A clean Sudoku app built with Flutter. Every puzzle is uniquely generated, and its difficulty is derived from the logical solving techniques required to complete it. <b>Features:</b> * Logic-based difficulty - difficulty is derived from the techniques needed to solve a puzzle (Hidden Single, Naked Pair, X-Wing, Swordfish, and more). * In-game assists - notes/pencil marks, auto-notes, undo, conflict highlighting, and validation. * Statistics & leaderboard - track your solve times per difficulty, with a top-10 board shown on the solved overlay. * Resume - your current game is saved locally so you can continue right where you left off. * Theming - light and dark modes plus custom color themes with a live preview. * Responsive layout - adapts the control placement for phones and larger screens. The app works fully offline, stores all data locally on your device.