This example demonstrates a minimal React application that renders an empty `<div>` element as its entire user interface. The code manually loads React 16.9.0, ReactDOM, and D3 v5.11.0 via CDN script tags in the HTML, then uses `ReactDOM.render` to mount a functional `App` component into the root DOM node. While the component itself contains no visualizations, the setup serves as a foundation for integrating D3 with React, with the body hidden by `overflow: hidden` and all content constrained to the viewport.