"Reduce visual effects" was a sledgehammer: body.reduce-effects * forced
animation:none + transition-duration:0s on every element. That froze every CSS loading
spinner mid-rotation — including the dash-header worker-service spinners (musicbrainz /
spotify / deezer / … .active .<svc>-spinner) — which read as BROKEN rather than "off".
It also killed cheap hover feedback like the Quick Actions buttons.
The actual lag (esp. Firefox, see the #935 sweep) is backdrop-filter / box-shadow /
filter re-rasterizing every frame — NOT the animations themselves. Transform- and
opacity-only motion (the spinners) composites for ~free.
So: keep forcing the expensive properties to none (unchanged — that's the real fix),
but drop the blanket animation/transition kills. !important author declarations outrank
animation + transition declarations in the cascade, so any keyframe/transition that
tries to set blur/shadow/filter is still neutralized even while it runs — the spinner
spins, just without the glow. Net: functional spinners stay alive, Quick Actions hover
(transform + border-colour) returns, box-shadow transitions are no-ops (shadow forced
none), and the GPU-heavy rendering that caused the lag stays gone. The worker-orb CANVAS
is unaffected (JS-gated separately) and stays off under reduce-effects, as intended.
Static guard test pins the contract: the global rule must keep the expensive-property
kills and must NOT reintroduce blanket animation:none / transition:0s.
