This interactive map displays world countries using a natural Earth projection rendered as SVG paths. Users can pan and zoom the map via D3’s `zoom` behavior, which applies transforms to a group element. Country boundaries come from TopoJSON data, with names joined from a TSV table using `reduce`. Hovering highlights a country in red, while the background sphere is colored blue. The code leverages `d3.geoPath`, `d3.geoNaturalEarth1`, and topojson’s `feature` method to generate the geographic shapes.