document.documentElement.clientHeight || document.body.clientHeight;
    localStorage.setItem("htmlHeight",htmlHeight);
}
// 初始化
setRem();
window.onresize = function () {
    setRem()
}
window.addEventListener("load", setRem());