/* Transición suave para el cambio */
.nav-button i {
     transition: transform 0.3s ease, color 0.3s ease;
}

     /* Animación especial para el check */
     .nav-button i.fa-check {
          color: green;
          animation: pop 0.5s ease;
     }

/* Definimos la animación */
@keyframes pop {
     0% {
          transform: scale(0.5);
          opacity: 0;
     }

     50% {
          transform: scale(1.3);
          opacity: 1;
     }

     100% {
          transform: scale(1);
          opacity: 1;
     }
}