display:none discards scrollTop in WebKitGTK, so navigating away
from album/artist/genre grids and back reset scroll to top.
Replace inline style.display toggling with a CSS class that uses
visibility:hidden + height:0 + overflow:hidden. This collapses
the element visually while keeping the DOM alive with its scroll
state intact. contain:strict on hidden views ensures zero layout
cost while collapsed.
contain:strict includes size containment which caused a timing issue
where the flex-based main-panel height wasn't resolved before the
virtualizer measured its container, resulting in track-list rendering
at ~20% height on first load until something triggered a relayout.
- contain: layout style on .content-area to isolate main+queue from header/sidebar
- contain: strict on .main-panel for maximum layout isolation
- contain: layout style paint on .main-panel > * for paint containment per view
- contain: layout style paint on sidebar to isolate from main panel
- contain: layout style on .bottom-bar to isolate footer from content reflows