document.addEventListener('DOMContentLoaded', () => {
    const menuBtns = document.querySelectorAll('#menuBtn');
    const navOverlay = document.getElementById('navOverlay');
    const closeBtn = document.getElementById('closeBtn');
    menuBtns.forEach(btn => {
        btn.addEventListener('click', () => { navOverlay.classList.add('open'); });
    });
    if (closeBtn) {
        closeBtn.addEventListener('click', () => { navOverlay.classList.remove('open'); });
    }
});