This example shows a simple smiley face rendered as an SVG using React components. A yellow background circle, two eyes, and an arc-based mouth are positioned using SVG transforms. The mouth is drawn with the D3 `arc()` API, while React functional components `BackgroundCircle`, `Eyes`, and `Mouth` handle the rendering. All geometry is defined by constant dimensions, and the SVG is centered on a 960×500 canvas.