This map visualizes global happiness index levels using a choropleth world map. It colors each country based on its happiness score, with a blue color scale representing ranges from roughly 4.0 (India) to 7.8 (Finland). The visualization is built using D3.js and relies on TopoJSON data from the world atlas for country boundaries, loaded via the `topojson-client` library. The map uses the `d3.geoNaturalEarth1` projection and `d3.geoPath` to render the country shapes. A custom tooltip displays each country’s name and happiness score on mouse hover.