This example shows a minimal HTML page that uses D3.js to select an SVG element and change its background color to red. The code loads D3 v7 from a CDN, then uses `d3.select` to target the `<svg>` and the `style` method to apply the background color. It also logs the selection to the console for inspection. The page demonstrates basic D3 selection and styling with a simple, declarative approach, serving as a starting point for building more complex charts.