/*星*/
.star {
  position: absolute;
  padding: 0;
  margin: 0;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: -10;
}
.star li {
  width: 20px;
  position: absolute;
  list-style: none;
  top: 0px;
  animation: fall 4s linear infinite, ease-in-out infinite alternate;
}
.star li img{width:100%;}
@keyframes fall {
  to {
    top: 134%;
  }
}

.star li:nth-child(1) {
  left: 2%;
  animation: fall 25s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(2) {
  left: 5%;
  animation: fall 41s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(3) {
  left: 11%;
  animation: fall 30s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(4) {
  left: 13%;
  animation: fall 20s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(5) {
  left: 17%;
  animation: fall 24s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(6) {
  left: 18%;
  animation: fall 45s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(7) {
  left: 30%;
  animation: fall 27s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(8) {
  left: 34%;
  animation: fall 60s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(9) {
  left: 42%;
  animation: fall 28s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(10) {
  left: 43%;
  animation: fall 50s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(11) {
  left: 50%;
  animation: fall 26s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(12) {
  left: 52%;
  animation: fall 40s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(13) {
  left: 64%;
  animation: fall 23s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(14) {
  left: 67%;
  animation: fall 50s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(15) {
  left: 71%;
  animation: fall 24s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(16) {
  left: 75%;
  animation: fall 40s linear infinite, ease-in-out infinite alternate;
}
.star li:nth-child(17) {
    left: 80%;
    animation: fall 26s linear infinite, ease-in-out infinite alternate;
  }
  .star li:nth-child(18) {
    left: 82%;
    animation: fall 43s linear infinite, ease-in-out infinite alternate;
  }
.star li:nth-child(19) {
    left: 94%;
    animation: fall 29s linear infinite, ease-in-out infinite alternate;
  }
.star li:nth-child(20) {
    left: 91%;
    animation: fall 40s linear infinite, ease-in-out infinite alternate;
  }