This example creates an abstract, animated SVG composition inspired by Sol LeWitt. It uses a full-window SVG canvas and draws a complex, irregular shape defined by an SVG path. The path is used in two separate mask elements, each controlling the visibility of a set of horizontal and vertical lines. By using these masks, the geometric line pattern is revealed only within the shape's boundaries, creating a dynamic interplay between form and structure. The code directly manipulates the SVG DOM through JavaScript and the `createElementNS` API.