.loader {
    width: 50px;
    height: 50px;
    transform: translateY(100%);
    border-radius: 50%;
    background: #0079ff;
    position: relative;
}

.loader:before , .loader:after{
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: #0079ff;
    left: 50%;
    transform: translateX(-50%);
    top: -200%;
}
.loader:after {
    animation: moveX 0.5s infinite linear alternate;
}

@keyframes moveX {
    0% {
        top: 0% ;
        transform: translateX(-50%) scale(1.5);
    }
    50% {
        top: -75% ;
        transform: translateX(-50%) scale(0.5);
    }
    100% {
        top: -200%;
        transform: translateX(-50%) scale(1.5);
    }
}