.lightbox-overlay {
  display: none;
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0, 0, 0, 0.9);
  z-index: 1000;
  justify-content: center;
  align-items: center;
}
.lightbox-overlay.active {
  display: flex;
}
#lightbox-img {
  max-width: 90%;
  max-height: 90%;
  object-fit: contain;
  border: 3px solid black;
}
.close-btn {
  position: absolute;
  top: 20px; right: 30px;
  color: white; font-size: 40px; cursor: pointer;
}
.nav-btn {
  position: absolute;
  top: 50%; transform: translateY(-50%);
  background: rgba(255,255,255,0.1);
  color: white; border: none; font-size: 30px;
  padding: 15px 20px; cursor: pointer; transition: 0.2s;
}
.nav-btn:hover { background: rgba(255,255,255,0.3); }
.prev-btn { left: 20px; }
.next-btn { right: 20px; }
.gallery-thumb { width: 150px; margin: 5px; cursor: pointer; }