This example renders a hierarchical family tree as an SVG using D3.js v5’s `d3.tree()` layout and `d3.hierarchy()`. Node circles are sized by a `value` property and colored by both a `level` fill and a `type` stroke, while curved link paths between parents and children are stroked with each child’s level color. The data is a hardcoded JavaScript object with nested `children` arrays, and the visualization highlights the branching structure of names and relationships across three generations.