This visualization shows the hierarchical structure of world countries, organized by continent and subregion, as a horizontal tree layout. The data is loaded from a JSON file and rendered as SVG. Using d3.tree, d3.hierarchy, and d3.linkHorizontal, the code draws curved links between nodes and displays country names with font sizes that decrease by depth. The visualization supports zooming and panning via d3.zoom, with a Playfair Display font and teal-colored paths for the connections.