This stylized bar chart displays the top 10 most populous countries using a horizontal layout with teal bars, a clean grid, and a Poppins font. It loads population data from the United Nations World Population Prospects 2019 via `d3.csv`, formats axis labels with `d3.format` to show values in billions, and includes a hover tooltip. The chart is built with React components that render SVG elements, using `d3.scaleBand` for the categorical y-axis and `d3.scaleLinear` for the numeric x-axis.