Stepped Rainbow Border: CSS Border Animation

Stepped Rainbow Border

Six solid rainbow segments ring the box and tick forward one slot at a time. The conic-gradient uses hard color stops with small gaps, and each 60 degree step eases in and out on its own.

Also known as: hard stop gradient border, segmented rainbow border, rainbow segments css.

Stepped rainbow

Color Base size 16px Dark background Hold hover state

HTML

<div class="bdr-stepped-rainbow-border">Stepped rainbow</div>

CSS

@property --bdr-stepped-rainbow-border-a {
  syntax: "<angle>";
  inherits: false;
  initial-value: 0deg;
}
.bdr-stepped-rainbow-border {
  --c: var(--bdr-color, #3b82f6);
  font-size: var(--bdr-size, 16px);
  position: relative;
  display: grid;
  place-items: center;
  width: 15em;
  height: 8.5em;
  border-radius: 1em;
  font-family: system-ui, sans-serif;
  font-weight: 600;
  box-sizing: border-box;
  border: 0.24em solid transparent;
  background:
    linear-gradient(#fff, #fff) padding-box,
    conic-gradient(from var(--bdr-stepped-rainbow-border-a),
      #ef4444 0 15.6%, transparent 0 16.67%,
      #f97316 0 32.3%, transparent 0 33.33%,
      #facc15 0 49%, transparent 0 50%,
      #22c55e 0 65.6%, transparent 0 66.67%,
      #3b82f6 0 82.3%, transparent 0 83.33%,
      #a855f7 0 99%, transparent 0) border-box;
  color: color-mix(in srgb, var(--c) 55%, #111827);
  animation: bdr-stepped-rainbow-border-tick 6s cubic-bezier(0.7, 0, 0.25, 1) infinite;
}
@keyframes bdr-stepped-rainbow-border-tick {
  0%      { --bdr-stepped-rainbow-border-a: 0deg; }
  16.667% { --bdr-stepped-rainbow-border-a: 60deg; }
  33.333% { --bdr-stepped-rainbow-border-a: 120deg; }
  50%     { --bdr-stepped-rainbow-border-a: 180deg; }
  66.667% { --bdr-stepped-rainbow-border-a: 240deg; }
  83.333% { --bdr-stepped-rainbow-border-a: 300deg; }
  100%    { --bdr-stepped-rainbow-border-a: 360deg; }
}

@media (prefers-reduced-motion: reduce) {
  .bdr-stepped-rainbow-border, .bdr-stepped-rainbow-border *, .bdr-stepped-rainbow-border::before, .bdr-stepped-rainbow-border::after, .bdr-stepped-rainbow-border *::before, .bdr-stepped-rainbow-border *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

Customizing this snippet

Color: set --bdr-color on the element or a parent. Currently previewing #3b82f6.
Base size: set --bdr-size. Every other dimension is in em, so the whole thing scales together. Currently previewing 16px.
Speed: change the duration on the transition or animation shorthand. Staggered delays are relative, so they keep their rhythm.
Reduced motion: the rule at the end of the CSS turns the motion off for people who asked their OS for less of it. Keep it.

Stepped Rainbow Border

HTML

CSS

Customizing this snippet

Similar border animations