This area chart shows world population growth by year, using a smooth filled curve to emphasize the upward trend. It loads data from a CSV and renders to SVG with D3 v6, using `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, and the `area` generator with `curveBasis`. Grid lines are drawn via axis tick sizes, and population labels are formatted using the `format` function to convert billions. The chart includes a rotated y-axis label and a title, styled with CSS.