/* =====================================================================
   sim-ai.com  --  The Patina of Intelligence
   Wabi-sabi / editorial-flow / book-scholarly
   ===================================================================== */

/* ---------- 1. Reset & base ---------- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* warm-earthy palette (exact hexes from DESIGN.md) */
    --aged-paper:      #F0E8DA;
    --earth-brown:     #4A3728;
    --moss-patina:     #7A8B6E;
    --annotation-ink:  #8A7B6B;
    --kintsugi-gold:   #C4956A;
    --crackle-cream:   #E8DCC8;
    --tea-stain:       #D4C4A8;
    --ink-wash:        #2A2018;

    --f-display:    'Jost', 'Futura', 'futura', sans-serif;
    --f-body:       'Spectral', Georgia, 'Times New Roman', serif;
    --f-margin:     'EB Garamond', Georgia, serif;

    --max-w:        1240px;
    --gutter:       clamp(1.2rem, 4vw, 3.2rem);
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    background-color: var(--aged-paper);
    color: var(--earth-brown);
    font-family: var(--f-body);
    font-size: clamp(1rem, 1.1vw, 1.12rem);
    line-height: 1.78;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* hide the inline <svg> that only carries <defs> */
.svg-defs {
    position: absolute;
    width: 0;
    height: 0;
    pointer-events: none;
}

/* ---------- 2. Background textures ---------- */

/* Paper grain layer (SVG noise turned into a full-screen filter wash) */
.paper-grain {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 1;
    background-color: var(--aged-paper);
    filter: url(#paperGrain);
    opacity: 0.55;
    mix-blend-mode: multiply;
}

/* Soft radial foxing -- tonal variation like old paper */
.paper-foxing {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 2;
    background-image:
        radial-gradient(ellipse 60% 50% at 18% 22%, rgba(196, 149, 106, 0.08), transparent 70%),
        radial-gradient(ellipse 40% 35% at 82% 38%, rgba(138, 123, 107, 0.07), transparent 70%),
        radial-gradient(ellipse 55% 45% at 30% 78%, rgba(122, 139, 110, 0.06), transparent 70%),
        radial-gradient(ellipse 50% 40% at 88% 88%, rgba(42, 32, 24, 0.05), transparent 70%);
    opacity: 0.9;
    mix-blend-mode: multiply;
}

/* Scattered hairline cracks (absolute, overlayed on full document) */
.scatter-cracks {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 3;
    opacity: 0.15;
}

.scatter-cracks .hairline-crack {
    fill: none;
    stroke: var(--kintsugi-gold);
    stroke-width: 1.2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

/* ---------- 3. Scroll container ---------- */
.patina-scroll {
    position: relative;
    z-index: 5;
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 var(--gutter);
}

.section {
    position: relative;
    padding: clamp(4rem, 9vw, 8rem) 0;
}

/* Section heading shared ornament */
.section-heading {
    display: flex;
    align-items: baseline;
    gap: 1.2rem;
    margin-bottom: 2.6rem;
    flex-wrap: wrap;
}

.section-numeral {
    font-family: var(--f-display);
    font-weight: 300;
    font-size: clamp(1.1rem, 1.3vw, 1.3rem);
    letter-spacing: 0.25em;
    color: var(--kintsugi-gold);
    text-transform: uppercase;
}

.section-title {
    font-family: var(--f-display);
    font-weight: 400;
    font-size: clamp(1.5rem, 2.8vw, 2.2rem);
    color: var(--earth-brown);
    letter-spacing: -0.005em;
}

.section-rule {
    flex: 1 1 120px;
    height: 1px;
    background: linear-gradient(90deg, var(--kintsugi-gold), transparent);
    opacity: 0.6;
    align-self: center;
    margin-top: 0.4rem;
}

/* ===================================================================
   SECTION I  --  THE VESSEL
   =================================================================== */
.vessel {
    min-height: 90vh;
    display: flex;
    flex-direction: column;
    padding-top: clamp(2rem, 4vw, 3rem);
}

.vessel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    padding-bottom: 2rem;
    flex-wrap: wrap;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.9rem;
    font-family: var(--f-display);
}

.brand-mark {
    font-weight: 500;
    font-size: 1.15rem;
    letter-spacing: 0.04em;
    color: var(--earth-brown);
}

.brand-rule {
    width: 40px;
    height: 1px;
    background: var(--kintsugi-gold);
    opacity: 0.8;
}

.brand-meta {
    font-family: var(--f-margin);
    font-style: italic;
    font-size: 0.86rem;
    color: var(--annotation-ink);
    letter-spacing: 0.02em;
}

.page-nav {
    display: flex;
    gap: 1.6rem;
    flex-wrap: wrap;
}

.nav-link {
    font-family: var(--f-display);
    font-weight: 400;
    font-size: 0.82rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--annotation-ink);
    padding: 0.25rem 0;
    border-bottom: 1px solid transparent;
    transition: color 0.4s ease, border-color 0.4s ease, letter-spacing 0.4s ease;
}

.nav-link:hover {
    color: var(--kintsugi-gold);
    border-bottom-color: var(--kintsugi-gold);
    letter-spacing: 0.22em;
}

/* Vessel stage -- the textured negative space containing title */
.vessel-stage {
    position: relative;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: clamp(2rem, 6vw, 5rem) clamp(1rem, 4vw, 4rem);
    min-height: 60vh;
}

/* Book-page L-shaped corner ornaments */
.corner-ornament {
    position: absolute;
    width: 44px;
    height: 44px;
    border: 1px solid var(--kintsugi-gold);
    opacity: 0.55;
}
.corner-tl { top: 0;    left: 0;    border-right: 0; border-bottom: 0; }
.corner-tr { top: 0;    right: 0;   border-left:  0; border-bottom: 0; }
.corner-bl { bottom: 0; left: 0;    border-right: 0; border-top:    0; }
.corner-br { bottom: 0; right: 0;   border-left:  0; border-top:    0; }

/* Skeleton cluster -- the opening loading state */
.skeleton-cluster {
    position: absolute;
    inset: clamp(2rem, 6vw, 5rem) clamp(1rem, 4vw, 4rem);
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 1.2rem;
    z-index: 2;
    opacity: 1;
    transition: opacity 0.9s ease-out;
}

.skeleton-cluster.faded {
    opacity: 0;
    pointer-events: none;
}

.skeleton-bar {
    height: 1.1rem;
    border-radius: 2px;
    background: linear-gradient(
        90deg,
        var(--crackle-cream) 25%,
        var(--aged-paper) 50%,
        var(--crackle-cream) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s ease-in-out infinite;
    opacity: 0.9;
}

.sk-eyebrow   { width: 32%;  height: 0.75rem; }
.sk-title-1   { width: 58%;  height: 3.4rem;  }
.sk-title-2   { width: 70%;  height: 3.4rem;  }
.sk-subtitle  { width: 48%;  height: 1rem; margin-top: 0.6rem; }

@keyframes shimmer {
    0%   { background-position:  200% 0; }
    100% { background-position: -200% 0; }
}

/* Actual vessel content (fades in after skeleton) */
.vessel-content {
    position: relative;
    z-index: 3;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 1.4s ease-out, transform 1.4s ease-out;
}

.vessel-content.revealed {
    opacity: 1;
    transform: translateY(0);
}

.eyebrow {
    font-family: var(--f-display);
    font-weight: 400;
    font-size: 0.82rem;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--kintsugi-gold);
    margin-bottom: 1.4rem;
}

.vessel-title {
    font-family: var(--f-display);
    font-weight: 700;
    font-size: clamp(2.6rem, 6vw, 5rem);
    line-height: 1.02;
    letter-spacing: -0.018em;
    color: var(--earth-brown);
    margin-bottom: 1.6rem;
}

.title-line {
    display: block;
}

.title-line:nth-child(2) {
    color: var(--ink-wash);
    font-style: italic;
    font-weight: 500;
}

.vessel-subtitle {
    font-family: var(--f-body);
    font-size: clamp(1.05rem, 1.25vw, 1.2rem);
    max-width: 46ch;
    line-height: 1.7;
    color: var(--annotation-ink);
    font-style: italic;
}

.vessel-footer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-top: auto;
    padding-top: 2rem;
    color: var(--annotation-ink);
    font-family: var(--f-margin);
    font-style: italic;
    font-size: 0.88rem;
    letter-spacing: 0.04em;
}

.footer-glyph {
    color: var(--kintsugi-gold);
    font-size: 0.9rem;
}

.footer-label {
    opacity: 0.85;
}

/* ===================================================================
   SECTION II  --  THE MARGIN NOTES
   =================================================================== */
.margin-notes {
    border-top: 1px solid rgba(196, 149, 106, 0.25);
}

.margin-grid {
    display: grid;
    grid-template-columns: 3fr 1.5fr;
    gap: 2rem;
    align-items: start;
}

/* --- body column --- */
.body-column {
    max-width: 62ch;
}

.body-column p {
    margin-bottom: 1.4rem;
    text-align: justify;
    hyphens: auto;
}

.drop-cap-p {
    text-align: justify;
}

.drop-cap {
    font-family: var(--f-display);
    font-weight: 700;
    font-size: 4.8rem;
    float: left;
    line-height: 0.85;
    padding: 0.38rem 0.6rem 0 0;
    color: var(--kintsugi-gold);
    font-feature-settings: "kern";
}

.body-column em {
    font-style: italic;
    color: var(--ink-wash);
}

.body-subhead {
    font-family: var(--f-display);
    font-weight: 400;
    font-size: 1.25rem;
    letter-spacing: 0.01em;
    color: var(--earth-brown);
    margin: 2.6rem 0 1rem;
    padding-left: 0.2rem;
}

.pull-quote {
    margin: 2.2rem 0 2.2rem 1.4rem;
    padding: 1rem 1.4rem;
    border-left: 2px solid var(--kintsugi-gold);
    font-family: var(--f-body);
    font-style: italic;
    font-size: 1.18rem;
    line-height: 1.55;
    color: var(--ink-wash);
    background: linear-gradient(90deg, rgba(212, 196, 168, 0.25), transparent);
}

/* --- annotation column (margin notes) --- */
.annotation-column {
    font-family: var(--f-margin);
    font-style: italic;
    font-size: 0.88rem;
    color: var(--annotation-ink);
    line-height: 1.6;
    padding-left: 1.2rem;
    border-left: 1px dotted rgba(138, 123, 107, 0.4);
    position: relative;
}

.annotation-head {
    font-family: var(--f-display);
    font-style: normal;
    font-weight: 400;
    font-size: 0.72rem;
    letter-spacing: 0.28em;
    text-transform: uppercase;
    color: var(--kintsugi-gold);
    margin-bottom: 1.4rem;
    padding-bottom: 0.6rem;
    border-bottom: 1px solid rgba(196, 149, 106, 0.35);
}

.margin-note {
    position: relative;
    margin-bottom: 1.6rem;
    padding-left: 1.2rem;
}

.margin-note .ref-mark {
    position: absolute;
    left: 0;
    top: 0;
    color: var(--kintsugi-gold);
    font-style: normal;
    font-size: 0.82rem;
}

.margin-note em {
    color: var(--earth-brown);
    font-style: italic;
}

.margin-quote {
    margin: 2rem 0;
    padding: 1.2rem 0.8rem 1rem 0.8rem;
    border-top: 1px solid rgba(196, 149, 106, 0.35);
    border-bottom: 1px solid rgba(196, 149, 106, 0.35);
    font-family: var(--f-body);
    font-style: italic;
    color: var(--earth-brown);
    text-align: center;
}

.mq-text {
    font-size: 1rem;
    line-height: 1.45;
}

.mq-attr {
    margin-top: 0.6rem;
    font-family: var(--f-margin);
    font-size: 0.8rem;
    color: var(--annotation-ink);
}

.margin-list {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px dotted rgba(138, 123, 107, 0.4);
}

.ml-head {
    font-family: var(--f-display);
    font-style: normal;
    font-weight: 400;
    font-size: 0.72rem;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--moss-patina);
    margin-bottom: 0.8rem;
}

.margin-list ul {
    list-style: none;
}

.margin-list li {
    position: relative;
    padding-left: 1.1rem;
    margin-bottom: 0.35rem;
    font-size: 0.86rem;
}

.margin-list li::before {
    content: "\00B6";
    position: absolute;
    left: 0;
    color: var(--kintsugi-gold);
    font-style: normal;
}

/* ===================================================================
   SECTION III  --  THE KINTSUGI LINE
   =================================================================== */
.kintsugi {
    padding-top: clamp(3rem, 6vw, 5rem);
    padding-bottom: clamp(3rem, 6vw, 5rem);
    text-align: center;
}

.kintsugi-above,
.kintsugi-below {
    font-family: var(--f-margin);
    font-style: italic;
    font-size: clamp(0.95rem, 1.1vw, 1.1rem);
    color: var(--annotation-ink);
    letter-spacing: 0.02em;
    max-width: 50ch;
    margin: 0 auto;
}

.kintsugi-above { margin-bottom: 1.8rem; }
.kintsugi-below { margin-top:    1.8rem; }

.kintsugi-band {
    width: 100vw;
    height: 120px;
    margin-left: calc(50% - 50vw);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    background:
        linear-gradient(180deg, transparent, rgba(212, 196, 168, 0.25), transparent);
    overflow: hidden;
}

.kintsugi-svg {
    width: 100%;
    height: 160px;
    display: block;
    filter: drop-shadow(0 0 4px rgba(196, 149, 106, 0.4));
}

#kintsugiPath {
    stroke-dasharray: 2600;
    stroke-dashoffset: 2600;
    transition: stroke-dashoffset 2.6s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.kintsugi-band.drawn #kintsugiPath {
    stroke-dashoffset: 0;
}

.kintsugi-fleck {
    stroke-dasharray: 80;
    stroke-dashoffset: 80;
    transition: stroke-dashoffset 1.1s ease-out;
}

.kintsugi-band.drawn .kintsugi-fleck {
    stroke-dashoffset: 0;
    transition-delay: 1.4s;
}

/* ===================================================================
   SECTION IV  --  THE INDEX
   =================================================================== */
.book-index {
    border-top: 1px solid rgba(196, 149, 106, 0.25);
}

.index-preamble {
    max-width: 48ch;
    margin-bottom: 2.8rem;
    font-style: italic;
    color: var(--annotation-ink);
    font-size: 1rem;
    line-height: 1.7;
}

.index-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(2rem, 4vw, 4rem);
}

.index-column {
    list-style: none;
}

.index-entry,
.index-sub {
    display: flex;
    align-items: baseline;
    gap: 0.4rem;
    padding: 0.32rem 0;
    font-family: var(--f-body);
}

.index-entry {
    font-size: 1rem;
    color: var(--earth-brown);
}

.index-sub {
    font-size: 0.92rem;
    color: var(--annotation-ink);
    padding-left: 1.4rem;
}

.entry-name {
    flex: 0 0 auto;
    max-width: 65%;
}

.entry-leader {
    flex: 1 1 auto;
    border-bottom: 1px dotted var(--kintsugi-gold);
    height: 0.7em;
    margin: 0 0.35rem;
    opacity: 0.7;
}

.entry-page {
    flex: 0 0 auto;
    font-family: var(--f-margin);
    font-style: italic;
    color: var(--kintsugi-gold);
    font-size: 0.9rem;
}

/* --- colophon --- */
.colophon {
    margin-top: clamp(4rem, 7vw, 6rem);
    text-align: center;
}

.colophon-rule {
    width: 100%;
    height: 1px;
    background: linear-gradient(
        90deg,
        transparent 0%,
        var(--kintsugi-gold) 20%,
        var(--kintsugi-gold) 80%,
        transparent 100%
    );
    opacity: 0.55;
    margin: 1.2rem 0;
}

.colophon-text {
    font-family: var(--f-margin);
    font-style: italic;
    font-size: 0.92rem;
    color: var(--annotation-ink);
    max-width: 58ch;
    margin: 0 auto;
    line-height: 1.6;
}

.colophon-text .glyph {
    color: var(--kintsugi-gold);
    font-style: normal;
    margin-right: 0.4rem;
}

.colophon-text .ink {
    color: var(--earth-brown);
    font-style: normal;
    letter-spacing: 0.1em;
}

/* ===================================================================
   Responsive -- collapse annotation column
   =================================================================== */
@media (max-width: 860px) {
    .margin-grid {
        grid-template-columns: 1fr;
        gap: 2.8rem;
    }

    .body-column {
        max-width: 100%;
    }

    .annotation-column {
        padding-left: 0;
        padding-top: 1.6rem;
        border-left: 0;
        border-top: 1px dotted rgba(138, 123, 107, 0.5);
    }

    .index-columns {
        grid-template-columns: 1fr;
    }

    .vessel-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .page-nav {
        gap: 1.1rem;
    }

    .drop-cap {
        font-size: 3.6rem;
        padding: 0.3rem 0.45rem 0 0;
    }
}

@media (max-width: 520px) {
    .brand-meta {
        display: none;
    }

    .pull-quote {
        margin-left: 0;
    }

    .kintsugi-band {
        height: 100px;
    }

    .kintsugi-svg {
        height: 120px;
    }
}