This example uses D3.js to create an interactive grid of horizontal and vertical stripes overlaid with two SVG masks. The masks, generated via `d3.symbol` and `d3.symbols`, reveal a series of geometric shapes—diamonds, stars, and others—at the center of the canvas. One mask is inverted, producing contrasting effects on the intersecting rectangles. The visualization is rendered entirely with SVG elements, sized dynamically to the full browser viewport, and built using D3 selections and joins in a React-agnostic setup.