This example reproduces a Sol LeWitt–style generative artwork by layering two sets of thin rectangular strips—vertical and horizontal—across the full viewport. Each set is masked using an SVG `<mask>` element, with the masks populated by D3 symbols (from `d3.symbol` and `symbols`) positioned in a row, alternating fill colors to create intersecting geometric patterns. The code uses `select`, `range`, and `join` from D3 v7 to bind data and render both the rectangles and the mask shapes dynamically.