This interactive choropleth map shows world countries colored by name, with a clickable legend that filters the map to highlight a selected country while dimming others. The visualization uses D3 v5 with `geoNaturalEarth1` projection and `geoPath` for rendering countries, and `d3.zoom` for pan and zoom. Data combines CSV attributes with TopoJSON country boundaries, while the ordinal color scale uses `schemeSpectral`. Clicking a legend item toggles the filter, adjusting opacity and stroke width for highlighted countries.