This example displays a world map using a natural Earth projection, with each country filled in light green and outlined with a semi-transparent black stroke. It loads geographic data from the world-atlas TopoJSON dataset and joins the country names from the corresponding TSV file using a `reduce` operation. The visualization demonstrates simple hover interaction, as the CSS `:hover` selector changes the fill color to orange. The code uses `d3.geoPath` and `d3.geoNaturalEarth1` to generate the SVG paths, with the sphere rendered in dark blue.