This example reproduces Sol LeWitt’s horizontal wall drawing using animated SVG masks to create a shifting circular aperture over a grid of horizontal and vertical lines. The visualization shows a pulsing black-and-white circle that expands and contracts, revealing and hiding the underlying striped composition as the masks animate. Built entirely with raw SVG elements and the Web Animations API via `animate` and `animateTransform`, the code generates 950-pixel-wide rectangles and vertical strips, applying `mask` and `mask2` to alternate visibility. The circular mask radius animates over five seconds, while a separate rotation transform spins the vertical lines, mimicking LeWitt’s geometric rules.