This example displays a yellow smiley face with eyes, a smile, and subtle eyebrows, resized to fill the browser window. It uses React components to structure the SVG elements, while D3’s `arc()` generator creates the curved paths for the mouth and eyebrows. The face, eyes, and strokes are drawn declaratively with SVG circles, with positions and radii computed from the viewport dimensions. Code leverages ReactDOM to mount the composition and D3 v6 for path generation.