This example shows a smiling face rendered as a yellow circle with two black eyes, scaled to fit the full browser window using React and SVG. The face is centered via a `<g>` transform, with the head radius calculated from the window height and a 20-pixel stroke. The code uses ReactDOM to mount the component and defines constants for eye placement, eye radius, and eye offset. The rendering relies on SVG elements like `<circle>` and React’s JSX syntax, with no interactive behavior or data source beyond the hardcoded geometric values.