.btn-shine {
  padding: 0 0 5rem 0;
  color: #fff;
  background: linear-gradient(
    to right,
    #4d4d4d 0,
    rgb(238, 238, 238) 10%,
    #4d4d4d 20%
  );
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: shine 8s infinite ease;
  animation-fill-mode: forwards;
  -webkit-text-size-adjust: none;
  font-weight: 500;
  font-size: 2rem;
  text-decoration: none;
  white-space: nowrap;
}

@keyframes shine {
  0% {
    background-position: 0;
    opacity: 100%;
  }
  50% {
    opacity: 50%;
  }
  100% {
    opacity: 100%;
    background-position: 330px;
  }
}

@media only screen and (max-width: 420px) {
  .btn-shine {
    font-size: 1.2rem;
    font-weight: 400;
  }
}