document.getElementById('categoryFilter').addEventListener('change', function () { const selectedCategory = this.value; const cards = document.querySelectorAll('.card-item'); cards.forEach(card => { const categories = card.dataset.category.split(' '); if ( selectedCategory === 'all' || categories.includes(selectedCategory) ) { card.classList.remove('d-none'); } else { card.classList.add('d-none'); } }); });