/* ============================================================
   LA SERENA DIGITAL — Knowledge Intelligence Platform
   Design: Dark academic newspaper / serious-divulgative
   ============================================================ */

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

:root {
    --bg-primary: #0f1117;
    --bg-secondary: #161822;
    --bg-card: #1a1d2b;
    --bg-card-hover: #1f2333;
    --border: #252836;
    --border-light: #2a2d3d;
    --text-primary: #e4e6ef;
    --text-secondary: #9498a8;
    --text-muted: #646878;
    --accent: #5b8dee;
    --accent-glow: #7aa2ff;
    --accent-warm: #f0a555;
    --tag-geology: #4a9d8f;
    --tag-mining: #c78b4a;
    --tag-environment: #5b9e5b;
    --tag-water: #5b8dee;
    --danger: #e0556a;
    --radius: 6px;
    --radius-lg: 10px;
    --shadow: 0 2px 8px rgba(0,0,0,0.3);
    --font-serif: 'Georgia', 'Times New Roman', serif;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', monospace;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent-glow); }

/* --- HEADER --- */
.site-header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
    height: 60px;
    display: flex;
    align-items: center;
    gap: 32px;
}

.logo {
    display: flex;
    align-items: baseline;
    gap: 8px;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-icon {
    font-size: 24px;
    color: var(--accent);
}

.logo-text {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 2px;
}

.logo-sub {
    color: var(--accent);
    font-weight: 400;
    letter-spacing: 3px;
}

.main-nav {
    display: flex;
    gap: 4px;
    flex: 1;
}

.nav-link {
    padding: 6px 14px;
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
}

.nav-link:hover,
.nav-link.active {
    background: rgba(91, 141, 238, 0.12);
    color: var(--accent-glow);
}

.header-tagline {
    font-size: 11px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
    white-space: nowrap;
}

/* --- MAIN CONTENT --- */
.main-content {
    max-width: 1280px;
    margin: 0 auto;
    padding: 32px 24px;
    flex: 1;
    width: 100%;
}

/* --- HERO SECTION --- */
.hero {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 24px;
    margin-bottom: 48px;
}

.hero-article {
    background: linear-gradient(135deg, var(--bg-card) 0%, #1d2035 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    position: relative;
    overflow: hidden;
}

.hero-article::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(91,141,238,0.08) 0%, transparent 70%);
    pointer-events: none;
}

.hero-empty {
    text-align: center;
    padding: 60px 40px;
}

.hero-badge {
    display: inline-block;
    background: var(--accent);
    color: white;
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    padding: 3px 10px;
    border-radius: 3px;
    margin-bottom: 16px;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 700;
    line-height: 1.25;
    margin-bottom: 16px;
}

.hero-title a {
    color: var(--text-primary);
    text-decoration: none;
}

.hero-title a:hover {
    color: var(--accent-glow);
}

.hero-summary {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
    max-width: 650px;
}

.hero-cta {
    color: var(--accent);
    font-size: 0.95rem;
    margin-top: 12px;
}

.hero-meta {
    display: flex;
    gap: 16px;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.hero-concepts {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.concept-tag {
    display: inline-block;
    background: rgba(91, 141, 238, 0.15);
    color: var(--accent-glow);
    font-size: 0.75rem;
    padding: 2px 8px;
    border-radius: 3px;
}

/* --- HERO SIDEBAR --- */
.hero-sidebar {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.sidebar-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
}

.sidebar-title {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--text-muted);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

.trending-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.trending-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
}

.trending-item.empty {
    color: var(--text-muted);
    font-style: italic;
}

.trending-name {
    font-weight: 600;
    flex: 1;
}

.trending-cat {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

.trending-count {
    background: rgba(91, 141, 238, 0.15);
    color: var(--accent-glow);
    font-size: 0.7rem;
    padding: 1px 6px;
    border-radius: 10px;
    font-weight: 600;
}

.mineral-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.mineral-tag {
    display: inline-block;
    background: rgba(240, 165, 85, 0.15);
    color: var(--accent-warm);
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 3px;
}

.mineral-tag.empty {
    color: var(--text-muted);
    background: transparent;
}

/* --- ARTICLE GRID --- */
.article-grid-section {
    margin-bottom: 48px;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 20px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--accent);
    display: inline-block;
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.article-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    transition: all 0.2s;
}

.article-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.empty-card {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
    grid-column: 1 / -1;
}

.empty-state {
    text-align: center;
    color: var(--text-muted);
}

.empty-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 12px;
}

.empty-state p {
    font-size: 0.9rem;
    line-height: 1.5;
}

.card-category {
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--accent);
    margin-bottom: 8px;
    font-weight: 600;
}

.card-title {
    font-family: var(--font-serif);
    font-size: 1.05rem;
    font-weight: 700;
    line-height: 1.35;
    margin-bottom: 10px;
}

.card-title a {
    color: var(--text-primary);
    text-decoration: none;
}

.card-title a:hover {
    color: var(--accent-glow);
}

.card-summary {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 14px;
}

.card-meta {
    display: flex;
    gap: 12px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* --- GRAPH TEASER --- */
.graph-teaser {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, #151829 100%);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    text-align: center;
}

.teaser-desc {
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 28px;
    font-size: 0.95rem;
    line-height: 1.6;
}

.teaser-stats {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px 32px;
    min-width: 120px;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-glow);
    font-family: var(--font-mono);
}

.stat-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 4px;
}

/* --- FOOTER --- */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    margin-top: auto;
}

.footer-inner {
    max-width: 1280px;
    margin: 0 auto;
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-stats {
    display: flex;
    gap: 20px;
}

.stat {
    display: flex;
    align-items: baseline;
    gap: 4px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.stat strong {
    font-size: 1rem;
    color: var(--accent-glow);
    font-family: var(--font-mono);
}

.footer-credit {
    font-size: 0.7rem;
    color: var(--text-muted);
    letter-spacing: 0.5px;
}

/* --- RESPONSIVE --- */
@media (max-width: 900px) {
    .hero {
        grid-template-columns: 1fr;
    }

    .hero-sidebar {
        flex-direction: row;
        flex-wrap: wrap;
    }

    .sidebar-box {
        flex: 1;
        min-width: 200px;
    }

    .main-nav {
        display: none;
    }

    .header-tagline {
        display: none;
    }
}

@media (max-width: 600px) {
    .hero-article {
        padding: 24px;
    }

    .hero-title {
        font-size: 1.4rem;
    }

    .article-grid {
        grid-template-columns: 1fr;
    }

    .teaser-stats {
        gap: 12px;
    }

    .stat-card {
        padding: 14px 20px;
        min-width: 80px;
    }
}