.slider {
padding: 4em;
width: 50vw;
height: auto;
margin: auto;
overflow: hidden;
}

.slider .slide-track {
display: flex;
animation: scroll 300s linear infinite;
-webkit-animation: scroll 300s linear infinite;
width: calc(1000px * 14);
}

.slider .slide {
width: 1000px;
}

.slider .slide img {
width: 100%;
}

@keyframes scroll {
0% {
-webkit-transform: translateX(0);
transform: translateX(0);
}
100% {
-webkit-transform: translateX(calc(-200px * 40));
transform: translateX(-200px * 40);
}
}