This example shows a stacked bar chart comparing values across three groups, with each bar subdivided into three colored segments representing different subgroups. The chart reads data from a CSV file hosted on GitHub, parsing it with `d3.csv` and mapping groups to the x-axis and numeric values to the y-axis. It uses `d3.scaleBand` for both group and subgroup positioning, `d3.scaleOrdinal` for the categorical color palette, and `d3.axisBottom` and `d3.axisLeft` to render the axes. The SVG output is built via D3's selection and append methods, with each group translated into position and rectangles drawn per subgroup.