This interactive stacked bar chart visualizes gender distribution across Chinese provinces, with controls to toggle between raw counts and percentage-of-total values. The visualization uses D3.js v3, loading province and gender data from CSV files and animating transitions between the two display modes via `transition()` calls. The chart resets the stack layout's offset between "zero" and "expand" to switch counting methods, while axis tick formats change accordingly. A custom legend maps categorical colors to gender segments, and hover effects reduce rectangle opacity for emphasis.