/* =========================================================
   xanadu.wiki — Illuminated Manuscript meets Terminal Phosphor
   Palette: Illuminated Twilight
   ========================================================= */

:root {
    --ink-black:        #1C1814;
    --deep-twilight:    #1A1A2E;
    --manuscript-brown: #3D2B1F;
    --faded-sienna:     #8B7355;
    --vellum-gold:      #D4A574;
    --parchment-cream:  #E8DFD0;
    --candle-amber:     #F0C675;
    --portal-glow:      #6B4E9B;
    --light-bg:         #F5F0E8;

    --rule-soft:        rgba(139, 115, 85, 0.30);
    --rule-vellum:      rgba(212, 165, 116, 0.45);

    --font-display:     'Cormorant Garamond', 'Cormorant', Georgia, serif;
    --font-body:        'Source Serif 4', 'Source Serif Pro', 'Cormorant Garamond', Georgia, serif;
    --font-mono:        'IBM Plex Mono', 'Inter', ui-monospace, monospace;
    --font-portal:      'Cinzel', 'Cormorant Garamond', serif;
}

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

html, body {
    background: var(--light-bg);
    color: var(--manuscript-brown);
    font-family: var(--font-body);
    font-size: 18px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

body {
    background-image:
        radial-gradient(circle at 12% 18%, rgba(139, 115, 85, 0.05) 0, transparent 40%),
        radial-gradient(circle at 88% 72%, rgba(139, 115, 85, 0.04) 0, transparent 45%),
        repeating-linear-gradient(0deg, transparent 0 39px, rgba(139, 115, 85, 0.025) 39px 40px);
}

a { color: inherit; text-decoration: none; }
em { font-style: italic; }

/* =========================================================
   PAGE GRID — 30% margin column / 70% main content
   ========================================================= */

.page-grid {
    display: grid;
    grid-template-columns: 30% 70%;
    min-height: 100vh;
    position: relative;
}

/* =========================================================
   MARGIN COLUMN — Sticky manuscript gloss
   ========================================================= */

.margin-column {
    position: sticky;
    top: 0;
    height: 100vh;
    overflow: hidden;
    background:
        linear-gradient(180deg, #EFE6D2 0%, #E8DFCE 100%);
    border-right: 1px solid var(--rule-soft);
    z-index: 2;
}

.margin-column::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        repeating-linear-gradient(0deg, transparent 0 25px, rgba(139, 115, 85, 0.04) 25px 26px),
        radial-gradient(ellipse at top right, rgba(60, 43, 31, 0.06), transparent 60%),
        radial-gradient(ellipse at bottom left, rgba(60, 43, 31, 0.05), transparent 50%);
    pointer-events: none;
}

.margin-column::after {
    content: "";
    position: absolute;
    top: 0; right: 0; bottom: 0;
    width: 1px;
    background: var(--rule-soft);
    pointer-events: none;
}

.margin-inner {
    position: absolute;
    top: 0; left: 0; right: 0;
    padding: 56px 44px 80px 56px;
    will-change: transform;
    transform: translateY(0);
    transition: none;
}

.margin-header { margin-bottom: 48px; }

.margin-folio {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--faded-sienna);
    opacity: 0.75;
    margin-bottom: 18px;
}

.margin-title {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 44px;
    letter-spacing: -0.02em;
    line-height: 1;
    color: var(--ink-black);
    margin-bottom: 14px;
}

.margin-title .dot { color: var(--vellum-gold); }

.margin-subtitle {
    font-family: var(--font-body);
    font-style: italic;
    font-size: 15px;
    color: var(--manuscript-brown);
    line-height: 1.55;
    max-width: 28ch;
}

.margin-illustration {
    margin: 36px 0 36px;
    display: flex;
    justify-content: center;
    opacity: 0.55;
}

.margin-illustration .ill {
    width: 78%;
    height: auto;
    display: block;
}

.margin-illustration .ill * {
    transition: stroke 0.6s ease, opacity 0.6s ease;
}

.margin-label {
    font-family: var(--font-mono);
    font-size: 10.5px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--faded-sienna);
    opacity: 0.8;
    margin-bottom: 14px;
    border-bottom: 1px solid var(--rule-soft);
    padding-bottom: 6px;
}

.margin-index { margin-bottom: 40px; }

.margin-list {
    list-style: none;
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 2;
    color: var(--faded-sienna);
}

.margin-list li {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 2px 0;
    border-bottom: 1px dotted rgba(139, 115, 85, 0.18);
    transition: color 0.3s ease, padding-left 0.3s ease;
    cursor: pointer;
}

.margin-list .num {
    color: var(--vellum-gold);
    font-weight: 500;
    min-width: 22px;
}

.margin-list a {
    color: var(--manuscript-brown);
    flex: 1;
    transition: color 0.3s ease;
}

.margin-list li:hover {
    padding-left: 6px;
    color: var(--portal-glow);
}

.margin-list li:hover a { color: var(--portal-glow); }

.margin-list li.is-active {
    background: linear-gradient(90deg, rgba(212, 165, 116, 0.18), transparent);
    padding-left: 6px;
}
.margin-list li.is-active a { color: var(--ink-black); font-weight: 500; }

.margin-marginalia {
    margin: 36px 0 24px;
    border-left: 1px solid var(--rule-soft);
    padding-left: 14px;
}

.ms-gloss {
    font-family: var(--font-mono);
    font-size: 11.5px;
    line-height: 1.75;
    color: var(--faded-sienna);
    opacity: 0.78;
    margin-bottom: 14px;
}

.gloss-mark {
    font-family: var(--font-display);
    color: var(--vellum-gold);
    font-size: 16px;
    margin-right: 6px;
    vertical-align: -1px;
}

.margin-crossref { margin-top: 36px; }

.crossref-list {
    list-style: none;
    font-family: var(--font-mono);
    font-size: 11.5px;
    line-height: 1.95;
    color: var(--faded-sienna);
    opacity: 0.85;
}

.crossref-list li {
    border-bottom: 1px dotted rgba(139, 115, 85, 0.15);
    padding: 3px 0;
}

.crossref-list em {
    color: var(--manuscript-brown);
    font-style: italic;
}

.margin-footer { margin-top: 48px; }

.ms-colophon {
    font-family: var(--font-mono);
    font-size: 10.5px;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--faded-sienna);
    text-align: center;
    margin-bottom: 10px;
}

.ms-colophon-text {
    font-family: var(--font-body);
    font-style: italic;
    font-size: 12.5px;
    color: var(--manuscript-brown);
    text-align: center;
    line-height: 1.6;
    opacity: 0.8;
}

/* =========================================================
   MAIN COLUMN — Knowledge Strata
   ========================================================= */

.main-column {
    min-height: 100vh;
    background: var(--light-bg);
    position: relative;
    z-index: 1;
}

.stratum {
    width: 100%;
    padding: 140px 8% 140px 7%;
    position: relative;
    overflow: hidden;
}

.stratum-light {
    background: var(--light-bg);
    color: var(--manuscript-brown);
}

.stratum-dark {
    background: var(--deep-twilight);
    color: var(--parchment-cream);
}

.stratum-light::before,
.stratum-dark::before {
    content: "";
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--rule-soft) 20%, var(--rule-soft) 80%, transparent);
}

.stratum-dark::before {
    background: linear-gradient(90deg, transparent, var(--rule-vellum) 20%, var(--rule-vellum) 80%, transparent);
}

.stratum-inner {
    max-width: 1100px;
    margin: 0 auto;
}

/* Frontispiece */
.stratum-frontispiece {
    background: var(--light-bg);
    padding: 18vh 8% 20vh 7%;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.stratum-frontispiece::before { display: none; }

.eyebrow {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--faded-sienna);
    margin-bottom: 32px;
}

.frontispiece-title {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: clamp(46px, 6.4vw, 92px);
    line-height: 1.04;
    letter-spacing: -0.025em;
    color: var(--ink-black);
    max-width: 18ch;
    margin-bottom: 38px;
}

.frontispiece-title .rule-inline {
    display: inline-block;
    width: 1.2ch;
    height: 0.06em;
    background: var(--vellum-gold);
    transform: translateY(-0.18em);
}

.flicker {
    color: var(--vellum-gold);
    animation: candleflicker 3s ease-in-out infinite;
    will-change: opacity;
}

.stratum-light .flicker {
    color: var(--vellum-gold);
}

@keyframes candleflicker {
    0%, 100% { opacity: 1; }
    25% { opacity: 0.92; }
    50% { opacity: 0.85; }
    75% { opacity: 0.95; }
}

.frontispiece-deck {
    font-family: var(--font-body);
    font-style: italic;
    font-size: 22px;
    line-height: 1.55;
    color: var(--manuscript-brown);
    max-width: 52ch;
    margin-bottom: 80px;
}

.scroll-cue {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--faded-sienna);
    display: flex;
    align-items: center;
    gap: 14px;
}

.cue-arrow {
    display: inline-block;
    color: var(--vellum-gold);
    font-size: 16px;
    animation: cuebob 2.6s ease-in-out infinite;
}

@keyframes cuebob {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(6px); }
}

/* Two-column editorial spread */
.two-col {
    display: grid;
    grid-template-columns: minmax(220px, 1fr) 1.6fr;
    gap: 64px;
    align-items: start;
    position: relative;
}

.two-col::before {
    content: "";
    position: absolute;
    top: 8px;
    bottom: 8px;
    left: calc((100% / 2.6) * 1 + 14px);
    width: 1px;
    background: var(--rule-soft);
}

.stratum-dark .two-col::before {
    background: var(--rule-vellum);
    opacity: 0.55;
}

.col-headline { padding-right: 8px; }

.stratum-roman {
    font-family: var(--font-display);
    font-style: italic;
    font-weight: 500;
    font-size: 22px;
    color: var(--vellum-gold);
    letter-spacing: 0.04em;
    margin-bottom: 18px;
}

.stratum-title {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: clamp(44px, 5vw, 76px);
    letter-spacing: -0.02em;
    line-height: 1.02;
    margin-bottom: 22px;
}

.stratum-light .stratum-title { color: var(--ink-black); }
.stratum-dark .stratum-title { color: var(--vellum-gold); }

.stratum-meta {
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--faded-sienna);
    line-height: 1.6;
    max-width: 26ch;
}

.stratum-dark .stratum-meta {
    color: var(--candle-amber);
    opacity: 0.78;
}

.col-body {
    max-width: 60ch;
}

.lede {
    font-family: var(--font-display);
    font-weight: 500;
    font-style: italic;
    font-size: 26px;
    line-height: 1.45;
    margin-bottom: 26px;
    letter-spacing: -0.005em;
}

.stratum-light .lede { color: var(--manuscript-brown); }
.stratum-dark .lede  { color: var(--parchment-cream); }

.col-body p {
    font-family: var(--font-body);
    font-size: 18px;
    line-height: 1.78;
    margin-bottom: 22px;
}

.stratum-light .col-body p { color: var(--manuscript-brown); }
.stratum-dark .col-body p  { color: var(--parchment-cream); }

.col-body em { color: inherit; }

.stratum-dark .col-body em { color: var(--candle-amber); font-style: italic; }
.stratum-light .col-body em { color: var(--ink-black); font-style: italic; font-weight: 500; }

.aside-note {
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 1.7;
    margin-top: 32px;
    padding: 18px 22px;
    border-left: 2px solid var(--vellum-gold);
    background: rgba(139, 115, 85, 0.06);
    color: var(--faded-sienna);
}

.stratum-dark .aside-note {
    background: rgba(212, 165, 116, 0.06);
    color: var(--candle-amber);
    opacity: 0.92;
    border-left-color: var(--candle-amber);
}

.mono { font-family: var(--font-mono); font-size: 0.95em; }

/* =========================================================
   PORTAL ZONES — collapsing two-column to single line
   ========================================================= */

.portal-zone {
    background: #0E0E1A;
    color: var(--vellum-gold);
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 22px;
    padding: 0 8%;
    position: relative;
    overflow: hidden;
    border-top: 1px solid rgba(212, 165, 116, 0.18);
    border-bottom: 1px solid rgba(212, 165, 116, 0.18);
}

.portal-zone::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(ellipse at center, rgba(212, 165, 116, 0.10), transparent 60%);
    pointer-events: none;
    opacity: 0;
    transition: opacity 1s ease;
}

.portal-zone.is-visible::before { opacity: 1; }

.portal-rule {
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--vellum-gold), transparent);
    transform: scaleX(0);
    transform-origin: center;
    transition: transform 0.9s cubic-bezier(0.22, 1, 0.36, 1);
}

.portal-rule-left  { transform-origin: right center; }
.portal-rule-right { transform-origin: left center; }

.portal-zone.is-visible .portal-rule { transform: scaleX(1); }

.portal-link,
.portal-link-static {
    font-family: var(--font-portal);
    font-weight: 500;
    font-size: 14px;
    letter-spacing: 0.18em;
    text-transform: lowercase;
    color: var(--vellum-gold);
    white-space: nowrap;
    text-shadow: 0 0 18px rgba(212, 165, 116, 0.35);
    transition: color 0.4s ease, text-shadow 0.4s ease, letter-spacing 0.4s ease;
    position: relative;
    padding: 0 6px;
}

.portal-link::before,
.portal-link::after {
    content: "·";
    color: var(--vellum-gold);
    margin: 0 0.4em;
    opacity: 0.6;
}

.portal-link:hover {
    color: var(--portal-glow);
    text-shadow: 0 0 24px rgba(107, 78, 155, 0.6);
    letter-spacing: 0.22em;
}

.portal-zone-final .portal-link-static {
    color: var(--candle-amber);
    text-shadow: 0 0 22px rgba(240, 198, 117, 0.4);
}

/* =========================================================
   SITE FOOTER
   ========================================================= */

.site-foot {
    background: var(--ink-black);
    color: var(--faded-sienna);
    padding: 60px 8%;
    text-align: center;
    border-top: 1px solid rgba(212, 165, 116, 0.18);
}

.foot-line {
    font-family: var(--font-mono);
    font-size: 11.5px;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    line-height: 1.8;
    margin-bottom: 12px;
    color: var(--faded-sienna);
    opacity: 0.78;
}

.foot-tumbler {
    font-size: 11px;
    color: var(--vellum-gold);
    letter-spacing: 0.22em;
    opacity: 0.85;
}

/* =========================================================
   PROGRESS QUILL — vertical descent indicator
   ========================================================= */

.progress-quill {
    position: fixed;
    top: 0;
    right: 0;
    width: 2px;
    height: 100vh;
    background: rgba(139, 115, 85, 0.10);
    z-index: 20;
    pointer-events: none;
}

.quill-fill {
    display: block;
    width: 100%;
    height: 0%;
    background: linear-gradient(180deg, var(--vellum-gold), var(--candle-amber));
    box-shadow: 0 0 8px rgba(212, 165, 116, 0.5);
    transition: height 0.18s linear;
}

/* =========================================================
   SECTION REVEAL — fade-up on scroll
   ========================================================= */

.stratum .stratum-inner > * {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 1.1s ease, transform 1.1s cubic-bezier(0.22, 1, 0.36, 1);
}

.stratum-frontispiece .stratum-inner > * {
    opacity: 1;
    transform: none;
}

.stratum.is-visible .stratum-inner > * {
    opacity: 1;
    transform: translateY(0);
}

.stratum.is-visible .stratum-inner > *:nth-child(2) { transition-delay: 0.10s; }
.stratum.is-visible .stratum-inner > *:nth-child(3) { transition-delay: 0.18s; }
.stratum.is-visible .stratum-inner > *:nth-child(4) { transition-delay: 0.24s; }

.two-col.is-revealed .col-headline,
.two-col.is-revealed .col-body { opacity: 1; transform: translateY(0); }

/* Make the inner two-col children animate too */
.two-col .col-headline,
.two-col .col-body {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 1s ease, transform 1s cubic-bezier(0.22, 1, 0.36, 1);
}

.stratum.is-visible .two-col .col-headline { opacity: 1; transform: translateY(0); transition-delay: 0.05s; }
.stratum.is-visible .two-col .col-body     { opacity: 1; transform: translateY(0); transition-delay: 0.18s; }

/* =========================================================
   RESPONSIVE — collapse margin column on narrow screens
   ========================================================= */

@media (max-width: 960px) {
    .page-grid {
        grid-template-columns: 1fr;
    }
    .margin-column {
        position: relative;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--rule-soft);
    }
    .margin-inner {
        position: relative;
        padding: 48px 32px 56px;
        transform: none !important;
    }
    .stratum {
        padding: 90px 6% 90px 6%;
    }
    .two-col {
        grid-template-columns: 1fr;
        gap: 36px;
    }
    .two-col::before { display: none; }
    .col-body { max-width: none; }
    .frontispiece-title { font-size: clamp(38px, 9vw, 64px); }
    .stratum-frontispiece { padding: 14vh 6% 14vh 6%; min-height: auto; }
}

@media (max-width: 560px) {
    html, body { font-size: 16px; }
    .portal-zone { padding: 0 5%; gap: 12px; }
    .portal-link, .portal-link-static { font-size: 12px; letter-spacing: 0.14em; }
    .lede { font-size: 21px; }
    .col-body p { font-size: 16.5px; }
}