text: jQuery(document).ready(function($){
  	var	scrolling = false;
  	var contentSections = $('.cd-section'),
  		verticalNavigation = $('.cd-vertical-nav'),
  		navigationItems = verticalNavigation.find('a'),
  		navTrigger = $('.cd-nav-trigger'),
  		scrollArrow = $('.cd-scroll-down');
  
  	$(window).on('scroll', checkScroll);
  
  	//smooth scroll to the selected section
  	verticalNavigation.on('click', 'a', function(event){
          event.preventDefault();
          smoothScroll($(this.hash));
          verticalNavigation.removeClass('open');
      });
  
      //smooth scroll to the second section
      scrollArrow.on('click', function(event){
      	event.preventDefault();
          smoothScroll($(this.hash));
      });
  
  	// open navigation if user clicks the .cd-nav-trigger - small devices only
      navTrigger.on('click', function(event){
      	event.preventDefault();
      	verticalNavigation.toggleClass('open');
      });
  
  	function checkScroll() {
  		if( !scrolling ) {
  			scrolling = true;
  			(!window.requestAnimationFrame) ? setTimeout(updateSections, 300) : window.requestAnimationFrame(updateSections);
  		}
  	}
  
  	function updateSections() {
  		var halfWindowHeight = $(window).height()/2,
  			scrollTop = $(window).scrollTop();
  		contentSections.each(function(){
  			var section = $(this),
  				sectionId = section.attr('id'),
  				navigationItem = navigationItems.filter('[href^="#'+ sectionId +'"]');
  			( (section.offset().top - halfWindowHeight < scrollTop ) && ( section.offset().top + section.height() - halfWindowHeight > scrollTop) )
  				? navigationItem.addClass('active')
  				: navigationItem.removeClass('active');
  		});
  		scrolling = false;
  	}
  
  	function smoothScroll(target) {
          $('body,html').animate(
          	{'scrollTop':target.offset().top},
          	300
          );
  	}
  });