D3 v5 Zoomable Sunburst
This zoomable sunburst visualizes the structure of a hierarchical dataset, using nested arcs to represent the flare data from Observable’s `@observablehq/flare` library. Each level of the hierarchy is depicted as a ring, with arc segments sized proportionally to the data values. Clicking on a segment triggers an animated transition using `transition.attrTween` and `d3.interpolate` to smoothly re-center the view on that node, showing its children in greater detail. The visualization is rendered with SVG inside a circular partition layout, and the code uses `d3.hierarchy`, `d3.partition`, and `d3.scaleOrdinal` with the `interpolateRainbow` color scheme to distinguish top-level categories.