padding: 0;
  margin: 0;
  width: 100vw;
  height: 100vh;
  position: relative;
  overflow: hidden;
  background: linear-gradient(#123, #111);
}
Kopyala

<div class="kartanesi"></div>
...
...
<div class="kartanesi"></div>
<div class="kartanesi"></div>
<!-- 50 tane! -->
Kopyala

.kartanesi{
  --size: 1vw;
  width: var(--size);
  height: var(--size);
  background: white;
  border-radius: 50%;
  position: absolute;
  top: -5vh;
}
Kopyala

@keyframes karyagisi{
  0%{
    transform: translate3d(0, 0, 0);
  }
  100%{
    transform: translate3d(0, 110vh, 0);
  }
}
Kopyala

.kartanesi:nth-child(1){
  --size: 0.6vw;
  left: 55vw;
  animation: karyagisi 8s linear infinite;
}
...
Kopyala