.sigmaweb-btn12 {
  position: relative;
  padding: 3px;
  background: linear-gradient(90deg, #03a9f4, #f441a5);
  border-radius: 0.9em;
  transition: all 0.4s ease;
}

.sigmaweb-btn12::before {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  border-radius: 0.9em;
  z-index: -10;
  filter: blur(0);
  transition: filter 0.4s ease;
}

.sigmaweb-btn12:hover::before {
  background: linear-gradient(90deg, #03a9f4, #f441a5);
  filter: blur(0.6em);
}
.sigmaweb-btn13:active::before {
  filter: blur(0.2em);
}