(function (designwidth, maxwidth) {
    var doc = document,
        win = window;
    var docel = doc.documentelement;
    var tid;
    var rootitem, rootstyle;

    function refreshrem() {
        var width = docel.getboundingclientrect().width;
        if (!maxwidth) {
            maxwidth = 540;
        }
        ;
        if (width > maxwidth) {
            width = maxwidth;
        }
        //与淘宝做法不同，直接采用简单的rem换算方法1rem=100px
        //var rem = width * 100 / designwidth;
		var rem = width * 100 / designwidth;
        //兼容uc开始
        rootstyle = "html{font-size:" + rem + 'px !important}';
        rootitem = document.getelementbyid('rootsize') || document.createelement("style");
        if (!document.getelementbyid('rootsize')) {
            document.getelementsbytagname("head")[0].appendchild(rootitem);
            rootitem.id = 'rootsize';
        }
        if (rootitem.stylesheet) {
            rootitem.stylesheet.disabled || (rootitem.stylesheet.csstext = rootstyle)
        } else {
            try {
                rootitem.innerhtml = rootstyle
            } catch (f) {
                rootitem.innertext = rootstyle
            }
        }
        //兼容uc结束
        docel.style.fontsize = rem + "px";
    };
    refreshrem();

    win.addeventlistener("resize", function () {
        cleartimeout(tid); //防止执行两次
        tid = settimeout(refreshrem, 300);
    }, false);

    win.addeventlistener("pageshow", function (e) {
        if (e.persisted) { // 浏览器后退的时候重新计算
            cleartimeout(tid);
            tid = settimeout(refreshrem, 300);
        }
    }, false);

    if (doc.readystate === "complete") {
        doc.body.style.fontsize = "16px";
    } else {
        doc.addeventlistener("domcontentloaded", function (e) {
            doc.body.style.fontsize = "16px";
        }, false);
    }
})(375, 750);