.so-spin-plane {
  margin: auto;
  -webkit-animation: so-spin-plane-spin 1s infinite linear;
          animation: so-spin-plane-spin 1s infinite linear;
}
@-webkit-keyframes so-spin-plane-spin {
  0% {
    -webkit-transform: perspective(120px) rotateX(0deg) rotateY(0deg);
            transform: perspective(120px) rotateX(0deg) rotateY(0deg);
  }
  50% {
    -webkit-transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg);
            transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg);
  }
  100% {
    -webkit-transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
            transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
  }
}
@keyframes so-spin-plane-spin {
  0% {
    -webkit-transform: perspective(120px) rotateX(0deg) rotateY(0deg);
            transform: perspective(120px) rotateX(0deg) rotateY(0deg);
  }
  50% {
    -webkit-transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg);
            transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg);
  }
  100% {
    -webkit-transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
            transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
  }
}