iamklim

function axelerateBackground(bgWrapperHeight) {
    var $bgWrapper = $('.bg_wrapper'); //parallax block inside body with position fixed and css background

    $(document).on('scroll', function() {
        var dHeight = $(document).height(),
            wHeight = $(window).height(),
            imgHeight = bgWrapperHeight ? bgWrapperHeight : $bgWrapper.height(), //height of parallax block
            coeff = (imgHeight - wHeight) / (dHeight - wHeight); //coefficient to avoid empty spaces on background

        var shift = -1 * ($(window).scrollTop() * coeff); //size of shift on the top

iamklim

function togglePopup() {

    var scrollPosition;

    $(document).on("click", '[data-id="show-popup"]', function(e) {
        e.preventDefault();

        var popup = '[data-id="popup"]';

        scrollPosition = $('body').scrollTop() === 0

iamklim

const throttle = (func, ms) => {
  let isThrottled = false;

  return (...args) => {
    if (!isThrottled) {
      func(...args);

      isThrottled = true;

      setTimeout(() => {