.pestana {
  display: none !important;
  opacity: 0;
  transition: opacity 0.3s ease-in-out;
}

.pestana.visible {
  display: block !important;
  opacity: 1;
}

.boton-de-pestana {
  opacity: 0.5;
  transition: opacity 0.3s ease-in-out;
}

.boton-de-pestana.activa {
  opacity: 1;
}