#private-call-dialog #call-controls:not([hidden]) {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
#private-call-dialog #call-controls[hidden],
#private-call-dialog #call-play[hidden] {
  display: none;
}
#private-call-dialog #call-controls > button { min-width: 0; }
#private-call-dialog #call-play:not([hidden]) {
  display: block;
  margin: .5rem auto;
}