This example shows a smiley face rendered as a large yellow circle with two eyes and a mouth, all positioned relative to the browser window’s center and sized based on its dimensions. Built with React and D3 v5, it uses D3’s `arc` generator to create the mouth’s curved path, while SVG circles handle the face and eyes. The drawing scales dynamically with the viewport, using `window.innerWidth` and `window.innerHeight` to set the canvas size.