This example visualizes a world map using D3.js with multiple map layers. It renders a blue sphere background and green country polygons with black borders using SVG paths, projected through the Natural Earth projection. The code uses `d3.geoPath`, `d3.geoNaturalEarth1`, and the `topojson` library’s `feature` function to convert TopoJSON data from the world-atlas package. Country boundaries are drawn from the 110m resolution dataset, and the map is currently static with no interaction.