rem屏幕自适应配置

rem.js屏幕自适应配置

(function (doc, win) {
  var docEl = doc.documentElement,
    resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
    recalc = function () {
      let clientWidth = docEl.clientWidth;
      if (!clientWidth) return;
      if (clientWidth > 375) {
        docEl.style.fontSize = 100 * (414 / 750) + 'px';
      } else {
        docEl.style.fontSize = 100 * (375 / 750) + 'px';
      }
    };

  if (!doc.addEventListener) return;
  win.addEventListener(resizeEvt, recalc, false);
  doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window);