.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
}

.thumbnail {
  width: 100%;
  height: 120px;
  object-fit: cover;
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  transition: transform 0.2s ease;
}

.thumbnail:hover {
  transform: scale(1.05);
}

.overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0,0,0,0.8);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.overlay img {
  max-width: 80%;
  max-height: 80%;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
  cursor: pointer;
}

.nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255,255,255,0.2);
  border: none;
  color: white;
  font-size: 2rem;
  padding: 0.5rem 1rem;
  cursor: pointer;
  border-radius: 4px;
  user-select: none;
}

.nav:hover {
  background: rgba(255,255,255,0.4);
}

.prev {
  left: 20px;
}

.next {
  right: 20px;
}