How to Play Light Up
Place light bulbs on white cells to illuminate the entire grid.
Rules:
1. Bulbs illuminate all cells in their row and column until blocked by a wall.
2. No two bulbs may illuminate each other (no two in same row/column without a wall between).
3. Numbered walls show exactly how many bulbs must be adjacent (up/down/left/right).
4. All white cells must be illuminated.
Controls: Click a white cell to place/remove a bulb.