Effects
Hue Rotate Animation
Cycles continuously through the colour wheel.
Opens with this animation loaded. Nothing is uploaded — the scene travels in the link.
.hue-cycle {
transform: translate3d(180px, 100px, 0);
width: 120px;
height: 120px;
background: #6366f1;
border-radius: 20px;
animation: hue-cycle-anim 3000ms linear 0ms infinite both;
will-change: transform, opacity;
}
@keyframes hue-cycle-anim {
0% {
filter: none;
}
100% {
filter: hue-rotate(360deg);
}
}
@media (prefers-reduced-motion: reduce) {
.hue-cycle {
animation: none;
transition: none;
}
}Why it is built this way
hue-rotate shifts every colour in the element at once, including text and borders, which is why it works on a whole component rather than needing per-property colour keyframes.
What it animates
1 property across 1 CSS declaration. The bar shows when each one is moving.
filterWhat it costs to run
Filter is handled by the compositor: no layout, no repaint, and the work can run off the main thread. This is the cheap end of CSS animation, which is why it stays smooth on a slow phone where other properties will not.
It runs for 3.00s across 2 keyframe stops, with every property moving over the same window.
A single linear curve on a plain box. Linear looks wrong on almost anything that starts and stops — but it is exactly right here, because a continuous loop that eases would visibly stutter at the seam where it repeats.
Accessibility
Nothing here hides content — filter moves over 3.00s and the element is visible throughout. The exported prefers-reduced-motion guard still silences it, which matters most for the looping ones: motion that never stops is the kind that makes people feel unwell.