Envelope
CSSTwo concentric rectangular frames with dimension line callouts that slowly expand outward before resetting at their boundary.
- Tier
- CSS
- Dependencies
- None
- Duration
- 4.2 s, loops
- Categories
- Backgrounds and ambient
- Use cases
- Security and trust, Ambient background
- Industries
- SaaS and software, Security and identity
- Style
- Technical · light stroke
- Set
- perimeter
- Tags
- geometricscaleambientminimalstroke
Companion assets
The same artwork, not animated. Derived from the entry’s own resting state, so it matches exactly.
Code
animation.svg
<svg xmlns="http://www.w3.org/2000/svg" fill="none" aria-hidden="true" class="pulsar pulsar-perimeter-envelope" data-pulsar="perimeter-envelope" viewBox="0 0 160 96"><rect width="56" height="32" x="52" y="32" stroke="currentColor" opacity=".35"></rect><g class="perimeter-envelope-outer"><rect width="76" height="48" x="42" y="24" fill="var(--pulsar-accent, currentColor)" fill-opacity=".05" stroke="var(--pulsar-accent, currentColor)" stroke-width="1.5"></rect><path stroke="var(--pulsar-accent, currentColor)" d="M38 28v-8h8"></path><path stroke="var(--pulsar-accent, currentColor)" d="M122 28v-8h-8"></path><path stroke="var(--pulsar-accent, currentColor)" d="M38 68v8h8"></path><path stroke="var(--pulsar-accent, currentColor)" d="M122 68v8h-8"></path></g><g class="perimeter-envelope-dims"><line x1="80" x2="80" y1="12" y2="18" stroke="currentColor" opacity=".6"></line><line x1="80" x2="80" y1="78" y2="84" stroke="currentColor" opacity=".6"></line><line x1="28" x2="34" y1="48" y2="48" stroke="currentColor" opacity=".6"></line><line x1="126" x2="132" y1="48" y2="48" stroke="currentColor" opacity=".6"></line></g></svg>
animation.css
.pulsar-perimeter-envelope {
display: block;
overflow: visible;
}
.pulsar-perimeter-envelope .perimeter-envelope-outer {
animation: perimeter-envelope-expand-anim 4200ms ease-in-out infinite;
transform-origin: 80px 48px;
}
.pulsar-perimeter-envelope .perimeter-envelope-dims {
animation: perimeter-envelope-dims-anim 4200ms ease-in-out infinite;
transform-origin: 80px 48px;
}
@keyframes perimeter-envelope-expand-anim {
0%,
100% {
transform: scale(0.94);
opacity: 0.7;
}
50% {
transform: scale(1.08);
opacity: 1;
}
}
@keyframes perimeter-envelope-dims-anim {
0%,
100% {
transform: scale(0.92);
}
50% {
transform: scale(1.1);
}
}
@media (prefers-reduced-motion: reduce) {
.pulsar-perimeter-envelope .perimeter-envelope-outer,
.pulsar-perimeter-envelope .perimeter-envelope-dims {
animation: none;
}
}