@keyframes shake {
  25% {
    transform: rotate(calc(var(--angle) * -1));
  }
  50% {
    transform: rotate(var(--angle));
  }
  100% {
    transform: rotate(0);
  }
}
.HOVER {
  --width: 100%;
  --time: 0.7s;
  border: 2px solid #959595;
  border-radius: 40px;
  position: relative;
  display: inline-block;
  padding: 8px 15px;
  color: #d6d6d6;
  background: #2c2828dd;
  overflow: hidden;
  cursor: pointer;
  text-decoration: none;
}
.HOVER span:last-child {
  position: relative;
  z-index: 5;
  transition: color var(--time);
}
.HOVER:hover span:last-child {
  color: #fff;
}
.HOVER span:first-child {
  position: absolute;
  display: block;
  content: "";
  z-index: 0;
  width: 0;
  height: 0;
  border-radius: 100%;
  background: #000;
  transform: translate(-50%, -50%);
  transition:
    width var(--time),
    padding-top var(--time);
  top: 50%;
  left: 50%;
}
.HOVER:hover span:first-child {
  width: calc(var(--width) * 2.25);
  padding-top: calc(var(--width) * 2.25);
}
.HOVER.FLASH span:first-child {
  background: #ff3b3b;
}
.animated {
  --angle: 5deg;
  animation: 0.3s shake;
}
.link {
  position: absolute;
  right: 10px;
  bottom: 10px;
  font-size: 1rem;
}
@media (max-width: 480px) {
  .HOVER {
    font-size: 13px;
  }
}