!(function (win, doc) {

    function setFontSize() {

        var docEl = doc.documentElement;

        var clientWidth = docEl.clientWidth;

        if (clientWidth <= 750) {

            docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';

        } else {

            docEl.style.fontSize = 100 + "px";

        }

    }

    resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize';

    var timer = null;

    win.addEventListener(resizeEvt, function () {

        clearTimeout(timer);

        timer = setTimeout(setFontSize, 300);

    }, false);

    win.addEventListener("pageshow", function (e) {

        if (e.persisted) {

            clearTimeout(timer);

            timer = setTimeout(setFontSize, 300);

        }

    }, false);

    // 初始化

    setFontSize();

}(window, document));