Choropleth Map
This choropleth map colors countries by their economy classification using a sequential ordinal color scale, with an interactive color legend and hover effects that highlight individual nations. The visualization loads world geometry from a TopoJSON file and joins it with tabular TSV data containing country identifiers and economic attributes. Built with D3 v5, it employs `d3.geoPath` with a natural Earth projection, `d3.scaleOrdinal` for color mapping, and `d3.zoom` for panning and zooming. The SVG rendering includes a custom legend component that updates based on the color scale’s domain.