js自适应

//屏幕宽度自适应

(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 = clientWidth / (1920 / 16) + "px";//1920设计图的宽度，16字体为基准

    };

  if (!doc.addEventListener) return;

  win.addEventListener(resizeEvt, recalc, false);

  doc.addEventListener("DOMContentLoaded", recalc, false);

})(document, window);