This interactive world map visualizes the cost of living index by country, using a red-to-blue color gradient where blue indicates higher costs. Hovering over a country reveals its name in green text. The visualization uses D3.js with `geoNaturalEarth1` projection and `geoPath` to render map features from TopoJSON data, while a sequential color scale maps the index values. The cost of living data is loaded from a local CSV file.