This example demonstrates how a D3.js visualization can respond to browser window resizing. It uses a CSS-styled container that fills the viewport, and a redraw function extracts the container’s current clientWidth and clientHeight to update the SVG dimensions. Two green, semi-transparent lines are drawn across the full width and height to form an X, visually confirming the resized area. The code relies on window.addEventListener("resize", redraw) and D3’s selection.merge pattern to update the existing line elements efficiently.