Fork of Smiley Face Part II
This example shows a full-screen smiley face rendered as a yellow circle with two black eyes, dynamically sized and positioned relative to the browser window. It uses React 16.9 and ReactDOM to declaratively construct an SVG, with dimensions and coordinates derived from `window.innerWidth` and `window.innerHeight`. The face’s components—head, eyes, and mouth—are defined as SVG elements, where the head is centered using a `<g>` transform and the eyes are offset via `cx` and `cy` props with fixed pixel values.