World Countries Tree
This visualization presents the World Countries Tree, a hierarchical diagram that organizes every country into its corresponding continent and subregion. The tree uses a vertical layout, with the root node "World" branching into continents like Asia and further into regional groupings and individual countries. Built with D3.js v5, the example employs the `tree` and `hierarchy` layout functions, rendering links as SVG paths and labeling nodes with text elements. Pan and zoom interactions are supported via the `zoom` behavior, and the data is loaded from a local `data.json` file.