Letterbox
Letterbox bars slam in, hold for half the run, then release. The hold is the point.
Usage
Focus mode
Meant for
Examples
On a Card
Bars slam in over the card's media, hold for half the run, then release. The hold is the point — it is what turns a transition into a mood. The bars are the dark media area showing past the clip.
The class is wm wm-letterbox — the first half is the marker the trigger and reduced-motion rules hook into, the second is the effect.