This treemap visualizes hierarchical education data, using nested rectangles sized proportionally to category values. Rendered as an animated SVG, the chart relies on D3’s `treemap` layout to compute the tile geometry, with transitions smoothly resizing groups when the view changes. The code explicitly sets an SVG container and applies `d3.hierarchy` to structure the nested data, while CSS styling controls the background. The visualization updates live, with labels and colored tiles clarifying the hierarchy. Data originates from a gist, and the animation demonstrates the treemap’s reflowing behavior.