This visualization displays a world map using an equirectangular projection, with white countries on a light blue ocean background that change to green on hover. The geographic data is loaded from the world-atlas countries-50m.json dataset and converted from TopoJSON to GeoJSON using the `feature` method. The map is rendered as SVG paths via D3’s `geoPath` and `geoEquirectangular` projection functions, with styling controlled by CSS selectors for the earth and country layers.