A choropleth map displays world countries colored by their economy category, which can be interactively filtered by clicking entries in an adjacent color legend. The map renders geographic boundaries using `d3.geoPath` with a `geoNaturalEarth1` projection, and supports panning and zooming through `d3.zoom`. Clicking a legend item, built with `d3.scaleOrdinal` and `schemeSpectral`, dims non-matching countries while highlighting the selected group. The data comes from the world-atlas TopoJSON and TSV files, with the visualization built using D3 v5 and SVG.