This interactive family tree diagram visualizes the Wilson family hierarchy using a D3.js v7 tree layout rendered as SVG. Nodes are represented by circles whose size corresponds to a numeric value, while stroke and fill colors encode the type and level properties from the bundled data.json hierarchy. Curved links connect parent and child nodes using bezier paths, with link colors derived from each node’s level attribute. The code uses `d3.hierarchy` and `d3.tree()` to compute positions, and custom styling via inline styles and CSS classes.