@keyframes principal_keyframes_aparecer_de_arriba{ 
    from{
        opacity: 0;
        top: -150px;
    }
    to{
        opacity: 1;
        top: 0;
    }
}

@-webkit-keyframes principal_keyframes_aparecer_de_arriba{
    from{
        opacity: 0;
        top: -150px;
    }
    to{
        opacity: 1;
        top: 0;
    }    
}