@keyframes slide {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-100%);
  }
}

.marcas{
  overflow: hidden;
  background: #EBEBEB;
  white-space: nowrap;
  position: relative;
  
}
.marcas:before,
.marcas:after {
  position: absolute;
  top: 0;
  width: 80px;
  height: 100%;
  content: "";
  z-index: 2;
}
.marcas:before {
  left: 0;
  background: linear-gradient(to left, rgba(255,255,255,0), #EBEBEB);
}
.marcas:after {
  right: 0;
  background: linear-gradient(to right, rgba(255,255,255,0), #EBEBEB);
}

.marcas:hover .marcas-slider {
  animation-play-state: paused;
}

.marcas-slider {
  display: inline-block;
  animation: 25s slide infinite linear;
}

.marcas-slider img{
  height: 50px;
  margin: 0 10px 10px 0;
  border-radius: 5px;
}