:root {
            --color-primary: #2563eb;
            --color-primary-deep: #1d4ed8;
            --color-primary-light: #60a5fa;
            --color-accent: #0d9488;
            --color-accent-warm: #f97316;
            --color-accent-soft: #fbbf24;
            --color-surface: #f8fafc;
            --color-surface-alt: #f1f5f9;
            --color-card: #ffffff;
            --color-text: #1e293b;
            --color-text-muted: #475569;
            --color-text-light: #64748b;
            --color-border: #e2e8f0;
            --color-border-hover: #cbd5e1;
            --color-shadow: rgba(30, 64, 175, 0.06);
            --color-shadow-hover: rgba(37, 99, 235, 0.14);
            --color-footer-bg: #0f172a;
            --color-footer-text: #cbd5e1;
            --color-tag-bg: #eff6ff;
            --color-tag-text: #1d4ed8;
            --color-success: #10b981;
            --gradient-hero: linear-gradient(135deg, #1e40af 0%, #2563eb 28%, #0d9488 62%, #0891b2 100%);
            --gradient-btn: linear-gradient(135deg, #2563eb, #0d9488);
            --gradient-btn-hover: linear-gradient(135deg, #1d4ed8, #0f766e);
            --radius-sm: 8px;
            --radius-md: 14px;
            --radius-lg: 20px;
            --radius-full: 50px;
            --transition: 0.2s ease;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: system-ui, -apple-system, 'Segoe UI', 'Roboto', 'Helvetica Neue', 'Noto Sans SC', sans-serif;
            background: var(--color-surface);
            color: var(--color-text);
            line-height: 1.6;
            scroll-behavior: smooth;
            -webkit-font-smoothing: antialiased;
            font-display: swap;
        }
        .container {
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 20px;
        }
        /* 头部导航（与首页一致） */
        .header {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            box-shadow: 0 1px 3px var(--color-shadow);
            position: sticky;
            top: 0;
            z-index: 50;
            border-bottom: 1px solid var(--color-border);
        }
        .navbar {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            padding: 12px 0;
            gap: 12px;
        }
        .logo {
            font-size: 1.55rem;
            font-weight: 750;
            background: var(--gradient-hero);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
            letter-spacing: -0.02em;
            text-decoration: none;
            white-space: nowrap;
        }
        .nav-links {
            display: flex;
            gap: 18px;
            align-items: center;
            flex-wrap: wrap;
            list-style: none;
        }
        .nav-links a {
            text-decoration: none;
            font-weight: 520;
            color: #334155;
            transition: color var(--transition);
            font-size: 0.9rem;
            white-space: nowrap;
            position: relative;
            padding: 4px 0;
        }
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--color-primary);
            border-radius: 2px;
            transition: width var(--transition);
        }
        .nav-links a:hover::after,
        .nav-links a.active::after {
            width: 100%;
        }
        .nav-links a:hover,
        .nav-links a.active {
            color: var(--color-primary);
        }
        .nav-links .btn-nav-cta {
            background: var(--gradient-btn);
            color: #fff !important;
            padding: 7px 18px;
            border-radius: var(--radius-full);
            font-weight: 600;
            transition: all var(--transition);
            font-size: 0.85rem;
            letter-spacing: 0.02em;
        }
        .nav-links .btn-nav-cta::after {
            display: none;
        }
        .nav-links .btn-nav-cta:hover {
            background: var(--gradient-btn-hover);
            transform: translateY(-1px);
            box-shadow: 0 4px 14px -4px rgba(37, 99, 235, 0.4);
        }
        .nav-toggle {
            display: none;
            background: none;
            border: none;
            font-size: 1.5rem;
            cursor: pointer;
            color: var(--color-text);
            padding: 4px 8px;
        }
        @media (max-width: 860px) {
            .nav-links {
                display: none;
                flex-direction: column;
                width: 100%;
                gap: 6px;
                padding-top: 8px;
            }
            .nav-links.open {
                display: flex;
            }
            .nav-toggle {
                display: block;
            }
            .nav-links a {
                padding: 8px 4px;
                font-size: 0.88rem;
                width: 100%;
            }
            .nav-links .btn-nav-cta {
                text-align: center;
                margin-top: 4px;
            }
        }
        /* 页面Hero */
        .page-hero {
            padding: 56px 0 32px;
            background: linear-gradient(170deg, #f8fafc 0%, #eff6ff 35%, #f0fdfa 70%, #fff 100%);
            text-align: center;
        }
        .page-hero h1 {
            font-size: clamp(1.8rem, 4.5vw, 2.4rem);
            font-weight: 800;
            background: var(--gradient-hero);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
            margin-bottom: 10px;
            letter-spacing: -0.02em;
        }
        .page-hero .sub {
            color: var(--color-text-muted);
            font-size: 1rem;
            max-width: 620px;
            margin: 0 auto 16px;
        }
        /* 步骤进度条 */
        .steps-overview {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 8px;
            margin-bottom: 30px;
        }
        .step-pill {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            padding: 6px 14px;
            border-radius: var(--radius-full);
            font-size: 0.8rem;
            font-weight: 500;
            color: var(--color-text);
            display: flex;
            align-items: center;
            gap: 5px;
        }
        .step-num {
            background: var(--color-primary);
            color: #fff;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-size: 0.7rem;
            font-weight: 700;
        }
        /* 内容卡片 */
        .tutorial-section {
            padding: 44px 0;
        }
        .tutorial-section h2 {
            text-align: center;
            font-size: 1.5rem;
            font-weight: 720;
            margin-bottom: 6px;
        }
        .tutorial-section .section-desc {
            text-align: center;
            color: var(--color-text-muted);
            margin-bottom: 26px;
            font-size: 0.9rem;
        }
        .grid-2col {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
            max-width: 900px;
            margin: 0 auto;
        }
        .card {
            background: var(--color-card);
            border: 1px solid var(--color-border);
            border-radius: var(--radius-md);
            padding: 20px;
            transition: all var(--transition);
        }
        .card:hover {
            box-shadow: 0 6px 18px -4px var(--color-shadow-hover);
            border-color: var(--color-primary-light);
        }
        .card h3 {
            font-size: 1rem;
            font-weight: 700;
            margin-bottom: 8px;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .card p,
        .card li {
            font-size: 0.85rem;
            color: var(--color-text-muted);
            line-height: 1.5;
        }
        .card ul {
            list-style: none;
            padding-left: 0;
        }
        .card ul li::before {
            content: '▪';
            color: var(--color-primary);
            margin-right: 6px;
        }
        .badge {
            display: inline-block;
            padding: 2px 8px;
            border-radius: 10px;
            font-size: 0.65rem;
            font-weight: 700;
            letter-spacing: 0.03em;
            vertical-align: middle;
            margin-left: 4px;
        }
        .badge-rec {
            background: #dcfce7;
            color: #166534;
        }
        .badge-adv {
            background: #ede9fe;
            color: #5b21b6;
        }
        .badge-warn {
            background: #fef3c7;
            color: #92400e;
        }
        /* 模式对比表 */
        .compare-table {
            width: 100%;
            max-width: 800px;
            margin: 16px auto;
            border-collapse: collapse;
            font-size: 0.85rem;
        }
        .compare-table th {
            background: #f1f5f9;
            padding: 10px 8px;
            text-align: left;
            font-weight: 600;
        }
        .compare-table td {
            padding: 10px 8px;
            border-bottom: 1px solid var(--color-border);
        }
        .compare-table tr:hover td {
            background: #f8fafc;
        }
        /* 手风琴FAQ */
        .faq-accordion {
            max-width: 700px;
            margin: 20px auto;
        }
        .faq-item {
            border: 1px solid var(--color-border);
            border-radius: var(--radius-sm);
            margin-bottom: 8px;
            background: var(--color-card);
        }
        .faq-header {
            width: 100%;
            text-align: left;
            background: none;
            border: none;
            padding: 14px 16px;
            font-weight: 600;
            font-size: 0.9rem;
            color: var(--color-text);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .faq-header::after {
            content: '▾';
            color: var(--color-primary);
            transition: transform 0.2s;
        }
        .faq-item.open .faq-header::after {
            transform: rotate(180deg);
        }
        .faq-body {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease;
        }
        .faq-item.open .faq-body {
            max-height: 400px;
        }
        .faq-content {
            padding: 0 16px 14px;
            font-size: 0.82rem;
            color: var(--color-text-muted);
        }
        /* 底部CTA */
        .cta-bottom {
            background: var(--color-footer-bg);
            color: #e2e8f0;
            padding: 40px 0;
            text-align: center;
        }
        .cta-bottom h2 {
            color: #fff;
            font-size: 1.6rem;
            margin-bottom: 8px;
        }
        .cta-bottom p {
            color: #cbd5e1;
            margin-bottom: 18px;
            font-size: 0.9rem;
        }
        .btn-cta-big {
            display: inline-block;
            background: var(--gradient-btn);
            color: #fff;
            font-weight: 700;
            padding: 14px 34px;
            border-radius: var(--radius-full);
            text-decoration: none;
            font-size: 1.05rem;
            transition: all 0.25s ease;
            box-shadow: 0 8px 20px -6px rgba(37, 99, 235, 0.5);
        }
        .btn-cta-big:hover {
            background: var(--gradient-btn-hover);
            transform: translateY(-2px);
            box-shadow: 0 12px 26px -8px rgba(37, 99, 235, 0.6);
        }
        .btn-outline-sm {
            display: inline-block;
            border: 1px solid var(--color-border);
            padding: 6px 14px;
            border-radius: var(--radius-full);
            font-size: 0.8rem;
            text-decoration: none;
            color: var(--color-text);
            transition: all var(--transition);
        }
        .btn-outline-sm:hover {
            border-color: var(--color-primary);
            color: var(--color-primary);
        }
        /* 页脚 */
        .footer {
            background: #0a0f1a;
            color: #cbd5e1;
            padding: 44px 0 24px;
            font-size: 0.82rem;
            border-top: 1px solid #1e293b;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
            gap: 30px;
            margin-bottom: 30px;
        }
        .footer-col h4 {
            color: #fff;
            margin-bottom: 12px;
            font-weight: 620;
            font-size: 0.85rem;
        }
        .footer-col a {
            display: block;
            color: #94a3b8;
            text-decoration: none;
            margin-bottom: 7px;
            transition: color var(--transition);
            font-size: 0.78rem;
        }
        .footer-col a:hover {
            color: #fff;
        }
        .copyright {
            text-align: center;
            padding-top: 22px;
            border-top: 1px solid #1e293b;
            color: #64748b;
            font-size: 0.72rem;
        }
        @media (max-width: 768px) {
            .grid-2col {
                grid-template-columns: 1fr;
            }
            .compare-table {
                font-size: 0.75rem;
            }
        }