Smiley Face Part II
A smiling face is drawn as a full-screen SVG, with a yellow circular head, two black eyes, and a black stroke outline, all positioned relative to the window dimensions. The React component `App` uses JSX to render the SVG elements, translating the coordinate system to the center of the viewport to place the circles. It employs React 16.9 via the UMD builds and `ReactDOM.render` to mount the visualization, with constant values for eye offsets, radius, and mouth width defining the facial features.