World Countries Tree
This visualization displays a hierarchical tree of world countries organized by geographic regions, rendered as an SVG using d3.v5. The tree layout employs `d3.tree` and `d3.hierarchy` to structure the data, with `d3.linkHorizontal` drawing curved paths between parent and child nodes. Text labels vary in font size based on depth, and users can pan and zoom the entire view via `d3.zoom`. The example loads data from a JSON file and is presented as a static, interactive diagram.