.stamp-collection__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
}
.stamp-collection__slot {
  aspect-ratio: 1;
  background: var(--card-accent);
  border: 2px dashed var(--border);
  border-radius: var(--r-xs);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
  color: var(--text-4);
}