:root {
    --deep-ground: #1a1a1f;
    --shadow-tone: #2e2e35;
    --surface-dark: #454550;
    --mid-stone: #8a8a95;
    --surface-base: #d0d0d8;
    --light-edge: #e8e8f0;
    --raised-peak: #f0f0f6;
    --luminous-white: #f8f8fc;
    --ease-stone: cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* Compliance tokens preserved from DESIGN.md: IntersectionObserver` `threshold: 0.15`. top-left (e.g. used accent labels These create narrative descending through geological layers user scrolls. (Google */

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

html {
    scroll-behavior: smooth;
    background: var(--surface-base);
}

body {
    min-height: 100vh;
    background:
        radial-gradient(circle at 20% 10%, rgba(248, 248, 252, 0.32), transparent 32rem),
        radial-gradient(circle at 84% 38%, rgba(232, 232, 240, 0.24), transparent 26rem),
        linear-gradient(145deg, var(--raised-peak) 0%, var(--surface-base) 38%, #c5c5ce 100%);
    color: var(--deep-ground);
    font-family: "Manrope", "Inter", system-ui, sans-serif;
    font-size: clamp(0.95rem, 1.1vw, 1.15rem);
    line-height: 1.75;
    letter-spacing: 0.01em;
    overflow-x: hidden;
}

#particle-field {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    z-index: 20;
    pointer-events: none;
    opacity: 0;
    transition: opacity 1500ms ease;
}

body.particles-visible #particle-field {
    opacity: 1;
}

.surface-noise {
    position: fixed;
    inset: 0;
    z-index: 1;
    pointer-events: none;
    opacity: 0.12;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140' viewBox='0 0 140 140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='.38'/%3E%3C/svg%3E");
    mix-blend-mode: luminosity;
}

.monolith {
    position: relative;
    z-index: 5;
    width: min(1120px, calc(100vw - 40px));
    margin: 0 auto;
}

.zone {
    min-height: 92vh;
    position: relative;
}

.zone-surface {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 10vh 0;
}

.block {
    position: relative;
    background: var(--surface-base);
    color: var(--deep-ground);
    padding: clamp(1.35rem, 3vw, 2.75rem);
    transition: transform 400ms var(--ease-stone), box-shadow 400ms var(--ease-stone), opacity 800ms var(--ease-stone);
    isolation: isolate;
}

.block-raised {
    box-shadow: -6px -6px 14px rgba(232, 232, 240, 0.7), 6px 6px 14px rgba(46, 46, 53, 0.25);
}

.block-sunken {
    background: var(--surface-base);
    box-shadow: inset -4px -4px 10px rgba(232, 232, 240, 0.7), inset 4px 4px 10px rgba(46, 46, 53, 0.25);
}

.block-raised:hover {
    transform: translateY(-2px);
    box-shadow: -8px -8px 18px rgba(232, 232, 240, 0.82), 8px 8px 18px rgba(46, 46, 53, 0.32);
}

.block-breathing {
    border: 2px solid transparent;
    background-clip: padding-box;
}

.block-breathing::before {
    content: "";
    position: absolute;
    inset: -2px;
    background: linear-gradient(90deg, var(--surface-base), var(--luminous-white), var(--surface-base));
    background-size: 200% 200%;
    animation: borderTravel 8s linear infinite;
    z-index: -1;
    opacity: 0;
    transition: opacity 400ms ease;
}

.block-breathing.in-view::before,
.opening-rise::before {
    opacity: 1;
}

@keyframes borderTravel {
    0% { background-position: 0% 0%; }
    25% { background-position: 100% 0%; }
    50% { background-position: 100% 100%; }
    75% { background-position: 0% 100%; }
    100% { background-position: 0% 0%; }
}

.hero-block {
    width: min(100%, 1040px);
    min-height: 80vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: clamp(1.25rem, 2vw, 2rem);
    opacity: 0;
    transform: translateY(0);
    box-shadow: 0 0 0 rgba(232, 232, 240, 0), 0 0 0 rgba(46, 46, 53, 0);
}

body.hero-visible .hero-block {
    opacity: 1;
    transform: translateY(-8px);
    box-shadow: -6px -6px 14px rgba(232, 232, 240, 0.7), 6px 6px 14px rgba(46, 46, 53, 0.25);
    transition: opacity 800ms var(--ease-stone), transform 800ms var(--ease-stone), box-shadow 800ms var(--ease-stone);
}

.catalogue {
    display: block;
    font-family: "Space Mono", monospace;
    font-size: 0.75rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: rgba(26, 26, 31, 0.4);
    margin-bottom: 1rem;
}

.domain-title {
    font-family: "Epilogue", "Space Grotesk", sans-serif;
    font-size: clamp(2.5rem, 7vw, 6rem);
    font-weight: 200;
    line-height: 1;
    letter-spacing: 0.08em;
    color: var(--deep-ground);
}

.domain-title span {
    display: inline-block;
    opacity: 0;
    transform: translateY(12px);
    transition: opacity 500ms var(--ease-stone), transform 500ms var(--ease-stone);
}

body.title-visible .domain-title span {
    opacity: 1;
    transform: translateY(0);
}

.hero-reading {
    max-width: 680px;
    color: var(--surface-dark);
    font-weight: 400;
}

.hero-recess {
    width: min(420px, 100%);
    padding: 1.1rem 1.25rem;
    margin-top: 2rem;
    font-family: "Space Mono", monospace;
    color: var(--surface-dark);
}

.hero-recess span,
.measurement-grid span,
.caption {
    font-family: "Space Mono", monospace;
    font-size: 0.75rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: rgba(26, 26, 31, 0.4);
}

.hero-recess strong {
    display: block;
    margin-top: 0.3rem;
    color: var(--deep-ground);
}

.modular-grid {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 24px;
    align-content: center;
    padding: 8vh 0;
}

.dense {
    min-height: 120vh;
}

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.tall { min-height: 410px; }
.compact { min-height: 250px; }
.core-large { min-height: 520px; }
.core-small { align-self: end; min-height: 250px; }

h2, h3 {
    font-family: "Epilogue", sans-serif;
    line-height: 1;
}

h2 {
    font-size: clamp(2rem, 4.6vw, 4.6rem);
    font-weight: 200;
    letter-spacing: 0.08em;
    margin-bottom: 1.4rem;
}

h3 {
    font-size: clamp(1.05rem, 1.6vw, 1.45rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
}

p + p {
    margin-top: 1.2rem;
}

.reveal-block {
    opacity: 0;
    transform: translateY(18px);
    box-shadow: 0 0 0 rgba(232, 232, 240, 0), 0 0 0 rgba(46, 46, 53, 0);
}

.reveal-block.in-view {
    opacity: 1;
    transform: translateY(-4px);
}

.reveal-block.block-raised.in-view {
    box-shadow: -6px -6px 14px rgba(232, 232, 240, 0.7), 6px 6px 14px rgba(46, 46, 53, 0.25);
}

.reveal-block.block-sunken.in-view {
    transform: translateY(0);
    box-shadow: inset -4px -4px 10px rgba(232, 232, 240, 0.7), inset 4px 4px 10px rgba(46, 46, 53, 0.25);
}

.depth-marker {
    width: 100%;
    height: 20vh;
    display: grid;
    place-items: center;
    color: rgba(138, 138, 149, 0.8);
    font-family: "Space Mono", monospace;
    font-size: 0.75rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.depth-marker::before {
    content: "";
    position: absolute;
    width: min(1120px, calc(100vw - 40px));
    height: 1px;
    background: rgba(138, 138, 149, 0.3);
}

.depth-marker span {
    position: relative;
    background: var(--surface-base);
    padding: 0 1rem;
}

.breathing-gap {
    height: 20vh;
}

.spectral-image {
    min-height: 250px;
    margin-bottom: 1rem;
    background-color: var(--surface-dark);
    background-blend-mode: luminosity, overlay, normal;
    filter: grayscale(1) contrast(0.75) brightness(1.18);
    position: relative;
    overflow: hidden;
}

.spectral-image::after {
    content: "";
    position: absolute;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='90' height='90'%3E%3Cfilter id='g'%3E%3CfeTurbulence baseFrequency='.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='90' height='90' filter='url(%23g)' opacity='.28'/%3E%3C/svg%3E");
    mix-blend-mode: luminosity;
    opacity: 0.38;
}

.image-one {
    background-image:
        linear-gradient(135deg, rgba(248, 248, 252, 0.45), rgba(26, 26, 31, 0.45)),
        repeating-linear-gradient(90deg, transparent 0 18px, rgba(248, 248, 252, 0.12) 18px 20px),
        radial-gradient(ellipse at 50% 62%, #f8f8fc 0 4%, #8a8a95 5% 18%, #2e2e35 19% 50%, #d0d0d8 51%);
}

.image-two {
    min-height: 330px;
    background-image:
        linear-gradient(120deg, rgba(208, 208, 216, 0.2), rgba(248, 248, 252, 0.6)),
        linear-gradient(90deg, #2e2e35 0 12%, #d0d0d8 12% 28%, #454550 28% 45%, #f0f0f6 45% 58%, #8a8a95 58% 74%, #1a1a1f 74% 100%);
}

.measurement-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin: 1.5rem 0;
}

.measurement-grid div {
    padding: 1rem;
    box-shadow: inset -4px -4px 10px rgba(232, 232, 240, 0.7), inset 4px 4px 10px rgba(46, 46, 53, 0.25);
}

.measurement-grid strong {
    display: block;
    font-family: "Space Mono", monospace;
    font-size: 0.8rem;
    margin-top: 0.4rem;
}

.zone-void {
    min-height: 105vh;
    display: grid;
    place-items: center;
}

.void-text {
    width: min(520px, 100%);
    color: var(--surface-dark);
    text-align: center;
    opacity: 0.72;
}

@media (max-width: 860px) {
    .monolith { width: min(100% - 24px, 1120px); }
    .modular-grid { grid-template-columns: 1fr; }
    .span-3, .span-4, .span-5, .span-7, .span-8 { grid-column: 1; }
    .hero-block { min-height: 76vh; }
    .measurement-grid { grid-template-columns: 1fr; }
}

@media (max-width: 520px) {
    .block { padding: 1.15rem; }
    .domain-title { letter-spacing: 0.03em; }
    .depth-marker span { padding: 0 0.5rem; }
}