.topButton {
  position: fixed;
  bottom: 24px;
  right: 18px;
  width: 54px;
  height: 54px;
  border-radius: 50%;

  background: linear-gradient(135deg, var(--default), var(--highlight));

  color: white;
  border: none;
  cursor: pointer;
  font-size: 20px;

  z-index: 999;

  opacity: 0;
  visibility: hidden;
  pointer-events: none;

  transform: translateY(10px);

  transition:
    opacity 0.3s ease,
    transform 0.3s ease,
    visibility 0.3s ease,
    box-shadow 0.25s ease;

  box-shadow:
    0 10px 24px rgba(0, 0, 0, 0.28),
    0 0 15px rgba(245, 158, 11, 0.25);
}

.topButton.visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;

  transform: translateY(0);
}

.topButton:hover {
  box-shadow:
    0 0 20px rgba(245, 158, 11, 0.7),
    0 0 40px rgba(255, 79, 216, 0.4),
    0 10px 30px rgba(0, 0, 0, 0.4);

  transform: translateY(-2px);
}

.topButton::after {
  content: "";
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--default), var(--highlight));
  opacity: 0.15;
  filter: blur(8px);
  z-index: -1;
  animation: pulseGlow 3s infinite;
}

.topButton:active {
  transform: scale(0.92);
}

@keyframes pulseGlow {
  0% {
    transform: scale(1);
    opacity: 0.15;
  }

  50% {
    transform: scale(1.08);
    opacity: 0.25;
  }

  100% {
    transform: scale(1);
    opacity: 0.15;
  }
}