Normal sudoku rules apply. The grid is covered in fog. Placing correct digits reveals clues in the surrounding 3x3 area. No guessing is required. Digits an equal distance to the circled centre of a lavender zipper line sum to the central digit. A digit in a yellow circle counts the number of odd digits on the attached line (including itself and the central cell). A digit in a blue square counts the number of even digits on the attached line (including itself and the central cell). Zipper lines only move orthogonally and don't share cells with other zipper lines.