This example shows a cartoon smiley face built from reusable React components. The face consists of a yellow background circle, two black eyes, and a mouth shape defined by a D3 arc generator with a thick arc path. The `Face` component assembles these parts inside a `FaceContainer` that centers an SVG group via a transformation. The code uses React 17 and D3 v6 for the arc geometry, rendering in an SVG with explicit width, height, stroke, and offset proportions.