@keyframes spin{
    from {transform: rotate(0deg);}
    to   {transform: rotate(359deg);}
}

.loader {

    position: relative;

    &:before{
        content: '';
        width: 30px;
        height: 30px;
        border: solid grey;
        border-width: 3px 2px 0px 0px;
        border-radius: 50%;
        position: absolute;
        top: 50%;
        left: 50%;
        animation: spin 0.8s infinite linear;
    }

}