This example displays a choropleth map of China’s provinces, colored by economic group using an ordinal color scale from `d3.scaleOrdinal` and `schemeSpectral`. It renders geographic boundaries with `d3.geoPath` and a natural Earth projection, and supports interactive pan and zoom via `d3.zoom`. A legend, built with custom SVG circles and text, shows category colors. Province data comes from a local `chinaMap.json` file, with additional metadata merged from a TSV source.