This choropleth map visualizes confirmed COVID-19 cases per country over time, with each nation’s cumulative case count encoded by color on a natural Earth projection. Clicking a legend entry highlights matching countries and dims others, while a zoom interaction allows panning and scaling the SVG map. The visualization uses d3.geoPath and d3.geoNaturalEarth1 for geographic rendering, d3.scaleOrdinal with schemeSpectral for the color scale, and d3.zoom for interactivity. Data comes from a CSV file containing daily case counts from January through June 2020, joined with world topology from TopoJSON via d3.csv and topojson.feature.