octocat.css

.github-corner svg {
  color:#ffffff;
  fill:#151513;
}

.github-corner .octo-arm {
  transform-origin: 50% 85%;
}

@media (hover: hover) {
  .github-corner:hover .octo-arm {
    animation:octocat-wave 5600ms ease-in-out;
    animation-iteration-count: infinite;
  }
}

@media (hover: none) {
  .github-corner .octo-arm {
    animation:octocat-wave 5600ms ease-in-out;
    animation-iteration-count: infinite;
  }
}

@keyframes octocat-wave {
  0%,
  10%,
  100% {
    transform:rotate(0)
  }
  2%,
  6% {
    transform:rotate(-25deg)
  }
  4%,
  8% {
    transform:rotate(10deg)
  }
}