Добавьте это
$('.cd-primary-nav > li > a').on('click',function(){
      if(!toggleNav.hasClass('close-nav')) {
			
			toggleNav.addClass('close-nav');
			
			overlayNav.children('span').velocity({
				translateZ: 0,
				scaleX: 1,
				scaleY: 1,
			}, 500, 'easeInCubic', function(){
				navigation.addClass('fade-in');
			});
		}else {
			//navigation is open - close it and remove navigation layer
			toggleNav.removeClass('close-nav');
			
			overlayContent.children('span').velocity({
				translateZ: 0,
				scaleX: 1,
				scaleY: 1,
			}, 500, 'easeInCubic', function(){
				navigation.removeClass('fade-in');
				
				overlayNav.children('span').velocity({
					translateZ: 0,
					scaleX: 0,
					scaleY: 0,
				}, 0);
				
				overlayContent.addClass('is-hidden').one('webkitTransitionEnd otransitionend oTransitionEnd msTransitionEnd transitionend', function(){
					overlayContent.children('span').velocity({
						translateZ: 0,
						scaleX: 0,
						scaleY: 0,
					}, 0, function(){overlayContent.removeClass('is-hidden')});
				});
				if($('html').hasClass('no-csstransitions')) {
					overlayContent.children('span').velocity({
						translateZ: 0,
						scaleX: 0,
						scaleY: 0,
					}, 0, function(){overlayContent.removeClass('is-hidden')});
				}
			});
		}
    
  });