The quote grid reflows into N columns via auto-fill, so the real page gets ~1/N as tall. This prototype makes the minimap detect the live column count and redraw itself as the same N-column shape — restoring correct proportions and parallax. Drag the width slider (or resize your window) and watch the minimap follow.
What to try: drag the width slider from right (1 column → tall document, minimap is a single strip) to left (5+ columns → the document shortens and the minimap redraws into that many mini-columns). Toggle Single-column (current) to see today's behaviour for the same layout — note how the viewport box shrinks and parallax over-scrolls once the page goes multi-column, because the map still thinks the doc is tall. Click anywhere on the minimap to jump; drag the blue box to scrub. The detected count comes from reading getComputedStyle(quoteGroup).gridTemplateColumns — exactly what the shipping code will do.