/* roulang page: index */
:root {
            --primary: #0F52BA;
            --primary-hover: #0B3E8E;
            --accent: #E11D48;
            --bg-neutral: #F8FAFC;
            --bg-card: #FFFFFF;
            --text-title: #0F172A;
            --text-body: #334155;
            --text-muted: #64748B;
            --border-color: #E2E8F0;
            --shadow-subtle: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
            --shadow-hover: 0 12px 28px -4px rgba(15, 23, 42, 0.1);
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-neutral);
            color: var(--text-body);
            overflow-x: hidden;
        }

        .custom-container {
            max-width: 1280px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1.25rem;
            padding-right: 1.25rem;
        }

        .card-standard {
            background-color: var(--bg-card);
            border: 1px solid var(--border-color);
            border-radius: 1rem;
            box-shadow: var(--shadow-subtle);
            transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .card-standard:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-hover);
            border-color: #CBD5E1;
        }

        .nav-link {
            transition: color 0.2s ease, border-color 0.2s ease;
        }
        
        .nav-link.active {
            color: var(--primary);
            font-weight: 600;
            position: relative;
        }
        
        .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -6px;
            left: 0;
            right: 0;
            height: 2px;
            background-color: var(--primary);
            border-radius: 2px;
        }

        /* Hero vertical screen feel */
        .hero-vertical-card {
            aspect-ratio: 9 / 16;
            max-height: 520px;
            width: auto;
            border-radius: 1.5rem;
            overflow: hidden;
            box-shadow: 0 20px 40px -10px rgba(15, 82, 186, 0.2);
            border: 4px solid #FFFFFF;
        }

        /* Timeline connector */
        .timeline-line::before {
            content: '';
            position: absolute;
            top: 0;
            bottom: 0;
            left: 1.5rem;
            width: 2px;
            background-color: #E2E8F0;
        }

        @media (min-width: 768px) {
            .timeline-line::before {
                left: 50%;
                transform: translateX(-50%);
            }
        }

/* roulang page: article */
:root {
            --primary: #0F52BA;
            --primary-hover: #0B3E8E;
            --accent: #E11D48;
            --bg-neutral: #F8FAFC;
            --bg-card: #FFFFFF;
            --text-title: #0F172A;
            --text-body: #334155;
            --text-muted: #64748B;
            --border-color: #E2E8F0;
            --shadow-subtle: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
            --shadow-hover: 0 12px 28px -4px rgba(15, 23, 42, 0.1);
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-neutral);
            color: var(--text-body);
            overflow-x: hidden;
        }
        .custom-container {
            max-width: 1280px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1.25rem;
            padding-right: 1.25rem;
        }
        .article-container {
            max-width: 896px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1.25rem;
            padding-right: 1.25rem;
        }
        .card-standard {
            background-color: var(--bg-card);
            border: 1px solid var(--border-color);
            border-radius: 1rem;
            box-shadow: var(--shadow-subtle);
            transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-standard:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-hover);
            border-color: #CBD5E1;
        }
        .nav-link {
            transition: color 0.2s ease, border-color 0.2s ease;
        }
        .nav-link.active {
            color: var(--primary);
            font-weight: 600;
            position: relative;
        }
        .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -6px;
            left: 0;
            right: 0;
            height: 2px;
            background-color: var(--primary);
            border-radius: 2px;
        }
        /* Article typography refinements */
        .article-content {
            font-size: 1.0625rem;
            line-height: 1.85;
            color: #334155;
        }
        .article-content p {
            margin-bottom: 1.5rem;
        }
        .article-content h2 {
            font-size: 1.5rem;
            font-weight: 700;
            color: #0F172A;
            margin-top: 2.5rem;
            margin-bottom: 1.25rem;
            padding-bottom: 0.5rem;
            border-bottom: 1px solid #E2E8F0;
        }
        .article-content h3 {
            font-size: 1.25rem;
            font-weight: 600;
            color: #1E293B;
            margin-top: 2rem;
            margin-bottom: 1rem;
        }
        .article-content blockquote {
            border-left: 4px solid var(--primary);
            background-color: #F1F5F9;
            padding: 1rem 1.25rem;
            margin: 1.75rem 0;
            border-radius: 0 0.5rem 0.5rem 0;
            color: #475569;
            font-style: normal;
        }
        .article-content ul {
            list-style-type: disc;
            padding-left: 1.5rem;
            margin-bottom: 1.5rem;
        }
        .article-content li {
            margin-bottom: 0.5rem;
        }
        .article-content img {
            border-radius: 0.75rem;
            margin: 2rem auto;
            max-width: 100%;
            height: auto;
            box-shadow: var(--shadow-subtle);
        }

/* roulang page: category1 */
:root {
            --primary: #0F52BA;
            --primary-hover: #0B3E8E;
            --accent: #E11D48;
            --bg-neutral: #F8FAFC;
            --bg-card: #FFFFFF;
            --text-title: #0F172A;
            --text-body: #334155;
            --text-muted: #64748B;
            --border-color: #E2E8F0;
            --shadow-subtle: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
            --shadow-hover: 0 12px 28px -4px rgba(15, 23, 42, 0.1);
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-neutral);
            color: var(--text-body);
            overflow-x: hidden;
        }
        .custom-container {
            max-width: 1280px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1.25rem;
            padding-right: 1.25rem;
        }
        .card-standard {
            background-color: var(--bg-card);
            border: 1px solid var(--border-color);
            border-radius: 1rem;
            box-shadow: var(--shadow-subtle);
            transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-standard:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-hover);
            border-color: #CBD5E1;
        }
        .nav-link {
            transition: color 0.2s ease, border-color 0.2s ease;
        }
        .nav-link.active {
            color: var(--primary);
            font-weight: 600;
            position: relative;
        }
        .nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -6px;
            left: 0;
            right: 0;
            height: 2px;
            background-color: var(--primary);
            border-radius: 2px;
        }
        .filter-tab.active {
            background-color: var(--primary);
            color: #FFFFFF;
            border-color: var(--primary);
        }