This visualization displays the hierarchical structure of world countries, organized by continent and subregion, as a horizontal tree diagram. The data is sourced from a JSON file representing countries by geographic region. Using d3.js v5, the layout is computed with `d3.tree` and `d3.hierarchy`, with links drawn via `d3.linkHorizontal`. Each country name appears as text, with font size scaling by depth. The SVG rendering supports zoom and pan through a `d3.zoom` interaction, allowing exploration of the full tree. Text styling uses the Playfair Display font, with white shadows for legibility.