This example reproduces part of a Sol LeWitt wall drawing using only D3.js (version 7.9.0) and SVG, without relying on any external class. The artwork displays a grid of alternating horizontal and vertical thin white lines whose visibility is masked by two shapes: a large circular gradient-like cutout and a smaller solid black circle, producing layered geometric effects. The code builds the line grid using `d3.range` and `join` operations, then creates `mask` elements with paths and circles to selectively reveal the strokes. Rendering is performed entirely in the browser with SVG, adapting to the full window size.