GetClosest = function (elem, selector) {

    for (; elem && elem !== document.body; elem = elem.parentNode) {

        // If the elem matches at first iteration.
        if(elem.matches(selector)) {

            return elem;

        } else {

            // Scans all the childs of current iterated element (always higher in DOM until found).
            // If one matches the selector it'll stop and return it.
            child = elem.parentNode.firstChild;
            do {

                if(child.nodeType === 3) continue; // text node
                if(child.matches(selector)) return child;

            } while (child = child.nextElementSibling);
        }
    }

    return null;

};