/*
 * gabs.ai -- Design Language Implementation Notes
 * ---------------------------------------------------------------
 * Interaction Pattern: scroll-driven Interactive hover states are
 * orchestrated through IntersectionObserver instances with
 * thresholds at [0.18, 0.3, 0.5] -- e.g. [0.18] for marginalia.
 * Cormorant Garamond stands in
 * for Playfair Display as its primary display font; EB Garamond
 * carries body copy. Deepest shadow tone is #08050A, used inside
 * inset box-shadows to create the manuscript's gutter penumbra.
 */
:root {
    --color-oxblood: #3A0A0F;
    --color-void: #0D0507;
    --color-shadow: #08050A;
    --color-gold: #8B7335;
    --color-blood: #6B1020;
    --color-vellum: #D8C4A0;
    --color-parchment: #B09A78;
    --color-candle: #E8B84A;
    --color-umber: #1A0608;
    --font-display: 'Cormorant Garamond', serif;
    --font-body: 'EB Garamond', serif;
    --font-margin: 'Caveat', cursive;
    --font-label: 'Cormorant SC', serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background: var(--color-oxblood);
    color: var(--color-vellum);
    font-family: var(--font-body);
    font-size: clamp(1rem, 1.8vw, 1.25rem);
    line-height: 1.75;
    letter-spacing: 0.01em;
    overflow-x: hidden;
    background-image:
        url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.55  0 0 0 0 0.45  0 0 0 0 0.21  0 0 0 0.04 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
    background-attachment: fixed;
    background-blend-mode: overlay;
}

::selection {
    background: var(--color-blood);
    color: var(--color-candle);
}

.gutter-line {
    position: fixed;
    left: 2rem;
    top: 8%;
    width: 1px;
    height: 84%;
    background: var(--color-blood);
    z-index: 100;
    animation: gutterPulse 2.4s ease-in-out infinite;
    transition: opacity 2s ease;
}

@keyframes gutterPulse {
    0%, 100% { opacity: 0.45; }
    50% { opacity: 0.95; }
}

.folio-marker {
    position: fixed;
    left: 2.6rem;
    top: 50%;
    transform: translateY(-50%) rotate(-90deg);
    transform-origin: left top;
    font-family: var(--font-label);
    font-size: clamp(0.6rem, 1vw, 0.8rem);
    letter-spacing: 0.4em;
    color: var(--color-parchment);
    z-index: 101;
    opacity: 0.65;
    pointer-events: none;
    text-transform: uppercase;
    transition: opacity 0.6s ease, color 0.6s ease;
    white-space: nowrap;
}

.folio {
    min-height: 100vh;
    width: 100%;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-left: 5rem;
    padding-right: 3rem;
}

/* ========== FOLIO I -- THE SEAL ========== */
.folio-i {
    flex-direction: column;
    background:
        radial-gradient(ellipse at 20% 30%, rgba(139,115,53,0.05) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 60%, rgba(107,16,32,0.05) 0%, transparent 40%),
        radial-gradient(ellipse at 45% 80%, rgba(139,115,53,0.04) 0%, transparent 45%),
        var(--color-oxblood);
    box-shadow: inset 0 0 200px 60px rgba(13,5,7,0.7);
    overflow: hidden;
}

.bracket-watermark {
    position: absolute;
    font-family: var(--font-display);
    font-size: clamp(8rem, 16vw, 14rem);
    color: var(--color-gold);
    opacity: 0.07;
    line-height: 1;
    pointer-events: none;
    user-select: none;
    transition: transform 0.4s ease-out;
}

.bracket-left {
    top: 12%;
    left: 8%;
}

.bracket-right {
    bottom: 12%;
    right: 8%;
}

.seal-container {
    position: relative;
    text-align: center;
    z-index: 2;
}

.wax-seal {
    width: 130px;
    height: 130px;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 35%, var(--color-candle) 0%, var(--color-blood) 30%, #2a070d 90%);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
    box-shadow:
        0 6px 28px rgba(26,6,8,0.7),
        inset 0 -3px 8px rgba(0,0,0,0.45),
        inset 0 3px 8px rgba(232,184,74,0.18);
    animation: sealBreak 2.5s ease-out forwards;
    animation-delay: 0.6s;
    will-change: transform, opacity;
}

.seal-glyph {
    font-family: var(--font-display);
    font-size: 3.2rem;
    color: var(--color-vellum);
    opacity: 0.85;
    text-shadow: 0 1px 2px rgba(0,0,0,0.4);
}

@keyframes sealBreak {
    0%   { transform: scale(1) rotate(0deg); opacity: 1; filter: blur(0); }
    50%  { transform: scale(1.18) rotate(2deg); opacity: 0.75; }
    80%  { transform: scale(1.32) rotate(-3deg); opacity: 0.3; filter: blur(1px); }
    100% { transform: scale(1.55) rotate(0deg); opacity: 0; filter: blur(2px); }
}

.domain-name {
    font-family: var(--font-display);
    font-size: clamp(3rem, 10vw, 7rem);
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-vellum);
    line-height: 1.1;
    opacity: 0;
    animation: revealName 1.6s ease-out forwards;
    animation-delay: 2s;
    text-shadow: 0 2px 0 rgba(13,5,7,0.6), 0 0 30px rgba(232,184,74,0.08);
    will-change: transform, opacity;
}

@keyframes revealName {
    from { opacity: 0; transform: scale(0.94) translateY(8px); letter-spacing: 0.18em; }
    to   { opacity: 1; transform: scale(1) translateY(0);    letter-spacing: 0.12em; }
}

.quill-scratch {
    width: clamp(180px, 42%, 540px);
    height: 1px;
    background: linear-gradient(to right, transparent 0%, var(--color-gold) 20%, var(--color-gold) 80%, transparent 100%);
    margin-top: 3rem;
    opacity: 0;
    animation: fadeIn 1.2s ease-out forwards;
    animation-delay: 3s;
    filter: url(#turbulence);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 0.65; }
}

.folio-caption {
    font-family: var(--font-label);
    letter-spacing: 0.32em;
    text-transform: uppercase;
    font-size: clamp(0.65rem, 1.1vw, 0.8rem);
    color: var(--color-parchment);
    margin-top: 2rem;
    opacity: 0;
    animation: fadeIn 1.4s ease-out forwards;
    animation-delay: 3.4s;
}

/* ========== FOLIO II -- THE MARGINALIA ========== */
.folio-ii {
    background:
        radial-gradient(ellipse at 30% 50%, rgba(232,184,74,0.06) 0%, transparent 70%),
        radial-gradient(ellipse at 60% 40%, rgba(139,115,53,0.04) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(107,16,32,0.05) 0%, transparent 55%),
        var(--color-oxblood);
    align-items: flex-start;
    padding-top: clamp(4rem, 8vw, 8rem);
    padding-bottom: clamp(4rem, 8vw, 8rem);
    padding-left: clamp(5rem, 7vw, 8rem);
    padding-right: clamp(2rem, 5vw, 6rem);
    gap: 3rem;
    opacity: 0;
    transform: translateX(40px);
    transition: opacity 0.9s ease-out, transform 0.9s ease-out;
}

.folio-ii.revealed {
    opacity: 1;
    transform: translateX(0);
}

.marginalia-column {
    width: 38%;
    padding-top: 5rem;
    flex-shrink: 0;
    border-right: 1px solid rgba(139,115,53,0.18);
    padding-right: 2rem;
}

.annotation {
    font-family: var(--font-margin);
    font-size: clamp(0.85rem, 1.5vw, 1.1rem);
    color: var(--color-parchment);
    transform: rotate(var(--rotation)) translateY(20px);
    opacity: 0;
    margin-bottom: 2.4rem;
    padding-left: 1rem;
    border-left: 1px solid rgba(139,115,53,0.35);
    transition: transform 0.65s ease-out, opacity 0.7s ease-out;
    line-height: 1.4;
}

.annotation em {
    font-style: italic;
    color: var(--color-candle);
}

.annotation.visible {
    transform: rotate(var(--rotation)) translateY(0);
    opacity: var(--target-opacity);
}

.primary-text {
    width: 60%;
    padding-top: 4rem;
    position: relative;
}

.folio-title {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: clamp(1.6rem, 4vw, 2.8rem);
    letter-spacing: 0.06em;
    line-height: 1.25;
    color: var(--color-vellum);
    margin-bottom: 2rem;
    font-style: italic;
}

.folio-text {
    margin-bottom: 1.5rem;
    text-align: justify;
    max-width: 38em;
    color: var(--color-vellum);
    hyphens: auto;
}

.folio-text:first-of-type::first-letter {
    font-family: var(--font-display);
    font-size: 4em;
    float: left;
    line-height: 0.8;
    margin-right: 0.5rem;
    margin-top: 0.05em;
    color: var(--color-candle);
    font-weight: 700;
    text-shadow: 0 1px 2px rgba(0,0,0,0.5);
}

.ornament {
    text-align: center;
    font-family: var(--font-display);
    font-size: 1.6rem;
    color: var(--color-gold);
    opacity: 0.6;
    margin-top: 2rem;
}

/* ========== FOLIO III -- THE DIAGRAM ========== */
.folio-iii {
    background:
        radial-gradient(ellipse at center, rgba(139,115,53,0.05) 0%, transparent 60%),
        linear-gradient(180deg, var(--color-shadow) 0%, var(--color-void) 50%, var(--color-shadow) 100%);
    flex-direction: column;
    padding: clamp(2rem, 5vw, 4rem) 5rem;
    box-shadow: inset 0 0 240px 80px rgba(0,0,0,0.85);
}

.diagram-title {
    color: var(--color-parchment);
    margin-bottom: 1.5rem;
    text-align: center;
}

.alchemy-diagram {
    width: min(78vw, 640px);
    height: auto;
    filter: drop-shadow(0 0 12px rgba(232,184,74,0.05));
}

.diagram-path {
    stroke-dasharray: 2400;
    stroke-dashoffset: 2400;
    transition: stroke-dashoffset 3s ease-in-out;
}

.diagram-path.drawn {
    stroke-dashoffset: 0;
}

.diagram-label {
    font-family: 'Cormorant SC', 'Cormorant Garamond', serif;
    font-size: 13px;
    fill: var(--color-parchment);
    letter-spacing: 0.18em;
    text-anchor: middle;
}

.diagram-node {
    cursor: help;
}

.diagram-node circle {
    transition: transform 0.3s ease-out, fill 0.3s ease, r 0.3s ease;
    transform-origin: center;
    transform-box: fill-box;
}

.diagram-node:hover circle {
    fill: var(--color-candle);
    transform: scale(1.4);
}

.diagram-node:hover text {
    fill: var(--color-candle);
}

.diagram-node text {
    transition: fill 0.3s ease;
}

.diagram-center circle {
    animation: candleFlicker 3s ease-in-out infinite;
}

@keyframes candleFlicker {
    0%, 100% { opacity: 0.4; }
    50%      { opacity: 1; }
}

.diagram-caption {
    font-family: var(--font-label);
    font-size: clamp(0.7rem, 1.1vw, 0.85rem);
    letter-spacing: 0.2em;
    color: var(--color-gold);
    opacity: 0.7;
    margin-top: 1.6rem;
    text-align: center;
    text-transform: uppercase;
}

.diagram-tooltip {
    position: fixed;
    background: rgba(232,184,74,0.96);
    color: var(--color-void);
    font-family: var(--font-body);
    font-size: 0.88rem;
    font-style: italic;
    padding: 0.55rem 1rem;
    border-radius: 1px;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 200;
    max-width: 280px;
    box-shadow: 0 6px 18px rgba(0,0,0,0.5);
    line-height: 1.4;
}

.diagram-tooltip.active {
    opacity: 1;
}

/* ========== FOLIO IV -- THE CORRESPONDENCE ========== */
.folio-iv {
    background:
        radial-gradient(ellipse at 50% 50%, rgba(232,184,74,0.05) 0%, transparent 60%),
        radial-gradient(ellipse at 20% 80%, rgba(107,16,32,0.05) 0%, transparent 50%),
        var(--color-oxblood);
    flex-direction: column;
    padding: clamp(4rem, 7vw, 7rem) clamp(5rem, 6vw, 7rem);
    gap: 2rem;
}

.folio-iv .folio-title {
    text-align: center;
    color: var(--color-vellum);
}

.correspondence-pile {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
    max-width: 720px;
    width: 100%;
    position: relative;
}

.letter-card {
    background:
        radial-gradient(ellipse at 50% 50%, rgba(216,196,160,0.08) 0%, transparent 70%),
        rgba(26,6,8,0.65);
    border: 1px solid var(--color-gold);
    padding: clamp(1.5rem, 3vw, 2.5rem) clamp(1.5rem, 3vw, 3rem);
    width: 100%;
    position: relative;
    transform: rotate(var(--rotation)) translateY(40px);
    margin-bottom: -32px;
    opacity: 0;
    transition:
        transform 0.7s cubic-bezier(0.34, 1.56, 0.64, 1),
        opacity 0.5s ease-out,
        margin-bottom 0.7s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow: 0 6px 24px rgba(13,5,7,0.55);
    will-change: transform, opacity;
}

.letter-card::before {
    content: "";
    position: absolute;
    inset: 6px;
    border: 1px solid rgba(139,115,53,0.25);
    pointer-events: none;
}

.letter-card.spread {
    margin-bottom: 1.6rem;
    opacity: 1;
    transform: rotate(0deg) translateY(0);
}

.wax-seal-icon {
    position: absolute;
    top: 0.85rem;
    right: 1.15rem;
    font-size: 1.6rem;
    color: var(--color-blood);
    opacity: 0.7;
    text-shadow: 0 0 6px rgba(232,184,74,0.18);
}

.letter-meta {
    font-family: var(--font-label);
    font-size: clamp(0.65rem, 1.1vw, 0.8rem);
    color: var(--color-parchment);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 0.4rem;
    opacity: 0.7;
}

.letter-card h3 {
    font-family: var(--font-display);
    font-size: clamp(1.3rem, 2.6vw, 1.9rem);
    font-weight: 600;
    letter-spacing: 0.06em;
    color: var(--color-candle);
    margin-bottom: 0.85rem;
    font-style: italic;
}

.letter-card p:last-child {
    font-family: var(--font-body);
    font-size: clamp(0.95rem, 1.5vw, 1.1rem);
    color: var(--color-parchment);
    line-height: 1.7;
}

/* ========== FOLIO V -- THE COLOPHON ========== */
.folio-v {
    background:
        radial-gradient(ellipse at center, rgba(139,115,53,0.04) 0%, transparent 60%),
        var(--color-oxblood);
    flex-direction: column;
}

.colophon {
    text-align: center;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 1.2s ease-out 0.6s, transform 1.2s ease-out 0.6s;
    max-width: 520px;
    padding: 2rem;
}

.colophon.visible {
    opacity: 1;
    transform: translateY(0);
}

.colophon-date {
    font-family: var(--font-label);
    font-size: clamp(0.7rem, 1.1vw, 0.9rem);
    letter-spacing: 0.32em;
    color: var(--color-parchment);
    margin-bottom: 2rem;
    text-transform: uppercase;
}

.fleuron {
    font-family: var(--font-display);
    font-size: 3.2rem;
    color: var(--color-gold);
    margin-bottom: 2rem;
    opacity: 0.65;
}

.colophon-attribution {
    font-family: var(--font-display);
    font-size: clamp(1rem, 1.6vw, 1.25rem);
    color: var(--color-vellum);
    letter-spacing: 0.1em;
    margin-bottom: 1.5rem;
    font-style: italic;
}

.colophon-body {
    font-family: var(--font-body);
    font-size: clamp(0.85rem, 1.3vw, 1rem);
    color: var(--color-parchment);
    line-height: 1.8;
    margin-bottom: 2rem;
    opacity: 0.8;
}

.colophon-mark {
    font-family: var(--font-display);
    font-size: 1.3rem;
    color: var(--color-gold);
    letter-spacing: 0.2em;
    opacity: 0.55;
}

/* ========== Responsive ========== */
@media (max-width: 880px) {
    .folio {
        padding-left: 3.5rem;
        padding-right: 1.5rem;
    }
    .folio-ii {
        flex-direction: column;
        padding-left: 3.5rem;
    }
    .marginalia-column {
        width: 100%;
        padding-top: 1rem;
        padding-right: 0;
        border-right: none;
        border-bottom: 1px solid rgba(139,115,53,0.18);
        padding-bottom: 2rem;
        margin-bottom: 2rem;
    }
    .primary-text {
        width: 100%;
        padding-top: 1rem;
    }
    .gutter-line {
        left: 1rem;
    }
    .folio-marker {
        left: 1.4rem;
        font-size: 0.55rem;
    }
    .bracket-watermark {
        font-size: 7rem;
    }
}

@media (max-width: 520px) {
    .wax-seal {
        width: 100px;
        height: 100px;
    }
    .seal-glyph {
        font-size: 2.4rem;
    }
}