This example shows a full-window SVG grid of thin horizontal and vertical rectangles that combine to form a subtle crosshatch pattern. A white circular mask placed at the center of the canvas reveals a clean circular window through the grid, interrupting the lines. Built with React and D3 v7, the code constructs the SVG and its elements using native DOM methods like `createElementNS` and `setAttribute`, rather than JSX or D3 data joins. The grid density and circle radius scale directly with the browser window dimensions.