This choropleth map visualizes the percentage of adults with a bachelor’s degree or higher across U.S. counties, using a blue sequential color scale with a legend. It renders SVG paths via `d3.geoPath` and TopoJSON data from `us-10m.v1.json`, while county values are loaded from `education.csv` and mapped with `d3.map`. The color scale employs `d3.scaleThreshold` and `d3.schemeBlues[9]`, with county tooltips showing exact percentages and state boundaries drawn as white strokes.