.github-corner:hover .octo-arm {
  animation: octocat-wave 560ms ease-in-out
}

.github-corner svg {
  fill: gray;
  color: #fff;
}

.github-corner:hover svg {
  fill: #337ab7;
}

@keyframes octocat-wave {
  0%, 100% {
    transform: rotate(0deg)
  }
  20%, 60% {
    transform: rotate(-25deg)
  }
  40%, 80% {
    transform: rotate(10deg)
  }
}

@media (max-width: 500px) {
  .github-corner:hover .octo-arm {
    animation: none
  }

  .github-corner .octo-arm {
    animation: octocat-wave 560ms ease-in-out
  }
}