Fork of World Population Area Chart
This area chart visualizes world population growth over time, using a filled path to show the increasing trend. The SVG rendering relies on D3 v5 APIs including `scaleTime`, `scaleLinear`, `area`, and `curveBasis` to generate the smooth curve, with `axisLeft` and `axisBottom` providing labeled axes. Population data is loaded from a CSV file via `d3.csv`, parsed into numbers and Date objects, and styled with custom CSS classes. The chart includes a title, axis labels, and a custom tick formatter that abbreviates billions as "B".