This interactive bar chart visualizes the total number of illnesses from national foodborne disease outbreaks over time, with bars segmented by primary mode of contamination. The visualization uses the Vega-Lite API with reactive Vega and Vega-Lite specifications, rendered as SVG. Data is loaded dynamically from a CSV file using D3’s `csv` function, then filtered to remove null primary modes. The chart adapts to the browser window size via `.autosize()`, and custom configuration settings adjust axis labels and tick styling. Tooltips are enabled through the Vega-Tooltip handler.