*{
  /* 初始化 */
  margin: 0;
  padding: 0;
}
body{
  /* 100%窗口高度 */
  height: 100vh;
  /* 溢出隐藏 */
  overflow: hidden;
}
 span{
            width: 15px;
            height: 15px;
            background: url("../images/star.png") no-repeat;
            position: absolute;
            background-size:100% 100%;
            animation: flash 1s alternate infinite;
        }
        
        @keyframes flash {
            0%{opacity: 0;}
            100%{opacity: 1;}
        }

        span:hover{
            transform: scale(3, 3) rotate(180deg) !important;
            transition: all 1s;
        }
.container{
  /* 绝对定位 */
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:#000;
   background: url("../images/bg.jpg") no-repeat;
  /* 把背景图像扩展至足够大，以使背景图像完全覆盖背景区域 */
  background-size: cover;
  /* 定位背景图像为正中间 */
  background-position-x: center;
  /* 执行动画：动画名称 时长 线性的 无限次播放 */
  /*animation: animateBg 5s linear infinite;*/

}
.liuxing{
  position: absolute;
  top: 50%;
  left: 50%;
  width: 4px;
  height: 4px;
  background-color: #fff;
  border-radius: 50%;
  /* 发光效果 */
  box-shadow: 0 0 0 4px rgba(255,255,255,0.1),
  0 0 0 8px rgba(255,255,255,0.1),
  0 0 20px rgba(255,255,255,1);
  /* 执行动画 */
  animation: animate 3s linear infinite;
}
/* 拖尾效果 */
.liuxing::before{
  content: "";
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 300px;
  height: 3px;
  background: linear-gradient(90deg,#fff,transparent);
}
/* 接下来分别为每一个流星设置位置、动画延迟时间、动画时长 */
.liuxing:nth-child(1){
  top: 0;
  right: 0;
  /* initial关键字用于设置CSS属性为它的默认值 */
  left: initial;
  /* 动画延迟时间 */
  animation-delay: 0s;
  /* 动画时长 */
  animation-duration: 1s;
 
  
}
.liuxing:nth-child(2){
  top: 0;
  right: 80px;
  left: initial;
  animation-delay: 0s;
  animation-duration: 3s;
}
.liuxing:nth-child(3){
  top: 80px;
  right: 0;
  left: initial;
  animation-delay: 0.4s;
  animation-duration: 2s;
}
.liuxing:nth-child(4){
  top: 0;
  right: 180px;
  left: initial;
  animation-delay: 0.6s;
  animation-duration: 1.5s;
}
.liuxing:nth-child(5){
  top: 0;
  right: 400px;
  left: initial;
  animation-delay: 0.8s;
  animation-duration: 2.5s;
}
.liuxing:nth-child(6){
  top: 0;
  right: 600px;
  left: initial;
  animation-delay: 1s;
  animation-duration: 3s;
}
.liuxing:nth-child(7){
  top: 300px;
  right: 0;
  left: initial;
  animation-delay: 1.2s;
  animation-duration: 1.75s;
}
.liuxing:nth-child(8){
  top: 0;
  right: 700px;
  left: initial;
  animation-delay: 1.4s;
  animation-duration: 1.25s;
}
.liuxing:nth-child(9){
  top: 0;
  right: 1000px;
  left: initial;
  animation-delay: 0.75s;
  animation-duration: 2.25s;
}
.liuxing:nth-child(10){
  top: 0;
  right: 450px;
  left: initial;
  animation-delay: 2.75s;
  animation-duration: 2.25s;
}

/* 定义动画 */
/* 背景缩放动画 */
@keyframes animateBg {
  0%,100%{
      transform: scale(1);
  }
  50%{
      transform: scale(1.2);
  }
}
/* 流星划过动画 */
@keyframes animate {
  0%{
      transform: rotate(315deg) translateX(0);
      opacity: 1;
  }
  90%{
      opacity: 1;
  }
  100%{
      transform: rotate(315deg) translateX(-1000px);
      opacity: 0;
  }
}