Runs/circle · chain · Sonnet 5/004
circle · chain · Sonnet 5 · step 004 of 64
offline render, Chrome 154, light scheme, 2 s of virtual time
runs in a sandboxed frame with no origin; live pages may fetch CDN fonts the offline render did not
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Pulsing Circle</title>
<style>
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
width: 100vw;
height: 100vh;
display: flex;
justify-content: center;
align-items: center;
background: radial-gradient(circle at center, #1a1a2e 0%, #0d0d17 100%);
overflow: hidden;
}
svg {
width: min(400px, 80vmin);
height: min(400px, 80vmin);
overflow: visible;
}
.core {
animation: pulse 2.5s cubic-bezier(0.4, 0, 0.2, 1) infinite;
transform-origin: 200px 200px;
filter: url(#glow);
will-change: transform, opacity;
}
.ring {
fill: none;
stroke: #8ec5ff;
stroke-width: 2;
transform-origin: 200px 200px;
animation: ripple 2.5s ease-out infinite;
will-change: transform, opacity;
}
.ring--delay-1 {
animation-delay: 0.83s;
}
.ring--delay-2 {
animation-delay: 1.66s;
}
@keyframes pulse {
0%, 100% {
transform: scale(1);
opacity: 0.9;
}
50% {
transform: scale(1.05);
opacity: 1;
}
}
@keyframes ripple {
0% {
transform: scale(1);
opacity: 0.6;
}
100% {
transform: scale(1.35);
opacity: 0;
}
}
@media (prefers-reduced-motion: reduce) {
.core, .ring {
animation: none;
}
.ring {
opacity: 0.35;
}
}
</style>
</head>
<body>
<svg id="ae683f770" viewBox="0 0 400 400" role="img" aria-label="Pulsing blue circle animation">
<defs>
<radialGradient id="circleGradient" cx="35%" cy="35%" r="65%">
<stop offset="0%" stop-color="#8ec5ff"/>
<stop offset="55%" stop-color="#4a7dd9"/>
<stop offset="100%" stop-color="#1f3a75"/>
</radialGradient>
<filter id="glow" x="-50%" y="-50%" width="200%" height="200%">
<feGaussianBlur in="SourceGraphic" stdDeviation="8" result="blur"/>
<feMerge>
<feMergeNode in="blur"/>
<feMergeNode in="SourceGraphic"/>
</feMerge>
</filter>
</defs>
<circle class="ring" cx="200" cy="200" r="180"/>
<circle class="ring ring--delay-1" cx="200" cy="200" r="180"/>
<circle class="ring ring--delay-2" cx="200" cy="200" r="180"/>
<circle class="core" cx="200" cy="200" r="180" fill="url(#circleGradient)"/>
</svg>
</body>
</html>
what changed from step 003
+6 / -1 lines
} .core {- animation: pulse 2.5s ease-in-out infinite;+ animation: pulse 2.5s cubic-bezier(0.4, 0, 0.2, 1) infinite; transform-origin: 200px 200px; filter: url(#glow);+ will-change: transform, opacity; } .ring {⋯ line 37 transform-origin: 200px 200px; animation: ripple 2.5s ease-out infinite;+ will-change: transform, opacity; } .ring--delay-1 {⋯ line 68 .core, .ring { animation: none;+ }+ .ring {+ opacity: 0.35; } }
What the model said
Made two improvements to `0.html`: 1. **Smoother, higher-performance animation** — added `will-change: transform, opacity` on `.core` and `.ring` (hints the browser to optimize compositing) and switched the core's pulse to a `cubic-bezier` ease for a more natural feel than the default `ease-in-out`. 2. **Fixed reduced-motion fallback** — previously, disabling the animation left the rings at full default opacity (1), causing them to render as solid overlapping circles instead of a clean static glow. Now they settle at `opacity: 0.35` for a sensible static state.