/* ========== 全局样式 ========== */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            line-height: 1.6;
            color: #333;
            background-color: #f9fafb;
        }

        a {
            color: #2563eb;
            text-decoration: none;
        }

        a:hover {
            text-decoration: underline;
        }

        .container {
            max-width: 1100px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* ========== 导航栏 ========== */
        header {
            background-color: #ffffff;
            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
            position: sticky;
            top: 0;
            z-index: 100;
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 16px 0;
        }

        .logo {
            font-size: 1.7rem;
            font-weight: 700;
            color: #1e3a5f;
        }

        .nav-links {
            display: flex;
            list-style: none;
            gap: 24px;
        }

        .nav-links a {
            color: #4b5563;
            font-weight: 500;
            transition: color 0.2s;
        }

        .nav-links a:hover {
            color: #2563eb;
            text-decoration: none;
        }

        /* ========== 特性区域 ========== */
        .hero {
            background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 100%);
            color: #ffffff;
            padding: 80px 0;
            text-align: center;
        }

        .hero h1 {
            font-size: 2.8rem;
            margin-bottom: 16px;
            font-weight: 800;
        }

        .hero p {
            font-size: 1.2rem;
            margin-bottom: 32px;
            opacity: 0.9;
            max-width: 600px;
            margin-left: auto;
            margin-right: auto;
        }

        .btn {
            display: inline-block;
            padding: 14px 32px;
            border-radius: 8px;
            font-weight: 600;
            font-size: 1rem;
            cursor: pointer;
            transition: all 0.3s;
            border: none;
        }

        .btn-primary {
            background-color: #ffffff;
            color: #2563eb;
        }

        .btn-primary:hover {
            background-color: #f0f4ff;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
            text-decoration: none;
        }

        .btn-secondary {
            background-color: transparent;
            color: #ffffff;
            border: 2px solid #ffffff;
            margin-left: 12px;
        }

        .btn-secondary:hover {
            background-color: #ffffff;
            color: #2563eb;
            text-decoration: none;
        }

        .snap {
            padding: 30px 0;
            background-color: #ffffff;
        }

        .download {
            padding: 80px 0;
            background-color: #ffffff;
        }

        /* ========== 功能特性 ========== */
        .features {
            padding: 80px 0;
            background-color: #ffffff;
        }

        .section-title {
            text-align: center;
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 48px;
            color: #1e3a5f;
        }

        .feature-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 32px;
        }

        .feature-card {
            padding: 32px;
            border-radius: 12px;
            background-color: #f9fafb;
            border: 1px solid #e5e7eb;
            transition: transform 0.3s, box-shadow 0.3s;
        }

        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
        }

        .feature-icon {
            font-size: 2.5rem;
            margin-bottom: 16px;
        }

        .feature-card h3 {
            font-size: 1.3rem;
            margin-bottom: 12px;
            color: #1e3a5f;
        }

        .feature-card p {
            color: #6b7280;
        }

        /* ========== 使用步骤 ========== */
        .how-it-works {
            padding: 80px 0;
            background-color: #f9fafb;
        }

        .steps {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 32px;
            counter-reset: step-counter;
        }

        .step {
            text-align: center;
            position: relative;
        }

        .step-number {
            display: inline-block;
            width: 48px;
            height: 48px;
            line-height: 48px;
            border-radius: 50%;
            background-color: #2563eb;
            color: #ffffff;
            font-size: 1.3rem;
            font-weight: 700;
            margin-bottom: 16px;
        }

        .step h3 {
            margin-bottom: 8px;
            color: #1e3a5f;
        }

        .step p {
            color: #6b7280;
        }

        /* ========== 页脚 ========== */
        footer {
            background-color: #1e3a5f;
            color: #cbd5e1;
            padding: 40px 0;
            text-align: center;
        }

        footer p {
            margin: 0;
        }

        /* ========== 响应式设计 ========== */
        @media (max-width: 768px) {
            .hero h1 {
                font-size: 2rem;
            }

            .hero p {
                font-size: 1rem;
            }

            .nav-links {
                gap: 12px;
            }

            .btn-secondary {
                margin-left: 0;
                margin-top: 12px;
            }
        }