@keyframes ring {
  0%,
  100% {
    transform: rotate(0deg);
  }
  10%,
  30%,
  50%,
  70%,
  90% {
    transform: rotate(2deg);
  }
  20%,
  40%,
  60%,
  80% {
    transform: rotate(-2deg);
  }
}
.ringing {
  animation: ring 1s infinite;
}
.red-hangup {
  background-color: #e53935 !important;
  color: white !important;
  border: none;
}
.green-answer {
  background-color: #22c55e !important;
  color: white !important;
  border: none;
}