This choropleth map visualizes COVID-19 deaths per million across 20 countries, with a red sequential color scale ranging from light to dark based on mortality rates. The map uses a Robinson projection via `d3.geoRobinson` and renders country boundaries as SVG paths through `d3.geoPath`, with a tooltip revealing the country name and death rate on hover. Geographic data comes from the world-atlas TopoJSON file, joined to the CSV dataset by ISO_A3 codes, and a linear gradient legend with an axis labels the color scale.