This example reproduces a Sol LeWitt art piece using D3 v6, rendering a grid of horizontal and vertical stripes masked by two concentric circles. The visualization shows a geometric pattern of alternating line thicknesses, with the circular masks creating a layered negative-space effect. The code uses `d3.select`, `d3.range`, and `join` to generate SVG rectangles, while SVG `<mask>` elements with `circle` and `rect` shapes define the visible regions. All rendering occurs client-side in SVG, with dimensions set to the full window size.