/**
 * File skip-link-focus-fix.js.
 *
 * Helps with accessibility for keyboard only users.
 *
 * Learn more: https://git.io/vWdr2
 */
(function () {
    var isWebkit = navigator.userAgent.toLowerCase().indexOf('webkit') > -1
        , isOpera = navigator.userAgent.toLowerCase().indexOf('opera') > -1
        , isIe = navigator.userAgent.toLowerCase().indexOf('msie') > -1;
    if ((isWebkit || isOpera || isIe) && document.getElementById && window.addEventListener) {
        window.addEventListener('hashchange', function () {
            var id = location.hash.substring(1)
                , element;
            if (!(/^[A-z0-9_-]+$/.test(id))) {
                return;
            }
            element = document.getElementById(id);
            if (element) {
                if (!(/^(?:a|select|input|button|textarea)$/i.test(element.tagName))) {
                    element.tabIndex = -1;
                }
                element.focus();
            }
        }, false);
    }
})();