This interactive stacked bar chart visualizes religious populations across countries using data from the OSMI Mental Health in Tech Survey 2018. It renders horizontal bars with SVG and d3.svg.axis, color-coded by religion via d3.scale.category10. A d3.legend.color legend supports hover interactions: selecting a religion fades the base bars with an overlay rect and re-renders only that layer using d3.layout.stack. d3-tip displays tooltips showing exact population values on hover.