This example displays a horizontal bar chart of the top 10 most populous countries, with population values formatted in billions using the `d3.format` API. The chart customizes both axes by removing default domain lines and tick marks, adding a label for the population axis, and using a `scaleBand` for countries and a `scaleLinear` for populations. Data is loaded from a CSV file and rendered as SVG elements, with axis ticks styled through CSS.