Fork of Smiley Face Part II
This example shows a React-rendered SVG smiley face, centered and sized to the browser window. The face consists of a yellow circle with a black stroke, two black eye circles, and a mouth drawn as an arc. The mouth is generated using D3’s `arc` function to compute the path for an SVG `<path>`. The implementation separates components (`BackgroundCircle`, `Eyes`, and `Mouth`) in React, with fixed offsets and radii such as `eyeOffsetX`, `eyeRadius`, and `mouthRadius` to position features. The dimensions and center are derived from `window.innerWidth` and `window.innerHeight`, and the SVG scales to fill the viewport.