This example demonstrates a minimal React application that renders the text “Hello React!” in large, centered type. The code defines a single `App` component, which returns a `<div>` element with a CSS class, and mounts it to the `#root` DOM node using `ReactDOM.render`. It loads the React and ReactDOM libraries from a UMD bundle and relies on a precompiled `bundle.js` for the component. The visualization itself is purely a styled text message, showcasing basic component creation and rendering in React 16.13.1.