https://dukechinesedance.com/assets/js/template.js

1(function () {
2    function applyLazyBackgrounds() {
3        document.querySelectorAll('[data-bg-image], [data-bg-img]').forEach(function (el) {
4            var bg = el.getAttribute('data-bg-image') || el.getAttribute('data-bg-img');
5            if (bg && !el.style.backgroundImage) {
6                el.style.backgroundImage = 'url("' + bg + '")';
7            }
8        });
9    }
10
11    if (typeof window.lozad === 'function') {
12        window.lozad('.lozad', {
13            loaded: applyLazyBackgrounds
14        }).observe();
15    } else {
16        applyLazyBackgrounds();
17        document.querySelectorAll('img[data-src]').forEach(function (img) {
18            img.setAttribute('src', img.getAttribute('data-src'));
19        });
20    }
21
22    var toggle = document.querySelector('.wc-menu-toggle');
23    var nav = document.querySelector('.wc-nav');
24
25    if (!toggle || !nav) {
26        return;
27    }
28
29    toggle.addEventListener('click', function () {
30        var open = nav.classList.toggle('is-open');
31        toggle.setAttribute('aria-expanded', open ? 'true' : 'false');
32    });
33}());