World Countries Tree
This visualization displays the hierarchical structure of world countries, organized by continent and subregion. It uses a tree layout with horizontal links connecting parent and child nodes, rendered as SVG paths and text labels. The code employs D3 v5’s `tree`, `hierarchy`, and `linkHorizontal` functions to compute positions and generate curved paths, with `zoom` enabling interactive panning. Country names appear with font sizes scaled by depth from `data.json`, which groups nations under regions like Southern and Western Asia, making the geographic taxonomy easily explorable.