This visualization presents a world countries dataset as an interactive tree diagram, where each node reveals nested categories and numeric labels. The hierarchical layout renders horizontal links with curved paths, while text size scales with depth. Built with D3 v5, it uses `d3.tree`, `hierarchy`, and `linkHorizontal` to generate the SVG path geometry. The entire chart rotates 90 degrees via an SVG transform, and `d3.zoom` enables pan and zoom interactions. Country names are omitted, leaving only coded identifiers and hierarchical structure.