This example displays a minimal React application that renders the text “Hello React!” to the browser. It demonstrates how to integrate React with a visualization gallery setup, using `ReactDOM.render` to mount the component into a `#root` div. The code imports React and ReactDOM, defines a functional `App` component, and relies on a production build of React 16.9.0 loaded from a CDN. Styling removes default body margins and hides overflow, preparing the page for future visualization content.