<div class="full"></div>

.full {
  position:fixed;
  inset:-80px;
  z-index:346;
  display:grid;
  background:#fff;
  filter: blur(5px) contrast(10);
}
.full:before,
.full:after {
  content:"";
  grid-area:1/1;
  background:repeating-linear-gradient(90deg,#000 0 15px,#0000 0 50px);
  -webkit-mask:repeating-linear-gradient(#000 0 40px,#0000 0 80px);
  animation:f 1.5s cubic-bezier(0.5,180,0.5,-180) infinite;
}
.full:after {
  -webkit-mask:repeating-linear-gradient(#0000 0 40px,#000 0 80px);
  animation-delay:0.4s;
}

@keyframes f {
  50%,100% {transform:translate(0.1px)}
}