@-webkit-keyframes scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(calc(-250px * 4));
    }
}
@keyframes scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(calc(-250px * 4));
    }
}
.slider{
    height: 300px;
    margin: auto;
    overflow: hidden;
    position: relative;
    width: 1000px;
}
.slider::before, .slider::after {
    background: linear-gradient(to right, rgb(255,255,255,1) 0%, rgb(255,255,255,0) 100%);
    content: "";
    height: 300px;
    position: absolute;
    width: 100px;
    z-index: 2;
}
.slider::after {
  right: 0;
  top: 0;
  transform: rotateZ(180deg);
}
.slider::before {
  left: 0;
  top: 0;
}
.slider .slide-track {
  -webkit-animation: scroll 40s linear infinite;
          animation: scroll 40s linear infinite;
  display: flex;
  width: calc(300px * 5);
}
.slider .slide {
    height: 300px;
    width: 300px;
}