This zoomable sunburst chart visualizes hierarchical data, displaying restaurant categories (fast food, pizza, Mexican, etc.) across multiple cities, with each arc segment representing a portion of the total. The visualization uses D3 v5's hierarchical layout and partition functions to compute the arc geometry, rendering the sunburst as SVG paths with animated transitions. Clicking on a segment zooms into that subtree, using `d3.interpolate` and `transition.attrTween` to smoothly animate the arc angles and radii. The data originates from the Observable `@observablehq/flare` dataset, loaded dynamically via the Observable standard library's `require` function.