A bar chart shows the average daily screen time in hours for each app category, sorted from highest to lowest, based on a digital usage dataset loaded from a CSV file. Each bar is rendered as an SVG `rect` with a rounded corner, and the average value is labeled above each bar. The chart uses D3 v7 APIs including `d3.rollup` to aggregate data by category, `d3.mean` to compute averages, and `d3.scaleBand` with `d3.scaleLinear` for axes, with horizontal gridlines and axis labels.