This example shows an animated D3 tidy tree visualization of hip replacement experts, organized hierarchically by country, city, institution, and expert name. The code loads CSV data from a gist URL and uses `d3.csv`, `d3.hierarchy`, and `d3.tree()` with `d3.linkHorizontal` to render the collapsible tree structure as an SVG. Nodes are initially collapsed based on name length, and the layout adapts to the window size using `window.innerWidth`.