This map visualization displays the world’s countries by using a Mercator projection to render geographic features as filled SVG paths on a light gray sphere background. The code loads country boundaries from the world-atlas TopoJSON dataset and converts them to GeoJSON with `topojson.feature`, then draws each country using `d3.geoPath`. Styling applies a blue fill with dark strokes and a subtle opacity, while the hidden overflow and full-bleed body create an immersive, full-window presentation.