This example demonstrates how a D3.js visualization can adapt to browser window resizing by redrawing an SVG to match its container’s current dimensions. It shows two thick, semi-transparent green lines forming an X across the full chart area, with the lines and SVG width/height updating on every resize event. The code uses D3 v5’s `select` and `selectAll` with a data join, reading `clientWidth` and `clientHeight` from the container div, and listens for the window’s `resize` event to trigger the redraw function.