/* ===========================================================
   parallel.quest — Dimensional Survey Stylesheet
   Aurora gradient on midnight-blue foundation
   =========================================================== */

:root {
    --void-indigo: #0A0614;
    --abyssal-violet: #1B0A3C;
    --twilight-plum: #2D1A54;
    --lavender-mist: #C8BFD4;
    --pale-orchid: #E0D6F0;
    --spectral-teal: #00E5CC;
    --rift-coral: #FF6B8A;
    --prism-gold: #FFD166;
    --dusty-amethyst: #7B6FA0;

    --rift-x: 61.8%;
    --anaglyph-offset: 4px;
    --rift-glow: 8px;

    --font-serif: 'Playfair Display', 'Lora', Georgia, serif;
    --font-sans: 'Commissioner', 'Inter', system-ui, sans-serif;
    --font-mono: 'Fira Code', 'Space Mono', monospace;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    background: var(--void-indigo);
}

body {
    font-family: var(--font-sans);
    color: var(--lavender-mist);
    background: var(--void-indigo);
    overflow-x: hidden;
    min-height: 100vh;
    line-height: 1.72;
    font-size: 18px;
    font-weight: 400;
    position: relative;
}

/* ===========================================================
   Aurora ambient field (drifting low-opacity gradient)
   =========================================================== */
.aurora-field {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.aurora {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.12;
    mix-blend-mode: screen;
    animation: aurora-drift 28s ease-in-out infinite alternate;
}

.aurora-a {
    width: 70vw;
    height: 70vw;
    background: radial-gradient(circle, var(--spectral-teal), transparent 70%);
    top: -20vh;
    left: -10vw;
    animation-duration: 32s;
}

.aurora-b {
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, var(--rift-coral), transparent 70%);
    bottom: -15vh;
    right: -10vw;
    animation-duration: 38s;
    animation-delay: -8s;
}

.aurora-c {
    width: 50vw;
    height: 50vw;
    background: radial-gradient(circle, var(--prism-gold), transparent 70%);
    top: 40vh;
    left: 30vw;
    opacity: 0.07;
    animation-duration: 45s;
    animation-delay: -14s;
}

@keyframes aurora-drift {
    0% { transform: translate(0, 0) scale(1); opacity: 0.10; }
    50% { transform: translate(8vw, -6vh) scale(1.15); opacity: 0.16; }
    100% { transform: translate(-5vw, 8vh) scale(0.92); opacity: 0.08; }
}

/* ===========================================================
   Floating impossible geometry (background, slow rotation)
   =========================================================== */
.geometry-field {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 1;
    overflow: hidden;
}

.impossible-geo {
    position: absolute;
    opacity: 0.18;
    animation: geo-rotate 60s linear infinite;
    filter: drop-shadow(0 0 6px rgba(0, 229, 204, 0.18));
}

.geo-1 { width: 280px; height: 280px; top: 12vh; left: 8vw; animation-duration: 72s; }
.geo-2 { width: 320px; height: 320px; top: 130vh; right: 12vw; animation-duration: 90s; animation-direction: reverse; opacity: 0.14; }
.geo-3 { width: 260px; height: 260px; top: 280vh; left: 14vw; animation-duration: 60s; opacity: 0.16; }
.geo-4 { width: 240px; height: 240px; top: 420vh; right: 6vw; animation-duration: 80s; animation-direction: reverse; opacity: 0.20; }

@keyframes geo-rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ===========================================================
   The Rift Line — golden ratio vertical spine
   =========================================================== */
.rift-system {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 2;
}

.rift-line {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 1.5px;
    background: linear-gradient(
        to bottom,
        transparent 0%,
        var(--spectral-teal) 12%,
        var(--spectral-teal) 88%,
        transparent 100%
    );
    box-shadow: 0 0 var(--rift-glow) var(--spectral-teal),
                0 0 calc(var(--rift-glow) * 2) rgba(0, 229, 204, 0.4);
    animation: rift-breathe 12s ease-in-out infinite;
    transition: left 0.8s cubic-bezier(0.22, 1, 0.36, 1),
                background 1.2s ease, opacity 0.6s ease;
}

.rift-primary {
    left: var(--rift-x);
}

.rift-secondary {
    left: var(--rift-x);
    opacity: 0;
    background: linear-gradient(
        to bottom,
        transparent 0%,
        var(--rift-coral) 12%,
        var(--rift-coral) 88%,
        transparent 100%
    );
    box-shadow: 0 0 var(--rift-glow) var(--rift-coral),
                0 0 calc(var(--rift-glow) * 2) rgba(255, 107, 138, 0.4);
}

@keyframes rift-breathe {
    0%, 100% {
        box-shadow: 0 0 4px var(--spectral-teal),
                    0 0 8px rgba(0, 229, 204, 0.4);
    }
    50% {
        box-shadow: 0 0 12px var(--spectral-teal),
                    0 0 24px rgba(0, 229, 204, 0.55);
    }
}

/* Rift state: split (Layer 3) */
body.rift-split .rift-primary { left: calc(var(--rift-x) - 8vw); }
body.rift-split .rift-secondary {
    opacity: 1;
    left: calc(var(--rift-x) + 8vw);
}

/* Rift state: interference (Layer 4) */
body.rift-interfere .rift-primary { left: calc(var(--rift-x) - 1.5vw); }
body.rift-interfere .rift-secondary {
    opacity: 1;
    left: calc(var(--rift-x) + 1.5vw);
}

/* Rift state: resolution (Layer 5) */
body.rift-resolve .rift-primary { left: var(--rift-x); }
body.rift-resolve .rift-secondary { opacity: 0; left: var(--rift-x); }

.rift-progress {
    position: fixed;
    left: var(--rift-x);
    top: 0;
    width: 4px;
    height: 0;
    background: radial-gradient(circle at center, var(--prism-gold), transparent 70%);
    transform: translateX(-50%);
    pointer-events: none;
    z-index: 3;
    transition: height 0.2s linear;
    opacity: 0.55;
}

/* ===========================================================
   Moire interference overlay
   =========================================================== */
.moire-overlay {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 1;
    opacity: 0;
    transition: opacity 1.2s ease;
}

body.moire-active .moire-overlay { opacity: 0.32; }

.moire-grid {
    position: absolute;
    inset: -10%;
    background-image:
        repeating-linear-gradient(0deg, transparent 0, transparent 11px, rgba(0, 229, 204, 0.4) 11px, rgba(0, 229, 204, 0.4) 12px),
        repeating-linear-gradient(90deg, transparent 0, transparent 11px, rgba(0, 229, 204, 0.4) 11px, rgba(0, 229, 204, 0.4) 12px);
    mix-blend-mode: screen;
    animation: moire-drift 22s linear infinite;
}

.moire-a { transform: rotate(8deg) scale(1.04); }
.moire-b {
    transform: rotate(-7deg) scale(1.06);
    background-image:
        repeating-linear-gradient(0deg, transparent 0, transparent 13px, rgba(255, 107, 138, 0.35) 13px, rgba(255, 107, 138, 0.35) 14px),
        repeating-linear-gradient(90deg, transparent 0, transparent 13px, rgba(255, 107, 138, 0.35) 13px, rgba(255, 107, 138, 0.35) 14px);
    animation-direction: reverse;
}

@keyframes moire-drift {
    from { background-position: 0 0; }
    to { background-position: 80px 80px; }
}

/* ===========================================================
   Dimensional navigation (right edge, minimal)
   =========================================================== */
.dimension-nav {
    position: fixed;
    right: 28px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 20;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--dusty-amethyst);
}

.nav-label {
    display: block;
    margin-bottom: 18px;
    padding-left: 24px;
    color: var(--spectral-teal);
    opacity: 0.7;
    font-size: 9px;
    letter-spacing: 0.32em;
}

.dimension-nav ul {
    list-style: none;
    position: relative;
    padding-left: 24px;
}

.dimension-nav ul::before {
    content: '';
    position: absolute;
    left: 9px;
    top: 4px;
    bottom: 4px;
    width: 1px;
    background: linear-gradient(to bottom, var(--spectral-teal), var(--rift-coral), var(--prism-gold));
    opacity: 0.45;
}

.dimension-nav li {
    margin: 14px 0;
    position: relative;
}

.dimension-nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--dusty-amethyst);
    text-decoration: none;
    transition: color 0.4s ease, transform 0.4s ease;
    position: relative;
}

.dimension-nav .diamond {
    position: absolute;
    left: -19px;
    top: 50%;
    width: 9px;
    height: 9px;
    transform: translateY(-50%) rotate(45deg);
    background: var(--void-indigo);
    border: 1px solid var(--dusty-amethyst);
    transition: all 0.4s ease;
}

.dimension-nav .nav-text {
    opacity: 0.5;
    transition: opacity 0.4s ease, color 0.4s ease;
}

.dimension-nav a:hover .nav-text { opacity: 1; color: var(--rift-coral); }
.dimension-nav a:hover .diamond { border-color: var(--rift-coral); background: var(--rift-coral); }

.dimension-nav a.active .nav-text {
    color: var(--spectral-teal);
    opacity: 1;
}

.dimension-nav a.active .diamond {
    background: var(--spectral-teal);
    border-color: var(--spectral-teal);
    box-shadow: 0 0 12px var(--spectral-teal),
                0 0 24px rgba(0, 229, 204, 0.5);
    animation: node-pulse 2.4s ease-in-out infinite;
}

@keyframes node-pulse {
    0%, 100% { box-shadow: 0 0 8px var(--spectral-teal), 0 0 16px rgba(0, 229, 204, 0.4); }
    50% { box-shadow: 0 0 16px var(--spectral-teal), 0 0 32px rgba(0, 229, 204, 0.7); }
}

/* ===========================================================
   Layout backbone — dimensional passage
   =========================================================== */
.dimensional-passage {
    position: relative;
    z-index: 5;
}

.layer {
    position: relative;
    min-height: 100vh;
    padding: 12vh 8vw 12vh;
    overflow: hidden;
    transition: background 1.4s ease;
}

.layer-1 { min-height: 100vh; background: var(--void-indigo); }
.layer-2 { min-height: 120vh; background: linear-gradient(180deg, var(--void-indigo), var(--abyssal-violet) 30%); }
.layer-3 { min-height: 120vh; background: var(--abyssal-violet); }
.layer-4 { min-height: 100vh; background: linear-gradient(180deg, var(--abyssal-violet), var(--twilight-plum) 50%, var(--abyssal-violet)); }
.layer-5 { min-height: 100vh; background: linear-gradient(180deg, var(--abyssal-violet), var(--void-indigo) 60%); }

.layer-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--dusty-amethyst);
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin-bottom: 8vh;
    opacity: 0.75;
}

.layer-number {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 22px;
    color: var(--pale-orchid);
    letter-spacing: 0.04em;
    text-transform: none;
}

.dim-coord {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--dusty-amethyst);
    letter-spacing: 0.14em;
    opacity: 0.85;
}

.coord-bottom {
    position: absolute;
    bottom: 4vh;
    left: 8vw;
    opacity: 0.55;
}

/* ===========================================================
   Anaglyph headings — chromatic split signature
   =========================================================== */
.anaglyph {
    font-family: var(--font-serif);
    font-weight: 700;
    color: var(--abyssal-violet);
    line-height: 1.05;
    letter-spacing: -0.01em;
    position: relative;
    display: inline-block;
    text-shadow:
        var(--anaglyph-offset) 0 0 rgba(0, 229, 204, 0.62),
        calc(var(--anaglyph-offset) * -0.6) 0 0 rgba(255, 107, 138, 0.32);
    -webkit-text-stroke: 0.4px rgba(224, 214, 240, 0.85);
    transition: text-shadow 0.3s ease;
}

/* Re-target color so heading is readable on dark bg:
   primary text uses pale-orchid; teal/coral remain offset */
.anaglyph {
    color: var(--pale-orchid);
    text-shadow:
        var(--anaglyph-offset) 0 0 rgba(0, 229, 204, 0.7),
        calc(var(--anaglyph-offset) * -0.65) 0 0 rgba(255, 107, 138, 0.45);
}

.anaglyph-xl { font-size: clamp(56px, 9vw, 110px); letter-spacing: -0.02em; }
.anaglyph-lg { font-size: clamp(46px, 6vw, 78px); }

h2.anaglyph { font-size: clamp(34px, 4.4vw, 58px); margin-bottom: 22px; }

/* ===========================================================
   Layer 1 — Threshold
   =========================================================== */
.threshold-content {
    position: relative;
    max-width: 740px;
    margin: 8vh auto 0;
    text-align: center;
    z-index: 6;
    padding: 0 4vw;
}

.threshold-content .anaglyph {
    display: block;
    margin: 0 auto 28px;
    text-align: center;
}

.threshold-subtitle {
    font-family: var(--font-sans);
    font-weight: 300;
    font-size: clamp(16px, 1.6vw, 19px);
    color: var(--lavender-mist);
    max-width: 560px;
    margin: 0 auto 56px;
    line-height: 1.72;
    opacity: 0.9;
}

.philosophical-fragment {
    font-family: var(--font-serif);
    font-style: italic;
    font-weight: 400;
    color: var(--pale-orchid);
    font-size: clamp(20px, 2.2vw, 30px);
    letter-spacing: 0.04em;
    line-height: 1.5;
    margin: 64px auto;
    max-width: 600px;
    position: relative;
    padding: 0 32px;
}

.philosophical-fragment .fragment-marker {
    display: block;
    font-family: var(--font-mono);
    font-style: normal;
    font-size: 11px;
    color: var(--prism-gold);
    letter-spacing: 0.32em;
    margin-bottom: 14px;
    text-transform: uppercase;
    opacity: 0.75;
}

.scroll-cue {
    margin-top: 80px;
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    color: var(--spectral-teal);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.34em;
    text-transform: uppercase;
    animation: scroll-pulse 2.6s ease-in-out infinite;
    opacity: 0.85;
}

.cue-chevron {
    display: inline-block;
    animation: chevron-bounce 2.6s ease-in-out infinite;
}

@keyframes scroll-pulse {
    0%, 100% { opacity: 0.55; }
    50% { opacity: 1; }
}

@keyframes chevron-bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(8px); }
}

/* ===========================================================
   Layer 2 — Divergence (modular panels, alternating sides)
   =========================================================== */
.modular-panel {
    position: relative;
    background: rgba(45, 26, 84, 0.55);
    border: 1px solid rgba(123, 111, 160, 0.25);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    padding: 38px 42px 42px;
    max-width: 460px;
    margin-bottom: 12vh;
    opacity: 0.3;
    filter: blur(4px);
    transform: translateY(40px);
    transition:
        opacity 0.9s cubic-bezier(0.22, 1, 0.36, 1),
        filter 0.9s cubic-bezier(0.22, 1, 0.36, 1),
        transform 0.9s cubic-bezier(0.22, 1, 0.36, 1),
        background 0.6s ease;
    will-change: transform, filter, opacity;
}

.modular-panel.in-focus {
    opacity: 1;
    filter: blur(0);
    transform: translateY(0);
}

.modular-panel::before {
    content: '';
    position: absolute;
    top: -1px; left: -1px; right: -1px; height: 1px;
    background: linear-gradient(90deg, transparent, var(--spectral-teal), transparent);
    opacity: 0.6;
}

.panel-left { margin-left: 6vw; margin-right: auto; }
.panel-right { margin-left: auto; margin-right: 6vw; }
.panel-rift { margin-left: auto; margin-right: auto; max-width: 520px; }

.depth-front { z-index: 8; box-shadow: 0 18px 60px rgba(10, 6, 20, 0.55); }
.depth-mid { z-index: 6; box-shadow: 0 12px 40px rgba(10, 6, 20, 0.45); }
.depth-back { z-index: 4; opacity: 0.85; box-shadow: 0 8px 24px rgba(10, 6, 20, 0.35); }
.depth-back.in-focus { opacity: 0.95; }

.panel-coord {
    display: block;
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--dusty-amethyst);
    letter-spacing: 0.22em;
    text-transform: uppercase;
    margin-bottom: 18px;
    opacity: 0;
    transition: opacity 0.8s ease 0.3s;
}

.modular-panel.in-focus .panel-coord { opacity: 0.85; }

.modular-panel p {
    color: var(--lavender-mist);
    font-size: 17px;
    line-height: 1.78;
    margin-top: 8px;
    font-weight: 400;
}

.panel-tag {
    display: inline-block;
    margin-top: 22px;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--prism-gold);
    letter-spacing: 0.18em;
    text-transform: lowercase;
    padding: 6px 12px;
    border: 1px solid rgba(255, 209, 102, 0.35);
    border-radius: 2px;
    transition: all 0.4s ease;
}

.modular-panel:hover .panel-tag {
    color: var(--rift-coral);
    border-color: var(--rift-coral);
    transform: translateX(4px);
}

/* ===========================================================
   Layer 3 — Convergence (rift gap content, pull quote)
   =========================================================== */
.rift-gap-content {
    max-width: 620px;
    margin: 6vh auto;
    position: relative;
    z-index: 7;
}

.pull-quote {
    font-family: var(--font-serif);
    font-style: italic;
    font-weight: 400;
    color: var(--pale-orchid);
    font-size: clamp(24px, 3vw, 36px);
    line-height: 1.4;
    letter-spacing: 0.04em;
    text-align: center;
    margin: 14vh auto;
    max-width: 720px;
    padding: 32px 24px;
    position: relative;
    opacity: 0.4;
    transform: translateY(40px);
    transition: opacity 1s ease, transform 1s ease;
}

.pull-quote.in-focus { opacity: 1; transform: translateY(0); }

.pull-quote em {
    display: block;
    color: var(--pale-orchid);
}

.quote-mark {
    font-family: var(--font-serif);
    font-style: normal;
    color: var(--spectral-teal);
    font-size: 1.6em;
    line-height: 0;
    vertical-align: -0.32em;
    opacity: 0.85;
}

.quote-close { color: var(--rift-coral); }

.pull-quote cite {
    display: block;
    margin-top: 24px;
    font-family: var(--font-mono);
    font-style: normal;
    font-size: 11px;
    color: var(--dusty-amethyst);
    letter-spacing: 0.22em;
    text-transform: uppercase;
    opacity: 0.85;
}

/* ===========================================================
   Layer 4 — Interference (tilt-3d on scroll)
   =========================================================== */
.panel-tilt {
    transform-style: preserve-3d;
    perspective: 1000px;
    will-change: transform;
}

.panel-tilt.in-focus {
    transform: translateY(0) rotateX(var(--tilt-x, 0deg)) rotateY(var(--tilt-y, 0deg));
}

/* ===========================================================
   Layer 5 — Resolution
   =========================================================== */
.resolution-content {
    max-width: 680px;
    margin: 8vh auto;
    text-align: center;
    position: relative;
    z-index: 7;
}

.resolution-content .anaglyph {
    display: block;
    margin-bottom: 48px;
}

.resolution-text {
    margin: 32px auto 56px;
    color: var(--lavender-mist);
    font-size: 18px;
    line-height: 1.78;
    max-width: 560px;
}

.resolution-text p { margin-bottom: 20px; }
.resolution-text p:last-child { margin-bottom: 0; }

.closing-fragment {
    font-family: var(--font-serif);
    font-style: italic;
    color: var(--pale-orchid);
    font-size: clamp(18px, 2vw, 26px);
    letter-spacing: 0.04em;
    line-height: 1.5;
    margin: 60px auto 80px;
    max-width: 580px;
    padding: 0 24px;
}

.closing-fragment .fragment-marker {
    display: block;
    font-family: var(--font-mono);
    font-style: normal;
    font-size: 11px;
    color: var(--prism-gold);
    letter-spacing: 0.32em;
    margin-bottom: 14px;
    text-transform: uppercase;
    opacity: 0.75;
}

.end-mark {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    margin-top: 48px;
}

.end-glyph {
    font-size: 22px;
    color: var(--spectral-teal);
    transform: rotate(0deg);
    animation: end-glow 4s ease-in-out infinite;
}

.end-coord {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--dusty-amethyst);
    letter-spacing: 0.22em;
    text-transform: uppercase;
    opacity: 0.7;
}

@keyframes end-glow {
    0%, 100% { text-shadow: 0 0 8px var(--spectral-teal); opacity: 0.85; }
    50% { text-shadow: 0 0 22px var(--spectral-teal); opacity: 1; }
}

/* ===========================================================
   Particle fields — pure CSS per layer
   =========================================================== */
.particle-field {
    position: absolute;
    inset: 0;
    pointer-events: none;
    overflow: hidden;
    z-index: 2;
}

/* Layer 1: drifting Prism Gold diamonds */
.particles-diamonds {
    background-image:
        radial-gradient(2px 2px at 12% 18%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(1.5px 1.5px at 28% 72%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(2.5px 2.5px at 48% 36%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(1.5px 1.5px at 64% 84%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(2px 2px at 78% 52%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(1.5px 1.5px at 88% 22%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(2px 2px at 32% 8%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(1.5px 1.5px at 6% 92%, var(--prism-gold) 50%, transparent 51%);
    background-size: 100% 100%;
    background-repeat: no-repeat;
    animation: particles-rise 22s linear infinite;
    opacity: 0.7;
}

@keyframes particles-rise {
    0% { background-position-y: 0; opacity: 0.4; }
    50% { opacity: 0.85; }
    100% { background-position-y: -100vh; opacity: 0.4; }
}

/* Layer 2: horizontal scan lines drifting at different speeds */
.particles-scanlines {
    background-image:
        linear-gradient(90deg, transparent 0%, transparent 60%, rgba(0, 229, 204, 0.18) 60.5%, transparent 61%),
        linear-gradient(90deg, transparent 0%, transparent 30%, rgba(255, 107, 138, 0.14) 30.4%, transparent 31%),
        linear-gradient(90deg, transparent 0%, transparent 80%, rgba(255, 209, 102, 0.16) 80.5%, transparent 81%);
    background-size: 100% 32px, 100% 56px, 100% 84px;
    background-repeat: repeat-y;
    animation: scanlines-shift 16s linear infinite;
    opacity: 0.55;
}

@keyframes scanlines-shift {
    from { background-position: 0 0, 0 0, 0 0; }
    to { background-position: 100vw 0, -100vw 0, 60vw 0; }
}

/* Layer 3: concentric ring pulses */
.particles-rings {
    background-image:
        radial-gradient(circle at 22% 28%, transparent 0, transparent 18px, rgba(0, 229, 204, 0.18) 19px, transparent 22px),
        radial-gradient(circle at 76% 64%, transparent 0, transparent 26px, rgba(0, 229, 204, 0.14) 27px, transparent 30px),
        radial-gradient(circle at 52% 18%, transparent 0, transparent 14px, rgba(255, 107, 138, 0.18) 15px, transparent 18px),
        radial-gradient(circle at 38% 82%, transparent 0, transparent 22px, rgba(255, 107, 138, 0.14) 23px, transparent 26px);
    animation: rings-expand 8s ease-in-out infinite;
    opacity: 0.75;
}

@keyframes rings-expand {
    0%, 100% { background-size: 100% 100%; opacity: 0.45; }
    50% { background-size: 130% 130%; opacity: 0.85; }
}

/* Layer 4: blinking crosses */
.particles-crosses {
    background-image:
        linear-gradient(90deg, transparent 49%, var(--rift-coral) 49.5%, var(--rift-coral) 50.5%, transparent 51%),
        linear-gradient(0deg, transparent 49%, var(--rift-coral) 49.5%, var(--rift-coral) 50.5%, transparent 51%);
    background-size: 6px 6px, 6px 6px;
    background-position: 12% 18%, 12% 18%;
    background-repeat: no-repeat, no-repeat;
    animation: crosses-blink 1.8s ease-in-out infinite;
    opacity: 0.5;
}

@keyframes crosses-blink {
    0%, 100% { background-position: 12% 18%, 12% 18%; opacity: 0.2; }
    20% { background-position: 28% 42%, 28% 42%; opacity: 0.7; }
    40% { background-position: 64% 22%, 64% 22%; opacity: 0.4; }
    60% { background-position: 82% 68%, 82% 68%; opacity: 0.8; }
    80% { background-position: 36% 76%, 36% 76%; opacity: 0.5; }
}

/* Layer 5: diamonds with afterimage trails */
.particles-trails {
    background-image:
        radial-gradient(2px 2px at 14% 20%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(2px 2px at 14.5% 21%, rgba(255, 209, 102, 0.5) 50%, transparent 51%),
        radial-gradient(2px 2px at 15% 22%, rgba(255, 209, 102, 0.25) 50%, transparent 51%),
        radial-gradient(2px 2px at 62% 56%, var(--prism-gold) 50%, transparent 51%),
        radial-gradient(2px 2px at 62.5% 57%, rgba(255, 209, 102, 0.5) 50%, transparent 51%),
        radial-gradient(2px 2px at 63% 58%, rgba(255, 209, 102, 0.25) 50%, transparent 51%),
        radial-gradient(2px 2px at 38% 78%, var(--spectral-teal) 50%, transparent 51%),
        radial-gradient(2px 2px at 38.5% 79%, rgba(0, 229, 204, 0.5) 50%, transparent 51%),
        radial-gradient(2px 2px at 84% 32%, var(--rift-coral) 50%, transparent 51%),
        radial-gradient(2px 2px at 84.5% 33%, rgba(255, 107, 138, 0.5) 50%, transparent 51%);
    animation: trails-drift 28s linear infinite;
    opacity: 0.65;
}

@keyframes trails-drift {
    0% { background-position-y: 0; opacity: 0.45; }
    100% { background-position-y: -50vh; opacity: 0.45; }
}

/* ===========================================================
   Transition zones (50vh between layers)
   =========================================================== */
.transition-zone {
    position: relative;
    height: 50vh;
    width: 100%;
    overflow: hidden;
    background: linear-gradient(180deg,
        rgba(10, 6, 20, 0.1) 0%,
        rgba(27, 10, 60, 0.5) 50%,
        rgba(10, 6, 20, 0.1) 100%
    );
}

.transition-zone .bleed-line {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 1px;
    opacity: 0.55;
    animation: bleed-drift 6s ease-in-out infinite;
}

.bleed-coral {
    left: calc(var(--rift-x) - 14px);
    background: linear-gradient(to bottom, transparent, var(--rift-coral), transparent);
    box-shadow: 0 0 6px var(--rift-coral);
}

.bleed-teal {
    left: calc(var(--rift-x) + 14px);
    background: linear-gradient(to bottom, transparent, var(--spectral-teal), transparent);
    box-shadow: 0 0 6px var(--spectral-teal);
}

.bleed-gold {
    left: calc(var(--rift-x) + 14px);
    background: linear-gradient(to bottom, transparent, var(--prism-gold), transparent);
    box-shadow: 0 0 6px var(--prism-gold);
}

@keyframes bleed-drift {
    0%, 100% { transform: translateX(0); opacity: 0.45; }
    50% { transform: translateX(6px); opacity: 0.75; }
}

.transition-marker {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--dusty-amethyst);
    letter-spacing: 0.42em;
    text-transform: uppercase;
    opacity: 0.65;
    background: rgba(10, 6, 20, 0.6);
    padding: 6px 14px;
    border: 1px solid rgba(123, 111, 160, 0.3);
}

/* Pseudo-moire grid in transition zones */
.transition-zone::before,
.transition-zone::after {
    content: '';
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.transition-zone::before {
    background-image:
        repeating-linear-gradient(0deg, transparent 0, transparent 9px, rgba(0, 229, 204, 0.18) 9px, rgba(0, 229, 204, 0.18) 10px);
    transform: rotate(6deg);
    opacity: 0.4;
    mix-blend-mode: screen;
}

.transition-zone::after {
    background-image:
        repeating-linear-gradient(0deg, transparent 0, transparent 11px, rgba(255, 107, 138, 0.18) 11px, rgba(255, 107, 138, 0.18) 12px);
    transform: rotate(-7deg);
    opacity: 0.4;
    mix-blend-mode: screen;
}

/* ===========================================================
   Active layer indication (background transitions)
   =========================================================== */
body.layer-active-1 { background-color: var(--void-indigo); }
body.layer-active-2 { background-color: var(--abyssal-violet); }
body.layer-active-3 { background-color: var(--abyssal-violet); }
body.layer-active-4 { background-color: var(--twilight-plum); }
body.layer-active-5 { background-color: var(--void-indigo); }

body { transition: background-color 1.4s ease; }

/* ===========================================================
   Responsive
   =========================================================== */
@media (max-width: 900px) {
    :root { --rift-x: 50%; }

    .layer { padding: 8vh 5vw; }
    .panel-left, .panel-right { margin-left: auto; margin-right: auto; max-width: 92vw; }
    .modular-panel { padding: 28px 26px 32px; }

    .dimension-nav { right: 12px; font-size: 10px; }
    .dimension-nav .nav-text { display: none; }
    .dimension-nav ul { padding-left: 18px; }
    .dimension-nav .diamond { left: -16px; }
    .nav-label { display: none; }

    .geo-1, .geo-2, .geo-3, .geo-4 { width: 180px; height: 180px; opacity: 0.12; }

    .threshold-content { margin-top: 4vh; }
    .anaglyph-xl { font-size: clamp(40px, 11vw, 64px); }
}

@media (max-width: 560px) {
    body { font-size: 16px; }
    .layer { padding: 6vh 4vw; }
    .modular-panel { padding: 22px 20px 26px; }
    h2.anaglyph { font-size: clamp(26px, 7vw, 36px); }
    .pull-quote { font-size: clamp(20px, 5.5vw, 28px); margin: 8vh auto; }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .modular-panel { filter: none; transform: none; opacity: 1; }
}