This example creates a full-screen SVG pattern of horizontal and vertical stripes using D3’s `select`, `range`, and `join` methods. Two sets of 100 rectangles are generated, each masked to reveal or hide a circular region at the center. The code uses SVG `mask` elements with black-and-white circles to produce a cross-shaped visual intersection. The data is synthetic, generated via `range(n)`, and rendered entirely with D3 v6 and SVG attributes.