https://www.sanatoriumchemik.pl/public/js/stickyMenu.js

1document.addEventListener('DOMContentLoaded', function(){
2    const header = document.querySelector('#top');
3    const media = window.matchMedia('(min-width: 1200px)');
4
5    function checkMedia(media) {
6        if (media.matches) {
7            header.classList.add('sticky');
8            header.nextElementSibling.style.marginTop = `${header.offsetHeight}px`;
9        } else {
10            header.classList.remove('sticky');
11            header.nextElementSibling.style.marginTop = '0px';
12        }
13    }
14
15    checkMedia(media);
16    
17    media.addEventListener('change', function() {
18        checkMedia(this);
19    })
20
21});