/* Animation keyframes - you need to add prefixes */
@keyframes spin {
    from {
        transform: rotate(0deg);
    }

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

/* Loading animation container */
.loading {
    position: absolute;
    background: rgba(0,0,0,0.5);
    width: 100%;
    height: 100%;
    z-index: 1000000;
}

    /* Spinning circle (inner circle) */
    .loading .maskedCircle {
        width: 20px;
        height: 20px;
        border-radius: 12px;
        border: 3px solid white;
    }

    /* Spinning circle mask */
    .loading .mask {
        width: 12px;
        height: 12px;
        overflow: hidden;
    }

    /* Spinner */
    .loading .spinner {
        position: absolute;
        left: 50%;
        top: 50%;
        width: 26px;
        height: 26px;
        animation: spin 1s infinite linear;
    }