This choropleth map visualizes world GDP per country using a blue sequential color scale, where darker shades denote higher GDP values. Built with D3 v7, it renders geographic boundaries as SVG paths via `d3.geoPath` and a Natural Earth projection, then maps GDP data from a Plotly-hosted CSV to each country's fill color. Country shapes come from the world-atlas TopoJSON, processed with `topojson-client`. The map includes a title and uses a simple index-based data-to-feature mapping.