:root {
            --primary-color: #00d2ff;
            --secondary-color: #3a7bd5;
            --accent-color: #ff0055;
            --bg-dark: #0f172a;
            --bg-card: #1e293b;
            --text-light: #f8fafc;
            --text-gray: #94a3b8;
            --font-main: 'Inter', system-ui, -apple-system, sans-serif;
        }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        
        body {
            font-family: var(--font-main);
            background-color: var(--bg-dark);
            color: var(--text-light);
            line-height: 1.6;
            overflow-x: hidden;
        }

        a { text-decoration: none; color: inherit; transition: 0.3s; }
        ul { list-style: none; }

        /* --- 导航栏 --- */
        .navbar {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1.5rem 5%;
            position: fixed;
            width: 100%;
            top: 0;
            z-index: 1000;
            background: rgba(15, 23, 42, 0.8);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid rgba(255,255,255,0.05);
        }

        .logo {
            font-size: 1.5rem;
            font-weight: 800;
            background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            letter-spacing: -1px;
        }

        .nav-links a {
            margin-left: 2rem;
            font-size: 0.95rem;
            color: var(--text-gray);
            font-weight: 500;
        }

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

        .btn-login {
            border: 1px solid var(--primary-color);
            padding: 0.5rem 1.2rem;
            border-radius: 6px;
            color: var(--primary-color);
            font-size: 0.9rem;
        }

        .btn-login:hover {
            background: var(--primary-color);
            color: #fff;
        }

        /* --- 英雄区域 --- */
        .hero {
            height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            padding: 0 1rem;
            position: relative;
            background: radial-gradient(circle at top center, #1e293b 0%, #0f172a 70%);
        }

        .hero::before {
            content: '';
            position: absolute;
            width: 600px;
            height: 600px;
            background: var(--primary-color);
            filter: blur(150px);
            opacity: 0.15;
            border-radius: 50%;
            top: 20%;
            left: 50%;
            transform: translateX(-50%);
            z-index: 0;
        }

        .hero-content {
            z-index: 1;
            max-width: 800px;
            animation: fadeInUp 1s ease-out;
        }

        .hero h1 {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            line-height: 1.1;
        }

        .hero h1 span {
            color: var(--primary-color);
        }

        .hero p {
            font-size: 1.2rem;
            color: var(--text-gray);
            margin-bottom: 2.5rem;
        }

        .btn-group {
            display: flex;
            gap: 1rem;
            justify-content: center;
        }

        .btn {
            padding: 1rem 2.5rem;
            border-radius: 50px;
            font-weight: 600;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s ease;
            display: inline-block;
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: #fff;
            box-shadow: 0 10px 20px -10px var(--primary-color);
        }

        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 30px -10px var(--primary-color);
        }

        .btn-outline {
            background: transparent;
            border: 1px solid var(--text-gray);
            color: var(--text-light);
        }

        .btn-outline:hover {
            border-color: var(--primary-color);
            color: var(--primary-color);
            background: rgba(255,255,255,0.05);
        }

        /* --- 特性区域 --- */
        .features {
            padding: 6rem 5%;
            background: var(--bg-dark);
        }

        .section-header {
            text-align: center;
            margin-bottom: 4rem;
        }

        .section-header h2 {
            font-size: 2.5rem;
            margin-bottom: 1rem;
        }

        .section-header .line {
            width: 60px;
            height: 4px;
            background: var(--primary-color);
            margin: 0 auto;
            border-radius: 2px;
        }

        .grid-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
            max-width: 1200px;
            margin: 0 auto;
        }

        .card {
            background: var(--bg-card);
            padding: 2.5rem;
            border-radius: 16px;
            border: 1px solid rgba(255,255,255,0.05);
            transition: 0.3s;
            position: relative;
            overflow: hidden;
        }

        .card:hover {
            transform: translateY(-10px);
            border-color: var(--primary-color);
            box-shadow: 0 20px 40px -10px rgba(0,0,0,0.5);
        }

        .card-icon {
            font-size: 2.5rem;
            margin-bottom: 1.5rem;
            color: var(--primary-color);
        }

        .card h3 {
            font-size: 1.5rem;
            margin-bottom: 1rem;
            color: #fff;
        }

        .card p {
            color: var(--text-gray);
            font-size: 0.95rem;
        }

        /* --- 数据展示条 --- */
        .stats {
            background: var(--bg-card);
            padding: 3rem 5%;
            display: flex;
            justify-content: space-around;
            flex-wrap: wrap;
            text-align: center;
            border-top: 1px solid rgba(255,255,255,0.05);
            border-bottom: 1px solid rgba(255,255,255,0.05);
        }

        .stat-item h3 {
            font-size: 2.5rem;
            color: var(--primary-color);
            font-weight: 800;
        }

        .stat-item p {
            color: var(--text-gray);
            text-transform: uppercase;
            letter-spacing: 1px;
            font-size: 0.9rem;
            margin-top: 0.5rem;
        }

        /* --- 页脚 --- */
        footer {
            text-align: center;
            padding: 3rem;
            color: var(--text-gray);
            font-size: 0.9rem;
            border-top: 1px solid rgba(255,255,255,0.05);
        }

        /* --- 动画 --- */
        @keyframes fadeInUp {
            from { opacity: 0; transform: translateY(30px); }
            to { opacity: 1; transform: translateY(0); }
        }

        /* --- 响应式 --- */
        @media (max-width: 768px) {
            .hero h1 { font-size: 2.5rem; }
            .btn-group { flex-direction: column; }
            .navbar { padding: 1.5rem; }
            .nav-links { display: none; } /* 简化版：移动端隐藏菜单 */
        }