This example displays an area graph showing the relationship between sleeping hours and age group count. The visualization uses a smoothed curve to represent the data, with the area beneath the line filled in purple. The chart includes labeled axes for sleeping hours and age group count, with a title and gridlines. The code loads CSV data from a GitHub gist and uses d3.scaleTime, d3.scaleLinear, d3.axisBottom, d3.axisLeft, d3.line, and d3.area with d3.curveBasis to render the SVG graphic.