Sequences sunburst
This sunburst chart visualizes sequences of user actions on a website, showing the hierarchical flow of steps from "home" to "product," "search," "account," and other categories. Hovering over a segment fades all unrelated paths and displays the percentage of total visits that sequence represents in a breadcrumb trail. Built with d3.v4, the visualization uses `d3.partition()`, `d3.arc()`, and `d3.hierarchy()` to compute the radial layout from CSV data. The code also includes an animated transition that restores full opacity over one second when the mouse leaves the chart.