A map of the world is drawn as a natural Earth projection, with countries filled in light green against a dark blue sphere background, using SVG paths. The example loads GeoJSON data from the world-atlas TopoJSON file via `d3.json`, converts it with `feature` from TopoJSON, and renders it using `d3.geoPath` and `d3.geoNaturalEarth1`. The sphere and country outlines are styled through CSS classes, demonstrating a basic D3.js choropleth setup.