This SVG reproduction of Sol LeWitt’s *Vertical* artwork overlays a grid of horizontal and vertical black bars on a white background, with a circular mask revealing the central intersection. Using the raw SVG DOM API, the code creates 99 horizontal and 99 vertical rectangles, each 10 pixels thick and spaced 20 pixels apart, then applies a `<mask>` containing a centered white circle on a black rectangle to clip the bars, leaving only the circular region visible.