This example shows a yellow smiley face centered on a full-screen SVG canvas, rendered entirely with React elements. The face consists of a large yellow circle for the head, two smaller black circles for eyes, and a mouth implied by the head’s lower edge. The code uses React and ReactDOM to create and mount the SVG, calculating dimensions from `window.innerWidth` and `window.innerHeight` to scale responsively. Positions for the eyes and stroke widths are defined as constants, with the face centered using an SVG `<g>` transform.