This example visualizes world population growth from 1000 to 2020 as a smooth, red-filled area chart against a light gray grid. The chart uses D3 v5 with SVG rendering, employing `d3.scaleLinear` for both axes, `d3.area` with `d3.curveBasis` to generate the curved area, and `d3.axisLeft`/`d3.axisBottom` for labeled ticks. Population values are formatted in billions, with the y-axis label rotated vertically and the title centered above the plot. The code loads CSV data asynchronously and applies margins to position the visualization.