A horizontal dendrogram visualizes the hierarchical structure of world countries, organized by continent and region. The tree layout is generated with `d3.tree` and rendered as an SVG using `d3.linkHorizontal`, with nodes labeled by country name. The chart supports zooming and panning via the `d3.zoom` event, which transforms the SVG group. Text labels are styled with a serif font and a white text-shadow for readability. The data is loaded from a JSON file containing the geographic hierarchy.