A choropleth map of Slovakia shows the spread of COVID-19 infections by district, with red circles scaled by the number of diagnosed cases as of March 16, 2020. The map uses D3 v5 with `geoMercator` projection, `geoPath` for rendering district boundaries from TopoJSON data, and `scaleLinear` for circle sizes. A size legend and total case count are displayed, and the map supports zoom and pan interactions.