(() => {
  const modal = document.getElementById('imageModal');
  if (!modal) return;

  const img = document.getElementById('modalImage');
  const caption = document.getElementById('modalCaption');
  const closeBtn = modal.querySelector('.modal-close');
  let lastTrigger = null;

  const close = () => {
    modal.classList.remove('open');
    modal.setAttribute('aria-hidden', 'true');
    document.body.classList.remove('no-scroll');
    img.removeAttribute('src');
    if (lastTrigger) lastTrigger.focus({preventScroll:true});
  };

  const open = (btn) => {
    lastTrigger = btn;
    img.src = btn.dataset.image || '';
    img.alt = 'Affiche agrandie - ' + (btn.dataset.title || 'événement');
    caption.textContent = btn.dataset.title || '';
    modal.classList.add('open');
    modal.setAttribute('aria-hidden', 'false');
    document.body.classList.add('no-scroll');
    closeBtn.focus({preventScroll:true});
  };

  // Délégation : fonctionne aussi très bien au toucher sur smartphone.
  document.addEventListener('click', (event) => {
    const btn = event.target.closest('.poster-button');
    if (btn) {
      event.preventDefault();
      open(btn);
    }
  });

  closeBtn.addEventListener('click', close);
  modal.addEventListener('click', (event) => {
    if (event.target === modal) close();
  });

  document.addEventListener('keydown', (event) => {
    if (event.key === 'Escape' && modal.classList.contains('open')) close();
  });
})();