This pie chart visualizes the distribution of depression scores across sleep-pattern categories, showing how total depression values are partitioned into groups defined by hours of sleep. The visualization uses D3 v7’s `pie`, `arc`, `scaleOrdinal`, and `rollup` functions to aggregate and encode the data, with interactive hover tooltips and a static legend displaying category percentages. The underlying data comes from a CSV file of student grades and mental health, loaded via `d3.csv`.