This example demonstrates a zoomable, interactive world map rendered as an SVG, where hovering over individual countries changes their fill color from light green to red. The visualization uses the `d3.geoPath` and `d3.geoNaturalEarth1` projection to draw country polygons from a TopoJSON file (world-atlas countries-50m). Additionally, it integrates the `d3.zoom` module to enable pan and zoom via mouse events, with the `d3.event` handler updating the map's transform on each zoom action. The sphere background and country paths are styled via CSS classes.