.loader {
    width: 84px;
    height: 84px;
    position: relative;
}

    .loader:before, .loader:after {
        content: "";
        position: absolute;
        left: 50%;
        bottom: 0;
        width: 64px;
        height: 64px;
        border-radius: 50%;
        background: #FFF;
        transform: translate(-50%, -100%) scale(0);
        animation: push 2s infinite linear;
    }

    .loader:after {
        animation-delay: 1s;
    }

@keyframes push {
    0%, 50% {
        transform: translate(-50%, 0%) scale(1)
    }

    100% {
        transform: translate(-50%, -100%) scale(0)
    }
}