A choropleth map of global economies color-coded by development category, with an interactive legend that filters highlighted countries by clicking category swatches. Built with D3 v5, it combines `d3.geoNaturalEarth1`, `d3.geoPath`, and `d3.zoom` for panning and zooming the SVG-rendered map, while `d3.scaleOrdinal` and `schemeSpectral` assign colors from world-atlas TopoJSON data. Clicking a legend item dims non-matching countries and toggles the selection; tooltips show country names and values via SVG `<title>` elements.