This example shows the distribution of car classification categories (unacc, acc, good, vgood) as a pie chart with a legend. It uses D3.js to load CSV data, compute category counts, and render the chart as an SVG via `d3.pie()`, `d3.arc()`, and `d3.scaleOrdinal()` for color mapping. Percentage labels are placed on slices using a separate arc for label positioning, and the legend lists each category with its count.