This interactive tree diagram displays the hierarchical structure of world countries, organized by continent and subregion, with each country name rendered as a text label sized inversely to its depth. Built with D3 v5, it uses the hierarchy and tree layouts to compute node positions, and linkHorizontal to draw the curved connecting paths. The SVG visualization supports pan and zoom through d3.zoom, applying transforms to the group containing all elements. Data is loaded from an external JSON file, with styling provided by custom CSS including a serif font and text shadows.