This stacked bar chart visualizes the estimated religious breakdown of the 20 most populous countries in 2010, with each bar segment representing a religion’s population. Built with D3.js, it uses `d3.layout.stack` for layering, `d3.scale.ordinal` for country positioning, and `d3.legend.color` for the color legend. Hovering over bars triggers tooltips via `d3-tip`, while hovering over the legend highlights specific religions by redrawing foreground bars. Data originates from the Pew Research Center’s Global Religious Landscape, processed via a custom script, and rendered as animated SVG.