This example shows a yellow smiley face rendered as an SVG using React and D3. The face is centered on the screen and resizes to fit the browser window, with two black eyes and a curved mouth drawn using the D3 `arc()` generator. The code uses React functional components and ReactDOM to render the SVG, while D3 v5 provides the arc path generation. Static values define the eye offset, eye radius, mouth radius, and stroke width, making the face fixed in proportion rather than interactive.