/* ==========================================================================
   logic.quest - Art Deco Formalism & Aged Academic Parchment
   ========================================================================== */

/* --- CSS Custom Properties --- */
:root {
    --deep-walnut: #3B2616;
    --antique-parchment: #F2E8D5;
    --burnished-gold: #C4973B;
    --academic-teal: #2B6B5E;
    --claret-ink: #8B2F3A;
    --warm-ivory: #FAF6EE;
    --graphite: #4A4A4A;
    --faded-sage: #A8B5A0;
    --gold-light: #E8D48B;
    --gold-dark: #9A7428;

    --gold-gradient: linear-gradient(135deg, #C4973B 0%, #E8D48B 45%, #C4973B 55%, #9A7428 100%);

    --font-headline: 'Playfair Display', Georgia, serif;
    --font-body: 'Source Serif 4', 'Source Serif Pro', Georgia, serif;
    --font-mono: 'Inconsolata', 'Courier New', monospace;

    --section-padding: 64px;
}

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

html {
    scroll-snap-type: y mandatory;
    scroll-behavior: smooth;
    font-size: 16px;
    overflow-x: hidden;
}

body {
    font-family: var(--font-body);
    font-weight: 400;
    color: var(--graphite);
    background-color: var(--deep-walnut);
    line-height: 1.75;
    overflow-x: hidden;
}

.svg-filters {
    position: absolute;
    width: 0;
    height: 0;
    overflow: hidden;
}

/* --- Parallax Container --- */
#parallax-container {
    perspective: 1px;
    height: 100vh;
    overflow-x: hidden;
    overflow-y: auto;
    scroll-snap-type: y mandatory;
}

/* --- Proposition Sections (shared) --- */
.proposition-section {
    position: relative;
    min-height: 100vh;
    scroll-snap-align: start;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

/* Paper texture pseudo-element */
.proposition-section .section-bg {
    position: absolute;
    inset: 0;
    filter: url(#paper-noise);
    z-index: 0;
    pointer-events: none;
}

.proposition-section .section-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, transparent 50%, rgba(59, 38, 22, 0.15) 100%);
    pointer-events: none;
}

.section-content {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--section-padding);
}

/* --- Content Grid (3-column golden ratio) --- */
.content-grid {
    display: grid;
    grid-template-columns: 1fr 1.618fr 1fr;
    gap: 32px;
    align-items: start;
}

.content-inner {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* --- Section Backgrounds --- */
.section-axiom {
    background-color: var(--deep-walnut);
}
.section-axiom .section-bg {
    background-color: var(--deep-walnut);
}

.section-definitions {
    background-color: var(--antique-parchment);
}
.section-definitions .section-bg {
    background-color: var(--antique-parchment);
}

.section-prop1 {
    background-color: var(--antique-parchment);
}
.section-prop1 .section-bg {
    background-color: var(--antique-parchment);
}

.section-prop2 {
    background-color: var(--warm-ivory);
}
.section-prop2 .section-bg {
    background-color: var(--warm-ivory);
}

.section-prop3 {
    background-color: var(--antique-parchment);
}
.section-prop3 .section-bg {
    background-color: var(--antique-parchment);
}

.section-theorem {
    background-color: var(--deep-walnut);
}
.section-theorem .section-bg {
    background-color: var(--deep-walnut);
}

.section-qed {
    background-color: var(--deep-walnut);
}
.section-qed .section-bg {
    background-color: var(--deep-walnut);
}

/* --- Typography --- */
.proposition-number {
    font-family: var(--font-mono);
    font-weight: 500;
    font-size: 0.85rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--burnished-gold);
    margin-bottom: 8px;
}

.section-title {
    font-family: var(--font-headline);
    font-weight: 700;
    font-size: clamp(2.4rem, 5vw, 4.2rem);
    letter-spacing: 0.04em;
    font-variant-caps: small-caps;
    line-height: 1.15;
    color: var(--deep-walnut);
    margin-bottom: 8px;
}

.body-text {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: clamp(1.05rem, 1.2vw, 1.2rem);
    line-height: 1.75;
    color: var(--graphite);
    max-width: 640px;
}

/* Dark section text overrides */
.section-axiom .proposition-number,
.section-theorem .proposition-number,
.section-qed .proposition-number {
    color: var(--gold-light);
}

.section-axiom .section-title,
.section-theorem .section-title,
.section-qed .section-title {
    color: var(--antique-parchment);
}

.section-axiom .body-text,
.section-theorem .body-text,
.section-qed .body-text {
    color: var(--antique-parchment);
}

/* --- Section 1: Axiom --- */
.axiom-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 32px;
}

.axiom-statement {
    font-family: var(--font-headline);
    font-weight: 700;
    font-style: italic;
    font-size: clamp(2rem, 4vw, 3.6rem);
    letter-spacing: 0.02em;
    line-height: 1.3;
    color: var(--antique-parchment);
}

.golden-rule {
    width: 200px;
    height: 2px;
    background: var(--gold-gradient);
    border: none;
    border-radius: 1px;
}

/* --- Section 2: Definitions --- */
.definition-block {
    display: grid;
    grid-template-columns: auto auto 1fr;
    gap: 12px;
    align-items: baseline;
    padding: 16px 0;
    border-bottom: 1px solid rgba(164, 151, 59, 0.15);
}

.def-term {
    font-family: var(--font-headline);
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--deep-walnut);
    font-variant-caps: small-caps;
    letter-spacing: 0.04em;
}

.def-symbol {
    font-family: var(--font-mono);
    font-weight: 500;
    font-size: 0.85rem;
    color: var(--burnished-gold);
}

.def-body {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: clamp(1rem, 1.1vw, 1.1rem);
    color: var(--graphite);
    line-height: 1.65;
}

/* --- Deco Pilasters --- */
.deco-pilaster {
    width: 3px;
    height: 200px;
    background: var(--gold-gradient);
    margin: 0 auto;
    border-radius: 2px;
    position: relative;
}

.deco-pilaster::before,
.deco-pilaster::after {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 12px;
    height: 12px;
    background: var(--gold-gradient);
    clip-path: polygon(50% 0%, 100% 50%, 50% 100%, 0% 50%);
}

.deco-pilaster::before { top: -6px; }
.deco-pilaster::after { bottom: -6px; }

/* --- Marginal Notes --- */
.marginal-note {
    font-family: var(--font-mono);
    font-weight: 500;
    font-size: 0.75rem;
    color: var(--faded-sage);
    line-height: 1.5;
    margin-top: 24px;
    text-align: center;
    max-width: 160px;
    margin-left: auto;
    margin-right: auto;
}

.section-theorem .marginal-note,
.section-qed .marginal-note {
    color: var(--faded-sage);
}

/* --- Logic Block (Syllogism) --- */
.logic-block {
    background: rgba(59, 38, 22, 0.04);
    border-left: 3px solid var(--burnished-gold);
    padding: 24px 28px;
    margin: 16px 0;
    border-radius: 0 4px 4px 0;
}

.logic-line {
    font-family: var(--font-body);
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--graphite);
}

.logic-label {
    font-family: var(--font-mono);
    font-weight: 500;
    font-size: 0.85rem;
    color: var(--academic-teal);
    margin-right: 8px;
}

.logic-therefore {
    width: 100%;
    height: 2px;
    background: var(--gold-gradient);
    margin: 12px 0;
}

.logic-line.conclusion {
    font-weight: 600;
    color: var(--deep-walnut);
}

/* --- Truth Table Fragments --- */
.truth-table-fragment {
    margin-top: 24px;
    opacity: 0.35;
    transform: rotate(-3deg);
}

.truth-table-fragment table {
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--faded-sage);
    margin: 0 auto;
}

.truth-table-fragment td {
    padding: 4px 10px;
    border: 1px solid rgba(168, 181, 160, 0.25);
    text-align: center;
}

.truth-table-fragment tr:first-child td {
    font-weight: 500;
    border-bottom: 2px solid rgba(168, 181, 160, 0.4);
}

.section-theorem .truth-table-fragment td {
    color: rgba(168, 181, 160, 0.6);
    border-color: rgba(168, 181, 160, 0.15);
}

.section-theorem .truth-table-fragment tr:first-child td {
    border-bottom-color: rgba(168, 181, 160, 0.3);
}

/* --- Operator Showcase --- */
.operator-showcase {
    display: flex;
    gap: 24px;
    justify-content: center;
    margin: 24px 0;
    flex-wrap: wrap;
}

.operator-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 24px 32px;
    background: rgba(59, 38, 22, 0.03);
    border: 1px solid rgba(196, 151, 59, 0.2);
    border-radius: 4px;
    min-width: 140px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.operator-card:hover {
    border-color: var(--burnished-gold);
    box-shadow: 0 4px 20px rgba(196, 151, 59, 0.15);
}

.operator-symbol {
    width: 48px;
    height: 48px;
    position: relative;
}

/* Conjunction: wedge / chevron */
.conjunction-symbol::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 0;
    height: 0;
    border-left: 18px solid transparent;
    border-right: 18px solid transparent;
    border-bottom: 28px solid var(--academic-teal);
}

/* Disjunction: inverted arch */
.disjunction-symbol::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 0;
    height: 0;
    border-left: 18px solid transparent;
    border-right: 18px solid transparent;
    border-top: 28px solid var(--claret-ink);
}

/* Negation: horizontal bar */
.negation-symbol::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 40%;
    transform: translate(-50%, -50%);
    width: 32px;
    height: 4px;
    background: var(--burnished-gold);
    border-radius: 2px;
}
.negation-symbol::after {
    content: '';
    position: absolute;
    right: 6px;
    top: 40%;
    transform: translateY(-50%);
    width: 4px;
    height: 20px;
    background: var(--burnished-gold);
    border-radius: 2px;
}

.operator-name {
    font-family: var(--font-headline);
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--deep-walnut);
    font-variant-caps: small-caps;
    letter-spacing: 0.04em;
}

.operator-notation {
    font-family: var(--font-mono);
    font-weight: 500;
    font-size: 0.85rem;
    color: var(--burnished-gold);
}

/* --- Proof Structure --- */
.proof-structure {
    background: rgba(59, 38, 22, 0.04);
    border: 1px solid rgba(196, 151, 59, 0.15);
    border-radius: 4px;
    padding: 24px 28px;
    margin: 16px 0;
}

.proof-line {
    display: grid;
    grid-template-columns: 32px 1fr auto;
    gap: 16px;
    align-items: baseline;
    padding: 6px 0;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--graphite);
    opacity: 0;
    transform: translateX(-10px);
    transition: opacity 0.4s ease, transform 0.4s ease;
}

.proof-line.visible {
    opacity: 1;
    transform: translateX(0);
}

.proof-num {
    color: var(--faded-sage);
    text-align: right;
}

.proof-stmt {
    font-weight: 500;
    color: var(--deep-walnut);
}

.proof-just {
    font-size: 0.75rem;
    color: var(--faded-sage);
    font-style: italic;
}

.proof-line.conclusion {
    border-top: 2px solid var(--burnished-gold);
    margin-top: 8px;
    padding-top: 14px;
}

.proof-line.conclusion .proof-stmt {
    color: var(--academic-teal);
    font-weight: 500;
}

/* --- Theorem Section --- */
.theorem-quote {
    border-left: 3px solid var(--burnished-gold);
    padding: 20px 28px;
    margin: 20px 0;
    background: rgba(196, 151, 59, 0.05);
    border-radius: 0 4px 4px 0;
}

.theorem-quote p {
    font-family: var(--font-headline);
    font-weight: 700;
    font-style: italic;
    font-size: 1.3rem;
    line-height: 1.5;
    color: var(--antique-parchment);
}

.theorem-quote cite {
    display: block;
    margin-top: 12px;
    font-family: var(--font-body);
    font-weight: 400;
    font-style: normal;
    font-size: 0.9rem;
    color: var(--faded-sage);
}

.theorem-symbols {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin: 24px 0;
}

.theorem-sym {
    font-family: var(--font-mono);
    font-size: 2.4rem;
    color: var(--burnished-gold);
    opacity: 0.6;
    transition: opacity 0.4s ease, transform 0.4s ease;
}

.theorem-sym:hover {
    opacity: 1;
    transform: scale(1.15);
}

/* --- Section 7: Q.E.D. --- */
.qed-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

.qed-statement {
    font-family: var(--font-headline);
    font-weight: 700;
    font-style: italic;
    font-size: clamp(1.8rem, 3.5vw, 2.8rem);
    color: var(--antique-parchment);
    letter-spacing: 0.02em;
}

.qed-translation {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: 1.05rem;
    color: var(--faded-sage);
    line-height: 1.6;
}

.qed-tombstone {
    margin: 16px 0;
}

.tombstone-square {
    width: 20px;
    height: 20px;
    background: var(--gold-gradient);
    position: relative;
    transition: transform 0.5s ease;
}

.tombstone-square::before,
.tombstone-square::after {
    content: '';
    position: absolute;
    background: var(--burnished-gold);
}
.tombstone-square::before {
    top: -4px;
    left: -4px;
    width: 6px;
    height: 6px;
    clip-path: polygon(0 0, 100% 0, 0 100%);
}
.tombstone-square::after {
    bottom: -4px;
    right: -4px;
    width: 6px;
    height: 6px;
    clip-path: polygon(100% 0, 100% 100%, 0 100%);
}

.qed-coda {
    font-family: var(--font-mono);
    font-weight: 500;
    font-size: 0.85rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--faded-sage);
    opacity: 0.7;
}

.qed-converging-frame {
    width: 300px;
    height: 300px;
    border: 2px solid rgba(196, 151, 59, 0.3);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    pointer-events: none;
    transition: all 1s ease;
}

.qed-converging-frame::before {
    content: '';
    position: absolute;
    inset: 16px;
    border: 1px solid rgba(196, 151, 59, 0.2);
}

.qed-converging-frame::after {
    content: '';
    position: absolute;
    inset: 32px;
    border: 1px solid rgba(196, 151, 59, 0.1);
}

/* --- Ziggurat Frames --- */
.ziggurat-frame {
    position: absolute;
    inset: 0;
    z-index: 1;
    pointer-events: none;
}

.ziggurat-step {
    position: absolute;
    border: 1px solid rgba(196, 151, 59, 0.2);
}

.frame-level-1 .ziggurat-step {
    inset: 24px;
}

.frame-level-2 .ziggurat-step {
    inset: 20px;
}
.frame-level-2 .ziggurat-step.inner {
    inset: 36px;
    border-color: rgba(196, 151, 59, 0.12);
}

.frame-level-3 .ziggurat-step {
    inset: 16px;
}
.frame-level-3 .ziggurat-step.inner {
    inset: 30px;
    border-color: rgba(196, 151, 59, 0.15);
}
.frame-level-3 .ziggurat-step.innermost {
    inset: 44px;
    border-color: rgba(196, 151, 59, 0.08);
}

.frame-ornate .ziggurat-step {
    border-color: rgba(196, 151, 59, 0.35);
}
.frame-ornate .ziggurat-step.inner {
    border-color: rgba(196, 151, 59, 0.25);
}
.frame-ornate .ziggurat-step.innermost {
    border-color: rgba(196, 151, 59, 0.15);
}

/* Chamfered corners via clip-path */
.ziggurat-step {
    clip-path: polygon(
        8px 0, calc(100% - 8px) 0,
        100% 8px, 100% calc(100% - 8px),
        calc(100% - 8px) 100%, 8px 100%,
        0 calc(100% - 8px), 0 8px
    );
}

/* --- Corner Fans --- */
.corner-fan {
    position: absolute;
    width: 60px;
    height: 60px;
    z-index: 1;
    pointer-events: none;
    opacity: 0.3;
    background: conic-gradient(
        from 0deg,
        var(--burnished-gold) 0deg,
        transparent 10deg,
        var(--burnished-gold) 20deg,
        transparent 30deg,
        var(--burnished-gold) 40deg,
        transparent 50deg,
        var(--burnished-gold) 60deg,
        transparent 70deg,
        var(--burnished-gold) 80deg,
        transparent 90deg
    );
}

.fan-top-left {
    top: 0;
    left: 0;
    clip-path: polygon(0 0, 100% 0, 0 100%);
}
.fan-top-right {
    top: 0;
    right: 0;
    clip-path: polygon(0 0, 100% 0, 100% 100%);
}
.fan-bottom-left {
    bottom: 0;
    left: 0;
    clip-path: polygon(0 0, 0 100%, 100% 100%);
}
.fan-bottom-right {
    bottom: 0;
    right: 0;
    clip-path: polygon(100% 0, 0 100%, 100% 100%);
}

/* --- Flowing Curve Dividers --- */
.curve-divider {
    position: relative;
    height: 80px;
    background: transparent;
    z-index: 3;
    overflow: visible;
}

.curve-divider svg {
    width: 100%;
    height: 100%;
    display: block;
}

.flowing-curve {
    fill: none;
    stroke: var(--burnished-gold);
    stroke-width: 2;
    stroke-linecap: round;
    stroke-dasharray: 2000;
    stroke-dashoffset: 2000;
    transition: stroke-dashoffset 0.8s ease-out;
}

.flowing-curve.drawn {
    stroke-dashoffset: 0;
}

/* --- Sunburst Dividers --- */
.sunburst-divider {
    position: relative;
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 3;
    overflow: hidden;
}

.sunburst-center {
    width: 120px;
    height: 120px;
    background: conic-gradient(
        from 0deg,
        rgba(196, 151, 59, 0.3) 0deg,
        transparent 6deg,
        rgba(196, 151, 59, 0.3) 10deg,
        transparent 16deg,
        rgba(196, 151, 59, 0.3) 20deg,
        transparent 26deg,
        rgba(196, 151, 59, 0.3) 30deg,
        transparent 36deg,
        rgba(196, 151, 59, 0.3) 40deg,
        transparent 46deg,
        rgba(196, 151, 59, 0.3) 50deg,
        transparent 56deg,
        rgba(196, 151, 59, 0.3) 60deg,
        transparent 66deg,
        rgba(196, 151, 59, 0.3) 70deg,
        transparent 76deg,
        rgba(196, 151, 59, 0.3) 80deg,
        transparent 86deg,
        rgba(196, 151, 59, 0.3) 90deg,
        transparent 96deg,
        rgba(196, 151, 59, 0.3) 100deg,
        transparent 106deg,
        rgba(196, 151, 59, 0.3) 110deg,
        transparent 116deg,
        rgba(196, 151, 59, 0.3) 120deg,
        transparent 126deg,
        rgba(196, 151, 59, 0.3) 130deg,
        transparent 136deg,
        rgba(196, 151, 59, 0.3) 140deg,
        transparent 146deg,
        rgba(196, 151, 59, 0.3) 150deg,
        transparent 156deg,
        rgba(196, 151, 59, 0.3) 160deg,
        transparent 166deg,
        rgba(196, 151, 59, 0.3) 170deg,
        transparent 176deg,
        rgba(196, 151, 59, 0.3) 180deg,
        transparent 186deg,
        rgba(196, 151, 59, 0.3) 190deg,
        transparent 196deg,
        rgba(196, 151, 59, 0.3) 200deg,
        transparent 206deg,
        rgba(196, 151, 59, 0.3) 210deg,
        transparent 216deg,
        rgba(196, 151, 59, 0.3) 220deg,
        transparent 226deg,
        rgba(196, 151, 59, 0.3) 230deg,
        transparent 236deg,
        rgba(196, 151, 59, 0.3) 240deg,
        transparent 246deg,
        rgba(196, 151, 59, 0.3) 250deg,
        transparent 256deg,
        rgba(196, 151, 59, 0.3) 260deg,
        transparent 266deg,
        rgba(196, 151, 59, 0.3) 270deg,
        transparent 276deg,
        rgba(196, 151, 59, 0.3) 280deg,
        transparent 286deg,
        rgba(196, 151, 59, 0.3) 290deg,
        transparent 296deg,
        rgba(196, 151, 59, 0.3) 300deg,
        transparent 306deg,
        rgba(196, 151, 59, 0.3) 310deg,
        transparent 316deg,
        rgba(196, 151, 59, 0.3) 320deg,
        transparent 326deg,
        rgba(196, 151, 59, 0.3) 330deg,
        transparent 336deg,
        rgba(196, 151, 59, 0.3) 340deg,
        transparent 346deg,
        rgba(196, 151, 59, 0.3) 350deg,
        transparent 356deg,
        rgba(196, 151, 59, 0.3) 360deg
    );
    border-radius: 50%;
    transform: scale(0);
    transition: transform 0.8s ease-out;
}

.sunburst-center.expanded {
    transform: scale(1);
}

/* Small golden dot in the center */
.sunburst-center::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--gold-gradient);
}

/* --- Proposition Navigation --- */
#proposition-nav {
    position: fixed;
    right: 28px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 100;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.nav-thread-line {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 1px;
    background: rgba(196, 151, 59, 0.2);
    z-index: -1;
}

.nav-thread-fill {
    position: absolute;
    top: 0;
    width: 2px;
    left: -0.5px;
    background: var(--gold-gradient);
    z-index: -1;
    height: 0%;
    transition: height 0.3s ease;
}

.prop-marker {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2px solid rgba(196, 151, 59, 0.4);
    background: radial-gradient(circle at 35% 35%, #E8D48B 0%, #C4973B 50%, #9A7428 100%);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(59, 38, 22, 0.3), inset 0 1px 2px rgba(232, 212, 139, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
}

.prop-marker:hover {
    transform: scale(1.15);
    box-shadow: 0 3px 12px rgba(196, 151, 59, 0.4), inset 0 1px 2px rgba(232, 212, 139, 0.4);
}

.prop-marker.active {
    border-color: var(--burnished-gold);
    transform: scale(1.2);
    box-shadow: 0 3px 16px rgba(196, 151, 59, 0.5), inset 0 1px 3px rgba(232, 212, 139, 0.5);
}

.marker-label {
    font-family: var(--font-mono);
    font-weight: 500;
    font-size: 0.6rem;
    color: var(--deep-walnut);
    letter-spacing: 0;
    line-height: 1;
}

/* --- Progressive Disclosure Animations --- */
.reveal-element {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.4s ease-out, transform 0.4s ease-out;
}

.reveal-element.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* --- Responsive --- */
@media (max-width: 900px) {
    :root {
        --section-padding: 24px;
    }

    .content-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .margin-left,
    .margin-right {
        display: none;
    }

    .axiom-statement {
        font-size: clamp(1.6rem, 5vw, 2.4rem);
    }

    .operator-showcase {
        flex-direction: column;
        align-items: center;
    }

    #proposition-nav {
        right: 12px;
        gap: 14px;
    }

    .prop-marker {
        width: 26px;
        height: 26px;
    }

    .marker-label {
        font-size: 0.5rem;
    }

    .corner-fan {
        width: 40px;
        height: 40px;
    }

    .definition-block {
        grid-template-columns: auto 1fr;
        gap: 8px;
    }

    .def-symbol {
        display: none;
    }

    .proof-line {
        grid-template-columns: 28px 1fr;
        gap: 8px;
    }

    .proof-just {
        grid-column: 1 / -1;
        text-align: right;
    }

    .theorem-symbols {
        gap: 20px;
    }

    .theorem-sym {
        font-size: 1.8rem;
    }

    .qed-converging-frame {
        width: 200px;
        height: 200px;
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: clamp(1.8rem, 6vw, 2.4rem);
    }

    .ziggurat-frame {
        display: none;
    }

    .corner-fan {
        display: none;
    }

    #proposition-nav {
        right: 8px;
        gap: 10px;
    }

    .prop-marker {
        width: 22px;
        height: 22px;
    }
}