This example demonstrates a zoomable and pannable map of U.S. states, where clicking a state smoothly transitions the view to center and scale that state’s bounding box. It shows how to combine free-form zooming and panning with programmatic animated transitions. The visualization uses D3 v3 with the `d3.geo.albersUsa` projection, `d3.geo.path` for rendering GeoJSON features, and `d3.behavior.zoom` for user interaction. Clicking a state triggers a 750-millisecond zoom transition, while a background click resets the view. State boundaries are drawn as a TopoJSON mesh, and the map data comes from a TopoJSON file of U.S. states.