HTMLify

* {
    box-sizing: border-box;
}

body {
    background-color: #111;
    display: grid;
    place-items: center;
    height: 100vh;
}

.loader {
    width: 60px;
    height: 60px;
    display: inline-block;
    position: relative;
    background: radial-gradient(ellipse at center, #fff 69%, rgba(0, 0, 0, 0) 70%),
        linear-gradient(to right,
            rgba(0, 0, 0, 0) 47%,
            #fff 48%,
            #fff 52%,
            rgba(0, 0, 0, 0) 53%);
    background-size: 20px 20px, 20px auto;
    background-repeat: repeat-x;
    background-position: center bottom, center -5px;
}

.loader::before,
.loader::after {
    content: "";
    position: absolute;
    left: -20px;
    top: 0;
    width: 20px;
    height: 60px;
    background: radial-gradient(ellipse at center, #fff 69%, rgba(0, 0, 0, 0) 70%),
        linear-gradient(to right,
            rgba(0, 0, 0, 0) 47%,
            #fff 48%,
            #fff 52%,
            rgba(0, 0, 0, 0) 53%);
    background-size: 20px 20px, 20px auto;
    background-repeat: no-repeat;
    background-position: center bottom, center -5px;
    transform: rotate(0deg);
    transform-origin: 50% 0%;
    animation: move-left 1s linear infinite alternate;
}

.loader::after {
    animation: move-right 1s linear infinite alternate;
    left: 100%;
}

@keyframes move-left {
    0% {
        transform: rotate(22deg);
    }

    50% {
        transform: rotate(0deg);
    }
}

@keyframes move-right {

    0%,
    55% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(-22deg);
    }
}