First HTML page
This example shows a simple yellow circle rendered inside an SVG graphic, serving as an introduction to building data visualizations with React and D3 version 6. The code imports React and ReactDOM, then defines a functional App component that returns an SVG with a single circle element. ReactDOM renders this component into the root div in the HTML file, while a commented-out section demonstrates an alternative pure SVG approach. The example uses React 18.2.0 and ReactDOM 17.0.2 via CDN links, producing the static visual without any interactive features.