/* ============================================
   haskell.monster - Styles
   Palette: sunset-warm / retro academic
   ============================================ */

/* --- CSS Variables --- */
:root {
    --aged-parchment: #f4ead5;
    --old-desk: #2b1d0e;
    --typewriter-ink: #1a120b;
    --faded-ink: #5a4a3a;
    --sunset-amber: #d4763a;
    --crt-amber: #e8a832;
    --ribbon-red: #943028;
    --paper-shadow: #c8b89a;
    --terminal-warm: #1e1408;
}

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

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

body {
    background-color: var(--aged-parchment);
    color: var(--typewriter-ink);
    font-family: 'Lora', serif;
    font-weight: 400;
    font-size: clamp(1rem, 1.8vw, 1.15rem);
    line-height: 1.85;
    overflow-x: hidden;
}

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

/* --- Navigation --- */
.nav-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.6s ease;
    background: linear-gradient(to bottom, rgba(244, 234, 213, 0.95) 0%, rgba(244, 234, 213, 0) 100%);
}

.nav-bar.visible {
    opacity: 1;
    pointer-events: auto;
}

.nav-inner {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.nav-key {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 1px solid var(--faded-ink);
    background: transparent;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.1s ease, box-shadow 0.1s ease, background-color 0.15s ease;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.15), 0 1px 2px rgba(0,0,0,0.08);
    font-family: 'Roboto Slab', serif;
    font-weight: 700;
    font-size: 0.75rem;
    color: var(--typewriter-ink);
    letter-spacing: 0.02em;
}

.nav-key:hover {
    transform: scale(0.95);
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.25);
    background-color: rgba(212, 118, 58, 0.1);
}

.nav-key:active {
    transform: scale(0.9);
}

.nav-key.active {
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.25);
    background-color: rgba(212, 118, 58, 0.1);
    border-color: var(--sunset-amber);
}

.nav-key.active .nav-numeral {
    color: var(--sunset-amber);
}

.nav-numeral {
    font-size: 0.7rem;
    letter-spacing: 0.02em;
}

/* --- Manuscript Page Base --- */
.manuscript-page {
    position: relative;
    min-height: 100vh;
    overflow: hidden;
}

.page-light {
    background-color: var(--aged-parchment);
    box-shadow: inset 0 0 80px rgba(160, 130, 90, 0.12);
}

.page-dark {
    background-color: var(--old-desk);
    box-shadow: inset 0 0 80px rgba(0, 0, 0, 0.3);
}

/* --- Paper Texture Overlay --- */
.paper-texture {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 1;
}

.paper-texture[data-filter="1"] { filter: url(#paper-grain-1); }
.paper-texture[data-filter="2"] { filter: url(#paper-grain-2); }
.paper-texture[data-filter="3"] { filter: url(#paper-grain-3); }
.paper-texture[data-filter="4"] { filter: url(#paper-grain-4); }
.paper-texture[data-filter="5"] { filter: url(#paper-grain-5); }
.paper-texture[data-filter="6"] { filter: url(#paper-grain-6); }

/* --- Page Shadow (between stacked pages) --- */
.page-shadow {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 80px;
    background: linear-gradient(to bottom, transparent 0%, rgba(200, 184, 154, 0.15) 100%);
    pointer-events: none;
    z-index: 2;
}

.manuscript-page + .manuscript-page {
    box-shadow: 0 -4px 12px rgba(200, 184, 154, 0.4);
}

/* --- Lambda Watermarks --- */
.lambda-watermark {
    position: absolute;
    font-family: 'Noto Serif Display', serif;
    font-weight: 300;
    font-size: 40vw;
    color: rgba(90, 74, 58, 0.03);
    pointer-events: none;
    z-index: 1;
    top: 50%;
    left: 50%;
    translate: -50% -50%;
    line-height: 1;
    user-select: none;
}

.lambda-watermark-dark {
    color: rgba(244, 234, 213, 0.03);
}

/* --- Fold Marks (Title Page only) --- */
.fold-mark {
    position: absolute;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(to right, transparent 5%, rgba(160, 130, 90, 0.03) 20%, rgba(160, 130, 90, 0.03) 80%, transparent 95%);
    pointer-events: none;
    z-index: 2;
}

.fold-mark-1 { top: 33.33%; }
.fold-mark-2 { top: 66.66%; }

/* --- Coffee Stain Rings --- */
.coffee-stain {
    position: absolute;
    top: 23%;
    left: 78%;
    width: 180px;
    height: 180px;
    border-radius: 50%;
    background: radial-gradient(ellipse at center, rgba(180, 140, 80, 0.08) 0%, transparent 45%);
    pointer-events: none;
    z-index: 2;
    translate: -50% -50%;
}

/* --- Section Content --- */
.section-content {
    position: relative;
    z-index: 3;
    padding: 0 12%;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* --- Section Heading --- */
.section-heading-wrap {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 3rem;
}

.section-heading {
    font-family: 'Roboto Slab', serif;
    font-weight: 700;
    font-size: clamp(1.6rem, 3.5vw, 2.8rem);
    letter-spacing: 0.04em;
    color: var(--typewriter-ink);
    text-align: center;
}

.section-heading-dark {
    color: var(--aged-parchment);
}

.key-decor {
    display: inline-block;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: 1px solid var(--faded-ink);
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.15);
    flex-shrink: 0;
}

.key-decor-dark {
    border-color: rgba(244, 234, 213, 0.3);
}

/* --- Typewriter Underlines (horizontal rules) --- */
.typewriter-hr {
    border: none;
    font-family: 'Courier Prime', monospace;
    color: var(--faded-ink);
    letter-spacing: -0.05em;
    font-size: 1rem;
    text-align: center;
    overflow: hidden;
    height: 1.2em;
    line-height: 1.2;
}

/* =================================
   SECTION I: TITLE PAGE
   ================================= */
.title-content {
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding-top: 0;
    padding-bottom: 0;
}

.monster-silhouette {
    position: absolute;
    top: 50%;
    left: 50%;
    translate: -50% -50%;
    width: 60vw;
    max-width: 500px;
    pointer-events: none;
    z-index: 1;
}

.monster-svg {
    width: 100%;
    height: auto;
}

.title-block {
    text-align: center;
    position: relative;
    z-index: 2;
}

.site-title {
    font-family: 'Roboto Slab', serif;
    font-weight: 700;
    font-size: clamp(2.8rem, 7vw, 6rem);
    letter-spacing: 0.04em;
    color: var(--typewriter-ink);
    line-height: 1.15;
    min-height: 2.4em;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.title-line {
    display: block;
    overflow: hidden;
}

.title-char {
    display: inline-block;
    opacity: 0;
    transform: translateY(-1px);
}

.title-char.typed {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.04s ease, transform 0.06s ease;
}

.title-char.strike {
    font-weight: 800;
    transition: font-weight 0.03s ease;
}

.typewriter-underline {
    font-family: 'Courier Prime', monospace;
    color: var(--faded-ink);
    letter-spacing: -0.05em;
    font-size: 1.2rem;
    margin-top: 0.5rem;
    height: 1.5em;
    overflow: hidden;
}

.subtitle {
    font-family: 'Lora', serif;
    font-style: italic;
    font-weight: 400;
    font-size: clamp(0.9rem, 2vw, 1.15rem);
    color: var(--faded-ink);
    margin-top: 1.5rem;
    opacity: 0;
    transition: opacity 0.8s ease;
}

.subtitle.visible {
    opacity: 0.7;
}

/* =================================
   SECTION II: ABSTRACT
   ================================= */
.abstract-content {
    padding-top: 6rem;
    padding-bottom: 4rem;
}

.abstract-text {
    max-width: 700px;
    margin: 0 auto;
    padding: 0 3%;
}

.abstract-text p {
    margin-bottom: 1.5em;
    color: var(--typewriter-ink);
}

.abstract-text p strong {
    font-weight: 600;
}

.lambda-divider {
    font-family: 'Noto Serif Display', serif;
    font-weight: 300;
    font-size: clamp(4rem, 12vw, 10rem);
    color: var(--faded-ink);
    text-align: center;
    opacity: 0.12;
    margin: 2rem 0;
    line-height: 1;
    user-select: none;
}

/* --- Margin Annotations --- */
.margin-note {
    position: absolute;
    font-family: 'Lora', serif;
    font-style: italic;
    font-weight: 400;
    font-size: 0.75rem;
    color: var(--faded-ink);
    opacity: 0.5;
    white-space: nowrap;
    pointer-events: none;
    z-index: 4;
}

/* =================================
   SECTION III: DEFINITIONS
   ================================= */
.definitions-content {
    padding-top: 6rem;
    padding-bottom: 4rem;
    min-height: 100vh;
    justify-content: flex-start;
}

.index-card {
    background-color: var(--aged-parchment);
    border: none;
    border-radius: 2px;
    padding: 0;
    margin: 2rem auto;
    max-width: 620px;
    width: 100%;
    position: relative;
    box-shadow: 4px 4px 8px var(--paper-shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    background-image:
        radial-gradient(circle at 3px 3px, var(--sunset-amber) 1px, transparent 1px);
    background-size: 6px 6px;
    background-position: 0 0;
    background-clip: padding-box;
    border: 6px solid transparent;
    background-origin: border-box;
    overflow: hidden;
}

.index-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--aged-parchment);
    z-index: 0;
    border-radius: 2px;
}

.index-card:hover {
    box-shadow: 8px 8px 16px var(--paper-shadow), 0 0 20px rgba(212, 118, 58, 0.08);
    z-index: 10;
}

.card-red-rule-h {
    position: absolute;
    top: 15%;
    left: 0;
    right: 0;
    height: 1px;
    background-color: var(--ribbon-red);
    z-index: 1;
}

.card-red-rule-v {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 8%;
    width: 1px;
    background-color: var(--ribbon-red);
    z-index: 1;
}

.card-content {
    position: relative;
    z-index: 2;
    padding: 1.5rem 2rem 1.8rem calc(8% + 1.2rem);
}

.card-title {
    font-family: 'Courier Prime', monospace;
    font-weight: 700;
    font-size: clamp(0.95rem, 1.8vw, 1.15rem);
    color: var(--typewriter-ink);
    margin-bottom: 0.8rem;
    letter-spacing: 0.02em;
}

.card-code {
    font-family: 'Courier Prime', monospace;
    font-weight: 400;
    font-size: clamp(0.85rem, 1.4vw, 1rem);
    line-height: 1.7;
    letter-spacing: 0.02em;
    color: var(--sunset-amber);
    background: rgba(43, 29, 14, 0.04);
    padding: 0.5rem 0.8rem;
    margin-bottom: 1rem;
    border-left: 2px solid var(--sunset-amber);
    white-space: pre-wrap;
}

.card-text {
    font-family: 'Lora', serif;
    font-weight: 400;
    font-size: clamp(0.88rem, 1.5vw, 1rem);
    line-height: 1.75;
    color: var(--typewriter-ink);
}

/* =================================
   SECTION IV: TIMELINE
   ================================= */
.timeline-content {
    padding-top: 6rem;
    padding-bottom: 4rem;
    min-height: 100vh;
    justify-content: flex-start;
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 0;
}

.timeline-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    translate: -50% 0;
    background-image: radial-gradient(circle, var(--faded-ink) 1px, transparent 1px);
    background-size: 2px 8px;
    background-repeat: repeat-y;
}

.timeline-entry {
    position: relative;
    width: 50%;
    padding: 1rem 0;
}

.entry-left {
    padding-right: 40px;
    text-align: right;
}

.entry-right {
    margin-left: 50%;
    padding-left: 40px;
    text-align: left;
}

.timeline-dot {
    position: absolute;
    top: 1.4rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--crt-amber);
    border: 2px solid var(--aged-parchment);
    box-shadow: 0 0 0 2px var(--crt-amber);
    z-index: 2;
}

.entry-left .timeline-dot {
    right: -6px;
}

.entry-right .timeline-dot {
    left: -6px;
}

.timeline-card {
    display: inline-block;
    text-align: left;
}

.timeline-year {
    font-family: 'Roboto Slab', serif;
    font-weight: 700;
    font-size: clamp(1.1rem, 2vw, 1.4rem);
    color: var(--sunset-amber);
    display: block;
    margin-bottom: 0.3rem;
    letter-spacing: 0.04em;
}

.timeline-text {
    font-family: 'Lora', serif;
    font-weight: 400;
    font-size: clamp(0.85rem, 1.4vw, 0.95rem);
    line-height: 1.7;
    color: var(--typewriter-ink);
}

/* =================================
   SECTION V: CODE SPECIMEN
   ================================= */
.code-content {
    padding-top: 6rem;
    padding-bottom: 4rem;
    align-items: center;
}

.code-block {
    background-color: var(--terminal-warm);
    border: 1px solid rgba(232, 168, 50, 0.15);
    border-radius: 2px;
    padding: 2.5rem 3rem;
    max-width: 700px;
    width: 100%;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4), inset 0 0 60px rgba(30, 20, 8, 0.5);
    overflow-x: auto;
}

.code-text {
    font-family: 'Courier Prime', monospace;
    font-weight: 400;
    font-size: clamp(0.85rem, 1.4vw, 1rem);
    line-height: 1.7;
    letter-spacing: 0.02em;
    color: var(--aged-parchment);
    white-space: pre;
    tab-size: 2;
}

.code-line {
    display: block;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.code-line.revealed {
    opacity: 1;
}

.code-comment { color: var(--faded-ink); }
.code-keyword { color: var(--crt-amber); }
.code-type { color: var(--sunset-amber); }
.code-fn { color: var(--aged-parchment); }
.code-op { color: var(--crt-amber); opacity: 0.8; }
.code-str { color: #b8956a; }
.code-num { color: var(--sunset-amber); }

/* =================================
   SECTION VI: COLOPHON
   ================================= */
.colophon-section {
    min-height: 50vh;
}

.colophon-content {
    min-height: 50vh;
    padding-top: 4rem;
    padding-bottom: 4rem;
    align-items: center;
}

.catalog-card {
    background-color: var(--aged-parchment);
    border: 2px solid var(--faded-ink);
    border-radius: 2px;
    max-width: 600px;
    width: 100%;
    overflow: hidden;
}

.catalog-header {
    background-color: var(--old-desk);
    padding: 0.8rem 1.5rem;
    border-bottom: 2px solid var(--faded-ink);
}

.catalog-label {
    font-family: 'Roboto Slab', serif;
    font-weight: 700;
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    color: var(--aged-parchment);
    text-transform: uppercase;
}

.catalog-ruled {
    padding: 1.2rem 1.5rem;
}

.catalog-line {
    display: flex;
    gap: 1rem;
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(90, 74, 58, 0.15);
    align-items: baseline;
}

.catalog-line:last-child {
    border-bottom: none;
}

.catalog-field {
    font-family: 'Courier Prime', monospace;
    font-weight: 700;
    font-size: 0.7rem;
    letter-spacing: 0.08em;
    color: var(--faded-ink);
    text-transform: uppercase;
    min-width: 100px;
    flex-shrink: 0;
}

.catalog-value {
    font-family: 'Courier Prime', monospace;
    font-weight: 400;
    font-size: clamp(0.8rem, 1.2vw, 0.9rem);
    line-height: 1.5;
    color: var(--typewriter-ink);
}

.catalog-footer {
    padding: 0.8rem 1.5rem;
    border-top: 2px solid var(--faded-ink);
    text-align: right;
}

.catalog-stamp {
    font-family: 'Roboto Slab', serif;
    font-weight: 700;
    font-size: 0.9rem;
    letter-spacing: 0.2em;
    color: var(--ribbon-red);
    opacity: 0.6;
    transform: rotate(-3deg);
    display: inline-block;
    border: 2px solid var(--ribbon-red);
    padding: 0.2rem 0.8rem;
    border-radius: 2px;
}

/* =================================
   SCROLL REVEAL ANIMATIONS
   ================================= */
.scroll-reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

.scroll-reveal-left {
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-reveal-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.scroll-reveal-right {
    opacity: 0;
    transform: translateX(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-reveal-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* Index cards: additional rotation entrance */
.index-card.scroll-reveal {
    opacity: 0;
    transform: translateY(20px) rotate(-1deg);
}

.index-card.scroll-reveal.visible {
    opacity: 1;
}

/* Restore individual rotations when visible */
.index-card.scroll-reveal.visible:nth-child(2) {
    transform: translateY(0) rotate(-0.3deg);
}
.index-card.scroll-reveal.visible:nth-child(3) {
    transform: translateY(0) rotate(0.5deg);
}
.index-card.scroll-reveal.visible:nth-child(4) {
    transform: translateY(0) rotate(-0.2deg);
}

/* =================================
   RESPONSIVE
   ================================= */
@media (max-width: 768px) {
    .section-content {
        padding: 0 6%;
    }

    .abstract-text {
        padding: 0;
    }

    .timeline-line {
        left: 20px;
    }

    .timeline-entry {
        width: 100%;
        padding-left: 50px;
        padding-right: 0;
        text-align: left;
    }

    .entry-left {
        padding-right: 0;
        text-align: left;
    }

    .entry-right {
        margin-left: 0;
        padding-left: 50px;
    }

    .entry-left .timeline-dot,
    .entry-right .timeline-dot {
        left: 14px;
        right: auto;
    }

    .margin-note {
        display: none;
    }

    .code-block {
        padding: 1.5rem 1.2rem;
    }

    .nav-inner {
        gap: 12px;
    }

    .nav-key {
        width: 30px;
        height: 30px;
    }

    .catalog-line {
        flex-direction: column;
        gap: 0.2rem;
    }

    .catalog-field {
        min-width: auto;
    }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    .scroll-reveal,
    .scroll-reveal-left,
    .scroll-reveal-right {
        opacity: 1;
        transform: none;
        transition: none;
    }

    .title-char {
        opacity: 1;
        transform: none;
    }

    .subtitle {
        opacity: 0.7;
        transition: none;
    }

    .code-line {
        opacity: 1;
        transition: none;
    }
}