This visualization shows the population of each country, broken down by religion, using a stacked bar chart. Each bar represents a country, sorted by total population, with colored segments for different religions and tooltips revealing exact population values. It is built using the Vega-Lite API, where the chart specification is defined programmatically via `vl.markBar()` and encoding methods. The underlying data is fetched as CSV using `d3.csv` from a remote gist, and the final visualization is rendered as an SVG canvas using the `vega` renderer.