This example displays a world map using an equirectangular projection, with countries rendered as purple filled shapes outlined in yellow. It uses D3 v5’s `d3.geoPath` and `geoEquirectangular` to draw the geographic features, while TopoJSON’s `feature` method extracts country geometries from the world-atlas dataset. The sphere background is blue, and hovering over a country changes its fill to green, implemented via a CSS `:hover` rule on SVG path elements.