https://mcunic.ru/wp-content/themes/covernews-pro/assets/fixed-header-script.js?ver=7.1.2

1jQuery(document).ready(function ($) {
2  // Here You can type your custom JavaScript...
3
4  var header = document.getElementById('site-navigation');
5  var masthead = document.getElementById('masthead');
6  var body = document.querySelector('body');
7  if (header) {
8    // window.onscroll = function () {
9    //     myFunction()
10    // };
11
12    var stickyheight = header.offsetHeight;
13    var sticky = header.offsetTop + stickyheight;
14    function myFunction() {
15      if (window.pageYOffset > sticky) {
16        header.classList.add('aft-sticky-navigation');
17      } else {
18        header.classList.remove('aft-sticky-navigation');
19      }
20
21      if (header.classList.contains('aft-sticky-navigation')) {
22        masthead.style.paddingBottom = stickyheight + 'px';
23      } else {
24        masthead.style.paddingBottom = 0;
25      }
26    }
27  }
28
29  var didScroll;
30  var lastScrollTop = 0;
31  var delta = 5;
32  var navbarHeight = $('#site-navigation').outerHeight();
33
34  $(window).on('scroll', function (event) {
35    didScroll = true;
36  });
37
38  setInterval(function () {
39    if (didScroll) {
40      hasScrolled();
41      didScroll = false;
42    }
43  }, 250);
44
45  function hasScrolled() {
46    var st = $(this).scrollTop();
47
48    // Make sure they scroll more than delta
49    if (Math.abs(lastScrollTop - st) <= delta) return;
50
51    // If they scrolled down and are past the navbar, add class .nav-up.
52    // This is necessary so you never see what is "behind" the navbar.
53    if (st > lastScrollTop && st > navbarHeight) {
54      // Scroll Down
55      if (
56        body.classList.contains('scrolldown-sticky-header') ||
57        body.classList.contains('scrollboth-sticky-header')
58      ) {
59        if (typeof myFunction === 'function') {
60          myFunction();
61        }
62        $('#site-navigation').removeClass('nav-down').addClass('nav-up');
63      } else {
64        $('#site-navigation').removeClass('nav-down').addClass('nav-up');
65      }
66    } else {
67      // Scroll Up
68
69      if (st + $(window).height() < $(document).height()) {
70        if (typeof myFunction === 'function') {
71          myFunction();
72        }
73        $('#site-navigation').removeClass('nav-up').addClass('nav-down');
74      }
75    }
76    lastScrollTop = st;
77  }
78});