This pie chart visualizes expense categories and their corresponding values from a CSV dataset. Using D3.js v7, the chart generates colored slices with SVG paths via `d3.pie()` and `d3.arc()`, with white labels positioned at arc centroids. A legend constructed with SVG rectangles and text displays each category alongside a color scale based on `d3.scaleOrdinal` and `d3.schemeCategory10`. The data is loaded asynchronously with `d3.csv`.