This example reproduces the second stage of a Sol LeWitt wall drawing using raw SVG and JavaScript. It creates two circular masks over a full-window canvas, then draws 100 horizontal and 100 vertical stripes. Horizontal stripes appear only inside the first mask, while vertical stripes are visible outside the second mask, producing a grid that shifts from a solid square to an open circle at the center. The code builds all elements dynamically using `document.createElementNS` and sets attributes directly, with no external libraries.