This example visualizes hierarchical data from a CSV file, plotting `team_score` values for each `team_name` as horizontal bars. The bar chart initially presents a top-level overview, with the ability to drill down into nested categories. The code uses D3 v6 APIs including `create`, `scaleLinear`, `scaleBand`, `axisBottom`, `axisLeft`, `csv`, and `hierarchy` to load external CSV data, construct the scales, and build the interactive, drillable bar chart. The rendering is done via an SVG container, with axes drawn on the left and bottom margins.