/* Back-to-top button */

#backToTop {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 8000;
  width: 52px;
  height: 52px;
  border-radius: 18px;
  border: 1px solid rgba(255,255,255,0.95);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: white;
  background: linear-gradient(135deg, #D4813A 0%, #A85E22 100%);
  box-shadow:
    inset 0 2px 0 rgba(255,255,255,0.3),
    0 6px 24px rgba(212,129,58,0.50),
    0 2px 8px rgba(0,0,0,0.10),
    0 0 0 0.5px rgba(212,129,58,0.2);
  opacity: 0;
  transform: translateY(20px) scale(0.85);
  transition: opacity 0.35s cubic-bezier(.34,1.4,.64,1), transform 0.35s cubic-bezier(.34,1.4,.64,1), box-shadow 0.25s ease;
  pointer-events: none;
  backdrop-filter: blur(16px);
}
#backToTop.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: all;
}
#backToTop:hover {
  transform: translateY(-5px) scale(1.12);
  box-shadow: 0 14px 40px rgba(212,129,58,0.7), 0 4px 12px rgba(0,0,0,0.15), inset 0 1.5px 0 rgba(255,255,255,0.35);
}
#backToTop:active {
  transform: translateY(-2px) scale(1.05);
}
/* Pulse ring animation */
#backToTop::before {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 2px solid rgba(212,129,58,0.4);
  animation: bttPulse 2.5s ease-in-out infinite;
  pointer-events: none;
}
@keyframes bttPulse {
  0%, 100% { transform: scale(1); opacity: 0.6; }
  50% { transform: scale(1.18); opacity: 0; }
}