This example shows a zoomable world map where clicking a country highlights it in pink, demonstrating unidirectional data flow through a simple render function. Built with D3 v5, it uses `d3.geoNaturalEarth1` and `d3.geoPath` to project and draw country boundaries from TopoJSON data loaded via `d3.json`, with country names from a TSV file. The view updates through an `onClick` handler that toggles a CSS class, while `d3.zoom` applies pan and zoom transformations to the map group.