A mouse follower rendered with React and SVG that tracks the pointer’s position in real time. The visualization shows a single black circle that moves across the 960×500 canvas as the user moves the mouse, using React’s `useState` to store the current cursor coordinates and `useCallback` to handle the `onMouseMove` event. The SVG `<circle>` updates its `cx` and `cy` attributes based on the clientX and clientY values from the event, creating a direct, lag-free response to user input.