This Sankey diagram visualizes the flow of categorical values across six attributes—buying, maintenance, doors, persons, luggage boot, and safety—from the car.data dataset. Nodes are colored by attribute using the `d3.scaleOrdinal` scheme, with labels and values displayed. The graph is constructed using a custom `d3.sankey()` implementation, with node dragging enabled via `d3.drag()`. The layout is computed through iterative breadth and depth algorithms, rendering SVG paths for links.