<button class="radikalwp-btn-aurora">همین حالا شروع کن<//button>

.radikalwp-btn-aurora {
  padding: 14px 38px;
  font-family: inherit;
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(115deg, #22d3ee, #818cf8, #e879f9, #22d3ee);
  background-size: 280% 100%;
  border: none;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: 0 10px 26px rgba(129, 140, 248, .38);
  animation: radikalwp-aurora-flow 6s ease infinite;
  transition: transform .25s ease, box-shadow .25s ease;
}
.radikalwp-btn-aurora:hover {
  transform: scale(1.04);
  box-shadow: 0 14px 34px rgba(129, 140, 248, .55);
}
@keyframes radikalwp-aurora-flow {
  0%, 100% { background-position: 0% 50%; }
  50%      { background-position: 100% 50%; }
}