/***author:Beginner**create:20190620**email:BeginnerMind@163.com*/var vRem;//全局变量添加vRem，记录当前状态下的rem值，方便js调用。(function(win) {    var designWidth=375,maxWidth=750,def_px=100,        doc = win.document,docEl = doc.documentElement,        resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',        recalc=function(){            console.log('rem init');            var width = docEl.getBoundingClientRect().width;            width=width>maxWidth?maxWidth:width;            vRem=Math.floor(width/designWidth*def_px);            document.getElementsByTagName("html")[0].style.cssText = 'font-size: ' + vRem +"px";        }    recalc();    if (!doc.addEventListener) return;    win.addEventListener(resizeEvt, recalc, false);    doc.addEventListener('DOMContentLoaded', recalc, false);})(window);