This visualization shows the hierarchical organization of world countries, grouped first by continent and then by subregion, with each country displayed as a leaf node. The tree layout positions nodes horizontally, and text size decreases with depth to emphasize the structure. Built with D3 v5, it uses `d3.tree`, `d3.hierarchy`, and `d3.linkHorizontal` to compute and draw the connections as SVG paths. Pan and zoom interactions are enabled via `d3.zoom`, and the data is loaded from a local JSON file structured with nested children arrays.