This visualization shows the hierarchical structure of world countries, organized by continent and subregion, as a node-link tree diagram. Built with D3 v5, it uses the `d3.tree` layout and `d3.hierarchy` to process the JSON data, while `d3.linkHorizontal` generates the curved connection paths. Text labels display each country with font sizes scaled by node depth, and the interaction model adds panning and zooming via `d3.zoom`. The SVG rendering employs the margin convention and a custom font, with subtle text shadows for readability.