CSS Native Agent Skill

.progress-bar {
  animation: grow-width linear both;
  animation-timeline: scroll(root block);
}

@keyframes grow-width {
  from { transform: scaleX(0); }
  to   { transform: scaleX(1); }
}

.reveal {
  animation: fade-in linear both;
  animation-timeline: view();
  animation-range: entry 0% entry 100%;
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(2rem); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Named ranges: cover | contain | entry | exit | entry-crossing | exit-crossing */
animation-range: entry 0% entry 100%;    /* animate during entry only */
animation-range: contain 0% contain 100%; /* animate while fully visible */
animation-range: entry 25% exit 75%;      /* custom start/end */

document.startViewTransition(() => {
  // Update the DOM synchronously
  updateContent();
});

/* Control the transition animation */
::view-transition-old(root) {
  animation: fade-out 200ms ease-out;
}
::view-transition-new(root) {
  animation: fade-in 300ms ease-in;
}

/* Named transitions for specific elements */
.hero-image { view-transition-name: hero; }

::view-transition-group(hero) {
  animation-duration: 400ms;
  animation-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

/* Both pages need this */
@view-transition { navigation: auto; }

/* Outgoing page */
.card { view-transition-name: card-detail; }

/* Incoming page */
.detail-hero { view-transition-name: card-detail; }

.card { view-transition-class: card; }

::view-transition-group(*.card) {
  animation-duration: 350ms;
  animation-timing-function: var(--ease-spring);
}

.dialog {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 300ms ease, transform 300ms ease,
              display 300ms allow-discrete;

  @starting-style {
    opacity: 0;
    transform: translateY(-1rem);
  }
}

.dialog[hidden] {
  opacity: 0;
  transform: translateY(-1rem);
  display: none;
}

.trigger {
  anchor-name: --my-trigger;
}

.tooltip {
  position: fixed;
  position-anchor: --my-trigger;
  position-area: top center;
  margin-bottom: 0.5rem;

  /* Fallback if no space on top */
  position-try-fallbacks: --bottom;
}

@position-try --bottom {
  position-area: bottom center;
  margin-top: 0.5rem;
}

.tooltip[popover]:popover-open {
  opacity: 1;
  transform: scale(1);
  transition: opacity 150ms ease, transform 150ms ease,
              display 150ms allow-discrete, overlay 150ms allow-discrete;

  @starting-style {
    opacity: 0;
    transform: scale(0.96);
  }
}

.card-container {
  container-type: inline-size;
  container-name: card;
}

@container card (min-width: 400px) {
  .card-content {
    animation: slide-in-right 400ms var(--ease-out-expo);
  }
}

@container card (max-width: 399px) {
  .card-content {
    animation: fade-in 300ms ease;
  }
}

@keyframes slide-in-right {
  from { transform: translateX(10cqw); opacity: 0; }
  to   { transform: translateX(0); opacity: 1; }
}

.reveal {
  clip-path: inset(0 100% 0 0);
  transition: clip-path 600ms cubic-bezier(0.77, 0, 0.175, 1);
}
.reveal.visible {
  clip-path: inset(0 0 0 0);
}

.glass {
  background: oklch(0.98 0.01 250 / 0.6);
  backdrop-filter: blur(12px) saturate(1.8);
  -webkit-backdrop-filter: blur(12px) saturate(1.8); /* Safari */
}

.overlay-text {
  mix-blend-mode: difference;
  color: white; /* inverts over any background */
}

.mesh {
  background:
    radial-gradient(at 20% 30%, oklch(0.7 0.2 310) 0%, transparent 50%),
    radial-gradient(at 80% 60%, oklch(0.6 0.18 250) 0%, transparent 50%),
    radial-gradient(at 50% 80%, oklch(0.75 0.15 170) 0%, transparent 50%),
    oklch(0.15 0.02 280);
}

.spinner {
  background: conic-gradient(from 0deg, transparent 0%, oklch(0.7 0.15 250) 100%);
  border-radius: 50%;
  mask: radial-gradient(farthest-side, transparent calc(100% - 4px), black calc(100% - 4px));
  animation: spin 1s linear infinite;
}