(function (designWidth = 20 / 375) {

    const docEle: HTMLElement = document.documentElement;
    const resizeEvt: string = "orientationchange" in window ? "orientationchange" : "resize";

    const recalc: EventListener = () => {
        const fontSize = Math.floor(docEle.clientWidth * designWidth);
        docEle.style.fontSize = fontSize + "px";
        const localFontSize = parseInt(window.getComputedStyle(docEle).getPropertyValue('font-size'));
        docEle.style.fontSize = fontSize * (fontSize / localFontSize) + "px";
    };

    on('DOMContentLoaded', recalc, document);
    on(resizeEvt, recalc);
    on('unload', () => { off('DOMContentLoaded', recalc); off(resizeEvt, recalc); })
})()