` * containing one `

` per marker. Each entry * carries `--callout-line` (post-strip 1-based line) and * `--callout-listing-lines` (the pre's total line count). * * The em-based formula was load-bearing on a fragile assumption: * that the overlay's per-line height (1.5em at 0.875em font) matches * the rendered pre's per-line height. mdbook's pre uses * `line-height: normal` (~1.13 for monospace), so the assumed 21px * was off from the true ~18px by 3px per line. For a 600-line diff * the cumulative drift pulled badges 1800px above their intended * line — landing inside whatever sibling pre happened to sit there. * * Fix: an inline `