https://www.charlesfarina.com/wp-content/themes/base-wp-premium/js/sticky-nav.js?ver=7.1.2

1/**
2 * sticky-nav.js
3 *
4 * License: GNU General Public License v2 or later
5 * License URI: http://www.gnu.org/licenses/gpl-2.0.html
6 * 
7 */
8
9jQuery(document).ready(function($) {
10	var $filter = $('.main-navigation');
11	var $filterSpacer = $('<div />', {
12		"class": "filter-drop-spacer",
13		"height": $filter.outerHeight()
14	});
15
16
17	if ($filter.size())
18	{
19		$(window).scroll(function ()
20		{
21			if (!$filter.hasClass('fix') && $(window).width() > 767  && $(window).scrollTop() > $filter.offset().top)
22			{
23				$filter.before($filterSpacer);
24				$filter.addClass("fix");
25			}
26			else if ($filter.hasClass('fix') && $(window).scrollTop() < $filterSpacer.offset().top)
27			{
28				$filter.removeClass("fix");
29				$filterSpacer.remove();
30			}
31		});
32	}
33
34});