This example demonstrates basic SVG shapes—a circle, rectangle, and line—styled with CSS and labeled with text. It shows how HTML, CSS, and SVG combine to create interactive graphics, with hover effects changing shape fills via the `.shape:hover` rule. The page uses an inline `<svg>` element, while the included `index.js` file imports `d3` to select the body and write "Hello D3", though that selection is not reflected in the visible output. The SVG is rendered directly in the HTML document with a white background and rounded border.