This example shows a yellow smiley face centered on a screen, with two black eyes and a yellow circular head scaled to the window height. The face is rendered as a React component using SVG primitives, with the center and eye positions calculated from `window.innerWidth` and `window.innerHeight`. The code uses React 16.9 and ReactDOM to mount the component into the DOM, and applies a `<g>` transform to translate the drawing to the screen’s center. Eye offsets and radii are defined as constants, while the head radius derives from the viewport height minus stroke width.