This visualization uses a treemap layout to display monthly household expenses, organized by spending category (vaste lasten, reserves, and huishoudelijke uitgaven) with numeric values from a CSV file. The code employs d3.stratify to build a hierarchy from the flat data, then d3.treemap to compute rectangle positions and sizes. Each leaf is rendered as a green SVG rectangle with a white text label showing the category name, using D3 v5 within a React framework. The chart uses a fixed 960×500 SVG canvas.