#btn--yp {
  box-sizing: content-box;
  position: fixed;
  z-index: 9;
  bottom: 1em;
  right: 1em;
  border: solid 1em transparent;
  width: 4.625em;
  height: 3.25em;
  background: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/2017/icon-yp.svg) 50%/cover content-box;
  font: 16px/ 1.25 trebuchet ms, sans-serif;
  text-indent: 200vw;
  text-shadow: none;
  filter: grayscale(1) drop-shadow(0 0 1px #e8e0e0);
  transition: .5s;
  white-space: nowrap;
}
#btn--yp:before {
  box-sizing: inherit;
  position: absolute;
  left: 0;
  bottom: 100%;
  margin: 1em -.5em;
  padding: .5em;
  width: 100%;
  border-radius: 5px;
  background: #e8e0e0;
  color: #000;
  text-align: center;
  text-decoration: none;
  text-indent: 0vw;
  white-space: normal;
  animation: float 1s ease-in-out infinite alternate;
  content: attr(data-txt);
}
#btn--yp:hover, #btn--yp:focus {
  outline: none;
  filter: grayscale(0) drop-shadow(0 0 1px crimson);
}

@keyframes float {
  to {
    transform: translateY(0.75em);
  }
}
body {
  background: #130912;
}

.seg {
  display: flex;
  position: absolute;
  top: 50%;
  left: 50%;
  width: 5em;
  height: 6px;
  transform: translate(-50%, -50%) rotate(calc(var(--k)/var(--n)*1turn)) translate(calc(6px/var(--tan) + .5*5em));
}
.seg::before, .seg::after {
  --i: 0;
  --sgn-i: calc(1 - 2*var(--i));
  flex: 1;
  margin: 0 1px;
  border-radius: 3px;
  transform-origin: calc(var(--i)*100%);
  background: linear-gradient(calc(var(--sgn-i)*-90deg), #3e1c33, #602749, #b14623, #f6921d);
  animation: zip 1s ease-out calc((var(--k)/var(--n) - 1)*2*1s) infinite alternate;
  content: "";
}
.seg::after {
  --i: 1 ;
}

@keyframes zip {
  0%, 50% {
    transform: none;
  }
  75%, 100% {
    transform: rotate(calc(var(--sgn-i)*68deg));
  }
}