This example presents a world map rendered with D3 v5 and TopoJSON, using the `geoMercator` projection and `geoPath` to draw country boundaries from the world-atlas countries-110m dataset. The SVG displays oceans in blue and countries in purple, with a hover effect that changes the fill color to pink via CSS. The code loads the TopoJSON data asynchronously with `d3.json`, converts it to GeoJSON using `feature`, and appends each country as a path element.