Smiley Head
A classic smiley face rendered as a static SVG graphic, centered within a 960×500 viewport. The face consists of three simple shapes: a large yellow circle for the head with a black outline, two smaller black circles for eyes, and a mouth drawn as a thick arc. Built with React and D3, the code uses D3’s `arc()` generator to create the mouth path, while the eyes and head are plain SVG circle elements. The composition is assembled inside a single `<g>` group that translates to the canvas center, with all dimensions and offsets defined as named constants.