This choropleth map visualizes total COVID-19 cases by country, using a spectral color scale to encode case counts on a natural Earth projection. The map supports pan and zoom via d3.zoom, with tooltips showing country names and case values. It renders with d3.geoPath and TopoJSON world data, while a custom color legend built with D3 scales displays the ordinal color mapping. The data is loaded from a TSV file joined to country geometries.