(function (doc, win) {
    const docel = document.documentelement,
        recalc = function () {
            const clientwidth = document.body.offsetwidth;
            if (!clientwidth) {
                return;
            }
            let _rem = 60 * (clientwidth / 1920);
// if (_rem < 60) {
// _rem = 60;
// }
            docel.style.fontsize = _rem + 'px';
        };

    if (!document.addeventlistener) {
        return;
    }
    recalc();
    window.addeventlistener('resize', recalc, false);
    document.addeventlistener('domcontentloaded', recalc, false);
})(document, window);