This example shows an interactive bar chart with multiple data series that can be toggled between grouped and stacked layouts via radio-button style controls. Additional buttons allow users to show or hide individual series. The visualization uses D3 v6 with SVG rendering and animated transitions, employing `d3.stack` to compute stacked values and `d3.scaleBand` and `d3.scaleLinear` for positioning. Data is generated procedurally using smooth random bumps, and mouseover interactions display tooltips with precise values.