Fixture P06: the original component below. Steps are a procedure, not completed test results.
Reload and record selected mode/support plus reader position. Focus reader with Tab; use ArrowDown/PageDown/End and record scrollTop plus bar transform, then Home. CSS mode should change the decorative bar with actual position.
Activate Go to arrival and Return to departure links with keyboard; record positions. Focus nested Packing list and scroll using native wheel/trackpad UI or keyboard; record nested and reader positions separately. Do not claim physical touch or boundary chaining unless observed.
Choose Scroll listener fallback using the native select; scroll reader to mid/end/start with keyboard and read inline/computed transform. No performance claim from matching progress.
Choose No effect; bar hidden but reader still scrolls and links work. Change back; positions should remain where native scrolling placed them. Tab to the outside Continue button.
Read-only inspect any scroll/wheel behavior; there are no wheel, touchmove or pointer cancellation handlers in source. Real reduced-motion, unsupported-timeline browser, touch, screen-reader output and measured rendering speed remain untested.