World Countries Tree
This tree visualization maps the hierarchical structure of world countries, grouping them by continent and subregion. The data, loaded from a JSON file, is rendered as an indented tree with connecting paths, where each node's font size decreases with depth. The visualization uses D3's `tree` layout, `hierarchy` for data structuring, and `linkHorizontal` for path generation, all rendered as SVG within a zoomable interface.