$()

in js/theme.js [418:429]


  $(article).each(function (i) {
    var offsetScroll = $(this).offset().top - $(window).scrollTop();
    if (
      offsetScroll <= topMenuHeight + 200 &&
      offsetScroll >= topMenuHeight - 200 &&
      scrollItems[i] == "#" + $(this).attr("id") &&
      $(".hidden:visible")
    ) {
      $(menuItems).removeClass("side-scroll-highlight");
      $(menuItems[i]).addClass("side-scroll-highlight");
    }
  });