| name | css-animations |
| description | CSS animation adapter patterns for HyperFrames. Use when authoring CSS keyframes, animation-delay based timing, animation-fill-mode, animation-play-state, or CSS-only motion that HyperFrames must seek deterministically during preview and rendering. |
CSS Animations for HyperFrames
HyperFrames can seek CSS keyframe animations through its css runtime adapter. Use this for simple repeated motifs, background motion, shimmer, glow, masks, and non-sequenced decoration.
For scene choreography, GSAP is usually clearer. CSS animations work best when the motion belongs to one element and has a fixed duration.
Contract
- Put the animated element in the DOM before runtime initialization finishes.
- Give timed elements a
data-start value so local animation time matches the clip.
- Use finite
animation-duration and animation-iteration-count because the negative-delay fallback cannot represent unbounded duration in environments without WAAPI-backed CSS animations.
- Prefer
animation-fill-mode: both so seeked states hold before and after active motion.
- Avoid wall-clock JavaScript, hover-triggered state, and class toggles that depend on user events.
The adapter discovers elements with computed animation-name, seeks their browser Animation handles when available, and falls back to pausing with negative animation-delay.
Basic Pattern
<div
id="pulse-ring"
class="clip pulse-ring"
data-start="0"
data-duration="4"
data-track-index="2"
></div>
<style>
.pulse-ring {
width: 280px;
height: 280px;
border: 4px solid rgba(255, 255, 255, 0.7);
border-radius: 50%;
animation-name: pulse-ring;
animation-duration: 1200ms;
animation-timing-function: cubic-bezier(0.2, 0, 0, 1);
animation-iteration-count: 3;
animation-fill-mode: both;
}
@keyframes pulse-ring {
from {
opacity: 0;
transform: scale(0.82);
}
35% {
opacity: 1;
}
to {
opacity: 0;
transform: scale(1.18);
}
}
</style>
Stagger Pattern
Use CSS custom properties to avoid duplicating keyframes:
<div class="clip dots" data-start="1" data-duration="3" data-track-index="3">
<span style="--i: 0"></span>
<span style="--i: 1"></span>
<span style="--i: 2"></span>
</div>
<style>
.dots span {
display: inline-block;
width: 18px;
height: 18px;
margin-right: 10px;
border-radius: 50%;
background: currentColor;
animation: dot-pop 900ms ease-out both;
animation-delay: calc(var(--i) * 120ms);
}
@keyframes dot-pop {
from {
opacity: 0;
transform: translateY(18px) scale(0.75);
}
to {
opacity: 1;
transform: translateY(0) scale(1);
}
}
</style>
Good Uses
- Decorative loops with a known repeat count.
- Mask, glow, shimmer, grain, and subtle parallax layers.
- Simple one-element entrances where a full JS timeline would be excessive.
Avoid
- Infinite CSS animations unless you have verified the browser exposes seekable WAAPI-backed CSS animation handles. Prefer a finite iteration count covering the visible duration.
- Animating layout properties like
top, left, width, or height when transforms work.
- Relying on hover, focus, scroll, or media queries to trigger render-critical motion.
- Changing animation classes after startup unless another deterministic timeline controls that change.
Validation
After editing CSS animation compositions:
npx hyperframes lint
npx hyperframes validate
Credits And References
