This example shows a responsive smiley face rendered as an SVG using React components for scalable vector graphics. The face consists of a yellow circle with a black stroke, two eye circles, and a mouth arc, all positioned relative to the window dimensions. The code uses React’s `createElement` API via JSX, `ReactDOM.render` to mount the app, and D3 v7’s `arc` function (imported but not used in the visible code) to define the mouth shape. Rendering adapts to the browser viewport through `window.innerWidth` and `window.innerHeight`.