A stylized horizontal bar chart displays the top 10 most populous countries, using length-encoded bars sorted by population value. The visualization, rendered as SVG within React, uses `d3.scaleBand` for the categorical y-axis and `d3.scaleLinear` for the numeric x-axis, with tick labels formatted using `d3.format` to abbreviate large numbers. The chart loads data from the United Nations World Population Prospects 2019 dataset, applying custom CSS styling to the axis ticks and marks.