/* ==========================================================================
   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(-6px);
  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%;
}

/* ==========================================================================
   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("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 9999;
  opacity: 0.4;
}

[data-theme="dark"] .grain::before {
  opacity: 0.25;
}

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

@media (prefers-reduced-motion: reduce) {
  .animate-fade-up, .animate-fade-in, .animate-scale-in {
    animation: none;
    opacity: 1;
    transform: none;
  }

  .reveal, .reveal-left, .reveal-right, .reveal-scale {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .card-hover:hover, .card-hover-subtle:hover {
    transform: none;
  }

  button:active, .btn:active, [role="button"]:active {
    transform: none;
  }

  .link-hover::after {
    transition: none;
  }
}