This example demonstrates a minimal React application that renders a large, centered “Hello React!” message. The code uses React 16.10.0 and ReactDOM to mount an `App` component into the DOM, with styling applied through a CSS class. It serves as a basic starter template, showing how to set up a React component structure and render it to the page without additional data or interactive features. The implementation relies on the `ReactDOM.render` API to attach the component to the root element.