This example visualizes a world map with dark blue oceans and light green countries, using a natural Earth projection. It renders SVG paths for the sphere and country borders, with semi-transparent black strokes on the countries. The code uses D3 v5 functions like `d3.select`, `d3.json`, `d3.geoPath`, and `d3.geoNaturalEarth1`, alongside the topojson library’s `feature` function to process GeoJSON data from the world-atlas package.