This visualization displays yearly GDP in billions of dollars, with time on the x-axis and GDP on the y-axis. A thick black line with a green area underneath represents the trend over time, using a basis curve for smoothing. The chart is rendered as SVG using D3 v5, employing `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, `line`, and `area` generators. Data is loaded as CSV from a GitHub gist, with axes styled via external CSS.