.subtitle::after {
  content: "";
  display: block;
  width: 100%;
  height: 4px;
  margin-top: 8px;

  background: linear-gradient(
    90deg,
    #00ffff,
    rgba(0,255,255,0.2)
  );

  border-radius: 2px;
  box-shadow: 0 0 12px rgba(0,255,255,0.6);

  transform: scaleX(0);
  transform-origin: center;
  opacity: 0;
}

.subtitle.animate::after {
  animation: lineGrow 0.9s ease-out forwards;
}

@keyframes lineGrow {
  0% {
    transform: scaleX(0);
    opacity: 0;
  }
  100% {
    transform: scaleX(1);
    opacity: 1;
  }
}