This visualization displays car fuel economy data as a horizontal bar chart, with each bar colored on a blue sequential scale according to its miles-per-gallon value. The visualization loads data from a CSV file and renders animated bars that grow from zero width, using d3.scaleBand and d3.scaleLinear for positioning and a d3.scaleSequential with d3.interpolateBlues for color encoding. It includes a color legend built with d3-legend and a linear gradient, plus interactive tooltips and value labels shown via d3 transitions.