This example demonstrates a minimal React application that renders a large “Hello React!” message centered on the page, using 13em font size. The code uses React 16.13.1 and ReactDOM to mount a functional `App` component into a `#root` div in the HTML. It imports React and ReactDOM via `import`, renders the component with `ReactDOM.render`, and relies on external production builds of React and React DOM loaded from unpkg in the HTML head. The visualization is text-only, driven by CSS for styling and alignment.