This interactive scatterplot displays air quality index (AQI) values over time, plotting each daily measurement as a point with a fixed size and full opacity. Hovering reveals the exact AQI value via tooltip. The visualization loads daily API data from a CSV file using `d3.csv`, then builds the chart with the vega-lite-api library, which registers Vega and Vega-Lite and renders to SVG. The chart automatically fits the window size and applies custom styling for readability.