@keyframes submitting {
  0%    { -webkit-mask-position: 0% 0%,   50% 0%,   100% 0% }
  12.5% { -webkit-mask-position: 0% 50%,  50% 0%,   100% 0% }
  25%   { -webkit-mask-position: 0% 100%, 50% 50%,  100% 0% }
  37.5% { -webkit-mask-position: 0% 100%, 50% 100%, 100% 50% }
  50%   { -webkit-mask-position: 0% 100%, 50% 100%, 100% 100% }
  62.5% { -webkit-mask-position: 0% 50%,  50% 100%, 100% 100% }
  75%   { -webkit-mask-position: 0% 0%,   50% 50%,  100% 100% }
  87.5% { -webkit-mask-position: 0% 0%,   50% 0%,   100% 50% }
  100%  { -webkit-mask-position: 0% 0%,   50% 0%,   100% 0% }
}