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                <figure class="rainbow bands"></figure>
<figure class="rainbow smooth"></figure>


  Pure CSS Rainbows - Part of Project Rainbow

/* Variables (Play with these) */
$rainbow-diameter: 300px;
$rainbow-thickness: 60px;
$animation-duration: 6s;
$background-colour: #1A3256;
$rainbow-filter: hue-rotate(-15deg) contrast(95%);
$rainbow-opacity: 1;
  #FF0000, // red
  #FF7F00, // orange
  #FFFF00, // yellow
  #00FF00, // green
  #0000FF, // blue
  #4B0082, // indigo
  #9400D3; // violet

/* Leave these alone */
$rainbow-radius: $rainbow-diameter / 2;
$colour-band-width: $rainbow-thickness / length($rainbow-colours);

// Generate a rainbow gradient
@mixin rainbowGradient($type) {
  // Base gradient
    circle at center,
    transparent $rainbow-radius - $rainbow-thickness,
    nth($rainbow-colours, -1) $rainbow-radius - $rainbow-thickness;
  // Generate banded or smooth radial gradient
  @for $i from 1 through length($rainbow-colours) {
    // Next colour
    $colour: nth($rainbow-colours, -$i);
    // Start of band
    $rainbow-gradient: append(
      $colour $rainbow-radius - ($rainbow-thickness - 
          $type == "smooth",
          // Smooth: Offset the band start by half a band for better blending
          $colour-band-width + ($colour-band-width / (length($rainbow-colours))),
          // Bands: Do not offset the band
        ) * ($i - 1)

    // End of band (only use this for type == band)
    @if($type == "bands") {
      $rainbow-gradient: append(
        $colour $rainbow-radius - ($rainbow-thickness - $colour-band-width * $i)
  background: radial-gradient($rainbow-gradient);

// the rainbow element
@mixin rainbow($type) {
  &::before {
    content: '';
    position: absolute;
    width: $rainbow-diameter;
    height: $rainbow-diameter;
    filter: $rainbow-filter;
    opacity: $rainbow-opacity;
    border-radius: 50%;
    @include rainbowGradient($type);

// Rainbow container
.rainbow {
  width: $rainbow-diameter;
  height: $rainbow-radius;
  margin: 0px;
  position: relative;
  overflow: hidden;

  // Rainbow classes
  &.bands { @include rainbow("bands"); }
  &.smooth { @include rainbow("smooth"); }
  // Animation element
  &::after {
    content: '';
    position: absolute;
    transform-origin: $rainbow-radius $rainbow-radius;
    width: $rainbow-diameter;
    height: $rainbow-radius;
    background-color: $background-colour;
    animation: wipe $animation-duration ease-in-out infinite;

// Wipe animation
@keyframes wipe {
  0% { transform: rotate(0deg); }
  20% { transform: rotate(180deg); }
  70% { transform: rotate(180deg); }
  90% { transform: rotate(360deg); }
  100% { transform: rotate(360deg); }

html, body {
  margin: 0px;
  height: 100%;

body {
  display: flex;
  justify-content: space-evenly;
  align-items: center;
  flex-wrap: wrap;
  background-color: $background-colour;