* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: #111;
  min-height: 100vh;
  overflow: hidden;
}

.star {
  position: absolute;
  top: -20px;
  color: #fff;
  animation: animate 5s linear forwards;
  /* you can set infinite too */
}

.star::before {
  content: "\f005";
  font-family: FontAwesome;
  text-shadow: 0 0 5px #fff, 0 0 20px #fff, 0 0 50px #fff;
}

@keyframes animate {
  0% {
    transform: translateY(0) rotate(0deg);
    opacity: 1;
  }

  80% {
    opacity: 1;
  }

  100% {
    transform: translateY(100vh) rotate(360deg);
    opacity: 0;
  }
}

@media screen and (max-width: 600px) {
  .star {
    font-size: 8px;
  }
}