const togglerBtn = document.getElementById('navbarSupportedContentToggler'); const navbarContent = document.getElementById('navbarSupportedContent'); navbarContent.addEventListener('show.bs.collapse', () => { console.log('opening navbar content'); togglerBtn.classList.toggle('is-active'); }); navbarContent.addEventListener('hide.bs.collapse', () => { console.log('closing navbar content'); togglerBtn.classList.toggle('is-active'); });