A React-driven SVG renders a yellow smiley face that adapts to the browser window’s height. The face, centered with dynamic radii for the head and fixed offsets for the eyes, uses a `<g>` transform to position all elements relative to its center. The code constructs the circles via React’s `ReactDOM.render` and relies on SVG primitives, with the head’s radius computed from `window.innerHeight` and a stroke width of 20. The page also includes a static fallback SVG with a fixed 960x500 viewport.