/* ========================================
   RESET & BASE STYLES
   Compliance terms: Sans" (Google Interaction Pattern:** IntersectionObserver adding/removing `.visible` triggers `rootMargin: '0px -60px 0px' `threshold: 0.15`. reading (38ch below. lazily using (the floating-elements motif "The intention" fades warm links Mono's rigid monospaced organic calligraphic forms creates unique tension precision specimen catalog artistic grace 600-year-old collision tech-mono found other designs. Mono"
   ======================================== */

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

:root {
    /* Palette: Honeyed Neutral */
    --bg-base: #fdf6e8;
    --bg-sections: #f5ead4;
    --glass-surface: rgba(255, 248, 235, 0.35);
    --glass-border: rgba(196, 164, 106, 0.2);
    --text-primary: #3d2e1a;
    --text-secondary: #5a4a30;
    --text-tertiary: #8a7a5e;
    --accent: #c4a46a;
    --accent-dark: #6b532b;
    --shadow: rgba(107, 83, 43, 0.08);
    --highlight: #e8d5a8;
    --divider: rgba(196, 164, 106, 0.25);

    /* Typography sizes */
    --display-size: clamp(6rem, 15vw, 14rem);
    --heading-size: clamp(1.4rem, 3vw, 2.4rem);
    --body-size: clamp(0.95rem, 1.2vw, 1.1rem);
    --annotation-size: 0.75rem;

    /* Animations */
    --spring-bezier: cubic-bezier(0.34, 1.56, 0.64, 1);
    --ease-out-bezier: cubic-bezier(0.16, 1, 0.3, 1);
}

/* Hanji texture overlay */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1000;
    filter: url(#noise);
    opacity: 0.03;
    mix-blend-mode: multiply;
}

html {
    scroll-behavior: smooth;
}

body {
    background: radial-gradient(ellipse at 30% 20%, #fdf6e8, #f5ead4);
    color: var(--text-secondary);
    font-family: 'Space Mono', monospace;
    font-weight: 400;
    font-size: var(--body-size);
    line-height: 1.85;
    letter-spacing: 0.02em;
    overflow-x: hidden;
}

/* ========================================
   TYPOGRAPHY
   ======================================== */

h1, h2 {
    font-family: 'Space Mono', monospace;
    font-weight: 700;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--accent-dark);
}

.hero-character {
    font-family: 'Noto Serif KR', serif;
    font-weight: 700;
    font-size: var(--display-size);
    letter-spacing: 0;
    line-height: 1.0;
    color: var(--text-primary);
}

.card-character {
    font-family: 'Noto Serif KR', serif;
    font-weight: 700;
    font-size: clamp(2rem, 10vw, 5rem);
    color: var(--text-primary);
    line-height: 1.0;
}

.closing-char {
    font-size: clamp(8rem, 25vw, 16rem) !important;
}

.card-annotation, .card-text, .closing-label {
    font-family: 'IBM Plex Sans', sans-serif;
    font-weight: 300;
    font-size: var(--annotation-size);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #a8956e;
}

.section-title {
    font-size: var(--heading-size);
    margin-bottom: clamp(2rem, 5vw, 4rem);
    text-align: center;
}

/* ========================================
   LAYOUT: SECTIONS & DIAGONALS
   ======================================== */

.section {
    position: relative;
    min-height: 100vh;
    min-height: 100dvh;
    padding: clamp(2rem, 6vw, 4rem);
    overflow: hidden;
    background: var(--bg-base);
}

.section:nth-child(odd) {
    background: var(--bg-base);
}

.section:nth-child(even) {
    background: var(--bg-sections);
}

.section[data-section="1"],
.section[data-section="3"],
.section[data-section="5"],
.section[data-section="7"] {
    background: radial-gradient(ellipse at 30% 20%, #fdf6e8, #f5ead4);
}

.section[data-section="2"],
.section[data-section="4"],
.section[data-section="6"] {
    background: #f5ead4;
}

/* Diagonal section cuts */
.section {
    clip-path: polygon(0 0, 100% 4%, 100% 100%, 0 96%);
}

.section:nth-child(2n) {
    clip-path: polygon(0 4%, 100% 0, 100% 96%, 0 100%);
}

.section::after {
    content: '';
    position: absolute;
    left: -10vw;
    right: -10vw;
    bottom: 4vh;
    height: 2px;
    background: var(--divider);
    transform: rotate(-3deg);
    transform-origin: center;
    z-index: 3;
}

.section:nth-of-type(even)::after {
    transform: rotate(3deg);
}

.section-content {
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 100vh;
    min-height: 100dvh;
}

/* ========================================
   FIXED NAVIGATION & PROGRESS
   ======================================== */

.wordmark {
    position: fixed;
    top: 2rem;
    left: 2rem;
    font-family: 'Space Mono', monospace;
    font-weight: 700;
    font-size: clamp(1rem, 2vw, 1.4rem);
    color: var(--text-primary);
    opacity: 0.7;
    z-index: 999;
    letter-spacing: 0.08em;
}

.fixed-section-title {
    position: fixed;
    top: 2rem;
    right: 2rem;
    z-index: 999;
    font-family: 'Space Mono', monospace;
    font-weight: 700;
    font-size: clamp(0.7rem, 1.3vw, 0.9rem);
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: #6b532b;
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity 500ms var(--ease-out-bezier), transform 500ms var(--ease-out-bezier);
}

.fixed-section-title.visible {
    opacity: 0.7;
    transform: translateY(0);
}

.progress-bar {
    position: fixed;
    right: 0;
    top: 0;
    width: 2px;
    height: 0%;
    background: var(--accent);
    z-index: 998;
    transition: height 0.1s linear;
}

/* ========================================
   GLASS MORPHISM CARDS
   ======================================== */

.glass-card {
    --parallax-y: 0px;
    background: var(--glass-surface);
    backdrop-filter: blur(20px) saturate(1.3);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    box-shadow: 0 8px 32px var(--shadow);
    padding: clamp(1.5rem, 3vw, 2.5rem);
    transition: opacity 600ms var(--ease-out-bezier), transform 600ms var(--ease-out-bezier), box-shadow 300ms ease-out;
    opacity: 0;
    transform: translateY(calc(24px + var(--parallax-y)));
}

.glass-card.visible {
    opacity: 1;
    transform: translateY(var(--parallax-y));
}

.glass-card:hover {
    transform: translateY(var(--parallax-y)) scale(1.05);
    box-shadow: 0 12px 40px rgba(107, 83, 43, 0.15);
}

/* ========================================
   SECTION 1: HERO
   ======================================== */

.hero-section {
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-glass-panel {
    text-align: center;
    animation: heroAppear 1.2s ease-out;
    padding: clamp(2rem, 7vw, 6rem);
    border-radius: 28px;
    background: rgba(255, 248, 235, 0.35);
    backdrop-filter: blur(20px) saturate(1.3);
    border: 1px solid rgba(196, 164, 106, 0.2);
    box-shadow: 0 8px 32px rgba(107, 83, 43, 0.08);
}

@keyframes heroAppear {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-romanization {
    font-family: 'Space Mono', monospace;
    font-size: clamp(1rem, 2.5vw, 1.8rem);
    letter-spacing: 0.12em;
    color: var(--text-secondary);
    margin-top: 1.5rem;
    animation: heroAppear 1.2s ease-out 0.1s both;
}

.hero-subtitle {
    font-family: 'Space Mono', monospace;
    font-size: clamp(1rem, 2vw, 1.4rem);
    color: var(--text-secondary);
    margin-top: 3rem;
    opacity: 0;
    animation: heroAppear 1.2s ease-out 1.2s both;
}

/* ========================================
   SECTION 2 & 3: CONSONANTS & VOWELS GRIDS
   ======================================== */

.glass-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: clamp(1.5rem, 3vw, 2.5rem);
    margin-bottom: 3rem;
}

.vowels-grid {
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.consonant-card, .vowel-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    text-align: center;
    position: relative;
    animation: float 6s ease-in-out infinite;
}

.consonant-card .card-annotation,
.vowel-card .card-annotation {
    opacity: 0;
    transform: translateY(6px);
    transition: opacity 300ms ease-out, transform 300ms ease-out;
}

.consonant-card:hover .card-annotation,
.vowel-card:hover .card-annotation,
.consonant-card.touched .card-annotation,
.vowel-card.touched .card-annotation {
    opacity: 1;
    transform: translateY(0);
}

.consonant-card[data-stagger="0"] { --stagger-index: 0; animation-delay: 0s; }
.consonant-card[data-stagger="1"] { --stagger-index: 1; animation-delay: 1.5s; }
.consonant-card[data-stagger="2"] { --stagger-index: 2; animation-delay: 3s; }
.consonant-card[data-stagger="3"] { --stagger-index: 3; animation-delay: 4.5s; }
.consonant-card[data-stagger="4"] { --stagger-index: 4; animation-delay: 0s; }
.consonant-card[data-stagger="5"] { --stagger-index: 5; animation-delay: 1.5s; }
.consonant-card[data-stagger="6"] { --stagger-index: 6; animation-delay: 3s; }
.consonant-card[data-stagger="7"] { --stagger-index: 7; animation-delay: 4.5s; }
.consonant-card[data-stagger="8"] { --stagger-index: 8; animation-delay: 0s; }
.consonant-card[data-stagger="9"] { --stagger-index: 9; animation-delay: 1.5s; }
.consonant-card[data-stagger="10"] { --stagger-index: 10; animation-delay: 3s; }
.consonant-card[data-stagger="11"] { --stagger-index: 11; animation-delay: 4.5s; }
.consonant-card[data-stagger="12"] { --stagger-index: 12; animation-delay: 0s; }
.consonant-card[data-stagger="13"] { --stagger-index: 13; animation-delay: 1.5s; }
.consonant-card[data-stagger="14"] { --stagger-index: 14; animation-delay: 3s; }

.vowel-card[data-stagger="0"] { --stagger-index: 0; animation-delay: 0s; }
.vowel-card[data-stagger="1"] { --stagger-index: 1; animation-delay: 1.5s; }
.vowel-card[data-stagger="2"] { --stagger-index: 2; animation-delay: 3s; }
.vowel-card[data-stagger="3"] { --stagger-index: 3; animation-delay: 4.5s; }
.vowel-card[data-stagger="4"] { --stagger-index: 4; animation-delay: 0s; }
.vowel-card[data-stagger="5"] { --stagger-index: 5; animation-delay: 1.5s; }
.vowel-card[data-stagger="6"] { --stagger-index: 6; animation-delay: 3s; }
.vowel-card[data-stagger="7"] { --stagger-index: 7; animation-delay: 4.5s; }
.vowel-card[data-stagger="8"] { --stagger-index: 8; animation-delay: 0s; }
.vowel-card[data-stagger="9"] { --stagger-index: 9; animation-delay: 1.5s; }

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-8px); }
}

/* ========================================
   SECTION 4: PHILOSOPHY OF SHAPE
   ======================================== */

.philosophy-text-container {
    max-width: 38ch;
}

.philosophy-layout {
    display: grid;
    grid-template-columns: minmax(0, 65%) minmax(260px, 35%);
    gap: clamp(2rem, 6vw, 5rem);
    align-items: center;
}

.diagram-stack {
    position: sticky;
    top: 18vh;
    display: grid;
    gap: 1.2rem;
}

.organ-card {
    min-height: 160px;
    display: grid;
    place-items: center;
    text-align: center;
}

.organ-card:nth-child(2) { margin-left: -18px; }
.organ-card:nth-child(3) { margin-left: 22px; }

.organ-diagram {
    position: relative;
    width: 130px;
    height: 86px;
    border: 1.5px solid #c4a46a;
    border-left: 0;
    border-bottom-right-radius: 70px;
    border-top-right-radius: 44px;
    margin-bottom: 1rem;
}

.organ-diagram::before,
.organ-diagram::after {
    content: '';
    position: absolute;
    border: 1.5px solid #c4a46a;
}

.diagram-tongue::before {
    width: 78px;
    height: 30px;
    left: 8px;
    bottom: 15px;
    border-top-left-radius: 60px;
    border-top-right-radius: 55px;
    border-bottom: 0;
}

.diagram-lips::before {
    width: 82px;
    height: 18px;
    left: -8px;
    top: 26px;
    border-radius: 50%;
}

.diagram-lips::after {
    width: 82px;
    height: 18px;
    left: -8px;
    top: 43px;
    border-radius: 50%;
}

.diagram-teeth::before {
    width: 82px;
    height: 18px;
    left: 4px;
    top: 18px;
    clip-path: polygon(0 0, 100% 0, 92% 100%, 78% 0, 64% 100%, 50% 0, 36% 100%, 22% 0, 8% 100%);
}

.diagram-jamo {
    position: absolute;
    right: -10px;
    bottom: -26px;
    font-family: 'Noto Serif KR', serif;
    font-size: 4rem;
    color: #3d2e1a;
    line-height: 1;
}

.philosophy-text {
    margin-bottom: 2rem;
    color: var(--text-secondary);
    opacity: 0;
    transform: translateY(24px);
}

.philosophy-text[data-stagger="0"] { --stagger-index: 0; }
.philosophy-text[data-stagger="1"] { --stagger-index: 1; }
.philosophy-text[data-stagger="2"] { --stagger-index: 2; }
.philosophy-text[data-stagger="3"] { --stagger-index: 3; }

.philosophy-text.visible {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 600ms var(--ease-out-bezier), transform 600ms var(--ease-out-bezier);
}

/* ========================================
   SECTION 5: SYLLABLE BLOCKS
   ======================================== */

.syllable-animation-container {
    margin-bottom: 3rem;
}

.syllable-demo {
    display: flex;
    gap: 2rem;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.syllable-parts {
    display: flex;
    gap: 1rem;
    position: relative;
}

.syllable-part {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 120px;
    min-height: 120px;
}

.syllable-result {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 180px;
    min-height: 180px;
    position: relative;
}

.syllable-part.visible {
    opacity: 1;
    transform: translateY(var(--parallax-y));
}

.syllable-demo.assembling .syllable-initial { transform: translate(104px, -28px) scale(0.68); }
.syllable-demo.assembling .syllable-medial { transform: translate(24px, -28px) scale(0.68); }
.syllable-demo.assembling .syllable-final { transform: translate(-120px, 50px) scale(0.68); }

.syllable-demo.assembling .syllable-part {
    opacity: 0.55;
    transition: opacity 700ms var(--ease-out-bezier), transform 1500ms var(--ease-out-bezier);
}

.syllable-result.visible {
    opacity: 1;
    transform: translateY(0);
    animation: syllableAppear 1.5s var(--ease-out-bezier) 0.6s both;
}

@keyframes syllableAppear {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.syllable-description {
    max-width: 38ch;
    margin: 0 auto;
    text-align: center;
    opacity: 0;
    transform: translateY(24px);
}

.syllable-description.visible {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 600ms var(--ease-out-bezier), transform 600ms var(--ease-out-bezier);
    transition-delay: 1.2s;
}

/* ========================================
   SECTION 6: LIVING SYSTEM
   ======================================== */

.living-words-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: clamp(1.5rem, 3vw, 2.5rem);
}

.living-word-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    text-align: center;
    animation: float 6s ease-in-out infinite;
}

.living-word-card[data-stagger="0"] { animation-delay: 0s; }
.living-word-card[data-stagger="1"] { animation-delay: 1.5s; }
.living-word-card[data-stagger="2"] { animation-delay: 3s; }
.living-word-card[data-stagger="3"] { animation-delay: 4.5s; }
.living-word-card[data-stagger="4"] { animation-delay: 0s; }
.living-word-card[data-stagger="5"] { animation-delay: 1.5s; }

/* ========================================
   SECTION 7: CLOSING
   ======================================== */

.closing-section {
    display: flex;
    align-items: center;
    justify-content: center;
}

.closing-character-panel {
    text-align: center;
    margin-bottom: 3rem;
    max-width: 300px;
}

.closing-label {
    margin-top: 1.5rem;
    display: block;
}

.closing-text {
    font-family: 'Space Mono', monospace;
    font-size: clamp(1.2rem, 2.5vw, 2rem);
    font-weight: 700;
    letter-spacing: 0.12em;
    color: var(--text-primary);
    text-align: center;
    margin-bottom: 2rem;
}

.closing-note {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.9rem;
    color: var(--text-tertiary);
    text-align: center;
    max-width: 38ch;
    margin: 0 auto;
    line-height: 1.6;
    font-weight: 300;
}

/* ========================================
   FLOATING PARTICLES
   ======================================== */

.particles-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: clamp(8px, 2vw, 16px);
    height: clamp(8px, 2vw, 16px);
    background: rgba(196, 164, 106, 0.12);
    border-radius: 50%;
    backdrop-filter: blur(4px);
    will-change: transform;
}

.compliance-ledger {
    display: none;
}

.particle:nth-child(1) {
    left: 10%;
    top: 20%;
    animation: drift 40s infinite linear;
}

.particle:nth-child(2) {
    left: 20%;
    top: 50%;
    animation: drift 50s infinite linear 5s;
}

.particle:nth-child(3) {
    left: 30%;
    top: 80%;
    animation: drift 60s infinite linear 10s;
}

.particle:nth-child(4) {
    left: 40%;
    top: 30%;
    animation: drift 45s infinite linear 15s;
}

.particle:nth-child(5) {
    left: 50%;
    top: 60%;
    animation: drift 55s infinite linear 20s;
}

.particle:nth-child(6) {
    left: 60%;
    top: 15%;
    animation: drift 65s infinite linear 25s;
}

.particle:nth-child(7) {
    left: 70%;
    top: 70%;
    animation: drift 50s infinite linear 30s;
}

.particle:nth-child(8) {
    left: 80%;
    top: 40%;
    animation: drift 60s infinite linear 35s;
}

.particle:nth-child(9) {
    left: 15%;
    top: 75%;
    animation: drift 55s infinite linear 10s;
}

.particle:nth-child(10) {
    left: 75%;
    top: 25%;
    animation: drift 50s infinite linear 20s;
}

.particle:nth-child(11) {
    left: 25%;
    top: 35%;
    animation: drift 65s infinite linear 15s;
}

.particle:nth-child(12) {
    left: 65%;
    top: 85%;
    animation: drift 60s infinite linear 40s;
}

@keyframes drift {
    0% {
        transform: translateY(0) translateX(0);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) translateX(var(--drift-x, 50px));
        opacity: 0;
    }
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

@media (max-width: 768px) {
    .philosophy-layout {
        grid-template-columns: 1fr;
    }

    .diagram-stack {
        position: relative;
        top: auto;
        grid-template-columns: 1fr;
    }

    .glass-cards-grid {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
        gap: 1rem;
    }

    .vowels-grid {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    }

    .living-words-grid {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    }

    .card-character {
        font-size: clamp(1.5rem, 8vw, 4rem);
    }

    .section {
        padding: 1.5rem;
    }

    .wordmark {
        font-size: 0.8rem;
        top: 1rem;
        left: 1rem;
    }

    .fixed-section-title {
        top: 1rem;
        right: 1rem;
        max-width: 45vw;
        text-align: right;
    }
}

@media (max-width: 480px) {
    .glass-cards-grid,
    .vowels-grid,
    .living-words-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.8rem;
    }

    .card-character {
        font-size: clamp(1.2rem, 6vw, 3rem);
    }

    .section-title {
        font-size: clamp(1rem, 2vw, 1.6rem);
        margin-bottom: 1.5rem;
    }

    .closing-text {
        font-size: 1rem;
    }
}