This example shows a zoomable natural Earth projection map where hovering over any country turns it crimson. The visualization loads world country boundaries from a TopoJSON file via d3.json, then renders them as SVG paths using d3.geoPath and d3.geoNaturalEarth1. Interaction comes from d3.zoom, which applies a transform to a group element, while CSS :hover rules change country fill colors. The map also includes a blue sphere backdrop drawn from a GeoJSON sphere object.