demo/src/app/index.module.css

@media (max-width: 1400px) {
  .login {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: url("../assets/background.jpg") no-repeat center center;
    background-size: cover;
    box-sizing: border-box;
  }

  .starts {
    width: 1px;
    height: 1px;
    background: transparent;
    box-shadow:
      145px 234px #fff,
      876px 543px #fff;
    animation: animStar 50s linear infinite;
  }

  .starts2 {
    width: 2px;
    height: 2px;
    box-shadow:
      445px 234px #fff,
      276px 943px #fff;
    animation: animStar 100s linear infinite;
  }

  .starts3 {
    width: 3px;
    height: 3px;
    background: transparent;
    box-shadow:
      745px 834px #fff,
      176px 243px #fff;
    animation: animStar 150s linear infinite;
  }
}

@media (min-width: 1400px) {
  .login {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: url("../assets/background.jpg") no-repeat center center;
    background-size: cover;
    box-sizing: border-box;
  }

  .starts {
    width: 1px;
    height: 1px;
    background: transparent;
    box-shadow:
      45vw 34vh #fff,
      76vw 43vh #fff;
    animation: animStar 50s linear infinite;
  }

  .starts2 {
    width: 2px;
    height: 2px;
    box-shadow:
      145vw 134vh #fff,
      76vw 143vh #fff;
    animation: animStar 100s linear infinite;
  }

  .starts3 {
    width: 3px;
    height: 3px;
    background: transparent;
    box-shadow:
      45vw 134vh #fff,
      176vw 43vh #fff;
    animation: animStar 150s linear infinite;
  }
}

@keyframes animStar {
  from {
    transform: translateY(0px);
  }
  to {
    transform: translateY(-2000px);
  }
}