Customizing audio player controls with CSS

I’m using the player for both video and audio.
For audio it’s common to have a pause button visible at all times. That is, a large pause button in the center of the screen.
I tried this:

.flowplayer.is-playing .fp-pause svg {
  opacity: 1; transform: scale(1.5);
}

but it’s only visible on mouse over. Is there a way to show it persistently? Thanks!!