D3 Practice - Animated Bar Chart
Eight vertical bars represent a fixed dataset of eight values at the start height of the chart. Upon loading, the bars animate upward via staggered delays and varied durations, with bars over the 300 threshold turning red while the others remain blue. The visualization uses D3 v4 with `d3.scaleBand` and `d3.scaleLinear` for positioning, and `transition().duration().delay()` for the animation, rendering as SVG rectangles within an axis-labeled coordinate system.