This chart visualizes sales data grouped by item type, with each bubble’s size representing total units sold and its color indicating the product category. Hovering over a bubble reveals a tooltip with the exact category and unit count. Built with React and D3 v7, the code rolls up the CSV data, applies an ordinal color scale, and uses `d3.pack()` to generate a circular treemap layout. All circles and labels are rendered as SVG elements, and a custom `wrap()` function formats the category names.