This example demonstrates how a D3.js visualization can respond to browser window resizing. It draws a green X composed of two thick, semi-transparent lines that stretch across the entire viewport, with the SVG element filling the page via CSS fixed positioning. The code uses `chartDiv.clientWidth` and `clientHeight` to extract the computed CSS size, then applies those dimensions to the SVG’s width and height attributes. A `redraw` function manages the SVG and line updates, and a window `resize` event listener triggers it whenever the viewport changes.