/* roulang page: index */
:root {
            --color-primary: #2563EB;
            --color-primary-dark: #1D4ED8;
            --color-primary-light: #EFF6FF;
            --color-accent: #0EA5E9;
            --color-bg: #F8FAFC;
            --color-card: #FFFFFF;
            --color-border: #E2E8F0;
            --color-text: #0F172A;
            --color-text-body: #334155;
            --color-text-muted: #64748B;
            --color-footer-bg: #1E293B;
        }
        * {
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", sans-serif;
            background: var(--color-bg);
            color: var(--color-text-body);
            line-height: 1.7;
            -webkit-font-smoothing: antialiased;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: color 0.2s;
        }
        button {
            cursor: pointer;
            font-family: inherit;
        }
        input,
        select,
        textarea {
            font-family: inherit;
            font-size: inherit;
        }
        .container {
            max-width: 1200px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1rem;
            padding-right: 1rem;
        }
        @media (min-width: 768px) {
            .container {
                padding-left: 1.5rem;
                padding-right: 1.5rem;
            }
        }
        .badge {
            display: inline-block;
            background: var(--color-primary-light);
            color: var(--color-primary);
            font-size: 0.75rem;
            font-weight: 500;
            border-radius: 9999px;
            padding: 0.25rem 0.875rem;
            line-height: 1.4;
        }
        .badge-amber {
            display: inline-block;
            background: #FEF3C7;
            color: #B45309;
            font-size: 0.75rem;
            font-weight: 500;
            border-radius: 9999px;
            padding: 0.25rem 0.875rem;
        }
        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--color-primary);
            color: #fff;
            font-weight: 500;
            font-size: 0.95rem;
            border-radius: 0.5rem;
            padding: 0.75rem 1.75rem;
            transition: background 0.2s, box-shadow 0.2s, transform 0.1s;
            border: 1px solid transparent;
        }
        .btn-primary:hover {
            background: var(--color-primary-dark);
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
        }
        .btn-primary:active {
            transform: translateY(1px);
        }
        .btn-outline {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: transparent;
            color: var(--color-primary);
            font-weight: 500;
            font-size: 0.95rem;
            border-radius: 0.5rem;
            padding: 0.75rem 1.75rem;
            border: 1px solid var(--color-primary);
            transition: background 0.2s, box-shadow 0.2s;
        }
        .btn-outline:hover {
            background: var(--color-primary-light);
        }
        .btn-lg {
            padding: 0.875rem 2rem;
            font-size: 1rem;
        }
        .nav-link {
            position: relative;
            color: var(--color-text-body);
            font-size: 0.9375rem;
            font-weight: 500;
            padding: 0.5rem 0.875rem;
            border-radius: 9999px;
            transition: background 0.2s, color 0.2s;
        }
        .nav-link:hover {
            color: var(--color-primary);
            background: rgba(37, 99, 235, 0.06);
        }
        .nav-link.active {
            background: var(--color-primary-light);
            color: var(--color-primary);
        }
        .mobile-nav-link {
            display: block;
            padding: 0.75rem 1rem;
            border-radius: 0.5rem;
            color: var(--color-text-body);
            font-weight: 500;
            font-size: 0.9375rem;
            transition: background 0.2s;
        }
        .mobile-nav-link:hover {
            background: var(--color-primary-light);
            color: var(--color-primary);
        }
        .stat-card {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            border-radius: 1rem;
            padding: 1.25rem;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
            transition: box-shadow 0.25s, transform 0.25s;
        }
        .stat-card:hover {
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
            transform: translateY(-2px);
        }
        .stat-icon {
            width: 2.5rem;
            height: 2.5rem;
            background: var(--color-primary-light);
            border-radius: 0.5rem;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.25rem;
            margin-bottom: 0.75rem;
        }
        .stat-number {
            font-size: 1.875rem;
            font-weight: 700;
            color: var(--color-primary);
            line-height: 1.2;
            font-variant-numeric: tabular-nums;
        }
        .stat-label {
            font-size: 0.8125rem;
            color: var(--color-text-muted);
            margin-top: 0.25rem;
        }
        .data-card {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            border-radius: 0.75rem;
            padding: 1.5rem;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
            transition: box-shadow 0.25s, transform 0.25s;
        }
        .data-card:hover {
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
            transform: translateY(-3px);
        }
        .data-card-icon {
            width: 2.5rem;
            height: 2.5rem;
            background: var(--color-primary-light);
            border-radius: 0.5rem;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.25rem;
        }
        .progress-bar {
            height: 0.375rem;
            background: #F1F5F9;
            border-radius: 9999px;
            overflow: hidden;
            margin-top: 0.75rem;
        }
        .progress-fill {
            height: 100%;
            background: var(--color-primary);
            border-radius: 9999px;
        }
        .service-card {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            border-radius: 0.75rem;
            overflow: hidden;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
            transition: box-shadow 0.3s, transform 0.3s;
            display: flex;
            flex-direction: column;
        }
        .service-card:hover {
            box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
            transform: translateY(-4px);
        }
        .service-badge {
            position: absolute;
            top: 0.75rem;
            left: 0.75rem;
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(4px);
            font-size: 0.75rem;
            font-weight: 600;
            padding: 0.25rem 0.75rem;
            border-radius: 9999px;
            color: var(--color-primary);
            box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
        }
        .service-badge.premium {
            background: rgba(255, 251, 235, 0.95);
            color: #B45309;
        }
        .tag {
            display: inline-block;
            background: #F1F5F9;
            color: var(--color-text-muted);
            font-size: 0.75rem;
            border-radius: 9999px;
            padding: 0.2rem 0.75rem;
            line-height: 1.4;
        }
        .compare-wrap {
            display: grid;
            grid-template-columns: 1fr;
            gap: 1.5rem;
            position: relative;
        }
        @media (min-width: 768px) {
            .compare-wrap {
                grid-template-columns: 1fr auto 1fr;
                align-items: stretch;
            }
        }
        .compare-card {
            background: #fff;
            border-radius: 0.75rem;
            padding: 1.75rem;
            border: 1px solid var(--color-border);
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
        }
        .compare-card-normal {
            background: #F8FAFC;
            border: 1px solid #E2E8F0;
            border-radius: 0.75rem;
            padding: 1.75rem;
        }
        .compare-card-premium {
            background: #F0F9FF;
            border: 1.5px solid var(--color-accent);
            border-radius: 0.75rem;
            padding: 1.75rem;
            box-shadow: 0 4px 16px rgba(14, 165, 233, 0.12);
        }
        .compare-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.6rem 0;
            border-bottom: 1px solid rgba(226, 232, 240, 0.6);
            font-size: 0.875rem;
            color: var(--color-text-body);
        }
        .compare-row:last-child {
            border-bottom: none;
        }
        .compare-label {
            color: var(--color-text-muted);
        }
        .compare-value {
            font-weight: 500;
        }
        .icon-check {
            color: #16A34A;
            font-size: 1.25rem;
        }
        .icon-x {
            color: #94A3B8;
            font-size: 1.25rem;
        }
        .compare-arrow {
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            color: var(--color-primary);
            font-weight: 700;
        }
        @media (min-width: 768px) {
            .compare-arrow {
                font-size: 2rem;
            }
        }
        .faq-item {
            background: #fff;
            border: 1px solid var(--color-border);
            border-radius: 0.75rem;
            margin-bottom: 0.75rem;
            overflow: hidden;
            transition: box-shadow 0.2s;
        }
        .faq-item:hover {
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
        }
        .faq-question {
            display: flex;
            justify-content: space-between;
            align-items: center;
            width: 100%;
            padding: 1.125rem 1.5rem;
            text-align: left;
            font-weight: 600;
            font-size: 0.9375rem;
            color: var(--color-text);
            background: transparent;
            border: none;
            transition: color 0.2s;
        }
        .faq-question.open {
            color: var(--color-primary);
        }
        .faq-icon {
            width: 1.5rem;
            height: 1.5rem;
            border-radius: 9999px;
            background: var(--color-primary-light);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1rem;
            color: var(--color-primary);
            flex-shrink: 0;
            transition: transform 0.3s;
        }
        .faq-icon.rotate {
            transform: rotate(45deg);
        }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease;
            font-size: 0.875rem;
            color: var(--color-text-body);
            line-height: 1.75;
            padding: 0 1.5rem;
            border-top: 1px solid transparent;
        }
        .faq-answer.open {
            max-height: 600px;
            padding: 0.875rem 1.5rem 1.125rem;
            border-top-color: #F1F5F9;
        }
        .form-input {
            width: 100%;
            background: #fff;
            border: 1px solid var(--color-border);
            border-radius: 0.5rem;
            padding: 0.75rem 1rem;
            font-size: 0.875rem;
            color: var(--color-text);
            outline: none;
            transition: border-color 0.2s, box-shadow 0.2s;
        }
        .form-input:focus {
            border-color: var(--color-primary);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }
        .form-label {
            display: block;
            font-size: 0.8125rem;
            font-weight: 600;
            color: var(--color-text);
            margin-bottom: 0.375rem;
        }
        .contact-icon {
            width: 2.5rem;
            height: 2.5rem;
            background: var(--color-primary-light);
            border-radius: 0.5rem;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.125rem;
            flex-shrink: 0;
        }
        .footer-link {
            color: #94A3B8;
            font-size: 0.875rem;
            transition: color 0.2s;
            display: inline-block;
            padding: 0.25rem 0;
        }
        .footer-link:hover {
            color: #fff;
        }
        .post-item {
            background: #fff;
            border: 1px solid var(--color-border);
            border-radius: 0.75rem;
            padding: 1.25rem;
            transition: box-shadow 0.25s, transform 0.25s;
        }
        .post-item:hover {
            box-shadow: 0 4px 14px rgba(0, 0, 0, 0.07);
        }
        .hero-grid-bg {
            background-image: linear-gradient(rgba(37, 99, 235, 0.06) 1px, transparent 1px),
                linear-gradient(90deg, rgba(37, 99, 235, 0.06) 1px, transparent 1px);
            background-size: 44px 44px;
        }
        @media (max-width: 768px) {
            .stat-number {
                font-size: 1.5rem;
            }
        }

/* roulang page: article */
:root {
            --color-primary: #2563EB;
            --color-primary-dark: #1D4ED8;
            --color-primary-light: #EFF6FF;
            --color-accent: #0EA5E9;
            --color-bg: #F8FAFC;
            --color-card: #FFFFFF;
            --color-border: #E2E8F0;
            --color-text: #0F172A;
            --color-text-body: #334155;
            --color-text-muted: #64748B;
            --color-footer-bg: #1E293B;
        }

        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", sans-serif;
            background: var(--color-bg);
            color: var(--color-text-body);
            line-height: 1.7;
            -webkit-font-smoothing: antialiased;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: color 0.2s;
        }

        button {
            cursor: pointer;
            font-family: inherit;
        }

        input,
        select,
        textarea {
            font-family: inherit;
            font-size: inherit;
        }

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

        @media (min-width: 768px) {
            .container {
                padding-left: 1.5rem;
                padding-right: 1.5rem;
            }
        }

        .site-header {
            position: sticky;
            top: 0;
            z-index: 50;
            background: #fff;
            border-bottom: 1px solid var(--color-border);
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
        }

        .badge {
            display: inline-block;
            background: var(--color-primary-light);
            color: var(--color-primary);
            font-size: 0.75rem;
            font-weight: 500;
            border-radius: 9999px;
            padding: 0.25rem 0.875rem;
            line-height: 1.4;
        }

        .badge-amber {
            display: inline-block;
            background: #FEF3C7;
            color: #B45309;
            font-size: 0.75rem;
            font-weight: 500;
            border-radius: 9999px;
            padding: 0.25rem 0.875rem;
        }

        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--color-primary);
            color: #fff;
            font-weight: 500;
            font-size: 0.95rem;
            border-radius: 0.5rem;
            padding: 0.75rem 1.75rem;
            transition: background 0.2s, box-shadow 0.2s, transform 0.1s;
            border: 1px solid transparent;
        }

        .btn-primary:hover {
            background: var(--color-primary-dark);
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
        }

        .btn-primary:active {
            transform: translateY(1px);
        }

        .btn-outline {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: transparent;
            color: var(--color-primary);
            font-weight: 500;
            font-size: 0.95rem;
            border-radius: 0.5rem;
            padding: 0.75rem 1.75rem;
            border: 1px solid var(--color-primary);
            transition: background 0.2s;
        }

        .btn-outline:hover {
            background: var(--color-primary-light);
        }

        .btn-lg {
            padding: 0.875rem 2rem;
            font-size: 1rem;
        }

        .nav-link {
            position: relative;
            color: var(--color-text-body);
            font-size: 0.9375rem;
            font-weight: 500;
            padding: 0.5rem 0.875rem;
            border-radius: 9999px;
            transition: background 0.2s, color 0.2s;
        }

        .nav-link:hover {
            color: var(--color-primary);
            background: rgba(37, 99, 235, 0.06);
        }

        .nav-link.active {
            background: var(--color-primary-light);
            color: var(--color-primary);
        }

        .mobile-nav-link {
            display: block;
            padding: 0.75rem 1rem;
            border-radius: 0.5rem;
            color: var(--color-text-body);
            font-weight: 500;
            font-size: 0.9375rem;
            transition: background 0.2s;
        }

        .mobile-nav-link:hover {
            background: var(--color-primary-light);
            color: var(--color-primary);
        }

        .mobile-menu {
            background: #fff;
            border-radius: 0.75rem;
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
            border: 1px solid var(--color-border);
            padding: 0.5rem;
        }

        .tag {
            display: inline-block;
            background: #F1F5F9;
            color: #475569;
            font-size: 0.75rem;
            padding: 0.25rem 0.75rem;
            border-radius: 9999px;
            line-height: 1.4;
        }
        
        .tag:hover {
            background: var(--color-primary-light);
            color: var(--color-primary);
        }

        .footer-link {
            color: #94A3B8;
            font-size: 0.875rem;
            transition: color 0.2s;
        }

        .footer-link:hover {
            color: #fff;
        }

        /* Breadcrumb */
        .breadcrumb {
            font-size: 0.875rem;
            color: var(--color-text-muted);
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 0.5rem;
        }

        .breadcrumb a {
            color: var(--color-text-muted);
            transition: color 0.2s;
        }

        .breadcrumb a:hover {
            color: var(--color-primary);
        }

        .breadcrumb .sep {
            color: #CBD5E1;
            font-size: 0.75rem;
        }

        .breadcrumb .cur {
            color: var(--color-text-body);
            max-width: 240px;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }

        /* Article header */
        .article-header {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            border-radius: 1rem;
            padding: 2rem 2rem 0;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
        }

        @media (max-width: 640px) {
            .article-header {
                padding: 1.5rem 1.5rem 0;
            }
        }

        .article-meta {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 0.875rem;
            font-size: 0.8125rem;
            color: var(--color-text-muted);
        }

        .article-cover {
            margin-top: 1.5rem;
            border-radius: 0.75rem;
            overflow: hidden;
        }

        .article-cover img {
            width: 100%;
            height: auto;
            aspect-ratio: 16 / 7;
            object-fit: cover;
        }

        /* Article body */
        .article-body {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            border-top: none;
            border-radius: 0 0 1rem 1rem;
            padding: 2rem;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
        }

        @media (max-width: 640px) {
            .article-body {
                padding: 1.5rem;
            }
        }

        .article-content {
            font-size: 1.0625rem;
            line-height: 1.85;
            color: var(--color-text-body);
        }

        .article-content h2 {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--color-text);
            margin-top: 2.25rem;
            margin-bottom: 1rem;
            line-height: 1.4;
        }

        .article-content h3 {
            font-size: 1.25rem;
            font-weight: 600;
            color: var(--color-text);
            margin-top: 1.75rem;
            margin-bottom: 0.75rem;
        }

        .article-content p {
            margin-bottom: 1.5rem;
        }

        .article-content a {
            color: var(--color-primary);
            text-decoration: underline;
            text-underline-offset: 3px;
        }

        .article-content a:hover {
            color: var(--color-primary-dark);
        }

        .article-content blockquote {
            border-left: 4px solid var(--color-accent);
            background: var(--color-primary-light);
            padding: 1rem 1.25rem;
            border-radius: 0 0.5rem 0.5rem 0;
            margin: 1.5rem 0;
            color: var(--color-text-body);
        }

        .article-content img {
            border-radius: 0.75rem;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
            margin: 1.5rem auto;
        }

        .article-content ul,
        .article-content ol {
            margin: 1rem 0 1.5rem;
            padding-left: 1.5rem;
        }

        .article-content ul {
            list-style: disc;
        }

        .article-content ol {
            list-style: decimal;
        }

        .article-content ul li,
        .article-content ol li {
            margin-bottom: 0.5rem;
        }

        .article-content hr {
            margin: 2rem 0;
            border: none;
            border-top: 1px solid var(--color-border);
        }

        /* Related cards */
        .related-card {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            border-radius: 0.75rem;
            overflow: hidden;
            box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
            transition: box-shadow 0.3s, transform 0.3s;
        }

        .related-card:hover {
            box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
            transform: translateY(-4px);
        }

        .related-card img {
            width: 100%;
            height: 10rem;
            object-fit: cover;
        }

        /* CTA band */
        .cta-band {
            background: linear-gradient(135deg, #EFF6FF 0%, #F0F9FF 100%);
            border: 1px solid #BFDBFE;
            border-radius: 1rem;
            padding: 2rem;
        }

        @media (max-width: 640px) {
            .cta-band {
                padding: 1.5rem;
            }
        }

        .line-clamp-2 {
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }

        /* focus accessibility */
        a:focus-visible,
        button:focus-visible {
            outline: 2px solid var(--color-primary);
            outline-offset: 2px;
            border-radius: 0.375rem;
        }