.collage {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  max-width: 900px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.collage img {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  display: block;
  border-radius: 4px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

@media (max-width: 700px) {
  .collage { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 450px) {
  .collage { grid-template-columns: repeat(2, 1fr); }
}