:root {
    --deg: 45deg;
}

body {
    margin: 0;
    min-height:100vh;
    background: #000;
    display: flex;
    justify-content: center;
    align-items: center;
}


ul {
    display: flex;
    padding: 0 25px;
    gap: 50px;
    position: relative;
    list-style: none;
    border-top: 12px solid #1e1e1e;
}

ul::before {
    content: '';
    width: 100%;
    height: 12px;
    background-color: #474646;
    position: absolute;
    top: -24px;
    left: 6px;
    transform: skewX(-45deg);
}

ul::after {
    content: '';
    width: 12px;
    height: 12px;
    background-color: #2e2e2e;
    position: absolute;
    top: -18px;
    left: 100%;
    transform: skewY(-45deg);
}

ul li {
    position: relative;
    top: -1px;
    width: 2px;
    height: 120px;
    background-color: #fff;
    transform-origin: 100% 0%;
    z-index: -1;
}

ul li::after {
    content: '';
    position: absolute;
    width: 50px;
    height: 50px;
    bottom: -25px;
    left: -25px;
    border-radius: 50%;
    background-image: radial-gradient(circle at center,
            #eee,
            #000);
}

ul li:nth-child(-n+2) {
    animation: ballMove 2s infinite ease-out;
    animation-fill-mode: forwards;
}

ul li:nth-last-child(-n+2) {
    --deg: -45deg;
    animation: ballMove 2s infinite ease-out;
    animation-delay: 1s;
}

@keyframes ballMove {
    50% {
        transform: rotateZ(var(--deg));
        animation-timing-function: ease-in;
    }

    0%, 25%, 75%, 100% {
        transform: rotateZ(0deg);
    }
}