This fork of the Infection Type Chart visualizes stacked bar counts of infection types—Unknown, Social, Relative, Travel—across Chinese provinces, with an animated toggle between absolute case numbers and percentage shares. Using D3 v3 with SVG, it employs `d3.layout.stack` to arrange the series and transitions to update bar geometry and axes on user input. The chart sorts provinces alphabetically, rotates x-axis labels, and includes a hand-built legend and hover tooltip styling from `styles.css`.