Smiley Face and Arcs
A smiling face rendered with SVG shapes inside a React component. The code uses D3's `arc` generator to create the mouth as a donut-shaped path, while the face, eyes, and stroke are drawn with basic SVG `circle` and `path` elements. All shapes are positioned manually using fixed coordinates and radii, and the face is centered via an SVG `g` transform. React handles the markup, and D3 v7 provides the arc geometry.