(function (w, d) {
    function setSize() {
        var screenWidth = d.documentElement.clientWidth;
        var currentFontSize = screenWidth * 100 / 750;
        d.documentElement.style.fontSize = currentFontSize + 'px';
    }
    w.addEventListener('resize', setSize);
    w.addEventListener('pageShow', setSize)
    w.addEventListener('DOMContentLoaded', setSize)
})(window, document)