*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #333;
}
.container{
    position: relative;
    display: flex;
    gap: 25px;
}
.container .box{
    position: relative;
    width: 360px;
    height: 360px;
    background: var(--clr);
}
.container .box::before{
    content: '';
    position: absolute;
    inset: 30px;
    background: #0002;
    border-radius: 10px;
}
.container .box span{
    position: absolute;
    inset: 0;
    rotate: calc(var(--i) * 90deg);
}
.container .box span::before{
    content: '';
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 15px;
    background-image: radial-gradient(circle at 10px 15px,#333 12px,transparent 13px);
    background-repeat: repeat;
    background-size: 40px 20px;
    animation: animate 0.5s linear infinite;
}
.container .box span::after{
    content: '';
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 10px;
    background-image: radial-gradient(circle at 10px -5px,transparent 12px,#333 13px);
    background-repeat: repeat;
    background-size: 20px 20px;
    animation: animate 0.5s linear infinite;
}
@keyframes animate{
    0%{
        background-position: 0 0;
    }
    100% {
        background-position: 40px 0;
    }
}