CSS Gradient Border Generator

.element {
  position: relative;
  padding: 20px;
  border-radius: 16px;
  background: white;
}

.element::before {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: 19px;
  background: linear-gradient(135deg, #6366f1, #ec4899);
  z-index: -1;
}