/* ABOUTME: Micro-interactions and motion polish — whispered transitions, never loud. */
/* ABOUTME: Consumes motion tokens from tokens.css. All rules disabled under prefers-reduced-motion. */

/* ---------------------------------------------------------------
   Funder row hover
   A tint shift only. No scale, no shadow, no border movement.
   Opt-in by adding .funder-row to the row element (usually an
   anchor wrapping the row content).
--------------------------------------------------------------- */

.funder-row {
  transition: background-color var(--duration-fast) var(--ease-linear-soft);
}

.funder-row:hover {
  background-color: var(--color-canvas-soft);
}

/* ---------------------------------------------------------------
   Loading shimmer — hairline placeholder.
   Replaces spinners on search results. Opt-in via .shimmer.
   The shimmer container paints the placeholder bars; each row
   inside acts as one "line" of faux content.
--------------------------------------------------------------- */

.shimmer {
  display: block;
}

.shimmer-row {
  position: relative;
  overflow: hidden;
  height: 1rem;
  margin-bottom: var(--space-3);
  background-color: var(--color-rule-soft);
  border-radius: var(--radius-sharp);
}

.shimmer-row::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 255, 255, 0.55) 50%,
    transparent 100%
  );
  transform: translateX(-100%);
  animation: shimmer-sweep var(--duration-slower) var(--ease-linear-soft) infinite;
}

.shimmer-row--short {
  width: 40%;
}

.shimmer-row--medium {
  width: 65%;
}

@keyframes shimmer-sweep {
  0% {
    transform: translateX(-100%);
  }
  100% {
    transform: translateX(100%);
  }
}

/* ---------------------------------------------------------------
   HTMX swap transitions — uses the CSS View Transitions API
   when the browser supports it. Progressively enhances; on
   browsers without support the swap is instant (no polyfill).

   Two layers:
   1. @view-transition auto — opts the document into same-document
      transitions for htmx-boosted navigation (feature-detect via
      the at-rule parser; unsupported browsers ignore it).
   2. ::view-transition-old / ::view-transition-new rules — the
      outgoing content fades out, the incoming content fades in
      and slides up a hairline.
--------------------------------------------------------------- */

@view-transition {
  navigation: auto;
}

::view-transition-old(root) {
  animation: vt-fade-out var(--duration-slow) var(--ease-linear-soft) both;
}

::view-transition-new(root) {
  animation: vt-fade-slide-in var(--duration-slow) var(--ease-out-editorial) both;
}

@keyframes vt-fade-out {
  to {
    opacity: 0;
  }
}

@keyframes vt-fade-slide-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------------------------------------------------------------
   Save button morph — "Save" to "Saved" with gold check.
   The .save-btn base class lives in tokens.css. This layer adds
   the morph animation when the saved variant mounts.
--------------------------------------------------------------- */

.save-btn {
  transition:
    background-color var(--duration-slow) var(--ease-out-soft),
    border-color var(--duration-slow) var(--ease-out-soft),
    color var(--duration-slow) var(--ease-out-soft);
}

.save-btn--saved .save-btn__check {
  display: inline-block;
  animation: save-check-in var(--duration-slow) var(--ease-out-soft) both;
}

@keyframes save-check-in {
  from {
    opacity: 0;
    transform: translateY(-1px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------------------------------------------------------------
   Sidebar active state — a hairline gold left border that slides
   between items on navigation. The active item gets .sidebar-link--active
   (or aria-current="page"); the border is a pseudo-element so it
   can animate position/height independently of layout.
--------------------------------------------------------------- */

.sidebar-link {
  position: relative;
  transition: color var(--duration-fast) var(--ease-linear-soft);
}

.sidebar-link::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  height: 0;
  width: 2px;
  background-color: var(--color-accent);
  transform: translateY(-50%);
  transition:
    height var(--duration-slow) var(--ease-out-soft),
    top var(--duration-slow) var(--ease-out-soft);
}

.sidebar-link[aria-current="page"]::before,
.sidebar-link--active::before {
  height: 70%;
}

/* ---------------------------------------------------------------
   Page transitions on non-HTMX navigation.
   A short fade-in on <main> via the --duration-base token, applied
   through .page-fade-in which base.html / base_app.html opt into.
--------------------------------------------------------------- */

main.page-fade-in,
.page-fade-in {
  animation: page-fade-in var(--duration-base) var(--ease-linear-soft) both;
}

@keyframes page-fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* ---------------------------------------------------------------
   Reduced motion — honor user preference. Every animation and
   transition above is reduced to effectively instant. Tokens
   already collapse durations to 0ms in tokens.css, but we belt-
   and-brace here by also disabling the keyframe animations so
   users with the preference get the resulting static state, not
   a 0ms animation loop.
--------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  .funder-row,
  .sidebar-link,
  .sidebar-link::before,
  .save-btn,
  main.page-fade-in,
  .page-fade-in {
    transition: none;
    animation: none;
  }

  .shimmer-row::after,
  ::view-transition-old(root),
  ::view-transition-new(root),
  .save-btn--saved .save-btn__check {
    animation: none;
  }
}