A yellow circle follows the mouse cursor across a full-window SVG canvas built with React. The component tracks pointer coordinates via the `onMouseMove` event handler and updates state with `useState`, re-rendering the circle’s `cx` and `cy` attributes on each move. Rendering is handled by ReactDOM and React 16.9, with the SVG viewport sized to `window.innerWidth` and `window.innerHeight`. No external data source is used; the visualization purely demonstrates interactive state-driven positioning.