KeelrLeek
67d98dfe79
The content fade mask on .scrollbody lives in the scrolling element's local box, so its cut stop (--flow-cut) must ride scroll to stay at a fixed screen line. Driving that from heroScroll's rAF lagged the native compositor scroll by a frame on fast flicks, so the cut slid up and rows briefly showed above where they should clip (user-reported). Move --flow-cut to a CSS scroll-driven animation (@property + @keyframes + animation-timeline: scroll(nearest block), @supports-gated), so it's a pure function of scroll position evaluated on the compositor and can't lag. The keyframe delta and animation-range share one oversized constant (100000px) so the value is base + scrollTop for ANY scroll distance — necessary because the artist page changes its own content height as it scrolls, making the total range non-constant. apply() keeps the per-frame path only as the unsupported-engine fallback. Verified live: screen cut constant at 217px across scrollTop 300..2500, --flow-cut == base+scrollTop exactly.