An interactive dendrogram displays a hierarchical breakdown of service quality indicators, with colored horizontal bars representing leaf node values. The visualization uses D3.js v4, specifically `d3.cluster()` for tree layout, `d3.stratify()` for hierarchical data structuring, and `d3.axisTop()` with custom tick formatting. Bars animate in width via SVG `transition()`, while node circles and labels are styled with CSS. Data comes from an embedded CSV file containing indicator IDs and corresponding values.