This map visualization displays world countries as filled green regions on a blue sphere, rendered entirely with SVG. It loads geographic data from the World Atlas TopoJSON file using `topojson.feature` to extract country boundaries, then projects them with a Mercator projection via `d3.geoMercator` and `d3.geoPath`. The code appends a sphere outline path and draws each country as a separate `path` element, with styling applied through CSS classes for fill and stroke.