This example shows a horizontal bar chart of population by country, using a blue gradient fill for the bars and a custom orange-to-red gradient for axis tick labels. The visualization demonstrates axis and scale customization with d3.scaleLinear, d3.scaleBand, d3.axisLeft, and d3.axisBottom, including formatted tick labels (e.g., converting "G" to "B" for billions) and extended tick lines. Data is loaded from a CSV file via d3.csv, with population values multiplied by 1000 during parsing. The SVG rendering applies margins, a title, and axis labels through d3 selections and SVG attributes.