1# Hitori23Shade cells to eliminate duplicate numbers in every row and column.4567## How to Play89The grid starts filled with numbers. Shade some cells black so that three10rules are satisfied:11121. **No duplicates**: No number appears more than once in any row or column among the unshaded (white) cells.132. **No adjacent shading**: No two shaded cells share an edge (diagonal is fine).143. **White connectivity**: All unshaded cells must form a single orthogonally connected region.1516The puzzle is solved when all three rules hold simultaneously.1718## Controls1920| Key | Action |21|-----|--------|22| Arrow keys / WASD / hjkl | Move cursor |23| Mouse left-click | Focus a cell |24| `x` | Shade cell (toggle) |25| `z` | Circle cell as confirmed white (toggle) |26| `Backspace` | Clear cell to unmarked |27| `Ctrl+H` | Toggle full help |28| `Ctrl+R` | Reset puzzle |29| `Escape` | Return to main menu |3031## Modes3233| Mode | Grid | Description |34|------|------|-------------|35| Mini | 5x5 | Gentle introduction |36| Easy | 6x6 | Straightforward logic |37| Medium | 8x8 | Moderate challenge |38| Tricky | 9x9 | Requires careful deduction |39| Hard | 10x10 | Advanced logic chains |40| Expert | 12x12 | Maximum challenge |4142## Elo Difficulty4344Named modes are compatibility presets. Use `--difficulty <0..3000>` to target a45specific Elo difficulty for generated puzzles.4647## Quick Start4849```bash50puzzletea new hitori mini51puzzletea new hitori medium52puzzletea new hitori expert53```