Rules & objective
Place bulbs only on white squares. Light travels horizontally and vertically until a black wall or the board edge; it never travels diagonally. Two bulbs must not illuminate each other. A numbered wall must have exactly that many bulbs in its four orthogonally adjacent squares; unnumbered walls have no count constraint. Every white square must be lit. An already lit white square does not need an explicit empty mark. These 90 independently generated puzzles use 5×5, 7×7 and 10×10 grids, 30 of each with rotations/reflections. They have unique solutions checked from public clues. Hints derive one forced bulb or empty mark from clues and current marks, never from an answer key. The hint only previews; confirm to apply or cancel it. Check reports local constraint consistency, not guaranteed correctness of every unfinished mark. Undo/redo restore real actions; Restart keeps this puzzle; New chooses another puzzle.
Controls
Arrows: select · Enter: act/confirm hint · Space: empty · X: clear · H: hint · U/R: undo/redo · Esc: cancel hint
Worked example
A bulb lights along its row and column until a black cell. Bulbs cannot see each other, and black-cell clues count edge-adjacent bulbs only.