Hello HTML
This example displays a static, yellow circle with a thick black outline, centered on a transparent background. It represents a bare minimum integration of React and D3 within an HTML page. The visualization is rendered as an SVG element directly through a React component, using the `ReactDOM.render` API to mount the application to a root div. The code imports React, ReactDOM, and D3 v6 from CDN sources, but notably, the D3 library is loaded yet not actively used for drawing, with the graphic itself defined by hardcoded SVG circle attributes.