This example demonstrates how a D3.js v5 visualization can dynamically respond to browser resizing. It draws two thick green lines forming an X shape that always spans the full width and height of the chart container. The code uses CSS positioning to fill the viewport, then extracts the container’s `clientWidth` and `clientHeight` in a `redraw` function to update the SVG’s dimensions. A window `resize` event listener triggers `redraw`, which rebinds and updates the line elements through D3’s data join pattern.