This example displays a world map using D3 version 5 and the TopoJSON library. It renders each country as a white SVG path with black outlines on a green background. The map uses the `d3.geoNaturalEarth1` projection and the `d3.geoPath` API to draw geographic features. Country boundaries come from the world-atlas countries-110m.json dataset, processed with TopoJSON's `feature` function.