This example renders a full-screen yellow smiley face with black stroke, two eyes, and a mouth using React components and D3’s `arc` generator to create mouth and teeth paths as SVG. The face is centered with dimensions tied to the viewport, and the teeth arc is offset slightly downward via a transform. Built with React 16 and D3 v5, the SVG elements are defined declaratively in JSX, with circle radii and arc angles computed from window dimensions.