This pie chart shows the proportion of total sales by product category, with labels on each slice and a legend to the side. It uses D3 v7’s `d3.rollups` to aggregate sales per category and `d3.pie` to generate arcs, while `d3.scaleOrdinal` assigns colors. Each slice’s centroid is computed with `d3.arc.centroid` for label placement, and the SVG is rendered from CSV data.