A horizontal bar chart ranks the 20 best-selling smartphone models by units sold, using a dark theme and brand-based color gradients. Built with React and D3 v6, it loads CSV data, sorts and slices it, then renders SVG bars with hover tooltips, gridlines, and labels. The chart maps model names to the y-axis and units sold to the x-axis, with D3’s `scaleBand` and `scaleLinear` handling layout and `scaleOrdinal` assigning colors.