This example demonstrates a minimal integration of React and D3, displaying the static text "Hello D3 & React" centered on the page. The application initializes a React component with a `useRef` hook and a `useEffect` hook to apply the text via D3's `select` function. It uses the `createRoot` API from `react-dom/client` to render the component into the DOM, while importing the `select` function from D3 v7. The visual output is a single large text element styled entirely by CSS.