span.rainbow {
  cursor: wait;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 0em;
}

/* I don't remember where I originally saw this lovely
bit of css, but it made me very happy a number of years
ago, and so here it lives on. Thank you, internet.
*/
.rainbow {
  -o-animation: rainbow 15s ease infinite;
  -webkit-animation: rainbow 15s ease infinite;
  -z-animation: rainbow 15s ease infinite;
  animation: rainbow 15s ease infinite;
  background: -moz-linear-gradient(
    0deg,
    #ff2400,
    #fedb00,
    /* PANTONE 108 C */ #fedb00,
    #e81d1d,
    #e8b71d,
    #e3e81d,
    #1de840,
    #1ddde8,
    #2b1de8,
    #dd00f3,
    #dd00f3,
    #440099,
    /* PANTONE Violet C */ #440099
  );
  background: -o-linear-gradient(
    0deg,
    #ff2400,
    #fedb00,
    #fedb00,
    #e81d1d,
    #e8b71d,
    #e3e81d,
    #1de840,
    #1ddde8,
    #2b1de8,
    #dd00f3,
    #dd00f3,
    #440099,
    #440099
  );
  background: -webkit-linear-gradient(
    0deg,
    #ff2400,
    #fedb00,
    #fedb00,
    #e81d1d,
    #e8b71d,
    #e3e81d,
    #1de840,
    #1ddde8,
    #2b1de8,
    #dd00f3,
    #dd00f3,
    #440099,
    #440099
  );
  background: linear-gradient(
    0deg,
    #ff2400,
    #fedb00,
    #fedb00,
    #e81d1d,
    #e8b71d,
    #e3e81d,
    #1de840,
    #1ddde8,
    #2b1de8,
    #dd00f3,
    #dd00f3,
    #440099,
    #440099
  );
  background: linear-gradient(
    0deg,
    #ff2400,
    #fedb00,
    #fedb00,
    #e81d1d,
    #e8b71d,
    #e3e81d,
    #1de840,
    #1ddde8,
    #2b1de8,
    #dd00f3,
    #dd00f3,
    #440099,
    #440099
  );
  background-size: 2500% 2500%;
}

/* ANIMATIONS */
@-webkit-keyframes rainbow {
  0% {
    background-position: 0% 82%;
  }
  50% {
    background-position: 100% 19%;
  }
  100% {
    background-position: 0% 82%;
  }
}

@-moz-keyframes rainbow {
  0% {
    background-position: 0% 82%;
  }
  50% {
    background-position: 100% 19%;
  }
  100% {
    background-position: 0% 82%;
  }
}

@-o-keyframes rainbow {
  0% {
    background-position: 0% 82%;
  }
  50% {
    background-position: 100% 19%;
  }
  100% {
    background-position: 0% 82%;
  }
}

@keyframes rainbow {
  0% {
    background-position: 0% 82%;
  }
  50% {
    background-position: 100% 19%;
  }
  100% {
    background-position: 0% 82%;
  }
}