This interactive tree diagram visualizes the hierarchical ownership structure of major car companies, from the root "Car Company" down to subsidiaries like Audi and Lamborghini. Built with React and D3.js, the visualization uses an SVG rendering with animated node expansion. The code defines a tree layout using `d3.layout.tree()` and draws connections with `d3.svg.diagonal()`, while CSS styles the nodes and links. The underlying data is a static JavaScript array of nested objects representing the corporate hierarchy.