An interactive donut chart displays the market capitalization of top Chinese companies on US exchanges, grouped by sector. Clicking a slice or legend item filters the chart to that industry, while a summary panel and tooltips reveal company-level details like IPO year and growth. Built with React and D3 v7, the visualization uses `pie()`, `arc()`, and `scaleOrdinal` for layout and coloring, with `ResizeObserver` for responsive sizing. Data is loaded from a CSV file via `d3.csv`.