@keyframes scroll {
    0% {
        transform: translateX(0);
   }
    100% {
        transform: translateX(calc(-250px * 7));
   }
}
.slider {
    background: white;
    box-shadow: 0 10px 20px -5px rgba(0, 0, 0, 0.125);
    height: 100px;
    margin: auto;
    overflow: hidden;
    position: relative;
}

.slider::after {
    right: 0;
    top: 0;
    transform: rotateZ(180deg);
}
.slider::before {
    left: 0;
    top: 0;
}
.slider .slide-track {
    animation: scroll 40s linear infinite;
    display: flex;
    width: calc(250px * 14);
}
.slider .slide {
    height: 100px;
}