This stacked bar chart shows the percentage distribution of marks across five mark ranges for five students, with each bar segment representing a proportion that sums to 1. Designed with D3 v7, the visualization uses `d3.stack()` and `d3.scaleOrdinal()` for color encoding, while `d3.scaleBand()` positions students on the y-axis. Hovering over any segment triggers a tooltip displaying the exact percentage for that mark range, using the `mousemove` event and D3’s formatting helper. The SVG rendering applies custom axis labels and a manual legend, with data loaded from a CSV file.