This example demonstrates a minimal React application that renders a centered “Hello React!” message at an oversized font scale. The code imports React and `createRoot` from `react-dom`, defines a functional `App` component returning a styled `div`, and mounts it to a `#root` element in the HTML. It uses the production UMD builds of React 18.2.0 and ReactDOM, with the page loading the compiled `bundle.js`. The rendering approach relies on React’s standard `createRoot` API to attach the component tree to the DOM.