/* ==========================================================================
   spa-transitions.css — SPA router visual layer
   --------------------------------------------------------------------------
   Progress bar, page transition animations, View Transition API integration,
   accessibility announcer, and reduced-motion fallbacks.
   ========================================================================== */

/* ======================== PROGRESS BAR ======================== */

.spa-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2.5px;
  z-index: 100000;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.4s ease;
}

.spa-progress.active {
  opacity: 1;
}

.spa-progress-bar {
  position: relative;
  height: 100%;
  background: var(--accent, #f0a63b);
  transform-origin: 0 0;
  transform: scaleX(0);
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: transform;
}

.spa-progress-bar::after {
  content: '';
  position: absolute;
  right: 0;
  top: -1px;
  width: 64px;
  height: 4px;
  background: var(--accent, #f0a63b);
  box-shadow: 0 0 12px var(--accent, #f0a63b),
              0 0 4px  var(--accent, #f0a63b);
  opacity: 0.7;
  border-radius: 0 50% 50% 0;
}

[dir="rtl"] .spa-progress-bar {
  transform-origin: 100% 0;
}

[dir="rtl"] .spa-progress-bar::after {
  right: auto;
  left: 0;
  border-radius: 50% 0 0 50%;
}


/* ======================== PAGE TRANSITIONS (CSS Fallback) ======================== */

.spa-leave {
  opacity: 0 !important;
  filter: blur(6px) !important;
  transform: scale(0.99) !important;
  transition: opacity 150ms ease,
              filter  150ms ease,
              transform 150ms ease !important;
}

.spa-enter-prep {
  opacity: 0 !important;
  filter: blur(6px) !important;
  transform: translateY(10px) scale(0.99) !important;
  transition: none !important;
}

.spa-enter {
  opacity: 1 !important;
  filter: blur(0) !important;
  transform: translateY(0) scale(1) !important;
  transition: opacity 250ms cubic-bezier(0, 0, 0.2, 1),
              filter  250ms cubic-bezier(0, 0, 0.2, 1),
              transform 250ms cubic-bezier(0, 0, 0.2, 1) !important;
}


/* ======================== VIEW TRANSITION API ======================== */

#page-content {
  view-transition-name: page-content;
}

::view-transition-old(root),
::view-transition-new(root) {
  animation: none;
  mix-blend-mode: normal;
}

::view-transition-old(page-content) {
  animation: spa-vt-out 150ms cubic-bezier(0.4, 0, 1, 1) both;
}

::view-transition-new(page-content) {
  animation: spa-vt-in 250ms cubic-bezier(0, 0, 0.2, 1) both;
}

@keyframes spa-vt-out {
  from {
    opacity: 1;
    filter: blur(0);
    transform: scale(1);
  }
  to {
    opacity: 0;
    filter: blur(6px);
    transform: scale(0.99);
  }
}

@keyframes spa-vt-in {
  from {
    opacity: 0;
    filter: blur(6px);
    transform: translateY(10px) scale(0.99);
  }
  to {
    opacity: 1;
    filter: blur(0);
    transform: translateY(0) scale(1);
  }
}


/* ======================== ACCESSIBILITY ======================== */

.spa-announcer {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}


/* ======================== REDUCED MOTION ======================== */

@media (prefers-reduced-motion: reduce) {
  .spa-progress-bar {
    transition-duration: 0.01ms;
  }

  .spa-leave,
  .spa-enter-prep,
  .spa-enter {
    transition-duration: 0.01ms !important;
    filter: none !important;
    transform: none !important;
  }

  ::view-transition-old(page-content),
  ::view-transition-new(page-content) {
    animation-duration: 0.01ms !important;
  }
}