No D3, no Chart.js — just scales, axes, ticks and gridlines computed by hand. Edit the data and the whole chart recomputes. This is everything a charting library does for you.
One label,value pair per line. The y-scale, ticks and bars all derive from your numbers.
Hover a bar to highlight. Resize the window — the chart is responsive because the SVG scales with its viewBox, while strokes stay crisp.