@-webkit-keyframes scroll {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(calc(-250px * 7));
  }
}

@keyframes scroll {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(calc(-250px * 7));
  }
}

.slider {
  background: rgb(31, 31, 31);
  box-shadow: 0 10px 20px -5px rgba(0, 0, 0, 0.125);
  height: 100px;
  margin: auto;
  overflow: hidden;
  position: relative;
  width: 100%;
  border-radius: 5px;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  -ms-border-radius: 5px;
  -o-border-radius: 5px;
}
.slider::before, .slider::after {
  background: linear-gradient(to right, rgb(156, 13, 13) 0%, rgba(255, 255, 255, 0) 100%);
  content: "";
  height: 100px;
  position: absolute;
  width: 100px;
  z-index: 2;
}
.slider::after {
  right: 0;
  top: 0;
  transform: rotateZ(180deg);
  transition: all 0.5s ease;
  -webkit-transition: all 0.5s ease;
  -moz-transition: all 0.5s ease;
  -ms-transition: all 0.5s ease;
  -o-transition: all 0.5s ease;
}
.slider::before {
  left: 0;
  top: 0;
}
.slider .slide-track {
  -webkit-animation: scroll 20s linear infinite;
  animation: scroll 20s linear infinite;
  display: flex;
  width: calc(250px * 14);
}
.slider .slide {
  height: 100px;
  width: 250px;
}