#back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  z-index: 9999;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background-color: #0d2238;
  border: 1px solid rgba(0, 224, 255, 0.4);
  color: #00e0ff;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease,
              background-color 0.2s ease, border-color 0.2s ease;
}
#back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
#back-to-top:hover {
  background-color: #103354;
  border-color: #00e0ff;
  box-shadow: 0 6px 24px rgba(0, 224, 255, 0.2);
}
#back-to-top svg {
  width: 20px;
  height: 20px;
  pointer-events: none;
}