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

.full {
  position:fixed;
  inset:-60px;
  z-index:576;
  display:grid;
}
.full:before,
.full:after{
  content:"";
  grid-area:1/1;
  background: conic-gradient(from  90deg at 4px 4px ,#0000 90deg,#2790b0 0);
  background-size:60px 60px;
  -webkit-mask:repeating-conic-gradient(from var(--s,0deg),#0000 0 90deg,#000 0 180deg) 0 0/120px 120px;
  animation:f 1s infinite linear alternate;
}
.full:after{
  --s:90deg;
  --p:-30px;
}
@keyframes f{
  0% ,20%  {transform:translate(0,0)}
  80%,100% {transform:translate(var(--p,30px),var(--p,30px))}
}