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

        body {
            font-family: system-ui, -apple-system, 'Segoe UI', 'Roboto', 'Helvetica Neue', sans-serif;
            background: linear-gradient(145deg, #f6f9fc 0%, #eef2f5 100%);
            color: #1a2c3e;
            line-height: 1.6;
            scroll-behavior: smooth;
        }

        .container {
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 2rem;
        }

        /* Header */
        .site-header {
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid rgba(0, 0, 0, 0.05);
            position: sticky;
            top: 0;
            z-index: 100;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02);
        }

        .navbar {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            padding: 1rem 0;
            gap: 1rem;
        }

        .logo-area {
            display: flex;
            align-items: center;
            gap: 0.75rem;
        }

        .logo-svg {
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .logo-text {
            font-size: 1.8rem;
            font-weight: 700;
            background: linear-gradient(135deg, #0f2b3d, #1e4a6e);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
            letter-spacing: -0.3px;
        }

        .badge {
            font-size: 0.7rem;
            background: #eef2ff;
            padding: 0.2rem 0.6rem;
            border-radius: 30px;
            color: #1e4a6e;
            font-weight: 500;
        }

        .nav-links {
            display: flex;
            gap: 2rem;
            list-style: none;
            flex-wrap: wrap;
        }

        .nav-links a {
            text-decoration: none;
            font-weight: 500;
            color: #2c4c6c;
            transition: color 0.2s;
            font-size: 1rem;
            white-space: nowrap;
        }

        .nav-links a:hover,
        .nav-links a.active {
            color: #0f6b9c;
            border-bottom: 2px solid #0f6b9c;
            padding-bottom: 0.25rem;
        }

        /* Hero 区域 */
        .feature-hero {
            padding: 4rem 0 2rem;
            text-align: center;
        }

        .feature-hero h1 {
            font-size: 2.8rem;
            font-weight: 800;
            background: linear-gradient(125deg, #0a2e42, #1f6390);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
            margin-bottom: 1rem;
            letter-spacing: -0.02em;
        }

        .feature-hero .subtitle {
            font-size: 1.1rem;
            color: #3a627c;
            max-width: 700px;
            margin: 0 auto 0.5rem;
        }

        .feature-hero .desc {
            font-size: 0.95rem;
            color: #4a7896;
            max-width: 600px;
            margin: 0 auto;
        }

        /* 通用区块标题 */
        .section-title {
            font-size: 2rem;
            font-weight: 700;
            color: #1a3a4e;
            margin-bottom: 0.5rem;
            text-align: center;
        }

        .section-subtitle {
            text-align: center;
            color: #4a7896;
            font-size: 1rem;
            margin-bottom: 2rem;
            max-width: 650px;
            margin-left: auto;
            margin-right: auto;
        }

        /* 规则引擎卡片网格 */
        .rule-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 1.8rem;
            margin: 2rem 0;
        }

        .rule-card {
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(4px);
            border-radius: 1.8rem;
            padding: 2rem 1.5rem;
            border: 1px solid rgba(255, 255, 255, 0.6);
            box-shadow: 0 10px 20px -10px rgba(0, 0, 0, 0.06);
            transition: all 0.25s;
            text-align: center;
        }

        .rule-card:hover {
            transform: translateY(-6px);
            background: white;
            box-shadow: 0 20px 30px -12px rgba(0, 0, 0, 0.12);
        }

        .rule-icon {
            font-size: 2.6rem;
            margin-bottom: 0.8rem;
        }

        .rule-card h3 {
            font-size: 1.4rem;
            font-weight: 700;
            margin-bottom: 0.8rem;
            color: #1a3a4e;
        }

        .rule-card p {
            color: #3e627c;
            font-size: 0.95rem;
            line-height: 1.6;
        }

        /* DNS 手风琴 */
        .dns-accordion {
            max-width: 800px;
            margin: 0 auto;
        }

        details.dns-item {
            background: rgba(255, 255, 255, 0.75);
            border-radius: 1.5rem;
            border: 1px solid rgba(0, 0, 0, 0.04);
            padding: 0.8rem 1.8rem;
            margin-bottom: 1rem;
            transition: all 0.2s;
        }

        details.dns-item[open] {
            background: white;
            box-shadow: 0 8px 20px -8px rgba(0, 0, 0, 0.08);
        }

        details.dns-item summary {
            font-weight: 650;
            font-size: 1.15rem;
            color: #1a3a4e;
            cursor: pointer;
            list-style: none;
            display: flex;
            align-items: center;
            gap: 0.5rem;
            padding: 0.5rem 0;
        }

        details.dns-item summary::-webkit-details-marker {
            display: none;
        }

        details.dns-item summary::before {
            content: '▹';
            font-size: 1.3rem;
            color: #1e5a7a;
            transition: transform 0.2s;
        }

        details.dns-item[open] summary::before {
            content: '▿';
        }

        .dns-content {
            padding: 0.5rem 0 1rem;
            color: #3e627c;
            line-height: 1.7;
        }

        /* 安全审计区块 */
        .audit-section {
            background: rgba(255, 255, 255, 0.7);
            border-radius: 2rem;
            padding: 2.5rem 2rem;
            margin: 2.5rem 0;
            border: 1px solid rgba(255, 255, 255, 0.6);
            box-shadow: 0 10px 20px -10px rgba(0, 0, 0, 0.06);
            text-align: center;
        }

        .audit-grid {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 1.5rem 2.5rem;
            margin-top: 2rem;
        }

        .audit-item {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-weight: 550;
            color: #1a3a4e;
            background: rgba(30, 90, 122, 0.06);
            padding: 0.6rem 1.4rem;
            border-radius: 2rem;
            font-size: 1rem;
        }

        .audit-item span {
            font-size: 1.3rem;
        }

        /* 性能优化列表 */
        .perf-list {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
            gap: 1.5rem;
            max-width: 1000px;
            margin: 0 auto;
        }

        .perf-item {
            background: rgba(255, 255, 255, 0.8);
            border-radius: 1.5rem;
            padding: 1.8rem 1.5rem;
            border: 1px solid rgba(0, 0, 0, 0.04);
            transition: all 0.2s;
            display: flex;
            gap: 1rem;
            align-items: flex-start;
        }

        .perf-item:hover {
            background: white;
            box-shadow: 0 12px 24px -10px rgba(0, 0, 0, 0.1);
        }

        .perf-icon {
            font-size: 2rem;
            flex-shrink: 0;
        }

        .perf-text h4 {
            font-weight: 700;
            margin-bottom: 0.4rem;
            color: #1a3a4e;
        }

        .perf-text p {
            color: #3e627c;
            font-size: 0.9rem;
            line-height: 1.6;
        }

        /* 内链区域 */
        .internal-links-section {
            padding: 2rem 0 4rem;
        }

        .internal-links-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1rem;
            max-width: 900px;
            margin: 0 auto;
        }

        .internal-link-card {
            display: flex;
            align-items: center;
            gap: 0.8rem;
            background: rgba(255, 255, 255, 0.7);
            border-radius: 1.2rem;
            padding: 1rem 1.3rem;
            text-decoration: none;
            color: #2c4c6c;
            font-weight: 500;
            transition: all 0.2s;
            border: 1px solid rgba(0, 0, 0, 0.04);
            font-size: 0.95rem;
        }

        .internal-link-card:hover {
            background: white;
            transform: translateX(4px);
            box-shadow: 0 6px 16px -6px rgba(0, 0, 0, 0.1);
            color: #0f6b9c;
        }

        .internal-link-card .link-arrow {
            margin-left: auto;
            color: #1e5a7a;
            font-weight: 700;
            font-size: 1.1rem;
            transition: transform 0.2s;
        }

        .internal-link-card:hover .link-arrow {
            transform: translateX(4px);
        }

        .info-banner {
            background: linear-gradient(100deg, #e7f0f5 0%, #dce8ef 100%);
            border-radius: 2rem;
            padding: 2rem 1.5rem;
            margin: 1rem auto 3rem;
            text-align: center;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            max-width: 800px;
        }

        .info-banner p {
            margin: 0;
        }

        .domain {
            font-family: monospace;
            background: rgba(0, 0, 0, 0.05);
            padding: 0.2rem 0.5rem;
            border-radius: 12px;
        }

        .site-footer {
            background: #0f2b38;
            color: #cbdbe2;
            padding: 2.5rem 0;
            margin-top: 2rem;
            border-top: 1px solid #203e4e;
        }

        .footer-content {
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 1.5rem;
            align-items: center;
        }

        .copyright {
            font-size: 0.85rem;
        }

        .footer-links a {
            color: #bfd7e5;
            text-decoration: none;
            margin-left: 1.5rem;
            font-size: 0.9rem;
        }

        .footer-links a:hover {
            color: white;
        }

        @media (max-width: 680px) {
            .container {
                padding: 0 1.25rem;
            }
            .navbar {
                flex-direction: column;
            }
            .nav-links {
                gap: 1rem;
            }
            .feature-hero h1 {
                font-size: 2rem;
            }
            .section-title {
                font-size: 1.6rem;
            }
            .rule-grid,
            .perf-list {
                grid-template-columns: 1fr;
            }
            .audit-grid {
                gap: 0.8rem;
            }
        }