A family tree of football players displays hierarchical relationships, with nodes colored by generation: red for the root, olive, green, and navy for subsequent levels. The visualization uses D3 v6’s `d3.stratify` and `d3.tree` to compute the layout from flat `{ child, parent }` data, rendering SVG circles and labels. On load, links animate from parent coordinates to child coordinates using `transition()`, while circles grow via a separate 800-millisecond transition.