Kamil

@keyframes arrow {
  0% {
    width: 60px;
  }
  
  25% {
    width: 260px;
    transform: translateX(0px);
  }
  
  50%, 75% {
    width: 60px;
    transform: translateX(200px);
  }
}

button {
  height: 64px;
  width: 256px;
  border-top-left-radius: 5px 50%;
  border-top-right-radius: 5px 50%;
  border-bottom-left-radius: 5px 50%;
  border-bottom-right-radius: 5px 50%;
  border: none;
}