1# Hitori23Shade cells to eliminate duplicate numbers in every row and column.45## Rules67- **No duplicates**: No number may appear more than once in any row or8 column among the unshaded (white) cells.9- **No adjacent shading**: No two shaded cells may share an edge.10 Diagonal contact is fine.11- **White connectivity**: All unshaded cells must form a single12 orthogonally connected region.1314The puzzle is solved when all three rules hold simultaneously.1516## Controls1718| Key | Action |19|-----|--------|20| `Arrows` / `wasd` / `hjkl` | Move cursor |21| `Mouse left-click` | Focus a cell |22| `x` | Toggle shade on cell |23| `z` | Toggle circle (confirmed white) |24| `Backspace` | Clear cell to unmarked |25| `Ctrl+H` | Toggle full help |26| `Ctrl+R` | Reset puzzle |27| `Escape` | Return to main menu |2829## Tips3031- **Circle the unique numbers first.** If a number appears only once in32 its row *and* column, it can never be shaded. Circling these cells33 gives you safe anchors to reason from.34- **Watch for forced shading.** When a number appears twice in a row or35 column and one copy is already circled, the other copy must be shaded.36- **Protect connectivity.** Before shading a cell, check whether it37 would split the white region into disconnected pieces. Cells that act38 as bridges between unshaded areas should almost always stay white.