World Countries Tree
This interactive treemap displays the hierarchical organization of world countries, starting with continents at the root and branching down through regions to individual countries as leaves. Built with D3 v5, the visualization uses a horizontal tree layout with curved links connecting parent and child nodes. The code employs `tree()`, `linkHorizontal()`, and `zoom()` APIs from the D3 framework, rendering nodes as text labels positioned along the hierarchy while SVG paths draw the connecting branches. Data is loaded from a local JSON file containing the country categorization structure.