Smiley Face Part I
A grid of 18 smiley faces, each with randomized facial features, appears within an SVG rendered by React. The code builds each face from reusable components: `BackgroundCircle` for the yellow head, `Eyes` for the offset eye circles, and a `Mouth` arc drawn using `d3.arc()`. `FaceContainer` groups the SVG elements and translates them to a center point. The `range` function from d3 generates the array of faces, and `Math.random()` varies eye position, radius, and mouth dimensions per face, producing a playful, varied collection.