This example shows a minimal React application that renders a single text message, “Hello Plans,” centered on the page. The app is built with React 16 and uses `ReactDOM.render` to mount the root component, while a separate `Plans` component returns a simple paragraph. The message’s large font size is set via inline CSS in `index.html`, and global styling is applied through an imported `index.css` file that adjusts heading font size. The code demonstrates basic component composition and styling integration.