This example shows a yellow smiley face rendered as an SVG, with eyes, a mouth, and a nose positioned relative to the center of the viewport. The face is drawn using React components that generate SVG elements, with circles for the head and eyes and a path for the mouth. The code uses React and ReactDOM to manage the SVG structure and the D3 `arc` generator from the `d3` library to compute the mouth and nose path coordinates. The face’s dimensions and positions are calculated from the window size, and the rendering approach relies on JavaScript-defined constants for offsets and radii.