*{
    margin: 0;
    padding: 0;
    /* CS3 盒子模型 */
    box-sizing: border-box;
  }
  
  body{
    background-color: #1d0035;
    /* 最小高度 */
    min-height: 100vh;
    overflow: hidden;
  }
  section {
    position: absolute;
    width: 100%;
    height: 100%;
    /* flex 弹性布局 */
    display: flex;
     /* 子元素居中对齐 */
    justify-content: center;
    align-items: center;
    /* 3D呈现 */
    transform-style: preserve-3d;
    /* 透视 */
    transform: perspective(700px);
  }
  
  .box{
    position: absolute;
     /* 3D呈现 */
    transform-style: preserve-3d;
    top:125px;
  }
  .box .cube{
    position: relative;
    width: 200px;
    height: 200px;
    transform-style: preserve-3d;
    /* 动画效果 */
    animation: animateCube 20s linear infinite;
  }
  @keyframes animateCube {
    0%{
        /* 3D旋转 沿Y轴 */
      transform: rotateY(0deg);
    }
    100%{
      transform: rotateY(360deg);
    }
  }
  .box .cube div{
    position: absolute;
    width: 100%;
    height: 100%;
    top:0;
    left: 0;
    transform-style: preserve-3d;
  }
  .box .cube div span{
    position: absolute;
    top:0;
    left:0;
    width: 100%;
    height: 100%;
    background: radial-gradient(#fb6200, #fb6200, #c3300f);
    transform: rotateY(calc(90deg * var(--i))) translateZ(100px);
  }
  .box .cube .top{
    position: absolute;
    top:0;
    left: 0;
    width: 200px;
    height: 200px;
    background-color: #b22708;
    transform: rotateX(90deg) translateZ(100px);
    display: flex;
    justify-content: center;
    align-items: center;
  }
  
  .box .cube .top::before{
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: #fb6200;
    filter: blur(50px);
    transform: translateZ(-400px);
    box-shadow: 0 0 120px rgba(251, 98, 0 , 0.2)
    0 0 200px rgba(251, 98, 0 , 0.4)
    0 0 300px rgba(251, 98, 0 , 0.6)
    0 0 400px rgba(251, 98, 0 , 0.8)
    0 0 500px rgba(251, 98, 0 , 1)
    ;
  }