A horizontal bar chart displays the population of the world's 10 most populous cities, using a pink background and steel-blue bars. The visualization ranks cities like Tokyo, Delhi, and Shanghai, with the x-axis formatted to show population figures with billion abbreviations. The chart is built with D3 v5, using `scaleLinear` for the x-axis, `scaleBand` for the y-axis, and `axisBottom` and `axisLeft` for the axes. Data is loaded from a CSV file and styled using external CSS.