<button class="radikalwp-btn-liquid"><span class="radikalwp-btn-liquid-blob b1"><//span><span class="radikalwp-btn-liquid-blob b2"><//span>شروع کن<//button>

.radikalwp-btn-liquid {
  position: relative; overflow: hidden; padding: 14px 40px; border: 0; border-radius: 16px; cursor: pointer;
  background: #4f46e5; color: #fff; font-size: 14px; font-weight: 700; font-family: inherit;
}
.radikalwp-btn-liquid-blob { position: absolute; bottom: -12px; border-radius: 50%; background: rgba(255,255,255,.25); transition: transform .8s ease; }
.radikalwp-btn-liquid-blob.b1 { width: 26px; height: 26px; right: 18%; }
.radikalwp-btn-liquid-blob.b2 { width: 18px; height: 18px; right: 55%; transition-delay: .12s; }
.radikalwp-btn-liquid:hover .radikalwp-btn-liquid-blob { transform: translateY(-46px); }