.loader {
    position: absolute;
    width: 70px;
    height: 70px;
    margin: auto;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    animation: scale 0.7s linear infinite;
}

@keyframes scale {
    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.1);
    }
}