/* ==========================================================================
   Vidra Motion System
   /shared/motion.css
   ========================================================================== */

/* === Entrance Animations === */

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-24px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(24px); }
  to { opacity: 1; transform: translateX(0); }
}

/* Entrance classes - apply to elements that should animate on page load */
.animate-fade-up {
  animation: fadeUp var(--duration-slow) var(--ease-out) both;
}

.animate-fade-in {
  animation: fadeIn var(--duration-slow) var(--ease-out) both;
}

.animate-scale-in {
  animation: scaleIn var(--duration-slow) var(--ease-out) both;
}

/* Stagger delays */
.delay-1 { animation-delay: 100ms; }
.delay-2 { animation-delay: 200ms; }
.delay-3 { animation-delay: 300ms; }
.delay-4 { animation-delay: 400ms; }
.delay-5 { animation-delay: 500ms; }
.delay-6 { animation-delay: 600ms; }
.delay-7 { animation-delay: 700ms; }
.delay-8 { animation-delay: 800ms; }

/* ==========================================================================
   Scroll Reveal
   Elements start hidden, JS adds .is-visible via IntersectionObserver
   ========================================================================== */

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Reveal variants */
.reveal-left {
  opacity: 0;
  transform: translateX(-24px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

.reveal-left.is-visible {
  opacity: 1;
  transform: translateX(0);
}

.reveal-right {
  opacity: 0;
  transform: translateX(24px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

.reveal-right.is-visible {
  opacity: 1;
  transform: translateX(0);
}

.reveal-scale {
  opacity: 0;
  transform: scale(0.95);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

.reveal-scale.is-visible {
  opacity: 1;
  transform: scale(1);
}

/* ==========================================================================
   Interactive States
   ========================================================================== */

/* Button press state */
button, .btn, [role="button"] {
  transition: transform var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out);
}

button:active, .btn:active, [role="button"]:active {
  transform: scale(0.97);
}

/* Card hover */
.card-hover {
  transition: transform var(--duration-base) var(--ease-out),
              box-shadow var(--duration-base) var(--ease-out),
              border-color var(--duration-base) var(--ease-out);
}

.card-hover:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

/* Subtle card hover (less dramatic) */
.card-hover-subtle {
  transition: transform var(--duration-base) var(--ease-out),
              box-shadow var(--duration-base) var(--ease-out),
              border-color var(--duration-base) var(--ease-out);
}

.card-hover-subtle:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Link hover underline animation */
.link-hover {
  position: relative;
  display: inline-block;
}

.link-hover::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--duration-base) var(--ease-out);
}

.link-hover:hover::after {
  width: 100%;
}

/* ==========================================================================
   Copy Feedback
   ========================================================================== */

.copy-feedback {
  position: relative;
}

.copy-feedback .copy-feedback__label {
  transition: opacity var(--duration-fast) var(--ease-out);
}

.copy-feedback.is-copied .copy-feedback__label {
  opacity: 0;
}

.copy-feedback::after {
  content: 'Copied!';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--color-success);
  opacity: 0;
  transform: scale(0.8);
  transition: opacity var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out);
  pointer-events: none;
}

.copy-feedback.is-copied::after {
  opacity: 1;
  transform: scale(1);
}

/* ==========================================================================
   Tabs
   ========================================================================== */

.tabs-nav {
  display: flex;
  gap: var(--space-1);
  border-bottom: 1px solid var(--color-border-muted);
  margin-bottom: var(--space-6);
  position: relative;
}

.tabs-nav__item {
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-muted);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out);
  margin-bottom: -1px;
}

.tabs-nav__item:hover {
  color: var(--color-text);
}

.tabs-nav__item.is-active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.tab-panel {
  display: none;
}

.tab-panel.is-active {
  display: block;
  animation: fadeIn var(--duration-base) var(--ease-out);
}

/* ==========================================================================
   Character Counter
   ========================================================================== */

.char-counter {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-subtle);
  text-align: right;
  margin-top: var(--space-1);
  transition: color var(--duration-fast) var(--ease-out);
}

.char-counter.is-warning {
  color: var(--color-warning);
}

.char-counter.is-over {
  color: var(--color-error);
  font-weight: var(--font-semibold);
}

/* ==========================================================================
   Hero Blobs (subtle background shapes)
   ========================================================================== */

.hero__blobs {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.hero__blob {
  position: absolute;
  border-radius: 50%;
  background: var(--color-primary);
  opacity: 0.05;
  filter: blur(80px);
  will-change: transform;
  contain: strict;
}

.hero__blob:nth-child(1) {
  width: 500px;
  height: 500px;
  top: -180px;
  right: -80px;
}

.hero__blob:nth-child(2) {
  width: 350px;
  height: 350px;
  bottom: -120px;
  left: -40px;
  background: var(--color-accent);
}

/* ==========================================================================
   Heading Accent Line
   ========================================================================== */

.reveal-heading {
  position: relative;
  display: inline-block;
}

.reveal-heading::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 3px;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  transition: width var(--duration-slower) var(--ease-out);
}

.reveal-heading.is-visible::after {
  width: 40px;
}

/* ==========================================================================
   Skeleton Loading
   ========================================================================== */

.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-bg-muted) 25%,
    var(--color-bg-subtle) 50%,
    var(--color-bg-muted) 75%
  );
  background-size: 200% 100%;
  animation: skeletonShimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

.skeleton--text {
  height: 1em;
  margin-bottom: var(--space-2);
}

.skeleton--text:last-child {
  width: 60%;
}

.skeleton--circle {
  border-radius: var(--radius-full);
}

@keyframes skeletonShimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ==========================================================================
   Gradient Text
   ========================================================================== */

.text-gradient {
  background: linear-gradient(
    135deg,
    var(--color-primary) 0%,
    var(--color-accent) 100%
  );
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ==========================================================================
   Auto-grow Textarea
   ========================================================================== */

.auto-grow {
  field-sizing: content;
  min-height: 3em;
  max-height: 50vh;
  resize: vertical;
}

/* ==========================================================================
   Reading Progress Bar
   ========================================================================== */

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--color-primary);
  z-index: 100;
  transition: width 100ms linear;
  width: 0%;
}

/* ==========================================================================
   Grain Texture Overlay
   ========================================================================== */

.grain::before {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  right: -50%;
  bottom: -50%;
  width: 200%;
  height: 200%;
  background-image: url("/shared/grain.png");
  background-repeat: repeat;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.07;
}

[data-theme="dark"] .grain::before {
  opacity: 0.04;
}

/* ==========================================================================
   Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  /* Kill all entrance animations */
  .animate-fade-up, .animate-fade-in, .animate-scale-in {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }

  /* Scroll reveal: show immediately */
  .reveal, .reveal-left, .reveal-right, .reveal-scale {
    opacity: 1;
    transform: none;
    transition: none;
  }

  /* Cards: keep color changes, remove motion */
  .card-hover:hover, .card-hover-subtle:hover {
    transform: none;
  }

  /* Buttons: no scale press */
  button:active, .btn:active, [role="button"]:active {
    transform: none;
  }

  /* Link underline: instant */
  .link-hover::after {
    transition: none;
  }

  /* Skeleton: static bar, no shimmer */
  .skeleton {
    animation: none;
  }

  /* Copy feedback: instant */
  .copy-feedback::after {
    transition: none;
  }

  /* Theme toggle: instant swap */
  .theme-toggle__sun,
  .theme-toggle__moon {
    transition: none;
  }

  /* Heading accent line: instant */
  .reveal-heading::after {
    transition: none;
  }

  /* Tab panels: no fade */
  .tab-panel.is-active {
    animation: none;
  }
}