This example demonstrates a minimal React application that renders a static “Hello React!” message centered on the page. The app uses React 16.13.1 with `ReactDOM.render` to mount a functional component into the `#root` div. The component returns a single `<div>` styled with a large font size via embedded CSS, and the code loads React and ReactDOM from external UMD scripts. No data or interaction is present; the example solely illustrates the basic setup for a React-based visualization or web app.