This stylized bar chart displays the ten most populous countries in 2020, using a horizontal layout with labels on the left and a proportional population axis on the bottom. The visualization is built with React and D3 v5, where `d3.scaleBand` positions the country categories and `d3.scaleLinear` maps population values to bar widths. The code uses custom React components for the axes and marks, rendering as SVG rectangles with native tooltips. Data loads asynchronously from a CSV file via `d3.csv`, and the axis labels apply a customized tick formatter that converts values into billions.