This bar chart visualizes COVID-19 case counts across four quarterly periods, with bars animating upward from the baseline on load. The color scale transitions from light teal to dark green based on count magnitude, and axes display tick labels for both quarters and case numbers. Built with React and D3 v5, it uses `d3.scaleBand` for the x-axis, `d3.scaleLinear` for the y-axis and color encoding, and SVG `rect` transitions (via `transition().duration().delay()`) to animate bar growth. Data is hardcoded in the React `useEffect` hook.