:root {
            --bg: #f8fafc;
            --surface: #ffffff;
            --text: #0f172a;
            --text-secondary: #475569;
            --text-muted: #64748b;
            --accent: #2563eb;
            --accent-hover: #1d4ed8;
            --accent-light: #eff6ff;
            --border: #e2e8f0;
            --border-light: #eef2ff;
            --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.04);
            --shadow: 0 8px 24px rgba(0, 0, 0, 0.06);
            --shadow-lg: 0 20px 32px rgba(0, 0, 0, 0.08);
            --radius-sm: 0.75rem;
            --radius: 1.25rem;
            --radius-lg: 2rem;
            --transition: 0.22s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        body {
            font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
            background: var(--bg);
            color: var(--text);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
        }

        .container {
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 1.5rem;
        }

        /* ===== HEADER ===== */
        header {
            background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
            color: #fff;
            position: sticky;
            top: 0;
            z-index: 100;
            box-shadow: 0 4px 16px rgba(0, 0, 0, 0.18);
            backdrop-filter: blur(8px);
        }
        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            padding: 0.9rem 0;
            gap: 0.8rem;
        }
        .logo h1 {
            font-size: 1.7rem;
            font-weight: 750;
            letter-spacing: -0.02em;
            white-space: nowrap;
        }
        .logo span {
            background: #3b82f6;
            font-size: 0.72rem;
            padding: 0.18rem 0.55rem;
            border-radius: 9999px;
            margin-left: 0.4rem;
            vertical-align: middle;
            font-weight: 600;
            letter-spacing: 0.02em;
        }
        .nav-links {
            display: flex;
            gap: 1.6rem;
            flex-wrap: wrap;
            list-style: none;
            align-items: center;
        }
        .nav-links a {
            color: #e2e8f0;
            text-decoration: none;
            font-weight: 500;
            font-size: 0.95rem;
            transition: color var(--transition);
            position: relative;
            padding: 0.25rem 0;
        }
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2px;
            background: #60a5fa;
            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: #60a5fa;
        }

        /* ===== PAGE HERO ===== */
        .page-hero {
            background: linear-gradient(125deg, #eef2ff 0%, #f9fafb 40%, #ffffff 100%);
            padding: 3rem 0 2rem 0;
            border-bottom: 1px solid var(--border);
            text-align: center;
        }
        .page-hero h1 {
            font-size: clamp(2rem, 4vw, 2.5rem);
            font-weight: 800;
            letter-spacing: -0.03em;
            background: linear-gradient(135deg, #0f172a 30%, #2563eb 100%);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
            margin-bottom: 0.6rem;
        }
        .page-hero .subtitle {
            font-size: 1.1rem;
            color: #475569;
            max-width: 680px;
            margin: 0 auto;
        }

        /* ===== SECTION ===== */
        .section {
            padding: 2.8rem 0;
        }
        .section-title {
            font-size: clamp(1.5rem, 3vw, 1.9rem);
            font-weight: 700;
            text-align: center;
            margin-bottom: 0.4rem;
            color: var(--text);
            letter-spacing: -0.02em;
        }
        .section-subtitle {
            text-align: center;
            color: var(--text-muted);
            font-size: 0.95rem;
            margin-bottom: 2rem;
        }

        /* ===== CARDS ===== */
        .card-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
        }
        .card {
            background: var(--surface);
            border-radius: var(--radius);
            padding: 1.6rem;
            box-shadow: var(--shadow-sm);
            border: 1px solid var(--border-light);
            transition: all var(--transition);
            position: relative;
        }
        .card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow);
            border-color: #b9d0f8;
        }
        .card-icon {
            font-size: 2.2rem;
            margin-bottom: 0.8rem;
            display: block;
        }
        .card h3 {
            font-size: 1.4rem;
            margin-bottom: 0.4rem;
            font-weight: 650;
            letter-spacing: -0.01em;
        }
        .card p {
            color: var(--text-secondary);
            font-size: 0.93rem;
            line-height: 1.6;
        }
        .highlight {
            background: #fef9c3;
            padding: 0.1rem 0.3rem;
            border-radius: 0.25rem;
            font-weight: 600;
            color: #854d0e;
        }
        .code-snippet {
            background: #1e293b;
            color: #e2e8f0;
            padding: 0.8rem 1.2rem;
            border-radius: var(--radius-sm);
            font-family: 'Fira Code', 'Consolas', monospace;
            font-size: 0.85rem;
            margin-top: 0.6rem;
            word-break: break-all;
            overflow-x: auto;
        }
        .btn-outline-sm {
            display: inline-block;
            padding: 0.45rem 1.1rem;
            font-size: 0.85rem;
            border-radius: 2rem;
            border: 1.5px solid var(--accent);
            color: var(--accent);
            text-decoration: none;
            font-weight: 500;
            transition: all var(--transition);
        }
        .btn-outline-sm:hover {
            background: var(--accent-light);
            transform: translateX(2px);
        }

        /* ===== COMPARE TABLE ===== */
        .compare-mini {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1.5rem;
            max-width: 750px;
            margin: 0 auto;
        }
        .compare-card {
            background: var(--surface);
            border-radius: var(--radius);
            padding: 1.5rem;
            border: 1px solid var(--border-light);
            text-align: center;
            box-shadow: var(--shadow-sm);
            transition: all var(--transition);
        }
        .compare-card:hover {
            box-shadow: var(--shadow);
            border-color: #b9d0f8;
        }
        .compare-card h4 {
            font-size: 1.15rem;
            margin-bottom: 0.8rem;
        }
        .compare-card ul {
            list-style: none;
            text-align: left;
            margin: 0.8rem 0;
            font-size: 0.88rem;
        }
        .compare-card ul li {
            padding: 0.25rem 0;
            color: var(--text-secondary);
        }
        .compare-card ul li::before {
            content: '✓ ';
            color: #22c55e;
            font-weight: 700;
        }

        /* ===== CTA ===== */
        .cta-bottom {
            background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #1e293b 100%);
            color: #fff;
            text-align: center;
            padding: 2.8rem 1.5rem;
            border-radius: var(--radius-lg);
            margin: 2rem 0;
            position: relative;
            overflow: hidden;
        }
        .cta-bottom::before {
            content: '';
            position: absolute;
            top: -50px;
            right: -50px;
            width: 200px;
            height: 200px;
            background: radial-gradient(circle, rgba(59, 130, 246, 0.25) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }
        .cta-bottom h3 {
            font-size: 1.7rem;
            font-weight: 700;
            margin-bottom: 0.6rem;
            position: relative;
            z-index: 2;
        }
        .cta-bottom p {
            color: #cbd5e1;
            margin-bottom: 1.4rem;
            position: relative;
            z-index: 2;
            font-size: 1rem;
        }
        .btn-primary {
            display: inline-flex;
            align-items: center;
            gap: 0.4rem;
            padding: 0.85rem 2.4rem;
            border-radius: 2.5rem;
            font-weight: 600;
            text-decoration: none;
            transition: all var(--transition);
            cursor: pointer;
            font-size: 1.05rem;
            background: #22c55e;
            color: #fff;
            box-shadow: 0 4px 16px rgba(34,197,94,0.35);
            border: none;
        }
        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 25px rgba(34,197,94,0.45);
        }

        /* ===== FOOTER ===== */
        footer {
            background: #0f172a;
            color: #cbd5e1;
            padding: 2rem 0;
            margin-top: 1.5rem;
            border-top: 1px solid #1e293b;
        }
        .footer-content {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 1rem;
            font-size: 0.9rem;
        }
        .copyright {
            text-align: center;
            padding-top: 1.2rem;
            margin-top: 1rem;
            border-top: 1px solid #1e293b;
            font-size: 0.8rem;
            color: #94a3b8;
        }

        @media (max-width: 768px) {
            .header-inner {
                flex-direction: column;
                align-items: flex-start;
            }
            .nav-links {
                gap: 1rem;
            }
            .compare-mini {
                grid-template-columns: 1fr;
            }
            .card-grid {
                grid-template-columns: 1fr;
            }
        }