/* roulang page: index */
:root {
            --primary: #2563EB;
            --primary-dark: #1D4ED8;
            --primary-light: #93C5FD;
            --primary-pale: #DBEAFE;
            --accent: #F59E0B;
            --bg: #F8FAFC;
            --bg-alt: #F1F5F9;
            --card-bg: #FFFFFF;
            --card-border: #E2E8F0;
            --text-main: #0F172A;
            --text-secondary: #475569;
            --text-muted: #94A3B8;
            --radius-lg: 16px;
            --radius-md: 12px;
            --radius-sm: 8px;
            --radius-full: 999px;
            --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05), 0 4px 12px rgba(15, 23, 42, 0.05);
            --shadow-hover: 0 12px 24px rgba(15, 23, 42, 0.09);
            --font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
            --transition: all 0.25s ease;
        }
        *, *::before, *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }
        body {
            font-family: var(--font-family);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text-main);
            background-color: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        a {
            color: inherit;
            text-decoration: none;
            transition: var(--transition);
        }
        a:hover {
            color: var(--primary);
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button, input, select, textarea {
            font-family: inherit;
            font-size: inherit;
            line-height: inherit;
        }
        button {
            cursor: pointer;
            border: none;
            background: none;
        }
        button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
            outline: 2px solid var(--primary-light);
            outline-offset: 2px;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding-left: 24px;
            padding-right: 24px;
        }
        @media (max-width: 768px) {
            .container {
                padding-left: 16px;
                padding-right: 16px;
            }
        }

        /* Header / Navigation */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 100;
            background: rgba(255, 255, 255, 0.96);
            border-bottom: 1px solid rgba(226, 232, 240, 0.8);
            backdrop-filter: blur(12px);
            box-shadow: 0 1px 4px rgba(15, 23, 42, 0.04);
        }
        .nav-wrapper {
            display: flex;
            align-items: center;
            justify-content: space-between;
            min-height: 68px;
            gap: 16px;
        }
        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-shrink: 0;
        }
        .nav-logo-icon {
            width: 36px;
            height: 36px;
            border-radius: var(--radius-sm);
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            display: flex;
            align-items: center;
            justify-content: center;
            color: #fff;
            font-size: 16px;
            font-weight: 700;
        }
        .nav-logo-text {
            font-size: 18px;
            font-weight: 700;
            color: var(--text-main);
            letter-spacing: 0.02em;
            white-space: nowrap;
        }
        .nav-logo-text .nav-logo-sub {
            display: block;
            font-size: 11px;
            font-weight: 500;
            color: var(--text-muted);
            letter-spacing: 0.06em;
        }
        .nav-links {
            display: flex;
            align-items: center;
            gap: 28px;
            list-style: none;
        }
        .nav-links a {
            font-size: 15px;
            font-weight: 500;
            color: var(--text-secondary);
            padding: 6px 2px;
            position: relative;
            white-space: nowrap;
        }
        .nav-links a:hover, .nav-links a.active {
            color: var(--primary);
        }
        .nav-links a.active::after {
            content: '';
            position: absolute;
            left: 0;
            right: 0;
            bottom: -2px;
            height: 2px;
            background: var(--primary);
            border-radius: 2px;
        }
        .nav-actions {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-shrink: 0;
        }
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 6px;
            padding: 10px 20px;
            border-radius: var(--radius-sm);
            font-size: 14px;
            font-weight: 600;
            transition: var(--transition);
            white-space: nowrap;
            border: 1px solid transparent;
            cursor: pointer;
        }
        .btn-primary {
            background: var(--primary);
            color: #fff;
        }
        .btn-primary:hover {
            background: var(--primary-dark);
            color: #fff;
        }
        .btn-primary:active {
            box-shadow: inset 0 2px 4px rgba(0,0,0,0.15);
        }
        .btn-outline {
            background: #fff;
            color: var(--primary);
            border-color: var(--primary);
        }
        .btn-outline:hover {
            background: var(--primary-pale);
            color: var(--primary-dark);
        }
        .nav-toggle {
            display: none;
            width: 44px;
            height: 44px;
            align-items: center;
            justify-content: center;
            font-size: 22px;
            color: var(--text-main);
            border-radius: var(--radius-sm);
            border: 1px solid var(--card-border);
            background: #fff;
        }
        @media (max-width: 1024px) {
            .nav-links {
                display: none;
                position: absolute;
                top: 68px;
                left: 0;
                right: 0;
                background: #fff;
                flex-direction: column;
                padding: 20px 24px;
                gap: 16px;
                border-bottom: 1px solid var(--card-border);
                box-shadow: 0 8px 16px rgba(15,23,42,0.08);
                z-index: 99;
            }
            .nav-links.open {
                display: flex;
            }
            .nav-toggle {
                display: flex;
            }
            .nav-actions {
                display: none;
            }
            .nav-actions.open {
                display: flex;
                position: absolute;
                top: calc(68px + 150px);
                left: 0;
                right: 0;
                padding: 0 24px 20px;
                background: #fff;
                gap: 12px;
                border-bottom: 1px solid var(--card-border);
                z-index: 99;
            }
        }
        @media (max-width: 640px) {
            .nav-logo-text {
                font-size: 15px;
            }
            .nav-logo-icon {
                width: 30px;
                height: 30px;
                font-size: 14px;
            }
        }

        /* Hero */
    .hero {
        background: var(--bg-alt);
        border-bottom: 1px solid var(--card-border);
        padding: 80px 0 64px;
    }
    @media (max-width: 768px) {
        .hero {
            padding: 48px 0 40px;
        }
    }
    .hero-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 48px;
        align-items: center;
    }
    @media (max-width: 1024px) {
        .hero-grid {
            grid-template-columns: 1fr;
            gap: 32px;
        }
    }
    .hero-content h1 {
        font-size: 40px;
        line-height: 1.25;
        font-weight: 700;
        color: var(--text-main);
        letter-spacing: 0.01em;
        margin-bottom: 20px;
    }
    @media (max-width: 768px) {
        .hero-content h1 {
            font-size: 28px;
            line-height: 1.3;
        }
    }
    .hero-subtitle {
        font-size: 16px;
        line-height: 1.8;
        color: var(--text-secondary);
        max-width: 520px;
        margin-bottom: 28px;
    }
    .hero-cta {
        display: flex;
        gap: 12px;
        flex-wrap: wrap;
    }
    .hero-visual {
        position: relative;
        border-radius: var(--radius-lg);
        overflow: hidden;
        box-shadow: var(--shadow-sm);
        min-height: 320px;
    }
    .hero-visual img {
        width: 100%;
        height: 100%;
        object-fit: cover;
        position: absolute;
        inset: 0;
    }
    .hero-visual::after {
        content: '';
        position: absolute;
        inset: 0;
        background: linear-gradient(125deg, rgba(37, 99, 235, 0.15) 0%, rgba(37, 99, 235, 0.02) 50%, rgba(15, 23, 42, 0.1) 100%);
        pointer-events: none;
    }
    .hero-metrics {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 16px;
        margin-top: 40px;
    }
    @media (max-width: 1024px) {
        .hero-metrics {
            grid-template-columns: repeat(2, 1fr);
        }
    }
    @media (max-width: 520px) {
        .hero-metrics {
            grid-template-columns: 1fr 1fr;
            gap: 10px;
        }
    }
    .metric-card {
        background: var(--card-bg);
        border: 1px solid var(--primary-pale);
        border-radius: var(--radius-md);
        padding: 18px 16px;
        box-shadow: var(--shadow-sm);
        transition: var(--transition);
    }
    .metric-card:hover {
        box-shadow: var(--shadow-hover);
        transform: translateY(-3px);
    }
    .metric-value {
        font-size: 28px;
        font-weight: 700;
        color: var(--primary);
        line-height: 1.2;
        margin-bottom: 4px;
    }
    .metric-label {
        font-size: 12px;
        color: var(--text-muted);
        font-weight: 500;
        letter-spacing: 0.04em;
    }

    /* Section common */
    .section {
        padding: 80px 0;
    }
    .section-alt {
        background: #fff;
    }
    .section-bg {
        background: var(--bg-alt);
    }
    @media (max-width: 768px) {
        .section {
            padding: 40px 0;
        }
    }
    .section-head {
        margin-bottom: 40px;
    }
    .section-tag {
        display: inline-block;
        font-size: 12px;
        font-weight: 600;
        color: var(--primary);
        background: var(--primary-pale);
        padding: 4px 12px;
        border-radius: var(--radius-full);
        letter-spacing: 0.06em;
        margin-bottom: 10px;
    }
    .section-title {
        font-size: 32px;
        line-height: 1.3;
        font-weight: 700;
        color: var(--text-main);
        margin-bottom: 10px;
    }
    @media (max-width: 768px) {
        .section-title {
            font-size: 24px;
        }
    }
    .section-desc {
        font-size: 16px;
        line-height: 1.8;
        color: var(--text-secondary);
        max-width: 760px;
    }

    /* Grids */
    .grid-3 {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 24px;
    }
    @media (max-width: 1024px) {
        .grid-3 {
            grid-template-columns: repeat(2, 1fr);
        }
    }
    @media (max-width: 640px) {
        .grid-3 {
            grid-template-columns: 1fr;
        }
    }
    .grid-4 {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 24px;
    }
    @media (max-width: 1024px) {
        .grid-4 {
            grid-template-columns: repeat(2, 1fr);
        }
    }
    @media (max-width: 640px) {
        .grid-4 {
            grid-template-columns: 1fr;
        }
    }

    /* Cards */
    .card {
        background: var(--card-bg);
        border: 1px solid var(--card-border);
        border-radius: var(--radius-lg);
        padding: 24px;
        box-shadow: var(--shadow-sm);
        transition: var(--transition);
    }
    .card:hover {
        box-shadow: var(--shadow-hover);
        transform: translateY(-4px);
    }
    .card-icon {
        width: 48px;
        height: 48px;
        border-radius: var(--radius-md);
        background: var(--primary-pale);
        color: var(--primary);
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 20px;
        margin-bottom: 14px;
    }
    .card-title {
        font-size: 18px;
        font-weight: 700;
        color: var(--text-main);
        margin-bottom: 8px;
    }
    .card-text {
        font-size: 14px;
        color: var(--text-secondary);
        line-height: 1.7;
    }
    .card-link {
        display: inline-flex;
        align-items: center;
        gap: 4px;
        font-size: 14px;
        font-weight: 600;
        color: var(--primary);
        margin-top: 12px;
    }
    .card-link:hover {
        color: var(--primary-dark);
    }
    .badge {
        display: inline-block;
        font-size: 12px;
        font-weight: 500;
        padding: 3px 10px;
        border-radius: var(--radius-full);
        background: var(--primary-pale);
        color: var(--primary);
        letter-spacing: 0.04em;
    }
    .badge-amber {
        background: #FEF3C7;
        color: #B45309;
    }
    .badge-green {
        background: #D1FAE5;
        color: #047857;
    }

    /* List cards */
    .list-card {
        display: flex;
        gap: 16px;
        background: var(--card-bg);
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        padding: 14px;
        box-shadow: var(--shadow-sm);
        transition: var(--transition);
        align-items: center;
    }
    .list-card:hover {
        box-shadow: var(--shadow-hover);
        transform: translateY(-2px);
    }
    .list-card-img {
        width: 160px;
        height: 100px;
        border-radius: var(--radius-sm);
        overflow: hidden;
        flex-shrink: 0;
    }
    .list-card-img img {
        width: 100%;
        height: 100%;
        object-fit: cover;
    }
    @media (max-width: 640px) {
        .list-card {
            flex-direction: column;
            align-items: stretch;
        }
        .list-card-img {
            width: 100%;
            height: 160px;
        }
    }
    .list-card-body {
        flex: 1;
        min-width: 0;
    }
    .list-card-title {
        font-size: 16px;
        font-weight: 700;
        color: var(--text-main);
        margin-bottom: 4px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }
    .list-card-desc {
        font-size: 14px;
        color: var(--text-secondary);
        margin-bottom: 6px;
        display: -webkit-box;
        -webkit-line-clamp: 2;
        -webkit-box-orient: vertical;
        overflow: hidden;
    }
    .list-card-meta {
        display: flex;
        gap: 10px;
        font-size: 12px;
        color: var(--text-muted);
    }

    /* Compare section */
    .compare-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 24px;
    }
    @media (max-width: 768px) {
        .compare-grid {
            grid-template-columns: 1fr;
        }
    }
    .compare-card {
        background: #fff;
        border: 1px solid var(--card-border);
        border-radius: var(--radius-lg);
        padding: 28px;
        box-shadow: var(--shadow-sm);
    }
    .compare-card:first-child {
        border-top: 3px solid var(--primary);
    }
    .compare-card.highlight {
        border-top: 3px solid var(--accent);
        background: #FFFBEB;
    }
    .compare-title {
        font-size: 20px;
        font-weight: 700;
        margin-bottom: 16px;
    }
    .compare-item {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 10px 0;
        border-bottom: 1px solid #F1F5F9;
        font-size: 14px;
    }
    .compare-item:last-child {
        border-bottom: none;
    }
    .compare-label {
        color: var(--text-secondary);
    }
    .compare-value {
        font-weight: 600;
        color: var(--text-main);
    }

    /* Timeline */
    .timeline {
        display: flex;
        flex-direction: column;
        gap: 0;
        position: relative;
        padding-left: 28px;
    }
    .timeline::before {
        content: '';
        position: absolute;
        left: 8px;
        top: 4px;
        bottom: 4px;
        width: 2px;
        background: var(--primary-light);
        border-radius: 2px;
    }
    .timeline-item {
        position: relative;
        padding-bottom: 32px;
    }
    .timeline-item:last-child {
        padding-bottom: 0;
    }
    .timeline-item::before {
        content: '';
        position: absolute;
        left: -24px;
        top: 4px;
        width: 12px;
        height: 12px;
        border-radius: 50%;
        background: var(--primary);
        border: 2px solid #fff;
        box-shadow: 0 0 0 2px var(--primary-light);
    }
    .timeline-year {
        font-size: 13px;
        font-weight: 700;
        color: var(--primary);
        margin-bottom: 4px;
    }
    .timeline-title {
        font-size: 16px;
        font-weight: 700;
        margin-bottom: 4px;
    }
    .timeline-desc {
        font-size: 14px;
        color: var(--text-secondary);
    }

    /* FAQ */
    .faq-list {
        max-width: 820px;
        margin: 0 auto;
        display: flex;
        flex-direction: column;
        gap: 12px;
    }
    .faq-item {
        background: #fff;
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        overflow: hidden;
        transition: var(--transition);
    }
    .faq-item:hover {
        border-color: var(--primary-light);
    }
    .faq-question {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 16px;
        padding: 16px 20px;
        cursor: pointer;
        font-size: 16px;
        font-weight: 700;
        color: var(--text-main);
        background: #fff;
        border: none;
        width: 100%;
        text-align: left;
    }
    .faq-question:hover {
        background: var(--primary-pale);
    }
    .faq-question .faq-icon {
        flex-shrink: 0;
        width: 24px;
        height: 24px;
        display: flex;
        align-items: center;
        justify-content: center;
        border-radius: 50%;
        background: var(--primary-pale);
        color: var(--primary);
        font-size: 14px;
        transition: var(--transition);
    }
    .faq-item.open .faq-icon {
        transform: rotate(45deg);
    }
    .faq-answer {
        display: none;
        padding: 0 20px 16px;
        font-size: 14px;
        color: var(--text-secondary);
        line-height: 1.8;
    }
    .faq-item.open .faq-answer {
        display: block;
    }

    /* Form */
    .form-card {
        background: #fff;
        border: 1px solid var(--primary-light);
        border-radius: var(--radius-lg);
        padding: 32px;
        box-shadow: var(--shadow-sm);
        max-width: 560px;
        margin: 0 auto;
    }
    .form-group {
        margin-bottom: 18px;
    }
    .form-label {
        display: block;
        font-size: 14px;
        font-weight: 500;
        color: var(--text-secondary);
        margin-bottom: 6px;
    }
    .form-input, .form-select, .form-textarea {
        width: 100%;
        height: 44px;
        padding: 10px 14px;
        border: 1px solid #CBD5E1;
        border-radius: var(--radius-sm);
        font-size: 15px;
        color: var(--text-main);
        background: #fff;
        transition: var(--transition);
    }
    .form-textarea {
        height: auto;
        min-height: 100px;
        resize: vertical;
    }
    .form-input:focus, .form-select:focus, .form-textarea:focus {
        border-color: var(--primary);
        box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
        outline: none;
    }
    .form-privacy {
        font-size: 12px;
        color: var(--text-muted);
        margin-top: 10px;
    }

    /* Footer */
    .site-footer {
        background: #1E293B;
        color: #E2E8F0;
        padding: 56px 0 28px;
    }
    .footer-grid {
        display: grid;
        grid-template-columns: 2fr 1fr 1fr 1fr;
        gap: 32px;
        margin-bottom: 40px;
    }
    @media (max-width: 768px) {
        .footer-grid {
            grid-template-columns: 1fr 1fr;
        }
    }
    @media (max-width: 520px) {
        .footer-grid {
            grid-template-columns: 1fr;
        }
    }
    .footer-brand {
        font-size: 20px;
        font-weight: 700;
        color: #fff;
        margin-bottom: 10px;
    }
    .footer-desc {
        font-size: 14px;
        color: #94A3B8;
        line-height: 1.7;
        max-width: 320px;
    }
    .footer-col-title {
        font-size: 15px;
        font-weight: 600;
        color: #fff;
        margin-bottom: 14px;
    }
    .footer-col ul {
        list-style: none;
        display: flex;
        flex-direction: column;
        gap: 10px;
    }
    .footer-col a {
        color: #93C5FD;
        font-size: 14px;
        transition: var(--transition);
    }
    .footer-col a:hover {
        color: #DBEAFE;
        text-decoration: underline;
    }
    .footer-bottom {
        border-top: 1px solid rgba(226, 232, 240, 0.2);
        padding-top: 20px;
        font-size: 13px;
        color: #94A3B8;
        display: flex;
        justify-content: space-between;
        flex-wrap: wrap;
        gap: 10px;
    }

    /* Chart bars */
    .chart-bars {
        display: flex;
        align-items: flex-end;
        gap: 16px;
        height: 180px;
        padding: 20px;
        background: #fff;
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        box-shadow: var(--shadow-sm);
    }
    .chart-bar {
        flex: 1;
        background: var(--primary);
        border-radius: 6px 6px 0 0;
        min-height: 20px;
        position: relative;
        transition: var(--transition);
    }
    .chart-bar:hover {
        background: var(--primary-dark);
    }
    .chart-bar-label {
        position: absolute;
        bottom: -24px;
        left: 50%;
        transform: translateX(-50%);
        font-size: 12px;
        color: var(--text-muted);
        white-space: nowrap;
    }

    /* Capsule tags */
    .capsule-group {
        display: flex;
        flex-wrap: wrap;
        gap: 12px;
    }
    .capsule {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        padding: 10px 20px;
        border-radius: var(--radius-full);
        background: #fff;
        border: 1px solid var(--card-border);
        font-size: 14px;
        font-weight: 500;
        color: var(--text-secondary);
        transition: var(--transition);
    }
    .capsule:hover {
        border-color: var(--primary);
        color: var(--primary);
        background: var(--primary-pale);
    }

    /* Region cards */
    .region-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 16px;
    }
    @media (max-width: 1024px) {
        .region-grid {
            grid-template-columns: repeat(2, 1fr);
        }
    }
    @media (max-width: 520px) {
        .region-grid {
            grid-template-columns: 1fr;
        }
    }
    .region-card {
        border-radius: var(--radius-md);
        overflow: hidden;
        border: 1px solid var(--card-border);
        background: #fff;
        box-shadow: var(--shadow-sm);
        transition: var(--transition);
        display: block;
    }
    .region-card:hover {
        box-shadow: var(--shadow-hover);
        transform: translateY(-4px);
    }
    .region-card img {
        width: 100%;
        height: 120px;
        object-fit: cover;
    }
    .region-card-body {
        padding: 14px 16px;
    }
    .region-card-title {
        font-size: 16px;
        font-weight: 700;
        margin-bottom: 4px;
    }
    .region-card-text {
        font-size: 13px;
        color: var(--text-secondary);
    }

    /* Notice cards */
    .notice-card {
        background: #FFFBEB;
        border: 1px solid #FDE68A;
        border-radius: var(--radius-md);
        padding: 20px 24px;
        display: flex;
        gap: 14px;
        align-items: flex-start;
    }
    .notice-icon {
        width: 36px;
        height: 36px;
        border-radius: 50%;
        background: #FEF3C7;
        color: #B45309;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 16px;
        flex-shrink: 0;
    }
    .notice-content {
        font-size: 14px;
        color: #92400E;
        line-height: 1.7;
    }

    /* Guarantee cards */
    .guarantee-card {
        background: var(--card-bg);
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        padding: 22px;
        text-align: left;
        transition: var(--transition);
    }
    .guarantee-card:hover {
        border-color: var(--primary-light);
        box-shadow: var(--shadow-sm);
    }
    .guarantee-icon {
        width: 44px;
        height: 44px;
        border-radius: var(--radius-md);
        background: var(--primary-pale);
        color: var(--primary);
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 18px;
        margin-bottom: 12px;
    }
    .guarantee-title {
        font-size: 16px;
        font-weight: 700;
        margin-bottom: 6px;
    }
    .guarantee-text {
        font-size: 14px;
        color: var(--text-secondary);
    }

    /* Quick answer */
    .qa-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }
    @media (max-width: 768px) {
        .qa-grid {
            grid-template-columns: 1fr;
        }
    }
    .qa-card {
        background: var(--card-bg);
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        padding: 20px;
        box-shadow: var(--shadow-sm);
    }
    .qa-question {
        font-size: 15px;
        font-weight: 700;
        color: var(--text-main);
        margin-bottom: 6px;
    }
    .qa-answer {
        font-size: 14px;
        color: var(--text-secondary);
        line-height: 1.7;
    }

    .hidden {
        display: none;
    }

/* roulang page: category1 */
:root {
        --primary: #2563EB;
        --primary-dark: #1D4ED8;
        --primary-light: #93C5FD;
        --primary-pale: #DBEAFE;
        --accent: #F59E0B;
        --bg: #F8FAFC;
        --bg-alt: #F1F5F9;
        --card-bg: #FFFFFF;
        --card-border: #E2E8F0;
        --text-main: #0F172A;
        --text-secondary: #475569;
        --text-muted: #94A3B8;
        --radius-lg: 16px;
        --radius-md: 12px;
        --radius-sm: 8px;
        --radius-full: 999px;
        --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05), 0 4px 12px rgba(15, 23, 42, 0.05);
        --shadow-hover: 0 12px 24px rgba(15, 23, 42, 0.09);
        --font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
        --transition: all 0.25s ease;
    }
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }
    html {
        scroll-behavior: smooth;
        -webkit-text-size-adjust: 100%;
    }
    body {
        font-family: var(--font-family);
        font-size: 16px;
        line-height: 1.7;
        color: var(--text-main);
        background-color: var(--bg);
        -webkit-font-smoothing: antialiased;
        -moz-osx-font-smoothing: grayscale;
    }
    a {
        color: inherit;
        text-decoration: none;
        transition: var(--transition);
    }
    a:hover {
        color: var(--primary);
    }
    img {
        max-width: 100%;
        height: auto;
        display: block;
    }
    button, input, select, textarea {
        font-family: inherit;
        font-size: inherit;
        line-height: inherit;
    }
    button {
        cursor: pointer;
        border: none;
        background: none;
    }
    button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
        outline: 2px solid var(--primary-light);
        outline-offset: 2px;
    }
    .container {
        max-width: 1200px;
        margin: 0 auto;
        padding-left: 24px;
        padding-right: 24px;
    }
    @media (max-width: 640px) {
        .container {
            padding-left: 16px;
            padding-right: 16px;
        }
    }

    /* ===== Header / Navigation ===== */
    .site-header {
        position: sticky;
        top: 0;
        z-index: 100;
        background: rgba(255, 255, 255, 0.96);
        border-bottom: 1px solid rgba(226, 232, 240, 0.8);
        backdrop-filter: blur(12px);
        box-shadow: 0 1px 4px rgba(15, 23, 42, 0.04);
    }
    .nav-wrapper {
        display: flex;
        align-items: center;
        justify-content: space-between;
        min-height: 68px;
        gap: 16px;
    }
    .nav-logo {
        display: flex;
        align-items: center;
        gap: 10px;
        flex-shrink: 0;
    }
    .nav-logo-icon {
        width: 36px;
        height: 36px;
        border-radius: var(--radius-sm);
        background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
        display: flex;
        align-items: center;
        justify-content: center;
        color: #fff;
        font-size: 16px;
        font-weight: 700;
    }
    .nav-logo-text {
        font-size: 18px;
        font-weight: 700;
        color: var(--text-main);
        letter-spacing: 0.02em;
        white-space: nowrap;
    }
    .nav-logo-text .nav-logo-sub {
        display: block;
        font-size: 11px;
        font-weight: 500;
        color: var(--text-muted);
        letter-spacing: 0.06em;
    }
    .nav-links {
        display: flex;
        align-items: center;
        gap: 28px;
        list-style: none;
    }
    .nav-links a {
        font-size: 15px;
        font-weight: 500;
        color: var(--text-secondary);
        padding: 6px 2px;
        position: relative;
        white-space: nowrap;
    }
    .nav-links a:hover, .nav-links a.active {
        color: var(--primary);
    }
    .nav-links a.active::after {
        content: '';
        position: absolute;
        left: 0;
        right: 0;
        bottom: -2px;
        height: 2px;
        background: var(--primary);
        border-radius: 2px;
    }
    .nav-actions {
        display: flex;
        align-items: center;
        gap: 10px;
        flex-shrink: 0;
    }
    .btn {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        gap: 6px;
        padding: 10px 20px;
        border-radius: var(--radius-sm);
        font-size: 14px;
        font-weight: 600;
        transition: var(--transition);
        white-space: nowrap;
        border: 1px solid transparent;
        cursor: pointer;
    }
    .btn-primary {
        background: var(--primary);
        color: #fff;
    }
    .btn-primary:hover {
        background: var(--primary-dark);
        color: #fff;
    }
    .btn-primary:active {
        box-shadow: inset 0 2px 4px rgba(0,0,0,0.15);
    }
    .btn-outline {
        background: #fff;
        color: var(--primary);
        border-color: var(--primary);
    }
    .btn-outline:hover {
        background: var(--primary-pale);
        color: var(--primary-dark);
    }
    .nav-toggle {
        display: none;
        width: 44px;
        height: 44px;
        align-items: center;
        justify-content: center;
        font-size: 22px;
        color: var(--text-main);
        border-radius: var(--radius-sm);
        border: 1px solid var(--card-border);
        background: #fff;
    }
    @media (max-width: 1024px) {
        .nav-links {
            display: none;
            position: absolute;
            top: 68px;
            left: 0;
            right: 0;
            background: #fff;
            flex-direction: column;
            gap: 0;
            padding: 12px 24px 20px;
            border-bottom: 1px solid var(--card-border);
            box-shadow: 0 12px 24px rgba(15,23,42,0.08);
            z-index: 99;
        }
        .nav-links.open {
            display: flex;
        }
        .nav-links li {
            width: 100%;
        }
        .nav-links a {
            display: block;
            padding: 12px 0;
            font-size: 16px;
            border-bottom: 1px solid var(--bg-alt);
        }
        .nav-links a.active::after {
            display: none;
        }
        .nav-links a.active {
            color: var(--primary);
            background: var(--primary-pale);
            padding-left: 12px;
            border-radius: var(--radius-sm);
        }
        .nav-toggle {
            display: flex;
        }
    }
    @media (max-width: 768px) {
        .nav-actions {
            display: none;
        }
    }

    /* ===== Section common ===== */
    .section {
        padding: 64px 0;
    }
    .section-alt {
        background: var(--bg-alt);
    }
    .section-white {
        background: #fff;
    }
    .section-title {
        font-size: 28px;
        font-weight: 700;
        line-height: 1.3;
        color: var(--text-main);
        margin-bottom: 8px;
    }
    .section-subtitle {
        font-size: 15px;
        color: var(--text-secondary);
        line-height: 1.7;
        max-width: 720px;
    }
    @media (min-width: 768px) {
        .section-title {
            font-size: 32px;
        }
    }

    /* ===== Breadcrumb ===== */
    .breadcrumb {
        display: flex;
        align-items: center;
        flex-wrap: wrap;
        gap: 6px;
        font-size: 13px;
        color: var(--text-muted);
        margin-bottom: 12px;
    }
    .breadcrumb a {
        color: var(--text-secondary);
    }
    .breadcrumb a:hover {
        color: var(--primary);
    }
    .breadcrumb .sep {
        color: var(--text-muted);
        font-size: 11px;
    }
    .breadcrumb .current {
        color: var(--primary);
        font-weight: 500;
    }

    /* ===== Category H1 area ===== */
    .category-hero {
        background: var(--bg-alt);
        border-bottom: 1px solid var(--card-border);
        padding: 48px 0 40px;
    }
    .category-hero h1 {
        font-size: 28px;
        font-weight: 700;
        line-height: 1.3;
        color: var(--text-main);
        margin-bottom: 12px;
    }
    .category-hero p {
        font-size: 15px;
        color: var(--text-secondary);
        line-height: 1.7;
        max-width: 720px;
    }
    @media (min-width: 768px) {
        .category-hero h1 {
            font-size: 32px;
        }
    }

    /* ===== Filter toolbar ===== */
    .filter-toolbar {
        display: flex;
        align-items: center;
        flex-wrap: wrap;
        gap: 8px;
        padding: 16px 0;
        border-bottom: 1px solid var(--card-border);
    }
    .filter-label {
        font-size: 13px;
        color: var(--text-muted);
        font-weight: 500;
        margin-right: 4px;
    }
    .filter-btn {
        padding: 7px 16px;
        border-radius: var(--radius-full);
        font-size: 13px;
        font-weight: 500;
        color: var(--text-secondary);
        background: #fff;
        border: 1px solid var(--card-border);
        transition: var(--transition);
        white-space: nowrap;
    }
    .filter-btn:hover {
        border-color: var(--primary-light);
        color: var(--primary);
        background: var(--primary-pale);
    }
    .filter-btn.active {
        background: var(--primary);
        color: #fff;
        border-color: var(--primary);
    }

    /* ===== List card ===== */
    .list-card {
        display: flex;
        gap: 16px;
        padding: 16px;
        background: #fff;
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        margin-bottom: 16px;
        transition: var(--transition);
    }
    .list-card:hover {
        box-shadow: var(--shadow-hover);
        transform: translateY(-2px);
    }
    .list-card-img {
        width: 160px;
        min-width: 160px;
        height: 100px;
        border-radius: var(--radius-sm);
        overflow: hidden;
        background: var(--bg-alt);
        flex-shrink: 0;
    }
    .list-card-img img {
        width: 100%;
        height: 100%;
        object-fit: cover;
    }
    .list-card-body {
        flex: 1;
        min-width: 0;
        display: flex;
        flex-direction: column;
        justify-content: space-between;
    }
    .list-card-title {
        font-size: 16px;
        font-weight: 600;
        color: var(--text-main);
        line-height: 1.4;
        margin-bottom: 6px;
    }
    .list-card-title:hover {
        color: var(--primary);
    }
    .list-card-desc {
        font-size: 13px;
        color: var(--text-secondary);
        line-height: 1.6;
        margin-bottom: 8px;
        display: -webkit-box;
        -webkit-line-clamp: 2;
        -webkit-box-orient: vertical;
        overflow: hidden;
    }
    .list-card-meta {
        display: flex;
        align-items: center;
        flex-wrap: wrap;
        gap: 6px;
        font-size: 12px;
        color: var(--text-muted);
    }
    .list-card-meta .badge {
        padding: 3px 10px;
        border-radius: var(--radius-full);
        font-size: 11px;
        font-weight: 500;
        background: var(--primary-pale);
        color: var(--primary-dark);
        white-space: nowrap;
    }
    .list-card-meta .badge-accent {
        background: #FEF3C7;
        color: #92400E;
    }
    .list-card-meta .badge-green {
        background: #D1FAE5;
        color: #065F46;
    }
    .list-card-date {
        margin-left: auto;
        white-space: nowrap;
    }
    @media (max-width: 640px) {
        .list-card {
            flex-direction: column;
        }
        .list-card-img {
            width: 100%;
            min-width: 100%;
            height: 160px;
        }
        .list-card-date {
            margin-left: 0;
        }
    }

    /* ===== Mini stat cards ===== */
    .stat-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 16px;
    }
    .stat-card {
        background: #fff;
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        padding: 18px 16px;
        text-align: center;
        transition: var(--transition);
    }
    .stat-card:hover {
        box-shadow: var(--shadow-sm);
    }
    .stat-number {
        font-size: 28px;
        font-weight: 700;
        color: var(--primary);
        line-height: 1.2;
        margin-bottom: 4px;
    }
    .stat-label {
        font-size: 13px;
        color: var(--text-secondary);
        font-weight: 500;
    }
    @media (max-width: 768px) {
        .stat-grid {
            grid-template-columns: repeat(2, 1fr);
        }
    }
    @media (max-width: 480px) {
        .stat-grid {
            grid-template-columns: 1fr 1fr;
            gap: 10px;
        }
        .stat-number {
            font-size: 22px;
        }
    }

    /* ===== Hot recommend cards ===== */
    .hot-grid {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 16px;
    }
    .hot-card {
        background: #fff;
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        overflow: hidden;
        transition: var(--transition);
    }
    .hot-card:hover {
        box-shadow: var(--shadow-hover);
        transform: translateY(-2px);
    }
    .hot-card-img {
        width: 100%;
        height: 120px;
        overflow: hidden;
        background: var(--bg-alt);
    }
    .hot-card-img img {
        width: 100%;
        height: 100%;
        object-fit: cover;
    }
    .hot-card-body {
        padding: 12px 14px;
    }
    .hot-card-title {
        font-size: 14px;
        font-weight: 600;
        color: var(--text-main);
        line-height: 1.4;
        margin-bottom: 4px;
    }
    .hot-card-tag {
        font-size: 12px;
        color: var(--text-muted);
    }
    @media (max-width: 1024px) {
        .hot-grid {
            grid-template-columns: repeat(2, 1fr);
        }
    }
    @media (max-width: 480px) {
        .hot-grid {
            grid-template-columns: 1fr;
        }
    }

    /* ===== Quick Q&A ===== */
    .qa-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }
    .qa-card {
        background: #fff;
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
        padding: 18px;
        transition: var(--transition);
    }
    .qa-card:hover {
        box-shadow: var(--shadow-sm);
    }
    .qa-question {
        font-size: 15px;
        font-weight: 600;
        color: var(--text-main);
        margin-bottom: 6px;
        display: flex;
        align-items: flex-start;
        gap: 8px;
    }
    .qa-question .qa-icon {
        color: var(--primary);
        font-size: 16px;
        flex-shrink: 0;
        margin-top: 2px;
    }
    .qa-answer {
        font-size: 13px;
        color: var(--text-secondary);
        line-height: 1.7;
        padding-left: 24px;
    }
    @media (max-width: 768px) {
        .qa-grid {
            grid-template-columns: 1fr;
        }
    }

    /* ===== Topic tags ===== */
    .topic-tags {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
    }
    .topic-tag {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        padding: 8px 18px;
        border-radius: var(--radius-full);
        font-size: 13px;
        font-weight: 500;
        color: var(--text-secondary);
        background: #fff;
        border: 1px solid var(--card-border);
        transition: var(--transition);
        white-space: nowrap;
    }
    .topic-tag:hover {
        border-color: var(--primary);
        color: var(--primary);
        background: var(--primary-pale);
    }
    .topic-tag i {
        font-size: 12px;
        color: var(--primary-light);
    }

    /* ===== Notice card ===== */
    .notice-card {
        background: #fff;
        border: 1px solid var(--card-border);
        border-left: 4px solid var(--primary);
        border-radius: var(--radius-md);
        padding: 20px 24px;
    }
    .notice-card h3 {
        font-size: 16px;
        font-weight: 600;
        color: var(--text-main);
        margin-bottom: 10px;
    }
    .notice-card ul {
        list-style: none;
        padding: 0;
    }
    .notice-card ul li {
        font-size: 14px;
        color: var(--text-secondary);
        line-height: 1.8;
        padding-left: 20px;
        position: relative;
        margin-bottom: 4px;
    }
    .notice-card ul li::before {
        content: '\f00c';
        font-family: 'Font Awesome 6 Free';
        font-weight: 900;
        position: absolute;
        left: 0;
        top: 2px;
        font-size: 12px;
        color: var(--primary);
    }

    /* ===== Back to top bar ===== */
    .back-bar {
        display: flex;
        align-items: center;
        justify-content: space-between;
        flex-wrap: wrap;
        gap: 12px;
        padding: 16px 20px;
        background: var(--bg-alt);
        border: 1px solid var(--card-border);
        border-radius: var(--radius-md);
    }
    .back-bar-text {
        font-size: 14px;
        color: var(--text-secondary);
    }
    .back-bar-actions {
        display: flex;
        gap: 10px;
        flex-wrap: wrap;
    }

    /* ===== Footer ===== */
    .site-footer {
        background: #0F172A;
        color: #E2E8F0;
        padding: 48px 0 24px;
        margin-top: 0;
    }
    .footer-grid {
        display: grid;
        grid-template-columns: 2fr 1fr 1fr 1fr;
        gap: 32px;
        margin-bottom: 32px;
    }
    .footer-brand {
        font-size: 20px;
        font-weight: 700;
        color: #fff;
        margin-bottom: 10px;
    }
    .footer-desc {
        font-size: 14px;
        color: #94A3B8;
        line-height: 1.7;
        max-width: 340px;
    }
    .footer-col-title {
        font-size: 14px;
        font-weight: 600;
        color: #fff;
        margin-bottom: 12px;
    }
    .footer-col ul {
        list-style: none;
    }
    .footer-col ul li {
        margin-bottom: 8px;
    }
    .footer-col ul li a {
        font-size: 14px;
        color: #94A3B8;
        transition: var(--transition);
    }
    .footer-col ul li a:hover {
        color: #93C5FD;
    }
    .footer-bottom {
        display: flex;
        align-items: center;
        justify-content: space-between;
        flex-wrap: wrap;
        gap: 8px;
        padding-top: 20px;
        border-top: 1px solid #1E293B;
        font-size: 12px;
        color: #64748B;
    }
    @media (max-width: 1024px) {
        .footer-grid {
            grid-template-columns: 1fr 1fr;
        }
    }
    @media (max-width: 640px) {
        .footer-grid {
            grid-template-columns: 1fr;
            gap: 24px;
        }
        .footer-bottom {
            flex-direction: column;
            align-items: flex-start;
        }
    }

    /* ===== Back to top floating ===== */
    .back-top {
        position: fixed;
        bottom: 24px;
        right: 24px;
        width: 44px;
        height: 44px;
        border-radius: var(--radius-full);
        background: var(--primary);
        color: #fff;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 18px;
        box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
        transition: var(--transition);
        z-index: 50;
        opacity: 0;
        visibility: hidden;
        transform: translateY(10px);
    }
    .back-top.visible {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }
    .back-top:hover {
        background: var(--primary-dark);
        color: #fff;
        box-shadow: 0 6px 16px rgba(37, 99, 235, 0.4);
    }

    /* ===== Section header ===== */
    .section-header {
        margin-bottom: 24px;
    }
    .section-header .section-title {
        margin-bottom: 6px;
    }
    .section-header .section-subtitle {
        margin-bottom: 0;
    }