:root {
        /* Light theme */
        --bg-primary: #ffffff;
        --bg-secondary: #f8fafc;
        --bg-tertiary: #f1f5f9;
        --text-primary: #1e293b;
        --text-secondary: #475569;
        --text-muted: #64748b;
        --border-color: #e2e8f0;
        --border-hover: #cbd5e1;
        --accent-primary: #3b82f6;
        --accent-hover: #2563eb;
        --success: #10b981;
        --warning: #f59e0b;
        --danger: #ef4444;
        --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
        --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
        --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    }

    [data-theme="dark"] {
        /* Dark theme */
        --bg-primary: #0f172a;
        --bg-secondary: #1e293b;
        --bg-tertiary: #334155;
        --text-primary: #f8fafc;
        --text-secondary: #cbd5e1;
        --text-muted: #94a3b8;
        --border-color: #334155;
        --border-hover: #475569;
        --accent-primary: #60a5fa;
        --accent-hover: #3b82f6;
        --success: #34d399;
        --warning: #fbbf24;
        --danger: #f87171;
        --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
        --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
        --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    }

    /* Apply theme to entire page */
    html[data-theme="dark"] {
        color-scheme: dark;
    }

    html[data-theme="light"] {
        color-scheme: light;
    }

    html[data-theme="dark"] body,
    html[data-theme="light"] body {
        background-color: var(--bg-primary);
        color: var(--text-primary);
        transition: background-color 0.3s ease, color 0.3s ease;
    }

    /* Use default header from main.css - no overrides */

    .container {
        max-width: 1200px;
        margin: 0 auto;
        padding: 0 1rem;
    }


    /* Main content */
    .main-content {
        padding: 2rem 0;
    }

    /* Hub header */
    .hub-header {
        text-align: center;
        margin-bottom: 3rem;
        padding: 2rem 0;
    }

    .hub-title {
        font-size: 2.5rem;
        font-weight: bold;
        color: var(--text-primary);
        margin-bottom: 1rem;
    }

    .hub-description {
        font-size: 1.1rem;
        color: var(--text-secondary);
        max-width: 600px;
        margin: 0 auto;
    }

    .categories-grid {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: 1.5rem;
        margin-bottom: 2rem;
    }

    .category-card {
        background: var(--bg-secondary);
        border: 1px solid var(--border-color);
        border-radius: 12px;
        padding: 1.5rem;
        transition: all 0.3s ease;
        cursor: pointer;
        position: relative;
        overflow: hidden;
    }

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

    .category-header {
        display: flex;
        align-items: center;
        gap: 1rem;
        margin-bottom: 1rem;
    }

    .category-icon {
        width: 3rem;
        height: 3rem;
        border-radius: 8px;
        display: flex;
        align-items: center;
        justify-content: center;
        color: white;
        font-size: 1.5rem;
        flex-shrink: 0;
        background-color: var(--text-muted); /* Default color */
    }

    .category-icon-svg {
        width: 1.5rem !important;
        height: 1.5rem !important;
        min-width: 1.5rem;
        min-height: 1.5rem;
    }

    .category-info {
        flex: 1;
        min-width: 0;
    }

    .category-title {
        font-size: 1.1rem;
        font-weight: 600;
        color: var(--text-primary);
        margin: 0;
        line-height: 1.3;
        word-wrap: break-word;
    }

    .category-description {
        font-size: 0.85rem;
        color: var(--text-muted);
        margin-top: 0.25rem;
    }

    .category-stats {
        display: flex;
        justify-content: space-between;
        align-items: center;
        margin-top: 1rem;
        padding-top: 1rem;
        border-top: 1px solid var(--border-color);
    }

    .article-count {
        font-size: 1.5rem;
        font-weight: bold;
        color: var(--accent-primary);
    }

    .article-label {
        font-size: 0.8rem;
        color: var(--text-muted);
    }


    /* Empty state */
    .empty-state {
        text-align: center;
        padding: 4rem 2rem;
        color: var(--text-muted);
    }

    .empty-state-icon {
        font-size: 4rem;
        margin-bottom: 1rem;
        opacity: 0.5;
    }

    /* No custom mobile buttons - using unified header */

    /* Using default mobile styles from main.css */

    /* Removed mobile back button references */

    /* Animations */
    @keyframes fadeIn {
        from {
            opacity: 0;
            transform: translateY(20px);
        }
        to {
            opacity: 1;
            transform: translateY(0);
        }
    }

    .category-card {
        animation: fadeIn 0.5s ease-out;
    }

    .category-card:nth-child(1) { animation-delay: 0.1s; }
    .category-card:nth-child(2) { animation-delay: 0.2s; }
    .category-card:nth-child(3) { animation-delay: 0.3s; }
    .category-card:nth-child(4) { animation-delay: 0.4s; }
    .category-card:nth-child(5) { animation-delay: 0.5s; }
    .category-card:nth-child(6) { animation-delay: 0.6s; }

/* Use default header from main.css - no overrides */