Responding to Resize
This example demonstrates how a D3.js visualization can respond dynamically to browser resizing. It uses CSS positioning to make the chart container fill the viewport, then queries its `clientWidth` and `clientHeight` properties on each resize event to update the SVG’s `width` and `height` attributes. The visualization redraws a large green X composed of two SVG `<line>` elements, using the `merge` method for efficient updates. The code relies on the `window.addEventListener("resize", redraw)` API to trigger the redraw function whenever the window dimensions change.