This example demonstrates a geometric masking effect by layering vertical and horizontal rectangles on an SVG canvas. Using D3 v7, it creates 100 vertical bars and 100 horizontal bars across the viewport, applying two SVG masks to reveal intersecting shapes. The first mask uses a white background with a black circle, while the second inverts the pattern, producing a cross-shaped visual interaction. The code relies on D3 selections, the `range()` generator, and SVG `mask` elements to achieve the composition.