.fondo-scroll {
  position: relative;
  overflow: hidden;
  -webkit-mask-image: linear-gradient(to top, transparent 0%, black 40%, black 100%);
  -webkit-mask-repeat: no-repeat;
  -webkit-mask-size: cover;
  mask-image: linear-gradient(to top, transparent 0%, black 40%, black 100%);
  mask-repeat: no-repeat;
  mask-size: cover;
}