#backto {
  clip-path: polygon(100% 20%, 46% 35%, 56% 1%, 2% 54%, 45% 96%, 42% 69%, 91% 83%);
  padding: 80px;
  background: rgba(0, 0, 0, 0.5);
  position: absolute;
  right: 2em;
  top: 2em;
  animation: squeeksqueeksqueeksqueek 5s cubic-bezier(0, .63, .39, .99) infinite;
  margin: 50px;
  z-index: 20;
  font-family: monospace;
  color: black;
}
@keyframes squeeksqueeksqueeksqueek {
  0%{ transform: skew(10deg, 10deg) } 
  50%{ transform: skew(-10deg, -10deg) }
  100%{ transform: skew(10deg, 10deg) }
}

#backto span {
  font-size: 1.5rem;
  filter: drop-shadow(-1px 1px 0px white)
    drop-shadow(1px -1px 0px white)
    drop-shadow(1px 1px 0px white)
    drop-shadow(-1px -1px 0px white);
}

#backto a {
  animation: gay 4s linear infinite;
}

@keyframes gay {
  0% {background: red;}
  10% {background: maroon;}
  20% {background: orange;}
  30% {background: yellow;}
  40% {background: green;}
  50% {background: blue;}
  60% {background: cyan;}
  70% {background: purple;}
  80% {background: magenta;}
  90% {background: magenta;}
  100% {background: red;}  
}