:root {
    --bg: #fdf7f4;
    --bg-alt: #f8f1ed;
    --surface: #ffffff;
    --surface-alt: #fff7f0;
    --text: #2f261f;
    --muted: #7a6f66;
    --accent: #e8a08b;
    --accent-strong: #d47b63;
    --accent-soft: rgba(232, 160, 139, 0.2);
    --mint: #b8dccb;
    --border: rgba(47, 38, 31, 0.12);
    --shadow: 0 24px 60px rgba(33, 26, 22, 0.12);
    --radius-lg: 26px;
    --radius-md: 18px;
    --radius-sm: 12px;
}

body.dark {
    --bg: #171313;
    --bg-alt: #1e1919;
    --surface: #1f1b1b;
    --surface-alt: #262121;
    --text: #f5efe9;
    --muted: #c1b5aa;
    --accent: #f0b39d;
    --accent-strong: #e28f75;
    --accent-soft: rgba(240, 179, 157, 0.18);
    --mint: #95c4b2;
    --border: rgba(245, 239, 233, 0.12);
    --shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Gowun Dodum', sans-serif;
    margin: 0;
    min-height: 100vh;
    color: var(--text);
    background: radial-gradient(circle at 10% 20%, rgba(232, 160, 139, 0.18), transparent 45%),
                radial-gradient(circle at 80% 15%, rgba(184, 220, 203, 0.3), transparent 45%),
                linear-gradient(160deg, var(--bg), var(--bg-alt));
    transition: background 0.3s ease, color 0.3s ease;
    position: relative;
    overflow-x: hidden;
}

h1, h2, h3 {
    font-family: 'Jua', sans-serif;
    margin: 0 0 12px;
    letter-spacing: 0.01em;
    font-weight: 700;
}

p {
    margin: 0;
}

.background-texture {
    position: fixed;
    inset: -10% -10% -20% -10%;
    background:
        radial-gradient(circle at 25% 30%, rgba(255, 223, 212, 0.55), transparent 55%),
        radial-gradient(circle at 70% 70%, rgba(184, 220, 203, 0.38), transparent 60%);
    opacity: 0.85;
    filter: blur(2px);
    z-index: 0;
    pointer-events: none;
}

.top-controls {
    position: fixed;
    top: 24px;
    right: 24px;
    display: flex;
    gap: 10px;
    z-index: 5;
}

#theme-toggle, #lang-toggle {
    padding: 8px 16px;
    cursor: pointer;
    background-color: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 13px;
    font-weight: 600;
    transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
}

#theme-toggle:hover, #lang-toggle:hover {
    transform: translateY(-2px);
    border-color: var(--accent);
}

.site-header {
    max-width: 1180px;
    margin: 0 auto;
    padding: 32px 24px 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    z-index: 2;
}

.brand {
    font-family: 'Jua', sans-serif;
    font-size: 26px;
    font-weight: 700;
}

.site-nav {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.nav-link {
    background: transparent;
    border: 1px solid transparent;
    color: var(--muted);
    font-size: 14px;
    font-weight: 600;
    padding: 8px 14px;
    border-radius: 999px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.nav-link:hover {
    color: var(--text);
    border-color: var(--border);
    background: var(--surface-alt);
}

.page {
    max-width: 1180px;
    margin: 0 auto;
    padding: 40px 24px 90px;
    position: relative;
    z-index: 2;
}

.hero {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 40px;
    align-items: center;
    padding: 24px 0 8px;
}

.tagline {
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.22em;
    color: var(--muted);
    margin-bottom: 12px;
}

#main-heading {
    font-size: clamp(30px, 3.3vw, 50px);
    line-height: 1.1;
}

.sub-heading {
    font-size: 16px;
    color: var(--muted);
    max-width: 520px;
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    align-items: center;
    gap: 18px;
    margin-top: 28px;
    flex-wrap: wrap;
}

#jump-stages,
#jump-themes {
    padding: 16px 28px;
    font-size: 16px;
    cursor: pointer;
    background: linear-gradient(140deg, var(--accent), var(--accent-strong));
    color: #fff;
    border: none;
    border-radius: 20px;
    box-shadow: 0 16px 30px rgba(217, 114, 63, 0.25);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    font-weight: 600;
}

#jump-stages:hover,
#jump-themes:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 35px rgba(217, 114, 63, 0.35);
}

.hero-note {
    font-size: 14px;
    color: var(--muted);
}

.meta-row {
    margin-top: 18px;
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.meta-pill {
    padding: 6px 12px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface-alt);
    font-size: 12px;
    color: var(--muted);
}

.hero-panel {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    display: grid;
    gap: 14px;
}

.hero-panel-title {
    font-weight: 600;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.16em;
    font-size: 12px;
}

.filter-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.filter-group {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.filter-divider {
    height: 1px;
    width: 100%;
    background: rgba(47, 38, 31, 0.08);
    margin: 4px 0 2px;
}

.filter-btn {
    border: 1px solid var(--border);
    background: var(--surface-alt);
    color: var(--text);
    padding: 8px 12px;
    border-radius: 999px;
    font-size: 13px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s ease;
}

.filter-btn.active {
    background: var(--accent-soft);
    border-color: var(--accent);
    color: var(--accent-strong);
}

.filter-note {
    font-size: 13px;
    color: var(--muted);
    line-height: 1.6;
}

.section {
    margin-top: 64px;
}

.section-header {
    display: grid;
    gap: 8px;
    margin-bottom: 24px;
}

.section-header p {
    color: var(--muted);
    line-height: 1.7;
}

.stage-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 18px;
}

.stage-card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 16px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    display: grid;
    gap: 12px;
    animation: fadeIn 0.4s ease-in-out;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.stage-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent);
    box-shadow: 0 18px 40px rgba(28, 22, 18, 0.12);
}

.stage-tag {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.18em;
    color: var(--muted);
}

.stage-title {
    font-size: 20px;
}

.stage-sub {
    color: var(--muted);
    font-size: 13px;
}

.card-list {
    display: grid;
    gap: 8px;
}

.card-item {
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--surface-alt);
    display: grid;
    gap: 6px;
}

.card-category {
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--accent-strong);
    font-weight: 600;
}

.card-title {
    font-weight: 600;
    font-size: 16px;
}

.card-desc {
    font-size: 16px;
    color: var(--muted);
    line-height: 1.6;
}

.card-detail {
    font-size: 15px;
    color: var(--muted);
    line-height: 1.6;
}

.accordion-btn {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    background: var(--surface-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 12px 14px;
    cursor: pointer;
    font-weight: 600;
    font-size: 16px;
    color: var(--text);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.accordion-btn.active {
    border-color: var(--accent);
    box-shadow: 0 12px 24px rgba(232, 160, 139, 0.15);
}

.accordion-panel {
    display: none;
    padding: 10px 14px 14px;
    border: 1px solid var(--border);
    border-top: none;
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    background: var(--surface-alt);
}

.accordion-panel.show {
    display: grid;
    gap: 10px;
}

.modal a.card-detail {
    color: var(--accent-strong);
    text-decoration: none;
    font-weight: 600;
}

.modal a.card-detail:hover {
    text-decoration: underline;
}

.accordion-list {
    margin: 0;
    padding-left: 16px;
    font-size: 15px;
    color: var(--muted);
    line-height: 1.6;
}

.cluster-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 18px;
}

.cluster-card {
    background: var(--surface);
    border-radius: var(--radius-md);
    padding: 18px;
    border: 1px solid var(--border);
    display: grid;
    gap: 10px;
    box-shadow: 0 16px 30px rgba(28, 22, 18, 0.08);
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.cluster-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent);
    box-shadow: 0 18px 36px rgba(28, 22, 18, 0.12);
}

.cluster-title {
    font-weight: 700;
}

.cluster-keywords {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.keyword-pill {
    padding: 6px 10px;
    border-radius: 999px;
    background: var(--accent-soft);
    color: var(--accent-strong);
    font-size: 12px;
    font-weight: 600;
}

.formula-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 18px;
}

.formula-card {
    background: var(--surface);
    border-radius: var(--radius-md);
    padding: 18px;
    border: 1px solid var(--border);
    display: grid;
    gap: 10px;
    box-shadow: 0 16px 30px rgba(28, 22, 18, 0.08);
}

.formula-card ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 8px;
    color: var(--muted);
    font-size: 13px;
    line-height: 1.6;
}

.disclaimer-card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 22px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.modal {
    position: fixed;
    inset: 0;
    background: rgba(20, 15, 13, 0.55);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
    z-index: 20;
}

.modal.show {
    opacity: 1;
    pointer-events: auto;
}

.modal-card {
    width: min(960px, 100%);
    max-height: 85vh;
    overflow: hidden;
    background: var(--surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    display: grid;
    grid-template-rows: auto 1fr;
}

.modal-header {
    padding: 18px 22px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    background: var(--surface-alt);
}

.modal-tag {
    font-size: 11px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--muted);
}

.modal-close {
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 12px;
    cursor: pointer;
    font-weight: 600;
}

.modal-body {
    padding: 20px 22px 24px;
    overflow: auto;
    display: grid;
    gap: 18px;
}

.modal-top5 {
    display: grid;
    gap: 8px;
    padding: 14px;
    border-radius: var(--radius-sm);
    background: var(--surface-alt);
    border: 1px solid var(--border);
    font-size: 16px;
}

.modal-sections {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.section-pill {
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--muted);
    border-radius: 999px;
    padding: 6px 14px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.section-pill:hover {
    border-color: var(--accent);
    color: var(--text);
    background: var(--surface-alt);
}

.section-pill.active {
    border-color: var(--accent-strong);
    color: var(--text);
    background: var(--accent-soft);
}

.modal-cards {
    display: grid;
    gap: 12px;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 980px) {
    .hero {
        grid-template-columns: 1fr;
    }

    .top-controls {
        position: static;
        justify-content: flex-end;
        margin: 20px 24px 0;
    }
}

@media (max-width: 640px) {
    .site-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .hero-cta {
        flex-direction: column;
        align-items: flex-start;
    }
}