This example shows a yellow smiley face drawn with SVG that follows the mouse cursor across the full browser window. The face is centered dynamically using window dimensions, with the eyes positioned relative to the center point. Built with React and ReactDOM, the code calculates the viewport size and renders an SVG circle for the face, while an inner group transform places the eyes at fixed offsets from the center. The implementation uses React's declarative syntax to generate the SVG markup.