/* roulang page: index */
/* ===== Design Variables ===== */
        :root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --primary-light: #3b82f6;
            --primary-bg: #eef2ff;
            --secondary: #0f172a;
            --secondary-light: #1e293b;
            --accent: #f59e0b;
            --accent-light: #fbbf24;
            --success: #10b981;
            --danger: #ef4444;
            --gray-50: #f8fafc;
            --gray-100: #f1f5f9;
            --gray-200: #e2e8f0;
            --gray-300: #cbd5e1;
            --gray-400: #94a3b8;
            --gray-500: #64748b;
            --gray-600: #475569;
            --gray-700: #334155;
            --gray-800: #1e293b;
            --gray-900: #0f172a;
            --white: #ffffff;
            --black: #000000;
            --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
            --radius-sm: 6px;
            --radius-md: 12px;
            --radius-lg: 20px;
            --radius-xl: 28px;
            --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
            --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 2px 8px rgba(0,0,0,0.04);
            --shadow-lg: 0 12px 40px rgba(0,0,0,0.12), 0 4px 16px rgba(0,0,0,0.06);
            --shadow-xl: 0 24px 60px rgba(0,0,0,0.16);
            --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
            --max-width: 1200px;
            --header-height: 72px;
            --glass-bg: rgba(255,255,255,0.72);
            --glass-border: rgba(255,255,255,0.30);
            --glass-shadow: 0 8px 32px rgba(0,0,0,0.08);
        }

        /* ===== Reset & Base ===== */
        *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
        html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
        body {
            font-family: var(--font-sans);
            font-size: 16px;
            line-height: 1.7;
            color: var(--gray-800);
            background: var(--gray-50);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
        a:hover { color: var(--primary-dark); }
        a:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; border-radius: var(--radius-sm); }
        img { max-width: 100%; height: auto; display: block; }
        button, input, select, textarea { font-family: inherit; font-size: inherit; }
        button { cursor: pointer; border: none; background: none; }
        ul, ol { list-style: none; }
        h1, h2, h3, h4, h5, h6 { line-height: 1.3; color: var(--gray-900); font-weight: 700; }
        h1 { font-size: clamp(2rem, 4.5vw, 3.2rem); }
        h2 { font-size: clamp(1.6rem, 3vw, 2.4rem); }
        h3 { font-size: clamp(1.2rem, 2vw, 1.6rem); }
        h4 { font-size: 1.15rem; }
        p { margin-bottom: 1em; color: var(--gray-600); }
        .container {
            width: 100%;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }
        .section { padding: 80px 0; }
        .section-title { text-align: center; margin-bottom: 16px; }
        .section-subtitle { text-align: center; font-size: 1.1rem; color: var(--gray-500); max-width: 680px; margin: 0 auto 48px; }
        .text-center { text-align: center; }
        .text-primary { color: var(--primary); }
        .text-accent { color: var(--accent); }
        .badge {
            display: inline-flex; align-items: center; gap: 6px;
            padding: 4px 14px; border-radius: 100px;
            font-size: 0.8rem; font-weight: 600;
            background: var(--primary-bg); color: var(--primary);
        }
        .badge-accent { background: #fef3c7; color: #b45309; }
        .badge-success { background: #d1fae5; color: #065f46; }
        .btn {
            display: inline-flex; align-items: center; justify-content: center; gap: 8px;
            padding: 12px 28px; border-radius: var(--radius-md);
            font-weight: 600; font-size: 0.95rem;
            transition: all var(--transition);
            border: 2px solid transparent;
        }
        .btn-primary { background: var(--primary); color: var(--white); border-color: var(--primary); }
        .btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); color: var(--white); transform: translateY(-2px); box-shadow: var(--shadow-md); }
        .btn-primary:active { transform: translateY(0); }
        .btn-outline { background: transparent; color: var(--primary); border-color: var(--primary); }
        .btn-outline:hover { background: var(--primary); color: var(--white); transform: translateY(-2px); box-shadow: var(--shadow-md); }
        .btn-outline:active { transform: translateY(0); }
        .btn-accent { background: var(--accent); color: var(--black); border-color: var(--accent); }
        .btn-accent:hover { background: var(--accent-light); color: var(--black); transform: translateY(-2px); box-shadow: var(--shadow-md); }
        .btn-lg { padding: 16px 36px; font-size: 1.05rem; border-radius: var(--radius-lg); }
        .btn-sm { padding: 8px 18px; font-size: 0.85rem; }
        .btn:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }

        /* ===== Glass Navigation ===== */
        header {
            position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
            height: var(--header-height);
            background: var(--glass-bg);
            backdrop-filter: blur(16px) saturate(180%);
            -webkit-backdrop-filter: blur(16px) saturate(180%);
            border-bottom: 1px solid var(--glass-border);
            box-shadow: var(--glass-shadow);
            transition: background var(--transition), box-shadow var(--transition);
        }
        header.scrolled { background: rgba(255,255,255,0.92); box-shadow: 0 4px 24px rgba(0,0,0,0.10); }
        .header-inner {
            display: flex; align-items: center; justify-content: space-between;
            height: var(--header-height); max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
        }
        .logo { font-size: 1.35rem; font-weight: 800; color: var(--gray-900); letter-spacing: -0.02em; display: flex; align-items: center; gap: 10px; }
        .logo-icon { width: 36px; height: 36px; background: linear-gradient(135deg, var(--primary), var(--primary-light)); border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; color: white; font-size: 1.1rem; }
        .logo:hover { color: var(--primary); }
        .nav-list { display: flex; align-items: center; gap: 8px; }
        .nav-list a {
            padding: 8px 18px; border-radius: var(--radius-sm);
            font-size: 0.92rem; font-weight: 500; color: var(--gray-700);
            transition: all var(--transition); position: relative;
        }
        .nav-list a:hover { color: var(--primary); background: var(--primary-bg); }
        .nav-list a.active { color: var(--white); background: var(--primary); }
        .nav-list a.active:hover { background: var(--primary-dark); }
        .nav-cta { margin-left: 12px; }
        .nav-cta .btn { padding: 8px 22px; font-size: 0.9rem; }
        .hamburger { display: none; flex-direction: column; gap: 5px; padding: 8px; cursor: pointer; background: none; border: none; }
        .hamburger span { width: 26px; height: 2.5px; background: var(--gray-800); border-radius: 2px; transition: all var(--transition); }
        .hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
        .hamburger.active span:nth-child(2) { opacity: 0; }
        .hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

        /* ===== Hero ===== */
        .hero {
            position: relative; min-height: 100vh; display: flex; align-items: center;
            padding-top: var(--header-height); overflow: hidden;
            background: var(--gray-900);
        }
        .hero-bg {
            position: absolute; inset: 0; z-index: 0;
            background: url('/assets/images/backpic/back-1.webp') center center / cover no-repeat;
            opacity: 0.55; transform: scale(1.05); filter: brightness(0.6) saturate(1.1);
        }
        .hero-overlay {
            position: absolute; inset: 0; z-index: 1;
            background: linear-gradient(135deg, rgba(15,23,42,0.88) 0%, rgba(30,41,59,0.72) 50%, rgba(15,23,42,0.88) 100%);
        }
        .hero-content { position: relative; z-index: 2; width: 100%; padding: 60px 0 80px; }
        .hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
        .hero-text .badge { margin-bottom: 20px; background: rgba(37,99,235,0.20); color: #93c5fd; border: 1px solid rgba(37,99,235,0.25); }
        .hero-text h1 { color: var(--white); margin-bottom: 20px; font-weight: 800; letter-spacing: -0.02em; }
        .hero-text h1 span { color: var(--accent); }
        .hero-text p { color: rgba(255,255,255,0.75); font-size: 1.1rem; max-width: 520px; margin-bottom: 32px; line-height: 1.8; }
        .hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
        .hero-actions .btn { font-size: 1rem; padding: 14px 32px; }
        .hero-stats { display: flex; gap: 40px; margin-top: 48px; }
        .hero-stat { text-align: left; }
        .hero-stat-number { font-size: 2rem; font-weight: 800; color: var(--white); line-height: 1.2; }
        .hero-stat-label { font-size: 0.85rem; color: rgba(255,255,255,0.55); margin-top: 4px; }
        .hero-visual {
            position: relative; display: flex; justify-content: center; align-items: center;
        }
        .hero-card {
            background: rgba(255,255,255,0.08); backdrop-filter: blur(12px);
            border: 1px solid rgba(255,255,255,0.12); border-radius: var(--radius-xl);
            padding: 36px; width: 100%; max-width: 460px;
            box-shadow: 0 24px 64px rgba(0,0,0,0.30);
        }
        .hero-card-header { display: flex; align-items: center; gap: 12px; margin-bottom: 24px; padding-bottom: 20px; border-bottom: 1px solid rgba(255,255,255,0.08); }
        .hero-card-header .icon { width: 44px; height: 44px; border-radius: var(--radius-md); background: var(--primary); display: flex; align-items: center; justify-content: center; color: white; font-size: 1.2rem; }
        .hero-card-header .info h4 { color: var(--white); font-size: 1rem; margin-bottom: 2px; }
        .hero-card-header .info span { font-size: 0.8rem; color: rgba(255,255,255,0.5); }
        .hero-card-field { margin-bottom: 16px; }
        .hero-card-field label { font-size: 0.8rem; color: rgba(255,255,255,0.5); display: block; margin-bottom: 6px; }
        .hero-card-field input {
            width: 100%; padding: 12px 16px; border-radius: var(--radius-sm);
            background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.10);
            color: var(--white); font-size: 0.95rem; transition: border var(--transition);
        }
        .hero-card-field input::placeholder { color: rgba(255,255,255,0.30); }
        .hero-card-field input:focus { outline: none; border-color: var(--primary); }
        .hero-card .btn { width: 100%; margin-top: 8px; padding: 14px; font-size: 1rem; }
        .hero-card-footer { margin-top: 16px; text-align: center; font-size: 0.82rem; color: rgba(255,255,255,0.4); }
        .hero-card-footer a { color: var(--accent); }

        /* ===== Features / Core Modules ===== */
        .features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
        .feature-card {
            background: var(--white); border-radius: var(--radius-lg);
            padding: 36px 28px; text-align: center;
            border: 1px solid var(--gray-200); box-shadow: var(--shadow-sm);
            transition: all var(--transition);
        }
        .feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--primary-bg); }
        .feature-icon {
            width: 64px; height: 64px; border-radius: var(--radius-md);
            background: var(--primary-bg); color: var(--primary);
            display: flex; align-items: center; justify-content: center;
            margin: 0 auto 20px; font-size: 1.6rem; transition: background var(--transition);
        }
        .feature-card:hover .feature-icon { background: var(--primary); color: var(--white); }
        .feature-card h3 { margin-bottom: 12px; font-size: 1.15rem; }
        .feature-card p { font-size: 0.92rem; color: var(--gray-500); margin-bottom: 0; }

        /* ===== Steps / Process ===== */
        .steps-section { background: var(--white); }
        .steps-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; position: relative; }
        .steps-grid::before {
            content: ''; position: absolute; top: 44px; left: 12%; right: 12%;
            height: 2px; background: linear-gradient(to right, var(--primary), var(--accent), var(--primary));
            z-index: 0; opacity: 0.3;
        }
        .step-item { text-align: center; position: relative; z-index: 1; }
        .step-number {
            width: 56px; height: 56px; border-radius: 50%;
            background: var(--primary); color: var(--white);
            display: flex; align-items: center; justify-content: center;
            margin: 0 auto 16px; font-size: 1.3rem; font-weight: 700;
            box-shadow: 0 0 0 6px var(--primary-bg);
        }
        .step-item:nth-child(2) .step-number { background: var(--accent); }
        .step-item:nth-child(3) .step-number { background: var(--success); }
        .step-item:nth-child(4) .step-number { background: var(--secondary); }
        .step-item h4 { margin-bottom: 8px; font-size: 1.05rem; }
        .step-item p { font-size: 0.88rem; color: var(--gray-500); margin-bottom: 0; max-width: 220px; margin-left: auto; margin-right: auto; }

        /* ===== Content / News List ===== */
        .content-section { background: var(--gray-50); }
        .content-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
        .content-card {
            background: var(--white); border-radius: var(--radius-lg); overflow: hidden;
            border: 1px solid var(--gray-200); box-shadow: var(--shadow-sm);
            transition: all var(--transition); display: flex; flex-direction: column;
        }
        .content-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
        .content-card-img {
            width: 100%; height: 200px; object-fit: cover; display: block;
            background: var(--gray-200);
        }
        .content-card-body { padding: 24px; flex: 1; display: flex; flex-direction: column; }
        .content-card-body .badge { align-self: flex-start; margin-bottom: 12px; }
        .content-card-body h3 { font-size: 1.08rem; margin-bottom: 10px; font-weight: 600; }
        .content-card-body h3 a { color: var(--gray-900); }
        .content-card-body h3 a:hover { color: var(--primary); }
        .content-card-body p { font-size: 0.9rem; color: var(--gray-500); margin-bottom: 16px; flex: 1; }
        .content-card-meta { display: flex; align-items: center; justify-content: space-between; font-size: 0.82rem; color: var(--gray-400); padding-top: 16px; border-top: 1px solid var(--gray-100); }
        .content-card-meta i { margin-right: 4px; }
        .content-empty {
            grid-column: 1 / -1; text-align: center; padding: 60px 20px;
            color: var(--gray-500); font-size: 1.05rem;
            background: var(--white); border-radius: var(--radius-lg); border: 1px dashed var(--gray-300);
        }

        /* ===== Why Us / Trust ===== */
        .trust-section { background: var(--gray-900); color: var(--white); }
        .trust-section .section-title { color: var(--white); }
        .trust-section .section-subtitle { color: rgba(255,255,255,0.6); }
        .trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; }
        .trust-item {
            text-align: center; padding: 32px 20px;
            background: rgba(255,255,255,0.04); border-radius: var(--radius-lg);
            border: 1px solid rgba(255,255,255,0.06); transition: all var(--transition);
        }
        .trust-item:hover { background: rgba(255,255,255,0.08); transform: translateY(-3px); }
        .trust-icon { font-size: 2rem; color: var(--accent); margin-bottom: 16px; }
        .trust-item h4 { color: var(--white); font-size: 1.1rem; margin-bottom: 8px; }
        .trust-item p { color: rgba(255,255,255,0.55); font-size: 0.88rem; margin-bottom: 0; }

        /* ===== FAQ ===== */
        .faq-section { background: var(--white); }
        .faq-list { max-width: 780px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
        .faq-item {
            border: 1px solid var(--gray-200); border-radius: var(--radius-md);
            overflow: hidden; transition: border var(--transition);
        }
        .faq-item:hover { border-color: var(--primary-light); }
        .faq-question {
            width: 100%; display: flex; align-items: center; justify-content: space-between;
            padding: 20px 24px; font-size: 1rem; font-weight: 600; color: var(--gray-800);
            background: var(--white); text-align: left; gap: 16px;
            transition: background var(--transition);
        }
        .faq-question:hover { background: var(--gray-50); }
        .faq-question i { color: var(--primary); transition: transform var(--transition); font-size: 0.85rem; }
        .faq-item.active .faq-question i { transform: rotate(180deg); }
        .faq-answer {
            max-height: 0; overflow: hidden; transition: max-height 0.4s ease, padding 0.3s ease;
            padding: 0 24px; color: var(--gray-600); font-size: 0.95rem; line-height: 1.8;
        }
        .faq-item.active .faq-answer { max-height: 300px; padding: 0 24px 20px; }

        /* ===== CTA ===== */
        .cta-section {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            position: relative; overflow: hidden;
        }
        .cta-section::before {
            content: ''; position: absolute; inset: 0;
            background: url('/assets/images/backpic/back-2.png') center center / cover no-repeat;
            opacity: 0.08; mix-blend-mode: overlay;
        }
        .cta-content { position: relative; z-index: 1; text-align: center; padding: 60px 0; }
        .cta-content h2 { color: var(--white); margin-bottom: 16px; }
        .cta-content p { color: rgba(255,255,255,0.80); max-width: 600px; margin: 0 auto 32px; font-size: 1.05rem; }
        .cta-content .btn { background: var(--white); color: var(--primary); border-color: var(--white); }
        .cta-content .btn:hover { background: transparent; color: var(--white); border-color: var(--white); transform: translateY(-2px); }

        /* ===== Footer ===== */
        footer {
            background: var(--gray-900); color: rgba(255,255,255,0.6);
            padding: 48px 0 24px; border-top: 1px solid rgba(255,255,255,0.06);
        }
        .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 32px; }
        .footer-brand .logo { color: var(--white); margin-bottom: 16px; }
        .footer-brand p { font-size: 0.9rem; color: rgba(255,255,255,0.45); max-width: 320px; line-height: 1.7; }
        .footer-col h5 { color: var(--white); font-size: 0.95rem; margin-bottom: 16px; font-weight: 600; }
        .footer-col ul li { margin-bottom: 10px; }
        .footer-col ul li a { font-size: 0.88rem; color: rgba(255,255,255,0.5); }
        .footer-col ul li a:hover { color: var(--white); }
        .footer-bottom {
            border-top: 1px solid rgba(255,255,255,0.06); padding-top: 20px;
            display: flex; align-items: center; justify-content: space-between;
            flex-wrap: wrap; gap: 12px; font-size: 0.85rem; color: rgba(255,255,255,0.35);
        }
        .footer-bottom a { color: rgba(255,255,255,0.4); }
        .footer-bottom a:hover { color: var(--white); }

        /* ===== Responsive ===== */
        @media (max-width: 1024px) {
            .hero-grid { grid-template-columns: 1fr; gap: 40px; }
            .hero-text p { max-width: 100%; }
            .hero-stats { gap: 24px; }
            .features-grid { grid-template-columns: repeat(2, 1fr); }
            .trust-grid { grid-template-columns: repeat(2, 1fr); }
            .footer-grid { grid-template-columns: repeat(2, 1fr); }
        }
        @media (max-width: 768px) {
            .hamburger { display: flex; }
            .nav-list {
                position: fixed; top: var(--header-height); left: 0; right: 0;
                background: var(--white); flex-direction: column; padding: 20px 24px;
                box-shadow: var(--shadow-lg); border-bottom: 1px solid var(--gray-200);
                transform: translateY(-120%); opacity: 0; pointer-events: none;
                transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
                border-radius: 0 0 var(--radius-lg) var(--radius-lg);
            }
            .nav-list.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
            .nav-list a { width: 100%; padding: 12px 16px; font-size: 1rem; }
            .nav-cta { margin-left: 0; width: 100%; margin-top: 8px; }
            .nav-cta .btn { width: 100%; justify-content: center; }
            .hero { min-height: auto; padding: 100px 0 60px; }
            .hero-stats { gap: 20px; flex-wrap: wrap; }
            .hero-stat-number { font-size: 1.5rem; }
            .features-grid { grid-template-columns: 1fr; }
            .steps-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
            .steps-grid::before { display: none; }
            .content-grid { grid-template-columns: 1fr; }
            .trust-grid { grid-template-columns: 1fr; }
            .footer-grid { grid-template-columns: 1fr; gap: 24px; }
            .footer-bottom { flex-direction: column; text-align: center; }
            .section { padding: 48px 0; }
            .hero-card { padding: 24px; }
        }
        @media (max-width: 520px) {
            .header-inner { padding: 0 16px; }
            .container { padding: 0 16px; }
            .hero-actions { flex-direction: column; }
            .hero-actions .btn { width: 100%; justify-content: center; }
            .steps-grid { grid-template-columns: 1fr; }
            .hero-card-header { flex-direction: column; text-align: center; }
            .trust-grid { grid-template-columns: 1fr; }
            .faq-question { font-size: 0.92rem; padding: 16px 18px; }
            .btn-lg { padding: 14px 24px; font-size: 0.95rem; }
        }

        /* ===== Utility ===== */
        .gap-8 { gap: 8px; }
        .mt-8 { margin-top: 8px; }
        .mt-16 { margin-top: 16px; }
        .mt-24 { margin-top: 24px; }
        .mt-32 { margin-top: 32px; }
        .mb-8 { margin-bottom: 8px; }
        .mb-16 { margin-bottom: 16px; }
        .mb-24 { margin-bottom: 24px; }
        .flex-center { display: flex; align-items: center; justify-content: center; }
        .text-sm { font-size: 0.88rem; }
        .text-xs { font-size: 0.78rem; }

/* roulang page: category1 */
/* ===== 设计变量 ===== */
        :root {
            --primary: #1a5cff;
            --primary-dark: #0d3fa0;
            --primary-light: #e8efff;
            --secondary: #ff6b35;
            --accent: #00c9a7;
            --bg-body: #f8faff;
            --bg-white: #ffffff;
            --bg-card: #ffffff;
            --bg-dark: #0b1a33;
            --text-dark: #0b1a33;
            --text-body: #2d3748;
            --text-muted: #6b7a8f;
            --text-light: #8899aa;
            --border-color: #e2e8f0;
            --border-light: #f0f4fa;
            --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
            --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.06);
            --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.08);
            --shadow-xl: 0 24px 64px rgba(0, 0, 0, 0.12);
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-lg: 20px;
            --radius-xl: 28px;
            --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
            --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
            --container-max: 1200px;
            --header-height: 72px;
        }

        /* ===== Reset & Base ===== */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        html {
            scroll-behavior: smooth;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        body {
            font-family: var(--font-sans);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text-body);
            background: var(--bg-body);
            min-height: 100vh;
            padding-top: var(--header-height);
        }
        a {
            color: var(--primary);
            text-decoration: none;
            transition: var(--transition);
        }
        a:hover {
            color: var(--primary-dark);
        }
        a:focus-visible {
            outline: 2px solid var(--primary);
            outline-offset: 2px;
            border-radius: 4px;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        button,
        input,
        textarea {
            font-family: inherit;
            font-size: inherit;
        }
        ul {
            list-style: none;
        }

        /* ===== Container ===== */
        .container {
            max-width: var(--container-max);
            margin: 0 auto;
            padding: 0 24px;
        }
        @media (max-width: 768px) {
            .container {
                padding: 0 16px;
            }
        }

        /* ===== 导航 ===== */
        header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            height: var(--header-height);
            background: rgba(255, 255, 255, 0.75);
            backdrop-filter: blur(18px) saturate(180%);
            -webkit-backdrop-filter: blur(18px) saturate(180%);
            border-bottom: 1px solid rgba(255, 255, 255, 0.3);
            box-shadow: 0 1px 12px rgba(0, 0, 0, 0.04);
            transition: var(--transition);
        }
        header.scrolled {
            background: rgba(255, 255, 255, 0.95);
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
            border-bottom: 1px solid var(--border-color);
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: var(--header-height);
            max-width: var(--container-max);
            margin: 0 auto;
            padding: 0 24px;
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 22px;
            font-weight: 700;
            color: var(--text-dark);
            white-space: nowrap;
            letter-spacing: -0.3px;
        }
        .logo .logo-icon {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            border-radius: var(--radius-sm);
            color: #fff;
            font-size: 20px;
            box-shadow: 0 4px 12px rgba(26, 92, 255, 0.25);
        }
        .logo span:last-child {
            background: linear-gradient(135deg, var(--text-dark), var(--primary));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        /* 导航列表 */
        .nav-list {
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .nav-list a {
            padding: 8px 16px;
            border-radius: var(--radius-sm);
            font-size: 15px;
            font-weight: 500;
            color: var(--text-body);
            transition: var(--transition);
            position: relative;
        }
        .nav-list a:hover {
            color: var(--primary);
            background: var(--primary-light);
        }
        .nav-list a.active {
            color: var(--primary);
            background: var(--primary-light);
            font-weight: 600;
        }
        .nav-list a.active::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 50%;
            transform: translateX(-50%);
            width: 20px;
            height: 3px;
            background: var(--primary);
            border-radius: 4px;
        }
        .nav-cta {
            margin-left: 12px;
        }
        .nav-cta .btn {
            padding: 8px 20px;
            font-size: 14px;
            border-radius: var(--radius-sm);
        }

        /* 移动端汉堡菜单 */
        .hamburger {
            display: none;
            flex-direction: column;
            gap: 5px;
            cursor: pointer;
            padding: 6px;
            border: none;
            background: none;
            z-index: 1100;
        }
        .hamburger span {
            display: block;
            width: 26px;
            height: 2.5px;
            background: var(--text-dark);
            border-radius: 4px;
            transition: var(--transition);
        }
        .hamburger.active span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 5px);
        }
        .hamburger.active span:nth-child(2) {
            opacity: 0;
        }
        .hamburger.active span:nth-child(3) {
            transform: rotate(-45deg) translate(5px, -5px);
        }

        @media (max-width: 820px) {
            .hamburger {
                display: flex;
            }
            .nav-list {
                position: fixed;
                top: var(--header-height);
                left: 0;
                right: 0;
                background: rgba(255, 255, 255, 0.98);
                backdrop-filter: blur(18px);
                flex-direction: column;
                padding: 24px 20px 32px;
                gap: 6px;
                box-shadow: 0 16px 40px rgba(0, 0, 0, 0.08);
                transform: translateY(-120%);
                opacity: 0;
                transition: var(--transition);
                border-bottom: 1px solid var(--border-color);
                align-items: stretch;
                border-radius: 0 0 var(--radius-lg) var(--radius-lg);
            }
            .nav-list.open {
                transform: translateY(0);
                opacity: 1;
            }
            .nav-list a {
                padding: 12px 16px;
                font-size: 16px;
                text-align: center;
            }
            .nav-list a.active::after {
                display: none;
            }
            .nav-cta {
                margin-left: 0;
                margin-top: 12px;
                text-align: center;
            }
            .nav-cta .btn {
                width: 100%;
                padding: 12px;
                font-size: 16px;
            }
        }

        /* ===== 通用按钮 ===== */
        .btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 28px;
            border-radius: var(--radius-sm);
            font-weight: 600;
            font-size: 15px;
            border: none;
            cursor: pointer;
            transition: var(--transition);
            text-align: center;
            justify-content: center;
            line-height: 1.4;
        }
        .btn-primary {
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: #fff;
            box-shadow: 0 4px 16px rgba(26, 92, 255, 0.3);
        }
        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 28px rgba(26, 92, 255, 0.4);
            color: #fff;
        }
        .btn-primary:active {
            transform: translateY(0);
            box-shadow: 0 2px 8px rgba(26, 92, 255, 0.3);
        }
        .btn-secondary {
            background: var(--bg-white);
            color: var(--primary);
            border: 2px solid var(--border-color);
            box-shadow: var(--shadow-sm);
        }
        .btn-secondary:hover {
            border-color: var(--primary);
            background: var(--primary-light);
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }
        .btn-secondary:active {
            transform: translateY(0);
        }
        .btn-sm {
            padding: 8px 18px;
            font-size: 13px;
        }
        .btn-lg {
            padding: 16px 36px;
            font-size: 17px;
            border-radius: var(--radius-md);
        }

        /* ===== Hero ===== */
        .hero {
            position: relative;
            min-height: 480px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: linear-gradient(135deg, #0b1a33 0%, #1a3a6b 50%, #0d3fa0 100%);
            overflow: hidden;
            padding: 80px 0 60px;
        }
        .hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background: url('/assets/images/backpic/back-1.webp') center center / cover no-repeat;
            opacity: 0.18;
            mix-blend-mode: overlay;
        }
        .hero::after {
            content: '';
            position: absolute;
            inset: 0;
            background: radial-gradient(ellipse at 30% 50%, rgba(26, 92, 255, 0.15), transparent 70%);
        }
        .hero .container {
            position: relative;
            z-index: 2;
            text-align: center;
            max-width: 800px;
        }
        .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: rgba(255, 255, 255, 0.12);
            backdrop-filter: blur(8px);
            border: 1px solid rgba(255, 255, 255, 0.15);
            padding: 6px 18px;
            border-radius: 40px;
            color: rgba(255, 255, 255, 0.9);
            font-size: 13px;
            font-weight: 500;
            letter-spacing: 0.3px;
            margin-bottom: 24px;
        }
        .hero-badge i {
            color: var(--accent);
        }
        .hero h1 {
            font-size: 48px;
            font-weight: 800;
            color: #fff;
            line-height: 1.2;
            letter-spacing: -1px;
            margin-bottom: 20px;
        }
        .hero h1 .highlight {
            background: linear-gradient(135deg, #60a5fa, var(--accent));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .hero p {
            font-size: 18px;
            color: rgba(255, 255, 255, 0.8);
            max-width: 640px;
            margin: 0 auto 32px;
            line-height: 1.7;
        }
        .hero-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            justify-content: center;
        }
        .hero-actions .btn {
            min-width: 160px;
        }
        .hero-actions .btn-outline-light {
            background: transparent;
            border: 2px solid rgba(255, 255, 255, 0.3);
            color: #fff;
        }
        .hero-actions .btn-outline-light:hover {
            background: rgba(255, 255, 255, 0.1);
            border-color: rgba(255, 255, 255, 0.6);
            transform: translateY(-2px);
        }

        @media (max-width: 768px) {
            .hero {
                min-height: 380px;
                padding: 60px 0 40px;
            }
            .hero h1 {
                font-size: 32px;
            }
            .hero p {
                font-size: 16px;
            }
            .hero-actions .btn {
                min-width: 140px;
                padding: 12px 24px;
            }
        }
        @media (max-width: 520px) {
            .hero h1 {
                font-size: 26px;
            }
            .hero p {
                font-size: 14px;
            }
            .hero-actions {
                flex-direction: column;
                align-items: center;
            }
            .hero-actions .btn {
                width: 100%;
                max-width: 280px;
            }
        }

        /* ===== 板块通用 ===== */
        .section {
            padding: 80px 0;
        }
        .section-alt {
            background: var(--bg-white);
        }
        .section-dark {
            background: var(--bg-dark);
            color: #fff;
        }
        .section-title {
            font-size: 34px;
            font-weight: 700;
            color: var(--text-dark);
            text-align: center;
            margin-bottom: 12px;
            letter-spacing: -0.5px;
            line-height: 1.3;
        }
        .section-sub {
            font-size: 17px;
            color: var(--text-muted);
            text-align: center;
            max-width: 640px;
            margin: 0 auto 48px;
            line-height: 1.7;
        }
        .section-dark .section-title {
            color: #fff;
        }
        .section-dark .section-sub {
            color: rgba(255, 255, 255, 0.7);
        }

        @media (max-width: 768px) {
            .section {
                padding: 56px 0;
            }
            .section-title {
                font-size: 26px;
            }
            .section-sub {
                font-size: 15px;
                margin-bottom: 32px;
            }
        }

        /* ===== 卡片网格 ===== */
        .grid-3 {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 28px;
        }
        .grid-2 {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 28px;
        }
        .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: 768px) {
            .grid-3,
            .grid-2,
            .grid-4 {
                grid-template-columns: 1fr;
                gap: 20px;
            }
        }

        /* ===== 卡片 ===== */
        .card {
            background: var(--bg-card);
            border-radius: var(--radius-md);
            padding: 28px 24px;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border-light);
            transition: var(--transition);
        }
        .card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-lg);
            border-color: var(--primary-light);
        }
        .card-icon {
            width: 52px;
            height: 52px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: var(--radius-sm);
            background: var(--primary-light);
            color: var(--primary);
            font-size: 22px;
            margin-bottom: 18px;
            transition: var(--transition);
        }
        .card:hover .card-icon {
            background: var(--primary);
            color: #fff;
        }
        .card h3 {
            font-size: 19px;
            font-weight: 600;
            color: var(--text-dark);
            margin-bottom: 10px;
        }
        .card p {
            font-size: 14.5px;
            color: var(--text-muted);
            line-height: 1.7;
        }
        .card .card-tag {
            display: inline-block;
            padding: 3px 12px;
            border-radius: 40px;
            background: var(--primary-light);
            color: var(--primary);
            font-size: 12px;
            font-weight: 500;
            margin-top: 14px;
        }

        /* ===== 特色板块 ===== */
        .feature-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            align-items: center;
        }
        .feature-image {
            border-radius: var(--radius-lg);
            overflow: hidden;
            box-shadow: var(--shadow-lg);
            background: var(--border-light);
            min-height: 320px;
            display: flex;
            align-items: center;
            justify-content: center;
            background-size: cover;
            background-position: center;
        }
        .feature-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        .feature-content h2 {
            font-size: 30px;
            font-weight: 700;
            color: var(--text-dark);
            margin-bottom: 16px;
            line-height: 1.3;
        }
        .feature-content p {
            font-size: 16px;
            color: var(--text-muted);
            line-height: 1.8;
            margin-bottom: 16px;
        }
        .feature-list {
            margin: 20px 0 24px;
        }
        .feature-list li {
            display: flex;
            align-items: flex-start;
            gap: 12px;
            padding: 8px 0;
            font-size: 15px;
            color: var(--text-body);
        }
        .feature-list li i {
            color: var(--accent);
            font-size: 16px;
            margin-top: 3px;
            flex-shrink: 0;
        }

        @media (max-width: 900px) {
            .feature-grid {
                grid-template-columns: 1fr;
                gap: 28px;
            }
            .feature-image {
                min-height: 240px;
                order: -1;
            }
            .feature-content h2 {
                font-size: 24px;
            }
        }

        /* ===== 步骤流程 ===== */
        .steps {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            counter-reset: step;
        }
        .step-item {
            text-align: center;
            padding: 32px 20px;
            background: var(--bg-white);
            border-radius: var(--radius-md);
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border-light);
            position: relative;
            transition: var(--transition);
        }
        .step-item:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-lg);
        }
        .step-number {
            width: 48px;
            height: 48px;
            margin: 0 auto 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: #fff;
            font-size: 20px;
            font-weight: 700;
            box-shadow: 0 6px 20px rgba(26, 92, 255, 0.25);
        }
        .step-item h4 {
            font-size: 17px;
            font-weight: 600;
            color: var(--text-dark);
            margin-bottom: 8px;
        }
        .step-item p {
            font-size: 14px;
            color: var(--text-muted);
            line-height: 1.6;
        }

        @media (max-width: 900px) {
            .steps {
                grid-template-columns: repeat(2, 1fr);
            }
        }
        @media (max-width: 520px) {
            .steps {
                grid-template-columns: 1fr;
            }
        }

        /* ===== 统计数字 ===== */
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
            text-align: center;
        }
        .stat-item {
            padding: 24px 16px;
        }
        .stat-number {
            font-size: 40px;
            font-weight: 800;
            color: #fff;
            line-height: 1.2;
            letter-spacing: -1px;
        }
        .stat-number .suffix {
            font-size: 24px;
            font-weight: 600;
            color: var(--accent);
        }
        .stat-label {
            font-size: 15px;
            color: rgba(255, 255, 255, 0.7);
            margin-top: 6px;
        }

        @media (max-width: 768px) {
            .stats-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 20px;
            }
            .stat-number {
                font-size: 32px;
            }
        }

        /* ===== FAQ ===== */
        .faq-list {
            max-width: 780px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 12px;
        }
        .faq-item {
            background: var(--bg-white);
            border-radius: var(--radius-md);
            border: 1px solid var(--border-light);
            box-shadow: var(--shadow-sm);
            overflow: hidden;
            transition: var(--transition);
        }
        .faq-item:hover {
            border-color: var(--primary-light);
        }
        .faq-question {
            padding: 20px 24px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 12px;
            cursor: pointer;
            font-size: 16px;
            font-weight: 600;
            color: var(--text-dark);
            background: none;
            border: none;
            width: 100%;
            text-align: left;
            transition: var(--transition);
        }
        .faq-question:hover {
            color: var(--primary);
        }
        .faq-question i {
            color: var(--primary);
            font-size: 18px;
            transition: var(--transition);
            flex-shrink: 0;
        }
        .faq-item.active .faq-question i {
            transform: rotate(180deg);
        }
        .faq-answer {
            padding: 0 24px 20px;
            font-size: 15px;
            color: var(--text-muted);
            line-height: 1.7;
            display: none;
        }
        .faq-item.active .faq-answer {
            display: block;
        }

        @media (max-width: 768px) {
            .faq-question {
                padding: 16px 18px;
                font-size: 15px;
            }
            .faq-answer {
                padding: 0 18px 16px;
                font-size: 14px;
            }
        }

        /* ===== CTA ===== */
        .cta-section {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            padding: 72px 0;
            text-align: center;
            position: relative;
            overflow: hidden;
        }
        .cta-section::before {
            content: '';
            position: absolute;
            inset: 0;
            background: url('/assets/images/backpic/back-2.png') center center / cover no-repeat;
            opacity: 0.06;
            mix-blend-mode: overlay;
        }
        .cta-section .container {
            position: relative;
            z-index: 2;
        }
        .cta-section h2 {
            font-size: 36px;
            font-weight: 700;
            color: #fff;
            margin-bottom: 16px;
        }
        .cta-section p {
            font-size: 18px;
            color: rgba(255, 255, 255, 0.85);
            max-width: 560px;
            margin: 0 auto 32px;
            line-height: 1.7;
        }
        .cta-section .btn {
            background: #fff;
            color: var(--primary);
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
        }
        .cta-section .btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
            background: #f8faff;
        }

        @media (max-width: 768px) {
            .cta-section {
                padding: 52px 0;
            }
            .cta-section h2 {
                font-size: 26px;
            }
            .cta-section p {
                font-size: 15px;
            }
        }

        /* ===== 页脚 ===== */
        footer {
            background: var(--bg-dark);
            color: rgba(255, 255, 255, 0.8);
            padding: 60px 0 0;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 1.8fr 1fr 1fr 1fr;
            gap: 40px;
            padding-bottom: 40px;
            border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        }
        .footer-brand .logo {
            color: #fff;
            font-size: 22px;
            margin-bottom: 16px;
        }
        .footer-brand .logo .logo-icon {
            background: linear-gradient(135deg, var(--primary), var(--accent));
        }
        .footer-brand .logo span:last-child {
            -webkit-text-fill-color: #fff;
            background: none;
        }
        .footer-brand p {
            font-size: 14px;
            color: rgba(255, 255, 255, 0.6);
            line-height: 1.7;
            max-width: 360px;
        }
        .footer-col h5 {
            font-size: 15px;
            font-weight: 600;
            color: #fff;
            margin-bottom: 18px;
            letter-spacing: 0.3px;
        }
        .footer-col ul li {
            margin-bottom: 10px;
        }
        .footer-col ul li a {
            color: rgba(255, 255, 255, 0.6);
            font-size: 14px;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        .footer-col ul li a:hover {
            color: var(--accent);
            padding-left: 4px;
        }
        .footer-bottom {
            padding: 24px 0;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 12px;
            font-size: 13px;
            color: rgba(255, 255, 255, 0.4);
        }
        .footer-bottom span:first-child {
            color: rgba(255, 255, 255, 0.5);
        }

        @media (max-width: 900px) {
            .footer-grid {
                grid-template-columns: 1fr 1fr;
                gap: 32px;
            }
            .footer-brand {
                grid-column: 1 / -1;
            }
            .footer-brand p {
                max-width: 100%;
            }
        }
        @media (max-width: 520px) {
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 24px;
            }
            .footer-bottom {
                flex-direction: column;
                text-align: center;
            }
        }

        /* ===== 面包屑 ===== */
        .breadcrumb {
            padding: 20px 0 0;
            font-size: 14px;
            color: var(--text-muted);
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 8px;
        }
        .breadcrumb a {
            color: var(--text-muted);
        }
        .breadcrumb a:hover {
            color: var(--primary);
        }
        .breadcrumb .sep {
            color: var(--border-color);
        }
        .breadcrumb .current {
            color: var(--text-dark);
            font-weight: 500;
        }

        /* ===== 页面内图片占位 ===== */
        .img-placeholder {
            background: var(--border-light);
            border-radius: var(--radius-md);
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 200px;
            color: var(--text-light);
            font-size: 14px;
            overflow: hidden;
        }
        .img-placeholder img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        /* ===== 标签 / 徽章 ===== */
        .tag {
            display: inline-block;
            padding: 4px 14px;
            border-radius: 40px;
            font-size: 12px;
            font-weight: 500;
            background: var(--primary-light);
            color: var(--primary);
        }
        .tag-accent {
            background: rgba(0, 201, 167, 0.12);
            color: #00997e;
        }
        .tag-warning {
            background: rgba(255, 107, 53, 0.12);
            color: #d4552a;
        }

        /* ===== 额外响应式 ===== */
        @media (max-width: 480px) {
            .hero h1 {
                font-size: 22px;
            }
            .section-title {
                font-size: 22px;
            }
            .card {
                padding: 20px 16px;
            }
            .card h3 {
                font-size: 17px;
            }
            .feature-content h2 {
                font-size: 20px;
            }
            .stat-number {
                font-size: 26px;
            }
        }

        /* ===== 过渡 & 工具 ===== */
        .text-center {
            text-align: center;
        }
        .mt-16 {
            margin-top: 16px;
        }
        .mt-24 {
            margin-top: 24px;
        }
        .mt-32 {
            margin-top: 32px;
        }
        .gap-12 {
            gap: 12px;
        }
        .flex-center {
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .fade-in {
            animation: fadeIn 0.6s ease-out;
        }
        @keyframes fadeIn {
            0% {
                opacity: 0;
                transform: translateY(20px);
            }
            100% {
                opacity: 1;
                transform: translateY(0);
            }
        }

/* roulang page: article */
/* ===== 设计变量 ===== */
        :root {
            --primary: #2563eb;
            --primary-dark: #1e40af;
            --primary-light: #3b82f6;
            --primary-50: #eff6ff;
            --primary-100: #dbeafe;
            --accent: #f59e0b;
            --accent-dark: #d97706;
            --bg: #ffffff;
            --bg-alt: #f8fafc;
            --bg-card: #ffffff;
            --text: #1e293b;
            --text-soft: #475569;
            --text-muted: #94a3b8;
            --border: #e2e8f0;
            --border-light: #f1f5f9;
            --radius-sm: 8px;
            --radius-md: 12px;
            --radius-lg: 16px;
            --radius-xl: 24px;
            --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
            --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
            --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
            --shadow-xl: 0 20px 60px rgba(0,0,0,0.15);
            --transition: 0.25s ease;
            --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
            --max-width: 1200px;
            --header-height: 76px;
        }

        /* ===== Reset & Base ===== */
        *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
        html { scroll-behavior: smooth; }
        body {
            font-family: var(--font);
            font-size: 16px;
            line-height: 1.7;
            color: var(--text);
            background: var(--bg);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }
        a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
        a:hover { color: var(--primary-dark); }
        a:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; border-radius: 4px; }
        img { max-width: 100%; height: auto; display: block; }
        ul, ol { list-style: none; }
        button, input, textarea { font-family: inherit; font-size: inherit; }
        button { cursor: pointer; border: none; background: none; }
        .container {
            width: 100%;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }
        @media (max-width: 768px) {
            .container { padding: 0 16px; }
        }

        /* ===== 导航 ===== */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            height: var(--header-height);
            transition: background var(--transition), box-shadow var(--transition), backdrop-filter var(--transition);
            background: rgba(255,255,255,0.72);
            backdrop-filter: blur(16px) saturate(1.8);
            -webkit-backdrop-filter: blur(16px) saturate(1.8);
            border-bottom: 1px solid rgba(226,232,240,0.5);
        }
        .header.scrolled {
            background: rgba(255,255,255,0.95);
            box-shadow: 0 1px 12px rgba(0,0,0,0.06);
        }
        .header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 100%;
        }
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 22px;
            font-weight: 700;
            color: var(--text);
            letter-spacing: -0.3px;
            flex-shrink: 0;
        }
        .logo .logo-icon {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 38px;
            height: 38px;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            border-radius: var(--radius-sm);
            color: #fff;
            font-size: 18px;
        }
        .logo:hover { color: var(--text); }
        .nav-list {
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .nav-list a {
            display: block;
            padding: 8px 18px;
            font-size: 15px;
            font-weight: 500;
            color: var(--text-soft);
            border-radius: var(--radius-sm);
            transition: background var(--transition), color var(--transition);
        }
        .nav-list a:hover,
        .nav-list a:focus-visible {
            background: var(--primary-50);
            color: var(--primary);
        }
        .nav-list a.active {
            background: var(--primary);
            color: #fff;
        }
        .nav-list a.active:hover {
            background: var(--primary-dark);
            color: #fff;
        }
        .nav-cta { margin-left: 12px; }
        .nav-toggle {
            display: none;
            font-size: 24px;
            color: var(--text);
            padding: 6px 10px;
            border-radius: var(--radius-sm);
            background: var(--bg-alt);
            transition: background var(--transition);
        }
        .nav-toggle:hover { background: var(--border); }
        @media (max-width: 900px) {
            .nav-toggle { display: flex; align-items: center; justify-content: center; }
            .nav-list {
                display: none;
                position: absolute;
                top: var(--header-height);
                left: 0;
                right: 0;
                flex-direction: column;
                background: rgba(255,255,255,0.98);
                backdrop-filter: blur(20px);
                -webkit-backdrop-filter: blur(20px);
                border-bottom: 1px solid var(--border);
                padding: 12px 20px 20px;
                gap: 4px;
                box-shadow: var(--shadow-lg);
            }
            .nav-list.open { display: flex; }
            .nav-list a { padding: 12px 16px; width: 100%; }
            .nav-cta { margin-left: 0; margin-top: 8px; width: 100%; }
            .nav-cta .btn { width: 100%; justify-content: center; }
        }

        /* ===== 按钮 ===== */
        .btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 28px;
            font-size: 15px;
            font-weight: 600;
            border-radius: var(--radius-sm);
            transition: all var(--transition);
            border: 2px solid transparent;
            text-align: center;
            line-height: 1.4;
        }
        .btn:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }
        .btn-primary {
            background: var(--primary);
            color: #fff;
            border-color: var(--primary);
        }
        .btn-primary:hover,
        .btn-primary:focus-visible {
            background: var(--primary-dark);
            border-color: var(--primary-dark);
            color: #fff;
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(37,99,235,0.3);
        }
        .btn-primary:active { transform: translateY(0); box-shadow: none; }
        .btn-outline {
            background: transparent;
            color: var(--primary);
            border-color: var(--primary);
        }
        .btn-outline:hover,
        .btn-outline:focus-visible {
            background: var(--primary);
            color: #fff;
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(37,99,235,0.2);
        }
        .btn-outline:active { transform: translateY(0); box-shadow: none; }
        .btn-ghost {
            background: transparent;
            color: var(--text-soft);
            border-color: transparent;
        }
        .btn-ghost:hover,
        .btn-ghost:focus-visible {
            background: var(--bg-alt);
            color: var(--text);
        }
        .btn-sm { padding: 8px 18px; font-size: 14px; gap: 6px; }
        .btn-lg { padding: 16px 36px; font-size: 17px; }
        .btn-accent {
            background: var(--accent);
            color: #fff;
            border-color: var(--accent);
        }
        .btn-accent:hover,
        .btn-accent:focus-visible {
            background: var(--accent-dark);
            border-color: var(--accent-dark);
            color: #fff;
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(245,158,11,0.3);
        }
        .btn-accent:active { transform: translateY(0); box-shadow: none; }

        /* ===== 文章 Hero ===== */
        .article-hero {
            padding: 140px 0 60px;
            background: var(--bg-alt);
            position: relative;
            overflow: hidden;
            min-height: 360px;
            display: flex;
            align-items: center;
        }
        .article-hero-bg {
            position: absolute;
            inset: 0;
            background: url('/assets/images/backpic/back-1.webp') center center / cover no-repeat;
            opacity: 0.15;
            z-index: 0;
        }
        .article-hero .container {
            position: relative;
            z-index: 1;
        }
        .article-hero-meta {
            display: flex;
            flex-wrap: wrap;
            gap: 12px 20px;
            margin-bottom: 16px;
            align-items: center;
        }
        .article-hero-category {
            display: inline-block;
            padding: 4px 14px;
            font-size: 13px;
            font-weight: 600;
            color: var(--primary);
            background: var(--primary-100);
            border-radius: 20px;
        }
        .article-hero-date {
            font-size: 14px;
            color: var(--text-muted);
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .article-hero-date i { font-size: 13px; }
        .article-hero h1 {
            font-size: 36px;
            font-weight: 800;
            line-height: 1.25;
            color: var(--text);
            max-width: 900px;
            letter-spacing: -0.5px;
            margin-bottom: 8px;
        }
        .article-hero-sub {
            font-size: 16px;
            color: var(--text-soft);
            max-width: 700px;
            line-height: 1.6;
        }
        @media (max-width: 768px) {
            .article-hero { padding: 120px 0 40px; min-height: 280px; }
            .article-hero h1 { font-size: 26px; }
            .article-hero-sub { font-size: 15px; }
        }
        @media (max-width: 520px) {
            .article-hero h1 { font-size: 22px; }
            .article-hero-meta { gap: 8px 14px; }
        }

        /* ===== 文章正文 ===== */
        .article-body {
            padding: 50px 0 60px;
            background: var(--bg);
        }
        .article-body .container {
            max-width: 840px;
        }
        .article-body .content {
            font-size: 17px;
            line-height: 1.85;
            color: var(--text);
        }
        .article-body .content p {
            margin-bottom: 1.4em;
        }
        .article-body .content h2,
        .article-body .content h3,
        .article-body .content h4 {
            margin-top: 1.8em;
            margin-bottom: 0.6em;
            font-weight: 700;
            line-height: 1.3;
            color: var(--text);
        }
        .article-body .content h2 { font-size: 26px; }
        .article-body .content h3 { font-size: 21px; }
        .article-body .content h4 { font-size: 18px; }
        .article-body .content ul,
        .article-body .content ol {
            margin-bottom: 1.4em;
            padding-left: 1.6em;
        }
        .article-body .content ul { list-style: disc; }
        .article-body .content ol { list-style: decimal; }
        .article-body .content li { margin-bottom: 0.4em; }
        .article-body .content blockquote {
            border-left: 4px solid var(--primary);
            padding: 12px 20px;
            margin: 1.4em 0;
            background: var(--primary-50);
            border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
            color: var(--text-soft);
            font-style: normal;
        }
        .article-body .content a { color: var(--primary); text-decoration: underline; text-underline-offset: 2px; }
        .article-body .content a:hover { color: var(--primary-dark); }
        .article-body .content img {
            border-radius: var(--radius-md);
            margin: 1.6em auto;
            box-shadow: var(--shadow-md);
        }
        .article-body .content code {
            background: var(--bg-alt);
            padding: 2px 8px;
            border-radius: 4px;
            font-size: 0.9em;
            color: var(--primary-dark);
        }
        .article-body .content pre {
            background: #1e293b;
            color: #e2e8f0;
            padding: 20px 24px;
            border-radius: var(--radius-md);
            overflow-x: auto;
            margin: 1.4em 0;
            font-size: 14px;
            line-height: 1.6;
        }
        .article-body .content pre code { background: transparent; color: inherit; padding: 0; }
        .article-empty {
            text-align: center;
            padding: 60px 20px;
        }
        .article-empty i { font-size: 48px; color: var(--text-muted); margin-bottom: 16px; }
        .article-empty h3 { font-size: 22px; color: var(--text); margin-bottom: 8px; }
        .article-empty p { color: var(--text-soft); margin-bottom: 20px; }
        @media (max-width: 768px) {
            .article-body .content { font-size: 16px; }
            .article-body .content h2 { font-size: 22px; }
            .article-body .content h3 { font-size: 18px; }
        }

        /* ===== 文章互动 ===== */
        .article-interact {
            padding: 40px 0 50px;
            background: var(--bg-alt);
            border-top: 1px solid var(--border);
        }
        .article-interact .container {
            max-width: 840px;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            gap: 20px;
        }
        .article-interact .share-label {
            font-size: 15px;
            font-weight: 600;
            color: var(--text-soft);
            display: flex;
            align-items: center;
            gap: 12px;
        }
        .article-interact .share-label a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background: var(--bg);
            color: var(--text-soft);
            border: 1px solid var(--border);
            transition: all var(--transition);
            font-size: 16px;
        }
        .article-interact .share-label a:hover {
            background: var(--primary);
            color: #fff;
            border-color: var(--primary);
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(37,99,235,0.2);
        }
        .article-interact .interact-actions {
            display: flex;
            gap: 12px;
            flex-wrap: wrap;
        }
        @media (max-width: 640px) {
            .article-interact .container { flex-direction: column; align-items: stretch; }
            .article-interact .share-label { justify-content: center; }
            .article-interact .interact-actions { justify-content: center; }
        }

        /* ===== FAQ 区块 ===== */
        .section-faq {
            padding: 60px 0 70px;
            background: var(--bg);
        }
        .section-faq .container {
            max-width: 840px;
        }
        .section-faq .section-title {
            text-align: center;
            font-size: 28px;
            font-weight: 800;
            margin-bottom: 10px;
            color: var(--text);
        }
        .section-faq .section-sub {
            text-align: center;
            font-size: 16px;
            color: var(--text-soft);
            margin-bottom: 36px;
        }
        .faq-item {
            border: 1px solid var(--border);
            border-radius: var(--radius-md);
            margin-bottom: 12px;
            overflow: hidden;
            transition: box-shadow var(--transition);
            background: var(--bg-card);
        }
        .faq-item:hover { box-shadow: var(--shadow-sm); }
        .faq-question {
            display: flex;
            align-items: center;
            justify-content: space-between;
            width: 100%;
            padding: 18px 24px;
            font-size: 16px;
            font-weight: 600;
            color: var(--text);
            background: transparent;
            text-align: left;
            transition: background var(--transition);
            gap: 12px;
        }
        .faq-question:hover { background: var(--bg-alt); }
        .faq-question:focus-visible { outline: 2px solid var(--primary); outline-offset: -2px; }
        .faq-question .faq-icon {
            flex-shrink: 0;
            width: 24px;
            height: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--primary);
            transition: transform var(--transition);
            font-size: 14px;
        }
        .faq-item.open .faq-question .faq-icon { transform: rotate(45deg); }
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease, padding 0.35s ease;
            padding: 0 24px;
        }
        .faq-item.open .faq-answer {
            max-height: 400px;
            padding: 0 24px 20px;
        }
        .faq-answer p {
            font-size: 15px;
            color: var(--text-soft);
            line-height: 1.7;
        }
        @media (max-width: 768px) {
            .section-faq .section-title { font-size: 24px; }
            .faq-question { padding: 14px 18px; font-size: 15px; }
            .faq-answer { padding: 0 18px; }
            .faq-item.open .faq-answer { padding: 0 18px 16px; }
        }

        /* ===== 页脚 ===== */
        footer {
            background: #0f172a;
            color: #cbd5e1;
            padding: 60px 0 0;
        }
        footer .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }
        footer .footer-brand .logo {
            color: #f1f5f9;
            margin-bottom: 14px;
        }
        footer .footer-brand .logo .logo-icon {
            background: linear-gradient(135deg, var(--primary-light), var(--primary));
        }
        footer .footer-brand p {
            font-size: 14px;
            line-height: 1.7;
            color: #94a3b8;
            max-width: 360px;
        }
        footer .footer-col h5 {
            font-size: 15px;
            font-weight: 700;
            color: #f1f5f9;
            margin-bottom: 16px;
        }
        footer .footer-col ul li { margin-bottom: 10px; }
        footer .footer-col ul li a {
            font-size: 14px;
            color: #94a3b8;
            transition: color var(--transition);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        footer .footer-col ul li a:hover { color: #f1f5f9; }
        footer .footer-col ul li a i { font-size: 14px; width: 16px; text-align: center; }
        footer .footer-bottom {
            border-top: 1px solid #1e293b;
            padding: 20px 0;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 10px;
            font-size: 13px;
            color: #64748b;
        }
        @media (max-width: 900px) {
            footer .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
            footer .footer-brand { grid-column: 1 / -1; }
        }
        @media (max-width: 520px) {
            footer .footer-grid { grid-template-columns: 1fr; gap: 24px; }
            footer .footer-bottom { flex-direction: column; text-align: center; }
        }

        /* ===== 通用 ===== */
        .text-center { text-align: center; }
        .mt-1 { margin-top: 10px; }
        .mt-2 { margin-top: 20px; }
        .mt-3 { margin-top: 30px; }
        .mb-1 { margin-bottom: 10px; }
        .mb-2 { margin-bottom: 20px; }
        .gap-1 { gap: 10px; }
        .gap-2 { gap: 20px; }
        .flex { display: flex; }
        .flex-wrap { flex-wrap: wrap; }
        .items-center { align-items: center; }
        .justify-center { justify-content: center; }

        /* ===== 滚动条 ===== */
        ::-webkit-scrollbar { width: 8px; }
        ::-webkit-scrollbar-track { background: var(--bg-alt); }
        ::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
        ::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

        /* ===== 选中 ===== */
        ::selection { background: var(--primary-100); color: var(--primary-dark); }

        /* ===== 打印 ===== */
        @media print {
            .header, .article-interact, .section-faq, footer { display: none; }
            .article-hero { padding: 20px 0; min-height: auto; }
            .article-body { padding: 20px 0; }
            .article-hero-bg { display: none; }
        }