A world map displays countries as green filled polygons with black strokes on a sky blue circular backdrop. The visualization loads geographic data from a local `worldmap.json` TopoJSON file and projects it using the Natural Earth projection. D3 v5’s `select`, `json`, `geoPath`, and `geoNaturalEarth1` APIs, combined with TopoJSON’s `feature` method, render the country boundaries as SVG paths within a 960 by 500 pixel viewport.