.numpuz-board {
  position: relative;
  background: var(--board-bg);
  border-radius: var(--radius-md);
  padding: 0;
  width: min(85vw, 400px);
  max-height: calc(100vh - 200px);
  aspect-ratio: 1;
  touch-action: none;
}

.numpuz-tile {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--tile-font-size);
  font-weight: var(--font-weight-bold);
  color: var(--tile-text-color);
  background: var(--tile-color);
  border-radius: var(--tile-radius);
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  transition: top 150ms ease, left 150ms ease, color 200ms ease;
}

.numpuz-tile:active {
  opacity: 0.85;
}

.numpuz-tile.correct {
  color: var(--color-success);
}

@keyframes solved-pop {
  0% { transform: scale(1); }
  50% { transform: scale(1.12); background: var(--color-surface-raised); }
  100% { transform: scale(1); background: var(--tile-color); }
}

.numpuz-tile.solved-pop {
  animation: solved-pop 350ms ease forwards;
  color: var(--color-success);
}