This example shows the top 10 most populous countries from the 2018 United Nations World Population Prospects estimate as a horizontal bar chart, using population values multiplied by 1,000. It highlights how to customize D3 v5 axes, including removing axis frames, adjusting tick marks, and formatting tick labels to convert G (giga) to B (billion) with `format('.3s')`. The chart is rendered as SVG using `d3.scaleLinear` and `d3.scaleBand`, with styles for tick text, lines, and title defined in CSS.