This example demonstrates a minimal React application that renders the static message "Hello React!" in large, centered text. The app uses React 16.13 and ReactDOM to define a simple functional component, `App`, which returns a `div` with the CSS class `.message`. The code then mounts this component into the page’s `#root` element via `ReactDOM.render()`. Styling for the oversized text comes from an inline `<style>` block in the HTML, and the project is built so that `index.js` compiles into a separate `bundle.js` for production.