@keyframes xx-logo {
      0% {
        transform: rotateY(0deg);
      }
      50% {
        transform: rotateY(360deg);
      }
      100% {
        transform: rotateY(0deg);
      }
    }

    @keyframes yq-logo {
      0% {
        transform: rotateY(180deg);
      }
      50% {
        transform: rotateY(-180deg);
      }
      100% {
        transform: rotateY(180deg);
      }
    }

    .logo-box {
      position: relative;
      width: 210px;
      height: 80px;
      /*border: 1px solid #000;*/
    }

    .xx-logo {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      z-index: 9;
      background-color: #fff;
      animation: xx-logo 20s linear infinite;
      backface-visibility: hidden;
    }

    .yq-logo {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      z-index: 1;
      animation: yq-logo 20s linear infinite;
    }