!(function (win, doc) {
    function setfontsize() {
        var winwidth = window.innerwidth;
        doc.documentelement.style.fontsize = (winwidth / 1920) * 100 + 'px';
    }
    var evt = 'onorientationchange' in win ? 'orientationchange' : 'resize';
    var timer = null;
    win.addeventlistener(evt, 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));