移动端fontSize适配

(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 = 50 * (clientWidth / 375) + ‘px’; //根据750的屏幕的，可自行修改
};
if (!doc.addEventListener) return;
recalc();
win.addEventListener(resizeEvt, recalc, false);
doc.addEventListener(‘DOMContentLoaded’, recalc, false);
}(document,window));