<button class="radikalwp-btn-border-anim">تخفیف ویژه<//button>

.radikalwp-btn-border-anim {
  position: relative;
  padding: 14px 32px;
  font-size: 16px;
  font-family: inherit;
  font-weight: bold;
  color: #111827;
  background: #fff;
  border: none;
  border-radius: 999px;
  cursor: pointer;
  z-index: 0;
}
.radikalwp-btn-border-anim::before {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: 999px;
  background: conic-gradient(#f59e0b, #ef4444, #8b5cf6, #06b6d4, #f59e0b);
  animation: radikalwp-spin 3s linear infinite;
  z-index: -1;
}
@keyframes radikalwp-spin { to { transform: rotate(1turn); } }