.banner {
     width: 100%; 
    height: 100vh;
    text-align: center;
    overflow: hidden;
    position: relative;

}

.banner .slider {
    position: absolute;
    width: 200px;
    height: 250px;
    top: 40%;
    left: calc(50% - 100px);
    transform-style: preserve-3d;
    transform: perspective(1000px);
    animation: autoRun 20s linear infinite;

}

@keyframes autoRun {
    from {
        transform: perspective(1000px)  rotateX(360deg);
    }
    to {
        transform: perspective(1000px)  rotateX(0deg);
    }
}


.banner .slider .item {
    position: absolute;
    inset: 0 0 0 0;
    transform: 
    rotateX(calc( (var(--position) - 1) * (360 / var(--quantity)) * 1deg))
        translateZ(500px);


}

.banner .slider .item img {
    width: 100%;
    height:  100%;   
    object-fit: cover;
}