const observer = new IntersectionObserver(entries => { entries.forEach(entry => { if (entry.isIntersecting) { if (entry.target.classList.contains('reverse')) entry.target.classList.add('table-item-animation-reverse'); else entry.target.classList.add('table-item-animation'); } }); }); let targets = document.querySelectorAll('.table-item'); targets.forEach(target => { observer.observe(target); })