This example shows a responsive smiley face drawn with React and rendered as SVG. The face fills the browser window, scaling its radius based on window height, with eyes offset symmetrically from center. The code uses React’s `createElement` and `ReactDOM.render`, setting circle attributes like `cx`, `cy`, `r`, and `stroke-width` within an SVG container. Static values for eye radius, offset, and mouth dimensions are defined as constants, while the face itself adapts to viewport size. No animation or interaction is present; it is a static visualization of geometric primitives.