This example features an interactive donut chart that visualizes categorical data. The visualization uses D3.js to render the chart, computing arc segments from the data values and applying a color scale to differentiate categories. Hovering over a segment triggers a CSS transition that highlights the slice, while a tooltip dynamically displays the segment name and its corresponding count. The code builds the SVG elements using `d3.arc` and `d3.pie` for the angles and paths, and the dataset is an array of named numeric categories.