Normal sudoku rules apply. The purple line is an entropic line. Any set of three sequential cells along an entropic line must contain a low digit (1,2,3), a middle digit (4,5,6), and a high digit (7,8,9). Digits on a thermometer must increase from the bulb. A white circle joins consecutive digits, and a black circle joins digits with a 1:2 ratio. Cell shading is just for aesthetics.