.wrap{
  max-width:250px;
}
.border_outer{
  
  transform-origin: center;
  animation-name: round_rotate;
  animation-duration: 8s;
  animation-iteration-count: infinite;
  transition-timing-function: linear;
  stroke-dasharray: 1000;
  stroke-dashoffset: 1000;
}

@keyframes round_rotate {
    from {
      transform:rotate(0deg);
  }
  50%{
   transform:rotate(-45deg);
      stroke-dashoffset: 0;
  }
    to {
      transform:rotate(0deg);
      stroke-dashoffset: 1000;
  }
}