Fork of World Countries Tree
This visualization displays the hierarchical structure of world countries, organized by continent and subregion, using a horizontal tree layout. The D3.js code employs `d3.tree` and `d3.hierarchy` to compute node positions, `d3.linkHorizontal` to draw curved connecting paths, and `d3.zoom` to enable pan and zoom interactions. Text labels for each country and region are rendered directly in SVG, with font sizes decreasing by depth level. Data comes from the included `data.json` file, which nests countries geographically.