gistfile1.js

var navElem = '.navigation-list.top-level';
	$('.toggle-mobile-nav').click(function(event) {
		event.preventDefault()
		$(navElem).toggle();
	});
	$('.top-level-item.dropdown').click(function(event) {
		event.preventDefault();
		console.log('clicked');

		$('.level-1').hide();
		$(this).children('.level-1').toggle();
	});

	$(window).resize(function() {
		if($(this).outerWidth() >= 768 ) {
			$(navElem).show();
		} else {
			$(navElem).hide();
		}
	});