This visualization presents a stacked bar chart of mobile operating system market share across five global regions, with Android, iOS, and Other segments summing to 100% per region. It uses D3 v7 to load CSV data via `d3.csv`, stack series with `d3.stack`, and scale values with `d3.scaleLinear` and `d3.scaleBand`. Rectangles are colored using `d3.schemeSet2`, and hover interactions display segment percentages through a custom tooltip. The SVG rendering features labeled axes with percentage tick formatting.