(function () {
  var lightbox = document.getElementById('lightbox');
  if (!lightbox) return;
  var img = document.getElementById('lightboxImg');
  var caption = document.getElementById('lightboxCaption');
  var closeBtn = document.getElementById('lightboxClose');

  function open(src, cap) {
    img.src = src;
    caption.textContent = cap || '';
    lightbox.hidden = false;
    document.body.style.overflow = 'hidden';
  }

  function close() {
    lightbox.hidden = true;
    img.src = '';
    document.body.style.overflow = '';
  }

  document.querySelectorAll('[data-lightbox]').forEach(function (link) {
    link.addEventListener('click', function (e) {
      e.preventDefault();
      open(link.getAttribute('data-full'), link.getAttribute('data-caption'));
    });
  });

  closeBtn.addEventListener('click', close);
  lightbox.addEventListener('click', function (e) {
    if (e.target === lightbox) close();
  });
  document.addEventListener('keydown', function (e) {
    if (e.key === 'Escape') close();
  });
})();