This example demonstrates a minimal interactive visualization built with React and ReactDOM, rendering a single SVG circle centered in the browser window. The circle’s position and radius are computed from the window’s dimensions using `window.innerWidth` and `window.innerHeight`. The code uses the React 16.9.0 UMD production builds loaded via `unpkg.com`, and the SVG circle is drawn directly through React’s JSX syntax. The example serves as a basic template for combining React’s declarative UI model with static SVG vector graphics.