A dynamic smiley face graphic fills the browser window using React and D3 v7, rendering SVG elements sized to the viewport. The face consists of three yellow and black circles for the head and eyes, plus an arc-generated mouth created with the `d3.arc()` API. Built with React 16.9, the component computes dimensions from `window.innerWidth` and `window.innerHeight`, then positions elements relative to the screen center. The mouth path is defined using `innerRadius`, `outerRadius`, and angular bounds from `Math.PI`, demonstrating a reusable D3 shape generator within a React component structure.