https://freiewelt.net/themes/custom/fw/js/scripts.js?v=VERSION%201.0

1function initMenu(){
2  var menuButton = document.querySelector("#mobile-menu-button");
3  menuButton.onclick = function(e){
4    e.preventDefault();
5    document.querySelector('body').classList.toggle('mobile-menu-expanded');
6  }
7}
8
9document.addEventListener('DOMContentLoaded', function(){
10  initMenu();
11
12const urlParams = new URLSearchParams(window.location.search);
13  const pageParam = urlParams.get('page');
14  if (pageParam) {
15    document.querySelector('body').classList.add('page-' + pageParam);
16  }
17
18}, false);
19
20
21
22
23
24
25
26
27// Hide Header on on scroll down
28var didScroll;
29var lastScrollTop = 0;
30var delta = 5;
31var navbarHeight = document.querySelector('header').offsetHeight;
32
33document.addEventListener('scroll', () =>{
34  didScroll = true;
35  if (document.scrollingElement.scrollTop > 1){
36    document.querySelector('body').classList.add('continued');
37  }
38  else {
39    document.querySelector('body').classList.remove('continued');
40  }
41});
42
43setInterval(() => {
44  if (didScroll) {
45    hasScrolled();
46    didScroll = false;
47  }
48}, 100);
49
50function hasScrolled() {
51  var st = document.scrollingElement.scrollTop;
52  if(Math.abs(lastScrollTop - st) <= delta)
53    return;
54  if (st == 0 || st < 1){
55    document.querySelector('header').classList.remove('nav-up');
56    document.querySelector('header').classList.remove('nav-down');
57  }
58  else{
59    if (st > lastScrollTop && st > navbarHeight){
60      // Scroll Down
61      document.querySelector('header').classList.remove('nav-down');
62      document.querySelector('header').classList.add('nav-up');
63    } else {
64      // Scroll Up
65      if(st + document.documentElement.clientHeight < document.documentElement.scrollHeight) {
66        document.querySelector('header').classList.add('nav-down');
67        document.querySelector('header').classList.remove('nav-up');
68      }
69    }
70  }
71  lastScrollTop = st;
72}