A full-screen SVG grid of thin black horizontal and vertical lines is masked to reveal two offset circular cutouts in the center of the canvas. The piece is a direct reproduction of a Sol LeWitt art concept, rendered using D3 v6. The code builds the lines by binding `d3.range(n)` data arrays to `rect` elements via `.join()`, while two layered SVG `<mask>` elements (one black rect with white circle, one white rect with black circle) define the visible apertures.