Fork of Smiley Face Part II
A full-window SVG smiley face is drawn, centered on the canvas with yellow circular head, black outline, and two black eyes. The React application calculates dimensions from `window.innerWidth` and `window.innerHeight`, then uses SVG `<circle>` elements within a translated `<g>` group to position features relative to the center. The code uses `ReactDOM.render` to mount the component, with styling constants for offsets, radii, and stroke width.