Fork of World Countries Tree
This visualization displays a hierarchical tree of world countries, organized by continent and then by subregion. It shows the structure of geographic classification from the root "World" down to individual nations. The visualization is built with D3 v5, using the `tree` and `hierarchy` layout functions to compute positions, and `linkHorizontal` to draw connecting paths. Node labels are rendered as SVG text elements, with font size scaling based on depth in the hierarchy. The JSON data source contains the country groupings, and the view supports zooming via D3's `zoom` event handler.