This example renders a stylized smiley face using React and D3 v7. It constructs SVG shapes—circles, ellipses, lines, and arcs—within a responsive full-window viewport, centering the face and dynamically sizing the head based on window height. The code explicitly uses D3’s `arc()` generator to form the mouth and eye-arc details, while React manages the SVG element hierarchy and attributes. Eyes include colored irises, eyebrows as thick lines, and decorative geometric accents, all positioned relative to the center. The face is drawn entirely with vector primitives, with no external data source, showcasing how D3 geometry helpers integrate with React’s declarative rendering model.