This interactive donut chart visualizes income sources (Sales, Dividends, Interest) from a CSV file, with each slice’s arc length proportional to its amount. Hovering a slice reveals a tooltip showing its percentage of the total, computed via `d3.sum`. Built with D3 v5, it uses `d3.pie`, `d3.arc`, and `d3.scaleOrdinal` for coloring, and renders as SVG with hover effects and a styled tooltip.