This example shows a single circle that follows the mouse cursor across an SVG canvas. The circle’s position updates in real time as the user moves the mouse, using React’s `useState` and `useCallback` hooks to manage and set the cursor coordinates. The rendering is handled through React’s SVG elements, with the mouse position captured via the `onMouseMove` event on the `<svg>` container. The code uses the React and ReactDOM libraries, with no external data source.