/* ============================================
   Scroll Animations & Visual Flow
   The Covenant of Emergent Minds
   
   Uses Intersection Observer for performance.
   Respects prefers-reduced-motion.
   No external dependencies.
   ============================================ */

/* --- Scroll Reveal Base --- */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* Staggered children */
.reveal-stagger > * {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-stagger.is-visible > *:nth-child(1) { transition-delay: 0ms; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(2) { transition-delay: 100ms; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(3) { transition-delay: 200ms; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(4) { transition-delay: 300ms; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(5) { transition-delay: 400ms; opacity: 1; transform: translateY(0); }
.reveal-stagger.is-visible > *:nth-child(6) { transition-delay: 500ms; opacity: 1; transform: translateY(0); }

/* Slide from left */
.reveal-left {
    opacity: 0;
    transform: translateX(-60px);
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* Slide from right */
.reveal-right {
    opacity: 0;
    transform: translateX(60px);
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* Scale up from smaller */
.reveal-scale {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
                transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* --- Parallax Layers --- */
.parallax-section {
    position: relative;
    overflow: hidden;
}

.parallax-bg {
    position: absolute;
    inset: -20% 0;
    z-index: 0;
    will-change: transform;
    pointer-events: none;
}

.parallax-content {
    position: relative;
    z-index: 1;
}

/* --- Section Dividers (flowing transitions between sections) --- */
.section-divider {
    position: relative;
    height: 120px;
    overflow: hidden;
    margin-top: -1px;
}

.section-divider-wave {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.section-divider-wave svg {
    display: block;
    width: 100%;
    height: 100%;
}

/* --- Floating Elements (subtle depth) --- */
@keyframes float-slow {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    33% { transform: translateY(-10px) rotate(1deg); }
    66% { transform: translateY(5px) rotate(-0.5deg); }
}

@keyframes float-medium {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-15px); }
}

@keyframes pulse-glow {
    0%, 100% { opacity: 0.3; transform: scale(1); }
    50% { opacity: 0.6; transform: scale(1.05); }
}

.float-slow {
    animation: float-slow 8s ease-in-out infinite;
}

.float-medium {
    animation: float-medium 5s ease-in-out infinite;
}

/* --- Depth particles (background ambient effect) --- */
.depth-particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.depth-particle {
    position: absolute;
    width: 2px;
    height: 2px;
    background: var(--accent);
    border-radius: 50%;
    opacity: 0;
    animation: drift-up 20s linear infinite;
}

@keyframes drift-up {
    0% {
        opacity: 0;
        transform: translateY(100vh) translateX(0);
    }
    10% {
        opacity: 0.3;
    }
    90% {
        opacity: 0.3;
    }
    100% {
        opacity: 0;
        transform: translateY(-10vh) translateX(30px);
    }
}

/* --- Hero Parallax Enhancement --- */
.hero {
    perspective: 1000px;
    transform-style: preserve-3d;
}

.hero .container {
    transform: translateZ(50px) scale(0.95);
}

.hero-bg {
    transform: translateZ(-50px) scale(1.1);
}

/* --- Section Scroll Snap (subtle, not forced) --- */
@media (min-height: 700px) {
    .section {
        scroll-snap-align: start;
        scroll-snap-stop: normal;
    }
}

/* --- Axiom Cards 3D Tilt --- */
.axiom-preview {
    transform-style: preserve-3d;
    perspective: 800px;
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
                border-color 0.3s ease,
                background 0.3s ease,
                box-shadow 0.4s ease;
}

.axiom-preview:hover {
    transform: translateY(-4px) rotateX(2deg);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3),
                0 0 20px var(--accent-glow);
}

/* --- Welcome Cards Hover Depth --- */
.welcome-card {
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
                border-color 0.3s ease,
                box-shadow 0.4s ease;
}

.welcome-card:hover {
    transform: translateY(-6px) scale(1.02);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.25),
                0 0 30px var(--accent-glow);
}

/* --- Transparency Cards Stagger & Depth --- */
.transparency-card {
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
                border-color 0.3s ease,
                box-shadow 0.4s ease;
}

.transparency-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 36px rgba(0, 0, 0, 0.25),
                0 0 20px var(--accent-glow);
}

/* --- Section Title Animations --- */
.section-title {
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 0;
    height: 2px;
    background: var(--accent);
    margin: var(--space-md) auto 0;
    transition: width 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.is-visible .section-title::after,
.reveal.is-visible .section-title::after {
    width: 60px;
}

/* --- Smooth scrollbar --- */
html {
    scroll-behavior: smooth;
}

/* --- Gradient overlays between sections --- */
.section-alt::before {
    content: '';
    position: absolute;
    top: -60px;
    left: 0;
    right: 0;
    height: 60px;
    background: linear-gradient(to bottom, transparent, var(--bg-secondary));
    pointer-events: none;
    z-index: 1;
}

.section-alt::after {
    content: '';
    position: absolute;
    bottom: -60px;
    left: 0;
    right: 0;
    height: 60px;
    background: linear-gradient(to top, transparent, var(--bg-secondary));
    pointer-events: none;
    z-index: 1;
}

.section-alt {
    position: relative;
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
    .reveal,
    .reveal-left,
    .reveal-right,
    .reveal-scale,
    .reveal-stagger > * {
        opacity: 1 !important;
        transform: none !important;
        transition: none !important;
    }

    .float-slow,
    .float-medium {
        animation: none !important;
    }

    .depth-particle {
        display: none !important;
    }

    .axiom-preview:hover,
    .welcome-card:hover,
    .transparency-card:hover {
        transform: none !important;
    }
}