This interactive family tree visualizes three generations of a family, starting from the root patriarch Subba Rao and branching to his children and grandchildren. The diagram uses a collapsible tree layout (via `d3.layout.tree` and SVG), where nodes are colored by generational level—orange, violet, and green—through the supplied `treeData` structure. Lines connect parents to children using `d3.svg.diagonal`, and users can click any node to expand or collapse its descendants, triggering a smooth transition animation. The page loads the D3.js v3 library from a CDN and runs entirely in the browser.