This example renders a cheerful smiley face using SVG, composed of a radial-gradient-filled face, two white eyes with black pupils, and an orange mouth drawn as an arc. It is built with React and D3 v7, specifically using the `arc` generator from the `d3` package to create the mouth’s path. The entire graphic is centered within a 960×500 viewport, with all shapes positioned via explicit coordinates and transforms. The code demonstrates how to mix React’s declarative JSX with D3’s geometric helpers, all inside a minimal HTML page.