This example generates a Sol Lewitt-inspired geometric composition using D3 v6 and SVG. It draws 100 horizontal and vertical rectangles across the full viewport, then applies two complementary circle masks to cut out circular voids and reveal the grid within. The code uses D3 selections, `range`, and `join` to create the rect elements, while `append('mask')` constructs custom mask definitions that alternate black and white fills to control visibility.