This example renders a smiling face using React and D3’s `arc` generator to draw the mouth as a thick semicircular path. The SVG is assembled declaratively in JSX, with yellow and orange circles for the head and nose, and black strokes for outlines. React 16.9 manages the component lifecycle, while D3 v6 provides the `arc` function for path geometry. The viewport is fixed at 960 by 500 pixels, with the face centered and intentionally cropped by the hidden overflow.