@keyframes fade-in
{
    0% { opacity: 0; visibility: hidden; }
    100% { opacity: 1; visibility: visible; }
}

@keyframes fade-out
{
    0% { opacity: 1; visibility: visible; }
    100% { opacity: 0; visibility: hidden; }
}

/* - * - * - * - * - * - * - * - * - * - * - * - * - * - * - */

@keyframes rotate
{
    from
    {
        transform: rotate(0deg);
    }

    to
    {
        transform: rotate(360deg);
    }
}