:paused

The :paused CSS pseudo-class selector is a resource state pseudo-class that will match an audio, video, or similar resource that is capable of being "played" or "paused", when that element is "paused".

A resource is paused if the user explicitly paused it, or if it is in a non-activated state.

:paused {
  /* ... */
}

:paused {
  border: 5px solid orange;
}