This example visualizes religious demographics across countries using a stacked bar chart, where each bar represents a country and colored segments show population counts by religion. Clicking a bar highlights it with a black stroke. The visualization processes CSV data with D3's `group()` and `stack()` functions to create stacked series, rendered as SVG rectangles with `scaleBand` for the x-axis and `scaleLinear` for the y-axis. Built with React and D3 v7, it uses imperative D3 joins within React components for rendering.