.slow {
    animation: rotation 3s;
}
.medium {
    animation: rotation 2s;
}
.fast {
    animation: rotation 1s;
}

.spinner {
    
    animation-timing-function: linear;
    animation-iteration-count: infinite;
    display: block;
    margin-left: auto;
    margin-right: auto;
    height:50px;
    width:50px;
}
@keyframes rotation {
    from {
        transform: rotate(0deg);        
    }

    to {
        transform: rotate(359deg);
    }
}