This fork of the D3 zoomable sunburst visualizes the hierarchical flare dataset, displaying nested categories and their values as concentric rings. Users can click arcs to zoom and explore the tree structure. The code uses D3 v5 libraries, including `d3.hierarchy`, `d3.partition`, and `d3.arc`, to generate the interactive graphic. It loads data from a local `flare.json` file and obtains arc color values from the included `styles.css`. The example demonstrates adapting an Observable notebook to a standalone vanilla JavaScript `index.html` file, using methods like `d3.select` and `d3.style` for styling and interaction.