:root {
    /* Typography compliance note: IBM Plex Mono very sparingly for DOI-like codes only. IBM Plex Sans Condensed** for archive labels. Source Serif 4** for long-form narrative passages. */
    --snow-vellum: #F8F5EA;
    --warm-paper: #E8DDC7;
    --graphite: #25231F;
    --footnote: #14213D;
    --vermilion: #C73E2F;
    --violet: #6B5BD6;
    --mint: #9FBFA8;
    --gold: #C4A35A;
    --serif-display: "Fraunces", serif;
    --serif-body: "Source Serif 4", serif;
    --condensed: "IBM Plex Sans Condensed", sans-serif;
    --mono: "IBM Plex Mono", monospace;
}

* { box-sizing: border-box; }

html {
    scroll-behavior: smooth;
    background: var(--snow-vellum);
}

body {
    margin: 0;
    color: var(--graphite);
    background:
        radial-gradient(circle at 14% 8%, rgba(159, 191, 168, 0.28), transparent 34vw),
        radial-gradient(circle at 88% 22%, rgba(196, 163, 90, 0.2), transparent 30vw),
        linear-gradient(125deg, var(--snow-vellum), #fffdf6 42%, var(--warm-paper));
    font-family: var(--serif-body);
    overflow-x: hidden;
}

button { font: inherit; }

.paper-grain {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 40;
    opacity: 0.38;
    background-image:
        repeating-linear-gradient(96deg, rgba(37, 35, 31, 0.025) 0 1px, transparent 1px 6px),
        repeating-linear-gradient(2deg, rgba(37, 35, 31, 0.018) 0 1px, transparent 1px 9px);
    mix-blend-mode: multiply;
}

.atlas-light {
    position: fixed;
    width: 52vw;
    height: 52vw;
    left: var(--light-x, 50%);
    top: var(--light-y, 18%);
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: 3;
    background: radial-gradient(circle, rgba(255,255,255,0.76), rgba(248,245,234,0.16) 45%, transparent 70%);
    filter: blur(8px);
    mix-blend-mode: soft-light;
}

.atlas-nav {
    position: fixed;
    left: 2rem;
    top: 1.4rem;
    z-index: 50;
    display: flex;
    gap: 0.65rem;
    align-items: center;
    font-family: var(--condensed);
    text-transform: uppercase;
    letter-spacing: 0.16em;
    font-size: 0.78rem;
    color: rgba(20, 33, 61, 0.68);
}

.atlas-nav span {
    padding-right: 0.35rem;
    color: rgba(37, 35, 31, 0.44);
}

.atlas-nav a {
    color: var(--footnote);
    text-decoration: none;
    border-bottom: 1px solid rgba(20, 33, 61, 0.22);
}

.chapter {
    position: relative;
    min-height: 100vh;
    padding: 7rem clamp(1.4rem, 5vw, 6rem);
    display: grid;
    align-items: center;
    isolation: isolate;
    perspective: 1400px;
}

.room-label, .coordinate-strip, .folio-tab, .marginalia, .fragment-code span, .shelf-paper span, .constellation-caption {
    font-family: var(--condensed);
    text-transform: uppercase;
    letter-spacing: 0.18em;
    color: rgba(20, 33, 61, 0.62);
    font-size: 0.82rem;
}

.room-label {
    position: absolute;
    top: 5.8rem;
    right: clamp(1.5rem, 6vw, 7rem);
    z-index: 5;
}

.blank-field {
    overflow: hidden;
    background: radial-gradient(ellipse at 54% 46%, rgba(255,255,255,0.72), rgba(248,245,234,0.2) 44%, transparent 68%);
}

.coordinate-strip {
    position: absolute;
    left: 7vw;
    bottom: 8vh;
    transform: rotate(-4deg);
}

.vellum-plane {
    position: absolute;
    background: rgba(248, 245, 234, 0.48);
    border-radius: 1.4rem 0.5rem 1.8rem 0.7rem;
    box-shadow: 0 22px 75px rgba(37, 35, 31, 0.09), inset 0 0 0 1px rgba(255,255,255,0.62);
    backdrop-filter: blur(2px);
    transform-style: preserve-3d;
    animation: slowDrift 18s ease-in-out infinite alternate;
}

.plane-a { width: 28vw; height: 38vh; left: 8vw; top: 18vh; transform: rotate(-14deg) translateZ(-80px); }
.plane-b { width: 20vw; height: 28vh; right: 9vw; top: 15vh; transform: rotate(12deg) translateZ(-120px); animation-delay: -5s; }
.plane-c { width: 36vw; height: 16vh; right: 18vw; bottom: 12vh; transform: rotate(-5deg) translateZ(-160px); animation-delay: -8s; }

.central-sheet {
    position: relative;
    width: min(76vw, 900px);
    min-height: 56vh;
    margin: auto;
    display: grid;
    place-items: center;
    align-content: center;
    padding: clamp(2rem, 5vw, 5rem);
    text-align: center;
    background:
        linear-gradient(112deg, rgba(255,255,255,0.86), rgba(248,245,234,0.62) 48%, rgba(232,221,199,0.58)),
        repeating-linear-gradient(0deg, transparent 0 27px, rgba(37,35,31,0.018) 28px 29px);
    border-radius: 1.8rem 0.45rem 2.4rem 0.65rem;
    box-shadow: 0 38px 120px rgba(20, 33, 61, 0.12), 0 1px 0 rgba(255,255,255,0.9) inset;
    transform: rotateX(var(--tilt-x, 0deg)) rotateY(var(--tilt-y, 0deg)) rotateZ(-1.5deg);
    transition: transform 900ms cubic-bezier(.2,.8,.15,1), box-shadow 900ms ease;
    z-index: 4;
}

.central-sheet.tilted { box-shadow: 0 48px 150px rgba(20, 33, 61, 0.18), -24px 0 55px rgba(196, 163, 90, 0.13); }

.fold-line { position: absolute; background: linear-gradient(90deg, transparent, rgba(37,35,31,0.1), transparent); opacity: 0.55; }
.fold-line.vertical { width: 1px; height: 86%; left: 50%; top: 7%; }
.fold-line.horizontal { width: 84%; height: 1px; left: 8%; top: 53%; }

.blind-stamp {
    margin: 1.2rem 0 0.9rem;
    font-family: var(--serif-display);
    font-size: clamp(3rem, 11vw, 9.8rem);
    font-weight: 700;
    line-height: 0.86;
    letter-spacing: -0.065em;
    color: rgba(248,245,234,0.52);
    text-shadow: 1px 1px 1px rgba(255,255,255,0.92), -1px -1px 2px rgba(37,35,31,0.22), 0 18px 30px rgba(20,33,61,0.08);
}

.emboss-caption {
    max-width: 41rem;
    margin: 0 auto 1.5rem;
    color: rgba(37,35,31,0.72);
    font-size: clamp(1rem, 2vw, 1.35rem);
}

.archive-action {
    border: 1px solid rgba(196, 163, 90, 0.52);
    background: rgba(248,245,234,0.62);
    color: var(--footnote);
    padding: 0.8rem 1.1rem;
    border-radius: 999px;
    font-family: var(--condensed);
    text-transform: uppercase;
    letter-spacing: 0.18em;
    cursor: pointer;
    box-shadow: 0 9px 24px rgba(196, 163, 90, 0.12);
}

.citation-orbit {
    position: absolute;
    width: 44vw;
    height: 44vw;
    border: 1px dashed rgba(107, 91, 214, 0.22);
    border-radius: 50%;
    right: -12vw;
    bottom: -20vw;
    animation: orbitTurn 42s linear infinite;
}

.citation-orbit span {
    position: absolute;
    width: 0.55rem;
    height: 0.55rem;
    background: var(--violet);
    border-radius: 50%;
    box-shadow: 0 0 20px rgba(107, 91, 214, 0.5);
}
.citation-orbit span:nth-child(1) { left: 20%; top: 8%; }
.citation-orbit span:nth-child(2) { right: 12%; top: 33%; }
.citation-orbit span:nth-child(3) { left: 48%; bottom: 0; }
.citation-orbit span:nth-child(4) { left: 2%; bottom: 33%; }
.citation-orbit span:nth-child(5) { right: 31%; bottom: 16%; }

.abstract-orbit { background: linear-gradient(180deg, rgba(248,245,234,0.1), rgba(232,221,199,0.36)); overflow: hidden; }
.orbit-field { position: relative; min-height: 76vh; transform-style: preserve-3d; }

.fragment, .method-page, .fogged-panel, .shelf-paper {
    background: linear-gradient(135deg, rgba(255,255,255,0.78), rgba(248,245,234,0.66) 58%, rgba(232,221,199,0.54));
    box-shadow: 0 28px 92px rgba(20, 33, 61, 0.1), inset 0 0 0 1px rgba(255,255,255,0.66);
}

.fragment { position: absolute; padding: clamp(1.3rem, 3vw, 3rem); border-radius: 1.2rem 0.35rem 1.7rem 0.45rem; }
.fragment h2, .method-page h2, .fogged-panel h2, .closing-note h2 {
    font-family: var(--serif-display);
    font-weight: 650;
    font-size: clamp(2.2rem, 5.8vw, 6.2rem);
    line-height: 0.92;
    margin: 0 0 1.2rem;
    letter-spacing: -0.045em;
    color: var(--footnote);
}
.fragment p, .method-page p, .fogged-panel p, .closing-note p { font-size: clamp(1.05rem, 1.7vw, 1.35rem); line-height: 1.55; }
.fragment-large { width: min(58vw, 760px); left: 4vw; top: 7vh; transform: rotate(-4deg); }
.fragment-code { right: 6vw; top: 7vh; width: 19rem; transform: rotate(9deg); font-family: var(--mono); }
.fragment-code strong { display: block; color: var(--violet); margin: 0.5rem 0; }
.fragment-small { right: 13vw; bottom: 3vh; width: 28rem; transform: rotate(-10deg); }
mark { background: transparent; color: var(--vermilion); font-family: var(--condensed); letter-spacing: 0.08em; text-transform: uppercase; }

.constellation { position: absolute; width: min(46vw, 560px); height: 23rem; right: 9vw; top: 29vh; }
.constellation svg { width: 100%; height: 100%; overflow: visible; }
.constellation-line { fill: none; stroke: var(--violet); stroke-width: 1.3; stroke-dasharray: 8 10; opacity: 0.55; }
.constellation circle { fill: var(--snow-vellum); stroke: var(--violet); stroke-width: 2; filter: drop-shadow(0 0 8px rgba(107, 91, 214, 0.35)); }
.constellation-caption { position: absolute; left: 8%; bottom: 3%; max-width: 18rem; }

.method-chamber { background: radial-gradient(circle at 20% 30%, rgba(159,191,168,0.22), transparent 28rem), var(--snow-vellum); overflow: hidden; }
.accordion-stack { position: relative; width: min(86vw, 1000px); min-height: 78vh; margin-left: 4vw; }
.method-page { position: absolute; padding: clamp(1.4rem, 3.6vw, 3.7rem); border-radius: 0.8rem 0.2rem 1.5rem 0.35rem; transform-origin: left center; transition: transform 900ms cubic-bezier(.2,.8,.15,1); }
.page-one { width: 56%; min-height: 68vh; left: 0; top: 4vh; transform: rotateY(-8deg) rotateZ(-2deg); }
.page-two { width: 42%; min-height: 56vh; left: 42%; top: 13vh; transform: rotateY(-18deg) rotateZ(3deg); background-color: rgba(232,221,199,0.52); }
.page-three { width: 32%; min-height: 40vh; right: 0; top: 24vh; transform: rotateY(-30deg) rotateZ(-4deg); }
.accordion-stack.unfolded .page-one { transform: rotateY(0deg) rotateZ(-1deg) translateX(-2vw); }
.accordion-stack.unfolded .page-two { transform: rotateY(0deg) rotateZ(1deg) translateX(3vw); }
.accordion-stack.unfolded .page-three { transform: rotateY(0deg) rotateZ(-2deg) translateX(5vw); }
.method-page h3 { font-family: var(--serif-display); color: var(--footnote); font-size: clamp(1.6rem, 3vw, 3rem); margin: 0.5rem 0; }
.method-page ol { padding-left: 1.2rem; font-size: 1.15rem; line-height: 1.7; }
.diagram-rings { width: 15rem; height: 15rem; margin-top: 2rem; border-radius: 50%; background: repeating-radial-gradient(circle, transparent 0 18px, rgba(20,33,61,0.16) 19px 20px), conic-gradient(from 20deg, transparent, rgba(159,191,168,0.4), transparent, rgba(196,163,90,0.32), transparent); }
.marginalia { display: block; color: var(--vermilion); transform: rotate(-3deg); }
.red-proof { color: var(--vermilion); font-family: var(--serif-display); font-size: 2rem !important; }
.punched-holes { position: absolute; right: 1.3rem; top: 1.6rem; display: grid; gap: 0.8rem; }
.punched-holes i { width: 0.8rem; height: 0.8rem; border-radius: 50%; background: rgba(37,35,31,0.13); box-shadow: inset 0 1px 4px rgba(37,35,31,0.18); }

.appendix-fog { overflow: hidden; background: linear-gradient(150deg, rgba(232,221,199,0.52), rgba(248,245,234,0.92)); }
.redaction-mist { position: absolute; inset: 8vh 5vw; border-radius: 3rem; background: rgba(255,255,255,0.34); backdrop-filter: blur(14px); box-shadow: inset 0 0 90px rgba(255,255,255,0.46), 0 30px 120px rgba(159,191,168,0.22); z-index: 0; }
.fogged-panel { position: relative; z-index: 2; width: min(70vw, 850px); padding: clamp(2rem, 5vw, 5rem); margin-left: 8vw; border-radius: 2.4rem 0.8rem 2rem 0.4rem; overflow: hidden; }
.appendix-thread { position: absolute; height: 2px; background: linear-gradient(90deg, transparent, var(--vermilion), var(--gold), transparent); opacity: 0.68; transform-origin: left center; animation: threadSlide 9s ease-in-out infinite alternate; }
.thread-a { width: 85%; left: -7%; top: 25%; transform: rotate(-8deg); }
.thread-b { width: 76%; left: 18%; top: 62%; transform: rotate(5deg); animation-delay: -2s; }
.thread-c { width: 52%; right: -4%; bottom: 18%; transform: rotate(-16deg); animation-delay: -5s; }
.erased-column { position: absolute; right: 7vw; bottom: 13vh; width: 26vw; display: grid; gap: 1.2rem; transform: rotate(8deg); }
.erased-column p { height: 1.1rem; margin: 0; background: rgba(37,35,31,0.08); filter: blur(3px); }
.erased-column p:nth-child(even) { width: 72%; margin-left: auto; }

.archive-window { min-height: 115vh; overflow: hidden; background: radial-gradient(ellipse at 50% 100%, rgba(20,33,61,0.86), rgba(20,33,61,0.12) 36%, transparent 68%), var(--snow-vellum); }
.panorama-shelf { position: relative; min-height: 52vh; width: 130vw; margin-left: -8vw; display: flex; align-items: flex-end; gap: 2vw; padding-top: 8vh; transform: translateX(var(--shelf-shift, 0)); transition: transform 600ms ease; }
.shelf-paper { flex: 0 0 19vw; min-width: 210px; height: 45vh; padding: 1.4rem; border-radius: 0.6rem 0.2rem 1.2rem 0.25rem; display: flex; flex-direction: column; justify-content: flex-end; }
.shelf-paper h3 { font-family: var(--serif-display); color: var(--footnote); font-size: clamp(1.6rem, 3vw, 3.2rem); line-height: 0.95; margin: 0.4rem 0 0; }
.shelf-paper.tall { height: 58vh; transform: rotate(-5deg); }
.shelf-paper.tilted { height: 44vh; transform: rotate(7deg); }
.shelf-paper.sealed { height: 61vh; transform: rotate(-1deg); }
.shelf-paper.sealed:before { content: ""; width: 4.2rem; height: 4.2rem; border-radius: 50%; background: radial-gradient(circle, #E8DDC7 0 22%, var(--gold) 23% 58%, rgba(196,163,90,0.36) 60%); box-shadow: 0 9px 22px rgba(196,163,90,0.28); margin-bottom: auto; }
.shelf-paper.low { height: 36vh; transform: rotate(4deg); }
.shelf-paper.moon { height: 50vh; border-radius: 50% 50% 1rem 1rem; transform: rotate(-8deg); }
.closing-note { position: relative; z-index: 4; width: min(54rem, 82vw); margin: 5vh auto 0; text-align: center; }

.chapter.in-view .fragment-large, .chapter.in-view .fogged-panel, .chapter.in-view .central-sheet { animation: revealPage 1100ms cubic-bezier(.2,.8,.15,1) both; }

@keyframes slowDrift { from { translate: 0 0; } to { translate: 2vw -2vh; } }
@keyframes orbitTurn { to { transform: rotate(360deg); } }
@keyframes threadSlide { from { translate: -4% 0; opacity: 0.36; } to { translate: 4% 0; opacity: 0.8; } }
@keyframes revealPage { from { opacity: 0.58; translate: 0 32px; } to { opacity: 1; translate: 0 0; } }

@media (max-width: 760px) {
    .atlas-nav { left: 1rem; gap: 0.45rem; font-size: 0.68rem; }
    .atlas-nav span { display: none; }
    .chapter { padding: 6rem 1rem; }
    .central-sheet { width: 92vw; }
    .fragment, .method-page { position: relative; inset: auto; width: auto; min-height: auto; margin: 1rem 0; transform: none !important; }
    .orbit-field, .accordion-stack { min-height: auto; width: auto; margin: 0; }
    .constellation { position: relative; width: 92vw; right: auto; top: auto; }
    .fogged-panel { width: 92vw; margin: 0; }
    .erased-column { display: none; }
    .panorama-shelf { width: auto; margin-left: 0; overflow: visible; flex-wrap: wrap; }
    .shelf-paper { flex-basis: 42vw; min-width: 0; }
}