px转rem 响应式

(function (doc, win) {  var docEl = doc.documentElement,    resizeEvt = ‘orientationchange‘ in window ? ‘orientationchange‘ : ‘resize‘,    recalc = function () {      var clientWidth = docEl.clientWidth;      if (!clientWidth) return;      docEl.style.fontSize = 100 * (clientWidth / 375) + ‘px‘//这里1px=0.01rem    };  if (!doc.addEventListener) return;  win.addEventListener(resizeEvt, recalc, false);  doc.addEventListener(‘DOMContentLoaded‘, recalc, false)})(document, window);