function fontsize() {
    let doc = document.documentelement,
        resizeevt = "orientationchange" in window ? "orientationchange" : "resize",
        recalc = function () {
            let winw = doc.clientwidth,
                size;
            if (!winw) return;

            if(winw <= 480){
                size = math.round(winw / 7.5);
            }else if (winw <= 768) {
                size = math.round(winw / 10.5);
                if (size > 65) {
                    size = 65;
                }
            } else if(winw <= 1200){
                size = math.round(winw / 13);
            } else if (winw <= 1800) {
                size = math.round(winw / 16);
            } else {
                size = 100;
            };
            doc.style.fontsize = size + 'px';
        };
    if (!document.addeventlistener) return;
    window.addeventlistener(resizeevt, recalc, false);
    document.addeventlistener("domcontentloaded", recalc, false);
};
fontsize();

const userbrowser = (function () {
    const ua = navigator.useragent;
    const testua = function (regexp) {
        return regexp.test(ua.tolowercase())
    };

    let userbrowserclient = function () {
        let client = '';
        if (/(iphone|ipad|ipod|ios)/i.test(ua)) {
            client = 'ios';
        } else if (/(android)/i.test(ua)) {
            client = 'android';
        } else {
            client = 'pc';
        }
        return client;
    };
    let userbrowsertype = function () {
        let shell = "none";
        let shellvs = "unknow";
        if (testua(/micromessenger/g)) {
            shell = "wechat"; // 微信浏览器
        } else if (testua(/qqbrowser/g)) {
            shell = "qq"; // qq浏览器
        } else if (testua(/ubrowser/g)) {
            shell = "uc"; // uc浏览器
        } else if (testua(/qihu 360se/g)) {
            shell = "360"; // 360浏览器
        } else if (testua(/2345explorer/g)) {
            shell = "2345"; // 2345浏览器
        } else if (testua(/metasr/g)) {
            shell = "sougou"; // 搜狗浏览器
        } else if (testua(/lbbrowser/g)) {
            shell = "liebao"; // 猎豹浏览器
        } else if (testua(/maxthon/g)) {
            shell = "maxthon"; // 遨游浏览器
        }
        return shell
    };

    return {
        userbrowserclient: userbrowserclient,
        userbrowsertype: userbrowsertype
    }
})();



function dynamicloadjs(url, callback) {
    var head = document.getelementsbytagname('head')[0];
    var script = document.createelement('script');
    script.type = 'text/javascript';
    script.src = url;
    script.defer = 'defer';
    if (typeof (callback) === 'function') {
        script.onload = script.onreadystatechange = function () {
            if (!this.readystate || this.readystate === 'loaded' || this.readystate === 'complete') {
                callback();
                script.onload = script.onreadystatechange = null;
            }
        }
    }
    head.appendchild(script);
}

if (userbrowser.userbrowserclient() == 'pc') {
    try {
        eval('()=>{}');
    } catch (eo) {
        dynamicloadjs("js/polyfill/polyfill.min.js");
    };
};