The weekly challenge. The board starts completely empty — not a single given digit. The constraints alone carry the whole solve. No clock, no pressure, and your progress follows you across devices. Chip away at it all week; finishing is the feat.

• Normal sudoku rules apply: fill every row, column, and 3×3 box with 1–9.
• Both main diagonals must also contain 1–9 with no repeats.
• Cages sum to the small clue in their top-left corner; digits cannot repeat in a cage.