This piece reproduces Sol LeWitt’s geometric art using only SVG primitives. A white triangular mask reveals horizontal black stripes, while an inverted mask reveals vertical white stripes, forming an overlapping lattice. The code uses the `document.createElementNS` API to build the SVG, and CSS masks (`url(#polygon-mask)`) to clip 150 horizontal and vertical rectangles. The composition adapts to the browser window dimensions.