/* Animacion de cargando */
.preloader {
  width: 70px;
  height: 70px;
  border: 10px solid black;
  border-top: 10px solid #666;
  border-radius: 50%;
  animation-name: girar;
  animation-duration: 2s;
  animation-iteration-count: infinite;
}
@keyframes girar {
  from {transform: rotate(0deg);}
  to {transform: rotate(360deg);}
}