This pie chart visualizes the distribution of horsepower across car models from a CSV dataset loaded via `d3.csv`. Each slice is rendered using `d3.pie` and `d3.arc` in an SVG, with labels positioned along an outer arc. Hovering a slice triggers a tooltip showing the model, horsepower value, and percentage of total. A color-coded legend, built with `d3.scaleOrdinal` and the Tableau10 scheme, accompanies the chart.