.swipe-hint {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  font-size: 28px;
  color: rgba(255,255,255,0.55);
  z-index: 9999;
  pointer-events: none;
  opacity: 0;
  animation: swipeBlink 1.4s ease-in-out infinite;
}

.swipe-hint.left { left: 18px; }
.swipe-hint.right { right: 18px; }

@keyframes swipeBlink {
  0% { opacity: 0; }
  50% { opacity: 0.7; }
  100% { opacity: 0; }
}