移动端手机屏幕适配

(function (doc, win) {
let docEl;
docEl = doc.documentElement;
let resizeEvt = ‘orientationchange’ in window ? ‘orientationchange’ : ‘resize’;
let recalc = function () {
let clientWidth = docEl.clientWidth;
if (!clientWidth) return
if (clientWidth >= 750) {
docEl.style.fontSize = ‘100px’
} else {
docEl.style.fontSize = 100 * (clientWidth / 750) + ‘px’
}
}
if (!doc.addEventListener) return;
win.addEventListener(resizeEvt, recalc, false);
doc.addEventListener(‘DOMContentLoaded’, recalc, false);
})(document, window)