/* hangul.day - Design Language Stylesheet */

:root {
    --paper: #F5EDE3;
    --paper-deep: #EDE0D0;
    --ink: #2C2418;
    --ink-light: #6B5D4F;
    --dancheong-red: #C4564A;
    --dancheong-blue: #4A7B8C;
    --dancheong-gold: #D4A843;
    --wash-pink: #E8C4B8;
    --wash-sage: #B8C9B4;
    --shadow: rgba(44, 36, 24, 0.08);
    --column-width: 42.5rem;
    --column-offset: -3%;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--paper);
    color: var(--ink);
    font-family: 'Source Serif 4', Georgia, serif;
    font-weight: 400;
    font-size: 18px;
    line-height: 1.72;
    letter-spacing: 0.005em;
    overflow-x: hidden;
}

/* ============ SVG Filters (hidden) ============ */

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

/* ============ Paper Grain Overlay ============ */

.paper-grain-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1000;
    opacity: 0.03;
    mix-blend-mode: multiply;
    filter: url(#paper-grain);
    background: var(--paper-deep);
}

/* ============ Panel Base ============ */

.panel {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.panel-hero {
    background-color: var(--paper);
}

.panel-origin {
    background-color: var(--paper-deep);
}

.panel-structure {
    background-color: var(--paper);
}

.panel-philosophy {
    background-color: var(--paper-deep);
}

.panel-legacy {
    background-color: var(--paper);
}

/* ============ Panel Content ============ */

.panel-content {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: var(--column-width);
    margin-left: auto;
    margin-right: auto;
    padding: 4rem 1.5rem;
    transform: translateX(var(--column-offset));
}

.content-column {
    width: 100%;
}

/* ============ Watercolor Washes ============ */

.watercolor-wash {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    opacity: 0;
    transition: opacity 2s ease-out;
}

.watercolor-wash.visible {
    opacity: 1;
}

.wash-pink::before,
.wash-pink::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
}

.wash-pink::before {
    top: -10%;
    right: -5%;
    width: 60%;
    height: 50%;
    background: radial-gradient(ellipse, var(--wash-pink) 0%, transparent 70%);
    opacity: 0.08;
}

.wash-pink::after {
    top: 30%;
    right: 10%;
    width: 40%;
    height: 40%;
    background: radial-gradient(ellipse, var(--wash-pink) 0%, transparent 65%);
    opacity: 0.06;
}

.wash-blue::before,
.wash-blue::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
}

.wash-blue::before {
    top: 10%;
    left: -10%;
    width: 55%;
    height: 60%;
    background: radial-gradient(ellipse, var(--dancheong-blue) 0%, transparent 70%);
    opacity: 0.07;
}

.wash-blue::after {
    bottom: 5%;
    left: 5%;
    width: 35%;
    height: 35%;
    background: radial-gradient(ellipse, var(--dancheong-blue) 0%, transparent 65%);
    opacity: 0.05;
}

.wash-sage::before,
.wash-sage::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(130px);
}

.wash-sage::before {
    top: 5%;
    right: -8%;
    width: 50%;
    height: 55%;
    background: radial-gradient(ellipse, var(--wash-sage) 0%, transparent 70%);
    opacity: 0.08;
}

.wash-sage::after {
    bottom: 10%;
    right: 15%;
    width: 30%;
    height: 30%;
    background: radial-gradient(ellipse, var(--wash-sage) 0%, transparent 60%);
    opacity: 0.06;
}

.wash-pink-alt::before,
.wash-pink-alt::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(110px);
}

.wash-pink-alt::before {
    bottom: -5%;
    left: -5%;
    width: 50%;
    height: 45%;
    background: radial-gradient(ellipse, var(--wash-pink) 0%, transparent 70%);
    opacity: 0.07;
}

.wash-pink-alt::after {
    top: 15%;
    left: 20%;
    width: 35%;
    height: 35%;
    background: radial-gradient(ellipse, var(--dancheong-red) 0%, transparent 70%);
    opacity: 0.04;
}

.wash-gold::before,
.wash-gold::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    filter: blur(150px);
}

.wash-gold::before {
    top: 10%;
    right: -5%;
    width: 45%;
    height: 50%;
    background: radial-gradient(ellipse, var(--dancheong-gold) 0%, transparent 70%);
    opacity: 0.07;
}

.wash-gold::after {
    bottom: 15%;
    left: 10%;
    width: 40%;
    height: 40%;
    background: radial-gradient(ellipse, var(--dancheong-gold) 0%, transparent 65%);
    opacity: 0.05;
}

/* ============ Jamo Particles ============ */

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

.jamo-particle {
    position: absolute;
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 300;
    color: var(--ink);
    opacity: 0.04;
    top: -15%;
    animation: jamo-drift var(--duration) linear infinite;
    animation-delay: var(--delay);
    left: var(--x);
    font-size: var(--size);
    will-change: transform;
}

.jamo-particle:nth-child(odd) {
    opacity: 0.06;
}

.jamo-particle:nth-child(3n) {
    opacity: 0.03;
}

@keyframes jamo-drift {
    0% {
        transform: translateY(-20vh) rotate(-5deg);
    }
    100% {
        transform: translateY(120vh) rotate(15deg);
    }
}

/* ============ Hero Section ============ */

.hero-content {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    transform: none;
    max-width: none;
    padding: 0;
}

.jamo-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(5, 1fr);
    width: min(80vw, 600px);
    aspect-ratio: 3 / 5;
    place-items: center;
}

.hero-title-wrap {
    grid-column: 1 / -1;
    grid-row: 2 / 4;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-hangul {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 900;
    font-size: clamp(8rem, 20vw, 16rem);
    color: var(--ink);
    line-height: 1;
    letter-spacing: -0.02em;
}

.hero-tagline {
    grid-column: 1 / -1;
    grid-row: 4;
    font-family: 'Zilla Slab', serif;
    font-weight: 700;
    font-size: clamp(1.2rem, 3vw, 1.75rem);
    color: var(--ink-light);
    text-align: center;
    letter-spacing: -0.02em;
    line-height: 1.05;
}

/* ============ Brush Dividers ============ */

.brush-divider {
    position: relative;
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(to bottom, var(--paper), var(--paper-deep));
    z-index: 3;
}

.brush-divider:nth-of-type(4n+1) {
    background: linear-gradient(to bottom, var(--paper), var(--paper-deep));
}

.brush-divider:nth-of-type(4n+3) {
    background: linear-gradient(to bottom, var(--paper-deep), var(--paper));
}

.brush-svg {
    width: 60%;
    max-width: 400px;
    height: auto;
    color: var(--ink-light);
    opacity: 0.3;
}

/* ============ Watermark Text ============ */

.panel-watermark {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 1;
    pointer-events: none;
}

.watermark-text {
    font-family: 'Playfair Display', serif;
    font-style: italic;
    font-weight: 400;
    font-size: clamp(8rem, 25vw, 14rem);
    color: var(--ink);
    opacity: 0.06;
    line-height: 1;
    user-select: none;
}

.watermark-gold {
    color: var(--dancheong-gold);
    opacity: 0.08;
}

/* ============ Typography ============ */

.section-heading {
    font-family: 'Zilla Slab', serif;
    font-weight: 700;
    font-size: clamp(2.5rem, 6vw, 3.5rem);
    line-height: 1.05;
    letter-spacing: -0.02em;
    color: var(--ink);
    margin-bottom: 2rem;
}

.body-text {
    font-family: 'Source Serif 4', Georgia, serif;
    font-weight: 400;
    font-size: 18px;
    line-height: 1.72;
    letter-spacing: 0.005em;
    color: var(--ink);
    margin-bottom: 1.5rem;
}

.body-text:last-child {
    margin-bottom: 0;
}

.body-text em {
    font-style: italic;
    font-weight: 600;
}

.numeral {
    font-family: 'Playfair Display', serif;
    font-style: italic;
    font-weight: 400;
}

.korean-term {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 500;
    font-size: 0.95em;
}

.closing-text {
    margin-top: 1rem;
    font-size: 20px;
    font-weight: 600;
    color: var(--ink);
}

/* ============ Zoom-Focus Animation ============ */

.zoom-target {
    opacity: 0;
    transform: scale(1.15);
    filter: blur(4px);
    transition: opacity 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94),
                transform 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94),
                filter 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.zoom-target.visible {
    opacity: 1;
    transform: scale(1);
    filter: blur(0px);
}

.zoom-target:nth-child(2) { transition-delay: 0.1s; }
.zoom-target:nth-child(3) { transition-delay: 0.2s; }
.zoom-target:nth-child(4) { transition-delay: 0.3s; }
.zoom-target:nth-child(5) { transition-delay: 0.4s; }

/* ============ Jamo Composition Animation ============ */

.jamo-compose {
    margin: 3rem 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

.jamo-stage {
    position: relative;
    width: 280px;
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.compose-jamo {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 900;
    font-size: 4rem;
    color: var(--ink);
    position: absolute;
    transition: all 1.2s cubic-bezier(0.34, 1.56, 0.64, 1);
    opacity: 0.3;
}

.compose-h {
    transform: translate(-120px, -40px) scale(2);
}

.compose-a {
    transform: translate(120px, 0px) scale(2);
}

.compose-n {
    transform: translate(0px, 100px) scale(2);
}

.jamo-stage.composed .compose-h {
    transform: translate(-25px, -20px) scale(1);
    opacity: 1;
}

.jamo-stage.composed .compose-a {
    transform: translate(25px, -20px) scale(1);
    opacity: 1;
}

.jamo-stage.composed .compose-n {
    transform: translate(0px, 25px) scale(1);
    opacity: 1;
}

.compose-result {
    opacity: 0;
    transition: opacity 0.6s ease 1.2s;
}

.jamo-stage.composed ~ .compose-result {
    opacity: 1;
}

.result-syllable {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 900;
    font-size: 5rem;
    color: var(--dancheong-red);
}

/* ============ Mouth Diagram ============ */

.mouth-diagram {
    margin: 2.5rem 0;
    display: flex;
    justify-content: center;
}

.mouth-profile {
    position: relative;
    width: 320px;
    height: 280px;
}

.mouth-outline {
    position: relative;
    width: 100%;
    height: 100%;
}

.mouth-head {
    position: absolute;
    width: 200px;
    height: 220px;
    border: 2px solid var(--ink-light);
    border-radius: 100px 100px 60px 80px;
    top: 10px;
    left: 40px;
    opacity: 0.3;
}

.mouth-upper-lip {
    position: absolute;
    width: 60px;
    height: 30px;
    border-bottom: 2.5px solid var(--ink-light);
    border-radius: 0 0 50% 50%;
    top: 110px;
    left: 30px;
}

.mouth-lower-jaw {
    position: absolute;
    width: 70px;
    height: 35px;
    border-top: 2.5px solid var(--ink-light);
    border-radius: 50% 50% 0 0;
    top: 145px;
    left: 25px;
}

.mouth-tongue {
    position: absolute;
    width: 80px;
    height: 20px;
    background: var(--ink-light);
    opacity: 0.15;
    border-radius: 40px 30px 0 10px;
    top: 138px;
    left: 60px;
    transform: rotate(-5deg);
}

.mouth-throat {
    position: absolute;
    width: 30px;
    height: 80px;
    border-left: 2.5px solid var(--ink-light);
    border-right: 2.5px solid var(--ink-light);
    border-radius: 5px;
    top: 160px;
    left: 130px;
    opacity: 0.4;
}

.articulation-points {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.art-point {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 8px;
}

.art-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--dancheong-red);
    flex-shrink: 0;
}

.art-label {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 500;
    font-size: 14px;
    color: var(--ink);
    white-space: nowrap;
}

.art-bilabial {
    top: 125px;
    left: 0;
    flex-direction: row-reverse;
}

.art-bilabial .art-label {
    text-align: right;
}

.art-alveolar {
    top: 95px;
    left: 55px;
}

.art-sibilant {
    top: 105px;
    left: 85px;
}

.art-velar {
    top: 70px;
    left: 160px;
}

.art-glottal {
    top: 190px;
    left: 170px;
}

/* ============ Sejong Seal ============ */

.panel-footer {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    z-index: 2;
}

.sejong-seal {
    display: flex;
    align-items: center;
    justify-content: center;
}

.seal-circle {
    width: 80px;
    height: 80px;
    border: 2px solid var(--dancheong-gold);
    border-radius: 50%;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.2;
}

.seal-ieung {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 300;
    font-size: 20px;
    color: var(--dancheong-gold);
    position: absolute;
    top: 12px;
    left: 50%;
    transform: translateX(-50%);
}

.seal-eu {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 300;
    font-size: 20px;
    color: var(--dancheong-gold);
    position: absolute;
    bottom: 18px;
    left: 50%;
    transform: translateX(-50%);
}

.seal-i {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 300;
    font-size: 20px;
    color: var(--dancheong-gold);
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
}

.footer-text {
    font-family: 'Noto Sans KR', sans-serif;
    font-weight: 300;
    font-size: 13px;
    color: var(--ink-light);
    letter-spacing: 0.1em;
}

/* ============ Responsive ============ */

@media (max-width: 768px) {
    .panel-content {
        padding: 3rem 5vw;
        transform: none;
    }

    .hero-hangul {
        font-size: clamp(5rem, 18vw, 10rem);
    }

    .section-heading {
        font-size: clamp(2rem, 5vw, 2.5rem);
    }

    .body-text {
        font-size: 16px;
    }

    .jamo-stage {
        width: 220px;
        height: 160px;
    }

    .compose-jamo {
        font-size: 3rem;
    }

    .compose-h {
        transform: translate(-80px, -30px) scale(1.8);
    }

    .compose-a {
        transform: translate(80px, 0px) scale(1.8);
    }

    .compose-n {
        transform: translate(0px, 70px) scale(1.8);
    }

    .result-syllable {
        font-size: 4rem;
    }

    .mouth-profile {
        width: 260px;
        height: 240px;
        transform: scale(0.85);
        transform-origin: center top;
    }

    .watermark-text {
        font-size: clamp(5rem, 20vw, 10rem);
    }
}