// Nav Bar
app.directive('stickyNav', ['$window', function($window){
  return {
    restrict: 'A',
    scope: '@',
    link: function(scope, element, attrs){

      var showingStickyNav = false;
      var navHeight = element.height();
      // var navOffset = element.offet().top;
      $(window).bind('scroll', function(){
        var scrollPosition = $(window).scrollTop();
        if(scrollPosition > navHeight && showingStickyNav === false){
          showingStickyNav = true;
          $('main').css({'padding-top': element.height()});

          element.velocity('fadeIn', {duration: 350, begin: function(){
            element.css({'position': 'fixed', 'top': 0, 'z-index': 3});
          }});
        }
        else if (scrollPosition < navHeight && showingStickyNav === true){
          showingStickyNav = false;
          $('main').css({'padding-top': 0});
          element.css({'position': 'relative', 'top': ''});
        }
      });
    }
  }
}]);