Focus system

A calm, minimal Sudoku practice space with Classic play, Daily puzzles, Strategy Coach hints, local progress, refined themes and installable PWA support.

Daily puzzles are generated from the date and difficulty.
Use Notes to mark candidates.
The start screen now includes today's dailies, a monthly completion calendar and a small archive launcher.
Your current puzzle, daily bests and progress stats are saved locally on this device.
Choose Light, Dark, Paper or Focus from the top-right theme control.
Difficulty now uses refined quality profiles, balanced clue patterns and an Expert tier, not just clue count.
Strategy Coach turns hints into progressive clues: area first, then cell, then reasoning, then apply/reveal.
Public release includes About, Privacy, SEO metadata, install/offline polish, game-feel feedback, player settings, stronger Daily experience, progressive strategy coaching, Expert puzzle quality, visual identity polish and v1.7.0 sharing/responsive repair.