This interactive treemap visualizes steel scrap trade values between the United States and its partner countries, filtered by import or export direction. Users can toggle between these flows and select a specific region, which aggregates data by partner country using d3.hierarchy from the CSV dataset. The visualization uses d3.treemap to layout cells, with a sequential color scale mapping value magnitude from lightblue to darkblue. Clicking a country cell drills down to reveal commodity-level details, while the reset button restores the aggregated country view.