World Countries Tree
This visualization displays the hierarchical structure of world countries, organized by continent and subregion. The layout uses a tree diagram with horizontal links connecting parent nodes to their children, and text labels sized inversely to depth. The implementation leverages d3.hierarchy, d3.tree, and d3.linkHorizontal to compute positions and draw SVG paths, while d3.zoom enables panning and scaling of the entire tree. Data comes from a JSON file containing the geographic classification of nations.