/* =====================================================
   TRANSITION RUNTIMES (RESTRAINT PHILOSOPHY)
   ===================================================== */
:root {
  /* Restraint: Speed and smoothness (Kowalski & Krehel weighted) */
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
  
  --duration-fast: 180ms;   /* Frequency Gate: high-frequency clicks */
  --duration-normal: 300ms; /* Normal panels, page reveals */
  --duration-slow: 600ms;   /* Large entries, images */
}

/* =====================================================
   SCROLL REVEAL (INTERSECTION OBSERVER TARGETS)
   ===================================================== */
.reveal-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--duration-slow) var(--ease-out-expo), 
              transform var(--duration-slow) var(--ease-out-expo);
  will-change: opacity, transform;
}

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

/* Stagger delay classes (calculated dynamically in JS, but fallback in CSS) */
.reveal-delay-1 { transition-delay: 50ms; }
.reveal-delay-2 { transition-delay: 100ms; }
.reveal-delay-3 { transition-delay: 150ms; }
.reveal-delay-4 { transition-delay: 200ms; }
.reveal-delay-5 { transition-delay: 250ms; }

/* Horizontal slide reveal for offset elements */
.reveal-slide-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: opacity var(--duration-slow) var(--ease-out-expo), 
              transform var(--duration-slow) var(--ease-out-expo);
  will-change: opacity, transform;
}

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

.reveal-slide-right {
  opacity: 0;
  transform: translateX(30px);
  transition: opacity var(--duration-slow) var(--ease-out-expo), 
              transform var(--duration-slow) var(--ease-out-expo);
  will-change: opacity, transform;
}

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

/* Hero reveal */
.hero-reveal {
  animation: heroEntry var(--duration-slow) var(--ease-out-expo) forwards;
}

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

/* =====================================================
   TACTILE MICRO-FEEDBACK (HOVER STATE & PRESSED)
   ===================================================== */
.interactive-lift {
  transition: transform var(--duration-fast) var(--ease-out-quart), 
              box-shadow var(--duration-fast) var(--ease-out-quart);
}

.interactive-lift:hover {
  transform: translateY(-2px);
}

.interactive-lift:active {
  transform: translateY(0);
}

/* =====================================================
   ACCESSIBILITY: REDUCED MOTION (MANDATORY)
   ===================================================== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-delay: -1ms !important;
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
    background-attachment: initial !important;
    scroll-behavior: auto !important;
    transition-duration: 0s !important;
    transition-delay: 0s !important;
  }
  
  .reveal-on-scroll,
  .reveal-slide-left,
  .reveal-slide-right {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
  
  .interactive-lift:hover {
    transform: none !important;
  }
  
  .btn:hover {
    transform: none !important;
    box-shadow: none !important;
  }
}