This example demonstrates a minimal interactive visualization where a single black circle follows the mouse cursor across the screen. Built with React and rendered as SVG, it updates the circle’s center coordinates based on pointer movement. The `onMouseMove` event handler captures the client’s X and Y positions, which are stored in React state and passed as `cx` and `cy` attributes. The code uses `useState` and `useCallback` for state management and event memoization, while the `ReactDOM.render` method mounts the component. The visualization is unconstrained by data, focusing purely on real-time positional feedback.