This pie chart visualizes the top 10 countries by average Air Quality Index (AQI) from a CSV file. Each slice represents a country, with its name labeled inside. A legend on the left lists each country with its corresponding AQI value, using colors from the `d3.scaleOrdinal` and `d3.schemeSet3` palette. The chart is rendered as an SVG using `d3.pie` and `d3.arc` to compute slice geometries, and `d3.csv` to load and parse the data.