This visualization demonstrates a minimal integration of React 19 and D3 v7, rendering the text "Hello D3 & React" in a large, centered message. It uses React hooks (`useRef`, `useEffect`) to manage a DOM reference, then calls D3's `select` function to update the text content within the React-managed component. The example serves as a starter template, showing how D3's selection API can be used inside a React component lifecycle.