This visualization shows the religious composition of the 20 most populous countries using stacked horizontal bars, where each bar segment represents a religion’s population share. A color legend allows hovering to highlight specific religions, while tooltips display exact population values. Built with D3 v3, it uses d3.layout.stack, d3.scale.ordinal, and d3.legend for the interactive color key, with SVG rendering and animated transitions triggered by legend hover states.