This example renders a smiling face as a React component, using D3’s `arc` generator to draw the mouth as a stroked path. The SVG contains a large circle with a linear gradient fill (from yellow to dark green) and a black outline, plus two fixed-position eye circles. All geometry is computed from constants for width, height, and offsets, and the entire graphic is centered via a translated `<g>` element. The code combines React’s declarative JSX with D3’s shape utilities to produce a static, vector-based illustration.