.button {
  padding: 15px 40px;
  background: linear-gradient(to right, #09021c, #0c061d);
  color: white;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: all 300ms ease-in-out;
  position: relative;
  isolation: isolate;
  overflow: hidden;
}

.button > span {
  position: absolute;
  z-index: -1;
  background: transparent;
  opacity: 0.5;
  width: 33.333%;
  height: 100%;
}

.button > :first-child {
  left: 0;
  top: 0;
}

.button > :last-child {
  right: 0;
  top: 0;
}

.button::before {
  content: "";
  position: absolute;
  z-index: -1;
  background: hsl(236, 19%, 25%);
  opacity: 0;
  width: 10%;
  aspect-ratio: 1;
  border-radius: 50%;
  inset: 0;
  margin: auto;
  transition: opacity 1000ms 200ms ease-in-out, transform 200ms ease-in-out;
}

.button:active::before {
  transform: scale(13);
  opacity: 1;
  transition: all 400ms ease-in-out;
}

.button:has(:first-child:active)::before {
  margin-left: 0;
}

.button:has(:last-child:active)::before {
  margin-right: 0;
}

.button:has(:first-child:active)::before,
.button:has(:last-child:active)::before {
  transition: all 400ms ease-in-out;
}