This example presents an interactive world map built with D3.js and the TopoJSON library, using the `d3.geoPath` and `d3.geoNaturalEarth1` projection to render countries from the World Atlas dataset. Hovering over a country highlights it in red, and a click permanently changes its fill to brown while increasing the stroke width, demonstrating simple CSS-based interaction tricks for selection feedback. The SVG rendering employs a light blue sphere background and light green countries with black borders.