A responsive smiley face drawn with React and rendered as SVG, positioned at the center of the viewport. The face uses a yellow circle with a black stroke, two black eye circles offset symmetrically, and dynamically calculates the face radius from the window height. The code leverages `window.innerWidth` and `window.innerHeight` to set the SVG dimensions, with React rendering the shape via JSX and `ReactDOM.render`. All facial features are defined by constant offsets and radii, producing a static, scalable illustration.