This interactive tool visualizes task progress using a physical metaphor: marbles move from a left container to a right container as steps are completed. Users set the number of tasks with a numeric input and click a button to advance progress by one marble. The visualization renders two steel-blue rectangles as containers in an SVG, with React managing the component structure and state updates. The interface is built with React and ReactDOM for rendering, while D3.js v5 is included for potential data binding or transitions, though the current implementation relies primarily on React's declarative JSX.