This example displays a small family-style network as a force-directed tree, with nine labeled nodes connected by curved, red or black links whose style varies according to link weight. Node radius and blue fill intensity reflect the number of connections per node. Built with D3 v5, it uses `d3.forceSimulation`, `d3.forceLink`, and `d3.forceManyBody` to position nodes, while SVG paths and circles render the graph. Users can drag nodes to reposition them, and the simulation updates continuously via tick events.