This visualization displays a hierarchical tree of world countries, organized by region and subregion, using a horizontal node-link layout. The code renders the structure with SVG paths and text labels, applying D3’s `tree()` layout, `hierarchy()`, `linkHorizontal()`, and `zoom()` for pan and zoom interactions. Data is loaded from a JSON file containing nested country groupings, with label font size decreasing by depth. The visualization uses a custom Playfair Display font and subtle text shadows for readability.