This example shows the hierarchical structure of world countries organized by continent and subregion as a horizontally laid-out tree diagram. The visualization uses D3 v5’s `tree` layout and `linkHorizontal` path generator to draw the branching links, with each country name rendered as text at varying font sizes based on depth. The data comes from a local `data.json` file, and the entire SVG viewport supports pan and zoom through D3’s `zoom` behavior. Styling applies a green stroke to the links and a serif font with white text shadows for readability.