This example renders a choropleth-style map of California zip code boundaries using SVG. It loads GeoJSON data from a GitHub repository and draws each zip code region as a path with a green fill and black outline. The code uses d3.json and d3.geoPath with a d3.geoMercator projection centered on California, scaling the map to fit the viewport. The visualization provides a static geographic overview of all zip code areas in the state.