This interactive grouped bar chart displays the number of students per grades (A, B, C) across different depression levels, using data from a CSV file on student grades and mental health. The visualization uses D3.js v7 and the `d3.scaleBand`, `d3.scaleLinear`, and `d3.axisBottom` APIs for layout. Bars animate in on load via the `transition` method, and hovering reveals a tooltip with exact counts. A clickable legend toggles grade visibility by adjusting bar opacity.