This visualization presents a hierarchical tree of world countries, organized by continent and subregion, with each leaf node labeled with its full country name. The tree layout uses an indented horizontal structure, with links drawn as smooth curves and text sized inversely to depth, so deeper nodes appear smaller. Built with D3 v6, the code employs `d3.hierarchy`, `d3.tree`, and `d3.linkHorizontal` to compute and render the layout as SVG paths and text elements. The chart also implements `d3.zoom` for pan and zoom interaction on the viewport.