Let's make a map with D3.js and add interaction
This example displays an interactive world map with D3.js, rendering countries as green SVG paths with black outlines over a black sphere. Hovering a country turns it dark red. It uses `d3.geoPath` with `d3.geoNaturalEarth1` for projection, `d3.zoom` for pan and zoom, and `topojson.feature` to convert TopoJSON data from the world-atlas package. Country names come from a TSV file linked by ISO code, shown as tooltips via SVG `<title>` elements.