A yellow smiley face with black-outlined eyes fills the browser window, centered and scaled to the viewport’s height. Built with React and rendered as SVG, the face’s circle radius derives from the window’s inner height minus half the stroke width, while eye offsets and radii are fixed constants. The code uses ReactDOM to mount the component into an HTML root element, with React’s production UMD builds loaded via CDN. The face is drawn using SVG `<circle>` elements within a `<g>` transform, animated only by window resizing.