/* Animación entrada + Billete interactivo: se voltea al hacer clic en uno de sus bordes */

.billete-flip {
  animation: billete-entrada 2.3s ;
}

@keyframes billete-entrada {
  from { opacity: 0;  }
  to { opacity: 1;  }
}
@media (prefers-reduced-motion: reduce) {
  .billete-flip { animation: none; }
}
 
.billete-flip {
  position: relative;
  width: 100%;
  max-width: 560px;
  margin: 0 auto;
  perspective: 1800px;
}
 
.billete-inner {
  position: relative;
  width: 100%;
  aspect-ratio: 3142 / 1654; /* proporción real de anverso.png / reverso.png (13,3 × 7 cm) */
  transform-style: preserve-3d;
  transform: rotateY(0deg);
  transition: transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
}
 
.billete-inner.volteado {
  transform: rotateY(180deg);
}
 
.billete-cara {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  backface-visibility: hidden;
  border-radius: 2px;
  box-shadow: 0 18px 30px rgba(20, 20, 15, 0.18);
}
 
.billete-reverso {
  transform: rotateY(180deg);
}
 
/* Zonas de agarre en los bordes izquierdo y derecho */
.billete-borde {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 16%;
  background: transparent;
  border: none;
  padding: 0;
  margin: 0;
  cursor: pointer;
  z-index: 2;
}
 
.billete-borde-izq { left: 0; }
.billete-borde-der { right: 0; }
.billete-borde { cursor: grab; }
.billete-borde:active { cursor: grabbing; }
 
.billete-borde:focus-visible {
  outline: 2px solid var(--accent, #2451FF);
  outline-offset: -2px;
}
 
@media (prefers-reduced-motion: reduce) {
  .billete-inner { transition: none; }
}