This example uses React and ReactDOM to render a single SVG smiley face that scales to fill the entire browser window. The face’s proportions are calculated from `window.innerWidth` and `window.innerHeight`, positioning the center, eyes, and stroke width dynamically. The SVG circle elements for the face and eyes are drawn within a transformed group, using hardcoded offsets for eye placement. This is a minimal, responsive vector graphic that demonstrates basic React-driven SVG generation.