This D3.js v7 example visualizes Hyundai sales data over time as a smooth, sky-blue area chart. The code loads CSV data from a GitHub gist, parses the year and sales values, and renders the chart into an SVG element. It uses D3's `scaleTime` and `scaleLinear` for axes, `axisBottom` and `axisLeft` for the gridlines, and the `area` generator with `curveBasis` to create the filled curve. The chart displays sales on the y-axis and time on the x-axis, with tick labels and lines styled via CSS.