:root {
            --primary-color: #1e293b;
            --secondary-color: #3b82f6;
            --accent-color: #f59e0b;
            --text-primary: #0f172a;
            --text-secondary: #64748b;
            --text-muted: #94a3b8;
            --bg-primary: #ffffff;
            --bg-secondary: #f8fafc;
            --bg-accent: #f1f5f9;
            --border-color: #e2e8f0;
            --border-light: #f1f5f9;
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
            --spacing-xs: 8px;
            --spacing-sm: 12px;
            --spacing-md: 16px;
            --spacing-lg: 20px;
            --spacing-xl: 28px;
            --spacing-2xl: 36px;
            --radius-md: 8px;
            --radius-lg: 12px;
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
            line-height: 1.6;
            color: var(--text-primary);
            background: var(--bg-secondary);
            margin: 0;
            padding: 0;
        }

        /* Back to top button */
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 44px;
            height: 44px;
            background: var(--primary-color);
            color: white;
            border: none;
            border-radius: 50%;
            cursor: pointer;
            box-shadow: 0 4px 14px rgba(0,0,0,0.25);
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
            z-index: 1000;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .back-to-top::before {
            content: '';
            width: 18px;
            height: 18px;
            background: currentColor;
            mask: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='currentColor'%3e%3cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2.5' d='M5 15l7-7 7 7'%3e%3c/path%3e%3c/svg%3e") no-repeat center;
            mask-size: contain;
        }

        .back-to-top.visible {
            opacity: 1;
            visibility: visible;
        }

        .back-to-top:hover {
            background: #334155;
            transform: translateY(-2px);
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            background: var(--bg-primary);
            box-shadow: var(--shadow);
            min-height: 100vh;
        }

        .header {
            text-align: center;
            padding: var(--spacing-xl) var(--spacing-lg);
            background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
            border-bottom: 1px solid var(--border-color);
        }

        h1 {
            font-size: 3rem;
            font-weight: 300;
            margin-bottom: var(--spacing-md);
            color: var(--text-primary);
            letter-spacing: -0.025em;
            line-height: 1.1;
        }

        .subtitle {
            font-size: 1.25rem;
            color: var(--text-secondary);
            font-weight: 400;
            max-width: 600px;
            margin: 0 auto;
            line-height: 1.5;
        }

        .section {
            padding: var(--spacing-lg) var(--spacing-xl);
            border-bottom: 1px solid var(--border-light);
            scroll-margin-top: 80px;
        }

        .section:last-child {
            border-bottom: none;
        }

        .section-title {
            font-size: 2rem;
            font-weight: 500;
            color: var(--text-primary);
            margin-bottom: var(--spacing-xl);
            letter-spacing: -0.025em;
            line-height: 1.2;
        }

        .intro {
            background: var(--bg-secondary);
            padding: var(--spacing-xl);
            border-radius: var(--radius-lg);
            border-left: 4px solid var(--text-secondary);
            margin-bottom: var(--spacing-lg);
        }

        .intro p {
            color: var(--text-secondary);
            font-size: 1.125rem;
            line-height: 1.7;
            margin: 0;
        }

        /* ── Tabs ── */
        .tabs { width: 100%; }

        .tab-nav {
            display: flex;
            gap: 2px;
            padding: 0 var(--spacing-xl);
            background: var(--bg-primary);
            border-bottom: 2px solid var(--border-color);
            overflow-x: auto;
            flex-wrap: nowrap;
            position: sticky;
            top: 52px;
            z-index: 50;
            scrollbar-width: none;
        }
        .tab-nav::-webkit-scrollbar { display: none; }

        .tab-btn {
            flex-shrink: 0;
            padding: 12px 16px;
            border: none;
            background: none;
            cursor: pointer;
            font-size: 0.85rem;
            font-weight: 500;
            color: var(--text-secondary);
            border-bottom: 2px solid transparent;
            margin-bottom: -2px;
            transition: all 0.2s ease;
            font-family: inherit;
            white-space: nowrap;
        }
        .tab-btn:hover {
            color: var(--text-primary);
            background: var(--bg-accent);
        }
        .tab-btn.active {
            color: var(--secondary-color);
            border-bottom-color: var(--secondary-color);
        }

        .tab-panel { display: none; }
        .tab-panel.active { display: block; }

        /* Grid Systems */
        .grid-2 {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: var(--spacing-xl);
        }

        .grid-3 {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--spacing-lg);
        }

        .grid-auto {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: var(--spacing-lg);
        }

        /* Cards */
        .card {
            background: var(--bg-primary);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-lg);
            padding: var(--spacing-lg);
            transition: all 0.3s ease;
        }

        .card:hover {
            transform: translateY(-2px);
            box-shadow: var(--shadow-lg);
        }

        .card-header {
            margin-bottom: var(--spacing-md);
            padding-bottom: var(--spacing-sm);
            border-bottom: 1px solid var(--border-light);
        }

        .card-title {
            font-size: 1.25rem;
            font-weight: 600;
            color: var(--text-primary);
            margin: 0;
        }

        .card-content {
            color: var(--text-secondary);
            line-height: 1.6;
        }

        /* Typography Samples */
        .font-family {
            background: var(--bg-primary);
            margin-bottom: var(--spacing-lg);
            padding: var(--spacing-lg);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow);
        }

        .font-name {
            color: var(--text-primary);
            font-size: 1.5rem;
            font-weight: 600;
            margin-bottom: var(--spacing-md);
            padding-bottom: var(--spacing-sm);
            border-bottom: 1px solid var(--border-color);
        }

        .font-sample {
            font-size: 2.25rem;
            margin: var(--spacing-md) 0;
            padding: var(--spacing-lg);
            background: var(--bg-secondary);
            border-radius: var(--radius-lg);
            text-align: center;
            color: var(--text-primary);
            border: 1px solid var(--border-color);
        }

        .font-info {
            display: grid;
            gap: var(--spacing-sm);
        }

        .info-box {
            padding: var(--spacing-md);
            border-radius: var(--radius-md);
            background: var(--bg-primary);
            border: 1px solid var(--border-color);
            line-height: 1.6;
        }

        .info-box.description { border-left: 4px solid #10b981; }
        .info-box.connotation { border-left: 4px solid var(--accent-color); }
        .info-box.usage       { border-left: 4px solid #8b5cf6; }

        .info-box strong {
            color: var(--text-primary);
            font-weight: 600;
        }

        /* Table Styles */
        .table-container {
            overflow-x: auto;
            background: var(--bg-primary);
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-color);
            box-shadow: var(--shadow);
        }

        .table-container table {
            width: 100%;
            border-collapse: collapse;
            font-size: 0.9rem;
        }

        .table-container thead tr {
            background: var(--bg-secondary);
        }

        .table-container th,
        .table-container td {
            padding: var(--spacing-sm);
            text-align: left;
            vertical-align: top;
            border-bottom: 1px solid var(--border-light);
        }

        .table-container th {
            font-weight: 600;
            color: var(--text-primary);
            border-bottom: 2px solid var(--border-color);
        }

        .table-container td {
            color: var(--text-secondary);
            line-height: 1.5;
        }

        .table-family { font-weight: 600; color: var(--text-primary); }

        .table-indicator {
            display: flex;
            align-items: center;
            gap: var(--spacing-xs);
        }

        .table-dot {
            width: 4px;
            height: 20px;
            border-radius: 2px;
            flex-shrink: 0;
        }

        /* Typography Classes with Real Fonts */
        .humanes  { font-family: 'Georgia', serif; }
        .garaldes { font-family: 'Playfair Display', serif; }
        .reales   { font-family: 'Times New Roman', serif; }
        .didones  { font-family: 'Bodoni Moda', serif; }
        .mecanes  { font-family: 'Roboto Slab', serif; }
        .lineales { font-family: 'Inter', sans-serif; }
        .incises  { font-family: 'Times New Roman', serif; letter-spacing: 0.05em; font-weight: 500; }
        .scriptes { font-family: 'Dancing Script', cursive; }
        .fractures{ font-family: 'UnifrakturMaguntia', cursive; }

        .font-mention {
            padding: 2px 6px;
            background: var(--bg-accent);
            border-radius: 4px;
            border: 1px solid var(--border-color);
            font-weight: 500;
        }

        /* Specialized Sections */
        .rules-section { background: var(--bg-secondary); border-top: 1px solid var(--border-color); }

        .trends-section {
            background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
            border: 1px solid var(--border-color);
            color: var(--text-primary);
        }

        .trends-section .section-title {
            color: var(--text-primary);
            background: linear-gradient(135deg, #3b82f6, #8b5cf6);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .trend-card {
            background: var(--bg-primary);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-lg);
            padding: var(--spacing-lg);
            transition: all 0.3s ease;
            box-shadow: var(--shadow);
        }

        .trend-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }

        .trend-card h3 {
            color: var(--text-primary);
            font-size: 1.25rem;
            font-weight: 600;
            margin-bottom: var(--spacing-sm);
            display: flex;
            align-items: center;
            gap: var(--spacing-sm);
        }

        .trend-card h3::before {
            content: '';
            width: 8px; height: 8px;
            background: var(--secondary-color);
            border-radius: 50%;
            flex-shrink: 0;
        }

        .trend-fonts { color: var(--secondary-color); font-weight: 500; margin-bottom: var(--spacing-sm); }
        .trend-card p { color: var(--text-secondary); line-height: 1.6; margin: 0; }

        .comic-section { background: #fef2f2; border-top: 1px solid #fecaca; }
        .comic-section .section-title { color: #991b1b; }

        .comic-sample {
            font-family: 'Comic Sans MS', cursive, sans-serif;
            font-size: 2.5rem;
            text-align: center;
            margin: var(--spacing-lg) 0;
            background: var(--bg-primary);
            padding: var(--spacing-xl);
            border-radius: var(--radius-lg);
            color: var(--text-primary);
            border: 1px solid #fecaca;
        }

        .comic-card {
            background: var(--bg-primary);
            padding: var(--spacing-lg);
            border-radius: var(--radius-lg);
            border: 1px solid #fecaca;
            margin-bottom: var(--spacing-md);
        }

        .comic-card h3 {
            color: #991b1b;
            font-size: 1.25rem;
            font-weight: 600;
            margin-bottom: var(--spacing-sm);
            display: flex;
            align-items: center;
            gap: var(--spacing-sm);
        }

        .comic-card h3::before {
            content: '';
            width: 6px; height: 6px;
            background: #dc2626;
            border-radius: 50%;
            box-shadow: 0 0 0 2px rgba(220,38,38,0.2);
            flex-shrink: 0;
        }

        .comic-card ul { margin-left: var(--spacing-md); color: var(--text-secondary); }
        .comic-card li { margin-bottom: var(--spacing-xs); line-height: 1.5; }

        .comic-quote {
            background: #fee2e2;
            padding: var(--spacing-lg);
            border-radius: var(--radius-lg);
            text-align: center;
            margin-top: var(--spacing-lg);
            border: 1px solid #fecaca;
        }

        .comparison-section { background: var(--bg-secondary); }

        .comparison-item {
            background: var(--bg-primary);
            padding: var(--spacing-lg);
            border-radius: var(--radius-lg);
            text-align: center;
            border: 1px solid var(--border-color);
            transition: all 0.3s ease;
        }

        .comparison-item:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }

        .comparison-text {
            font-size: 1.75rem;
            margin-bottom: var(--spacing-sm);
            color: var(--text-primary);
            font-weight: 400;
        }

        .comparison-label {
            color: var(--text-secondary);
            font-size: 0.875rem;
            font-weight: 600;
            margin-bottom: var(--spacing-xs);
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .tag {
            display: inline-block;
            background: var(--bg-accent);
            color: var(--text-secondary);
            padding: 4px var(--spacing-sm);
            border-radius: 16px;
            font-size: 0.75rem;
            font-weight: 500;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .guidelines {
            background: var(--bg-secondary);
            padding: var(--spacing-xl);
            border-radius: var(--radius-lg);
            margin-top: var(--spacing-xl);
            border: 1px solid var(--border-color);
        }

        .guidelines h3 { color: var(--text-primary); font-size: 1.25rem; font-weight: 600; margin-bottom: var(--spacing-md); }
        .guidelines p  { color: var(--text-secondary); margin-bottom: var(--spacing-sm); line-height: 1.6; }

        /* Lists */
        .styled-list { margin-left: var(--spacing-md); color: var(--text-secondary); }
        .styled-list li { margin-bottom: var(--spacing-xs); line-height: 1.6; }

        /* Utility */
        .highlight-box {
            background: var(--bg-accent);
            padding: var(--spacing-md);
            border-radius: var(--radius-md);
            margin: var(--spacing-sm) 0;
        }

        .warning-box {
            background: #fef2f2;
            padding: var(--spacing-md);
            border-radius: var(--radius-md);
            border-left: 4px solid #ef4444;
            margin: var(--spacing-sm) 0;
        }

        .info-note {
            background: var(--bg-secondary);
            padding: var(--spacing-lg);
            border-radius: var(--radius-md);
            border-left: 4px solid var(--secondary-color);
            margin-top: var(--spacing-lg);
        }

        .info-note h3 { color: var(--text-primary); margin-bottom: var(--spacing-sm); font-size: 1.125rem; }
        .info-note p  { color: var(--text-secondary); line-height: 1.6; margin: 0; }

        /* Tooltip */
        .tooltip {
            position: relative;
            cursor: help;
            border-bottom: 1px dotted var(--secondary-color);
            color: var(--secondary-color);
        }

        .tooltip::before {
            content: attr(data-tooltip);
            position: absolute;
            bottom: 125%;
            left: 50%;
            transform: translateX(-50%);
            background: var(--primary-color);
            color: white;
            padding: var(--spacing-sm) var(--spacing-md);
            border-radius: var(--radius-md);
            font-size: 0.875rem;
            line-height: 1.4;
            width: max-content;
            max-width: 250px;
            text-align: center;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
            z-index: 1000;
            box-shadow: var(--shadow);
        }

        .tooltip::after {
            content: '';
            position: absolute;
            bottom: 115%;
            left: 50%;
            transform: translateX(-50%);
            border: 5px solid transparent;
            border-top-color: var(--primary-color);
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
            z-index: 1000;
        }

        .tooltip:hover::before,
        .tooltip:hover::after { opacity: 1; visibility: visible; }

        @media (max-width: 768px) {
            .tooltip::before {
                position: fixed;
                bottom: var(--spacing-md);
                left: var(--spacing-md);
                right: var(--spacing-md);
                transform: none;
                max-width: none;
                width: auto;
            }
            .tooltip::after { display: none; }
        }

        @media (max-width: 1024px) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }

        @media (max-width: 768px) {
            .container { margin: 0; }
            .header    { padding: var(--spacing-xl) var(--spacing-lg); }
            .section   { padding: var(--spacing-xl) var(--spacing-lg); }
            h1 { font-size: 2.5rem; }
            .section-title { font-size: 1.75rem; }
            .font-family   { padding: var(--spacing-lg); }
            .font-sample   { font-size: 1.875rem; padding: var(--spacing-lg); }
            .grid-2, .grid-3, .grid-auto { grid-template-columns: 1fr; gap: var(--spacing-lg); }
            .card { padding: var(--spacing-md); }
            .comparison-text { font-size: 1.5rem; }
            .tab-nav { padding: 0 var(--spacing-md); }
            .tab-btn { padding: 10px 12px; font-size: 0.8rem; }
        }

        .footer {
            text-align: center;
            font-size: 0.72rem;
            font-weight: 400;
            padding: 10px 20px;
            background: #f8fafc;
            color: var(--text-muted);
            letter-spacing: 0.06em;
            border-top: 1px solid var(--border-color);
        }

        /* Overview Cards */
        .overview-section {
            padding: var(--spacing-xl);
            background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
            border-bottom: 1px solid var(--border-color);
        }

        .overview-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--spacing-md);
        }

        .overview-card {
            background: var(--bg-primary);
            border: 1px solid var(--border-color);
            border-radius: var(--radius-lg);
            padding: var(--spacing-lg);
            cursor: pointer;
            text-decoration: none;
            display: block;
            transition: all 0.25s ease;
            position: relative;
            overflow: hidden;
        }

        .overview-card::before {
            content: '';
            position: absolute;
            top: 0; left: 0; right: 0;
            height: 3px;
            background: var(--card-accent, var(--secondary-color));
            transform: scaleX(0);
            transform-origin: left;
            transition: transform 0.3s ease;
        }

        .overview-card:hover { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(0,0,0,0.1); border-color: transparent; }
        .overview-card:hover::before { transform: scaleX(1); }

        .overview-card-icon {
            width: 40px; height: 40px;
            margin-bottom: var(--spacing-sm);
            display: flex; align-items: center; justify-content: center;
            background: color-mix(in srgb, var(--card-accent, var(--secondary-color)) 12%, transparent);
            border-radius: 10px;
            color: var(--card-accent, var(--secondary-color));
        }

        .overview-card-icon svg { width: 22px; height: 22px; stroke: currentColor; stroke-width: 1.75; fill: none; stroke-linecap: round; stroke-linejoin: round; }

        .overview-card-tag { display: inline-block; font-size: 0.7rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--card-accent, var(--secondary-color)); margin-bottom: var(--spacing-xs); }
        .overview-card-title { font-size: 1.05rem; font-weight: 700; color: var(--text-primary); margin-bottom: var(--spacing-xs); line-height: 1.3; }
        .overview-card-desc { font-size: 0.85rem; color: var(--text-secondary); line-height: 1.55; margin: 0; }
        .overview-card-links { margin-top: var(--spacing-sm); display: flex; flex-wrap: wrap; gap: 6px; }
        .overview-card-link { font-size: 0.75rem; color: var(--card-accent, var(--secondary-color)); background: color-mix(in srgb, var(--card-accent, var(--secondary-color)) 10%, transparent); border-radius: 4px; padding: 2px 8px; font-weight: 500; }

        @media (max-width: 900px) { .overview-grid { grid-template-columns: repeat(2, 1fr); } }
        @media (max-width: 600px) { .overview-grid { grid-template-columns: 1fr; } }