This example shows a single teal circle rendered on a plain HTML page. The circle is positioned at a fixed x-coordinate with a set radius, demonstrating the minimal setup for a React component within an SVG canvas. It uses React and ReactDOM to mount the `App` component, which renders an SVG containing the `BackgroundImg` component, a simple `<circle>` element. The styling is applied via a global CSS rule, and the page loads React and ReactDOM from CDN links, producing a static, simple visualization.