.slider{
    position: relative;
    width: 200px;
    height: 200px;
    transform-style: preserve-3d;
    animation: rotate 30s linear infinite;
    left: 40%;
    margin-bottom: 18%;
    
}

@keyframes rotate {
    0%{ transform: perspective(1000px) rotateY(0deg);}
    
    100%{ transform: perspective(1000px) rotateY(360deg);}
    
}

.slider span{
    position: absolute;
    top: 20%;
    left: 0;
    margin-bottom: 20%;
    width: 100%;
    height: 100%;
    transform-origin: center;
    transform-style: preserve-3d;
    transform: rotateY(calc(var(--i)*45deg)) translateZ(350px);
}

.slider span img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 100px;
    object-fit: cover;
    transition: 2s;
}