/* ============================================
           SafeW安全知识库 样式
           延续全站统一视觉体系
           ============================================ */
        :root {
            --color-bg: #f7f2ee;
            --color-text-primary: #1a1a2e;
            --color-text-secondary: #52525b;
            --color-text-muted: #71717a;
            --color-purple: #a855f7;
            --color-indigo: #6366f1;
            --color-blue: #0ea5e9;
            --color-green: #10b981;
            --color-amber: #f59e0b;
            --gradient-primary: linear-gradient(135deg, #a855f7, #6366f1);
            --gradient-text: linear-gradient(120deg, #a855f7, #6366f1, #0ea5e9);
            --shadow-card: 0 12px 40px rgba(0, 0, 0, 0.06);
            --shadow-card-hover: 0 20px 36px rgba(0, 0, 0, 0.08);
            --radius-card: 22px;
            --radius-pill: 999px;
            --transition-smooth: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            background-color: var(--color-bg);
            color: var(--color-text-primary);
            line-height: 1.7;
            overflow-x: hidden;
            position: relative;
            min-height: 100vh;
        }
        body::before { content: ""; position: fixed; top: -20%; left: -10%; width: 60%; height: 60%; background: radial-gradient(circle at 30% 40%, rgba(168,85,247,0.2), transparent 55%); pointer-events: none; z-index: 0; }
        body::after { content: ""; position: fixed; bottom: -20%; right: -10%; width: 55%; height: 55%; background: radial-gradient(circle at 70% 60%, rgba(59,130,246,0.15), transparent 55%); pointer-events: none; z-index: 0; }
        .orb { position: fixed; border-radius: 50%; pointer-events: none; z-index: 0; filter: blur(60px); }
        .orb-green { top: 20%; right: 5%; width: 300px; height: 300px; background: rgba(34,197,94,0.12); }
        .orb-amber { bottom: 15%; left: 8%; width: 260px; height: 260px; background: rgba(245,158,11,0.10); }
        .orb-purple { top: 55%; right: 20%; width: 180px; height: 180px; background: rgba(168,85,247,0.10); }
        a { color: inherit; text-decoration: none; }
        img { max-width: 100%; display: block; }
        .container { max-width: 1100px; margin: 0 auto; padding: 0 24px; position: relative; z-index: 1; }

        /* 导航栏（全站一致） */
        .site-header { position: sticky; top: 20px; z-index: 1000; display: flex; justify-content: center; padding: 0 16px; }
        .nav-glass { display: flex; align-items: center; justify-content: space-between; gap: 20px; width: 100%; max-width: 1000px; background: rgba(255,255,255,0.55); backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px); border: 1px solid rgba(255,255,255,0.7); border-radius: var(--radius-pill); padding: 10px 22px; box-shadow: 0 12px 40px rgba(0,0,0,0.06); }
        .logo { display: flex; align-items: center; gap: 9px; font-size: 20px; font-weight: 800; color: var(--color-text-primary); flex-shrink: 0; }
        .logo-icon { width: 34px; height: 34px; background: var(--gradient-primary); border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 17px; box-shadow: 0 4px 14px rgba(168,85,247,0.3); color: white; }
        .main-nav ul { display: flex; list-style: none; gap: 4px; font-size: 13px; color: var(--color-text-secondary); flex-wrap: wrap; justify-content: center; }
        .main-nav li { display: flex; }
        .main-nav a { padding: 8px 12px; border-radius: var(--radius-pill); transition: var(--transition-smooth); font-weight: 500; white-space: nowrap; }
        .main-nav a:hover { color: var(--color-text-primary); background: rgba(255,255,255,0.6); }
        .main-nav a.active { color: var(--color-indigo); background: rgba(255,255,255,0.8); font-weight: 600; }
        .nav-actions { flex-shrink: 0; }

        /* 按钮 */
        .btn { display: inline-flex; align-items: center; justify-content: center; border-radius: var(--radius-pill); font-weight: 600; transition: var(--transition-smooth); cursor: pointer; border: none; }
        .btn-small { padding: 9px 20px; font-size: 13px; background: var(--color-text-primary); color: #fff; white-space: nowrap; }
        .btn-small:hover { background: #2d2d44; transform: translateY(-1px); }
        .btn-primary { padding: 14px 30px; font-size: 15px; background: var(--gradient-primary); color: #fff; box-shadow: 0 10px 28px rgba(168,85,247,0.3); }
        .btn-primary:hover { transform: translateY(-2px); box-shadow: 0 18px 36px rgba(168,85,247,0.4); }
        .btn-secondary { padding: 14px 26px; font-size: 15px; background: rgba(255,255,255,0.6); border: 1px solid rgba(255,255,255,0.8); color: var(--color-text-primary); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); }
        .btn-secondary:hover { background: rgba(255,255,255,0.8); transform: translateY(-2px); }

        /* 通用区块 */
        .section { padding: 60px 0; position: relative; }
        .section-heading { max-width: 650px; margin: 0 auto 40px; text-align: center; }
        .section-heading h2 { font-size: clamp(1.8rem, 4vw, 2.4rem); font-weight: 800; letter-spacing: -0.5px; margin-bottom: 12px; color: var(--color-text-primary); line-height: 1.3; }
        .section-heading p { color: var(--color-text-secondary); font-size: 15px; line-height: 1.8; }

        /* 知识库 Hero */
        .knowledge-hero {
            padding: 80px 0 40px;
            text-align: center;
        }
        .knowledge-hero-badge {
            display: inline-flex; align-items: center; gap: 8px; padding: 8px 20px; border-radius: var(--radius-pill);
            background: rgba(255,255,255,0.5); border: 1px solid rgba(255,255,255,0.7);
            backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
            font-size: 13px; color: var(--color-indigo); margin-bottom: 24px; font-weight: 500;
        }
        .knowledge-hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--color-green); box-shadow: 0 0 12px rgba(16,185,129,0.7); }
        .knowledge-hero h1 {
            font-size: clamp(2.2rem, 5vw, 3.2rem);
            font-weight: 900; line-height: 1.2; letter-spacing: -1.5px; margin-bottom: 16px;
        }
        .knowledge-hero .sub { color: var(--color-text-secondary); font-size: 16px; max-width: 700px; margin: 0 auto 30px; }

        /* 知识分类卡片 */
        .knowledge-category-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 24px;
            max-width: 1000px;
            margin: 0 auto;
        }
        .knowledge-category-card {
            background: rgba(255,255,255,0.4);
            border: 1px solid rgba(255,255,255,0.7);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-radius: var(--radius-card);
            padding: 30px 20px;
            text-align: center;
            transition: var(--transition-smooth);
        }
        .knowledge-category-card:hover {
            transform: translateY(-6px);
            box-shadow: var(--shadow-card-hover);
            background: rgba(255,255,255,0.55);
        }
        .category-icon { font-size: 44px; margin-bottom: 16px; }
        .knowledge-category-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
        .knowledge-category-card p { font-size: 13px; color: var(--color-text-secondary); line-height: 1.7; }

        /* 加密原理图解（创意版块） */
        .principle-section {
            background: rgba(255,255,255,0.2);
            border-radius: 40px;
            margin: 0 24px 40px;
            padding: 60px 0;
        }
        .principle-flow {
            display: flex; flex-wrap: wrap; justify-content: center; align-items: center;
            gap: 16px; max-width: 900px; margin: 0 auto;
        }
        .principle-node {
            background: rgba(255,255,255,0.4);
            border: 1px solid rgba(255,255,255,0.7);
            backdrop-filter: blur(16px);
            border-radius: 24px;
            padding: 24px 18px;
            flex: 1 1 180px;
            max-width: 220px;
            text-align: center;
        }
        .principle-node-icon { font-size: 40px; margin-bottom: 12px; }
        .principle-node h4 { font-size: 15px; font-weight: 700; margin-bottom: 8px; }
        .principle-node p { font-size: 12px; color: var(--color-text-secondary); line-height: 1.6; }
        .principle-arrow { font-size: 26px; color: var(--color-indigo); opacity: 0.6; }

        /* 威胁风险矩阵（创意版块） */
        .risk-matrix-section {
            padding: 80px 0;
        }
        .risk-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
            max-width: 900px;
            margin: 0 auto;
        }
        .risk-card {
            background: rgba(255,255,255,0.35);
            border: 1px solid rgba(255,255,255,0.7);
            backdrop-filter: blur(16px);
            border-radius: 24px;
            padding: 26px 20px;
            transition: var(--transition-smooth);
        }
        .risk-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-card); }
        .risk-icon { font-size: 36px; margin-bottom: 12px; }
        .risk-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
        .risk-card p { font-size: 13px; color: var(--color-text-secondary); line-height: 1.7; }
        .risk-level {
            display: inline-block; padding: 4px 12px; border-radius: 20px;
            font-size: 11px; font-weight: 600; margin-top: 10px;
        }
        .risk-high { background: rgba(239,68,68,0.15); color: #dc2626; }
        .risk-medium { background: rgba(245,158,11,0.15); color: #d97706; }
        .risk-low { background: rgba(16,185,129,0.15); color: #059669; }

        /* 最佳实践指南（创意版块） */
        .best-practice-section {
            background: rgba(255,255,255,0.2);
            border-radius: 40px;
            margin: 0 24px 40px;
            padding: 60px 0;
        }
        .practice-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 24px;
            max-width: 800px;
            margin: 0 auto;
        }
        .practice-card {
            background: rgba(255,255,255,0.4);
            border: 1px solid rgba(255,255,255,0.7);
            backdrop-filter: blur(16px);
            border-radius: 24px;
            padding: 26px 22px;
        }
        .practice-card h4 {
            font-size: 17px; font-weight: 700; margin-bottom: 12px;
            display: flex; align-items: center; gap: 10px;
        }
        .practice-card ul {
            list-style: none; display: flex; flex-direction: column; gap: 8px;
        }
        .practice-card li {
            font-size: 13px; color: var(--color-text-secondary);
            padding-left: 18px; position: relative;
        }
        .practice-card li::before {
            content: "◆"; position: absolute; left: 0; color: var(--color-indigo); font-size: 10px;
        }

        /* 知识库FAQ */
        .knowledge-faq-section {
            padding: 80px 0;
        }
        .faq-list {
            max-width: 800px; margin: 0 auto;
            display: flex; flex-direction: column; gap: 16px;
        }
        .faq-item {
            background: rgba(255,255,255,0.4);
            border: 1px solid rgba(255,255,255,0.7);
            backdrop-filter: blur(16px);
            border-radius: 20px;
            padding: 20px 24px;
        }
        .faq-q { font-weight: 700; font-size: 15px; margin-bottom: 8px; }
        .faq-a { font-size: 13px; color: var(--color-text-secondary); line-height: 1.7; }

        /* 最终CTA */
        .final-cta {
            padding: 70px 0; text-align: center; max-width: 850px; margin: 0 auto 90px;
            background: rgba(255,255,255,0.35); border: 1px solid rgba(255,255,255,0.7);
            backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px); border-radius: 36px;
        }
        .final-cta h2 { font-size: clamp(1.8rem, 4vw, 2.4rem); font-weight: 800; letter-spacing: -0.5px; margin-bottom: 12px; color: var(--color-text-primary); }
        .final-cta p { color: var(--color-text-secondary); margin-bottom: 28px; }
        .final-cta .btn { margin: 0 6px; }

        /* 页脚（全站一致） */
        .site-footer { padding: 50px 0 30px; border-top: 1px solid rgba(0,0,0,0.06); position: relative; z-index: 1; }
        .footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; max-width: 1000px; margin: 0 auto 40px; text-align: left; }
        .footer-brand .logo { margin-bottom: 16px; justify-content: flex-start; }
        .footer-brand p { font-size: 13px; color: var(--color-text-secondary); max-width: 260px; }
        .footer-col h4 { font-size: 15px; font-weight: 700; margin-bottom: 16px; color: var(--color-text-primary); }
        .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
        .footer-col ul li a { font-size: 13px; color: var(--color-text-secondary); transition: color 0.2s; }
        .footer-col ul li a:hover { color: var(--color-text-primary); }
        .footer-newsletter { max-width: 1000px; margin: 0 auto 30px; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; background: rgba(255,255,255,0.3); border: 1px solid rgba(255,255,255,0.6); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); border-radius: 16px; padding: 18px 22px; }
        .footer-newsletter span { font-size: 14px; font-weight: 600; color: var(--color-text-primary); }
        .newsletter-form { display: flex; gap: 10px; flex: 1; min-width: 250px; }
        .newsletter-form input { flex: 1; min-width: 200px; padding: 10px 16px; border-radius: var(--radius-pill); border: 1px solid rgba(255,255,255,0.8); background: rgba(255,255,255,0.6); font-size: 13px; color: var(--color-text-primary); outline: none; }
        .newsletter-form input::placeholder { color: #a1a1aa; }
        .newsletter-form button { padding: 10px 20px; border-radius: var(--radius-pill); border: none; background: var(--gradient-primary); color: #fff; font-weight: 600; font-size: 13px; cursor: pointer; transition: opacity 0.2s; white-space: nowrap; }
        .newsletter-form button:hover { opacity: 0.9; }
        .footer-bottom { max-width: 1000px; margin: 0 auto; display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 16px; font-size: 12px; color: #a1a1aa; }
        .footer-social { display: flex; gap: 14px; }
        .footer-social a { color: var(--color-text-secondary); transition: color 0.2s; font-size: 13px; }
        .footer-social a:hover { color: var(--color-text-primary); }

        /* 响应式 */
        @media (max-width: 768px) {
            .main-nav { display: none; }
            .nav-glass { justify-content: space-between; }
            .risk-grid { grid-template-columns: 1fr 1fr; }
            .practice-grid { grid-template-columns: 1fr; }
            .principle-flow { flex-direction: column; }
            .principle-arrow { transform: rotate(90deg); }
            .footer-grid { grid-template-columns: 1fr 1fr; }
        }
        @media (max-width: 480px) {
            .container { padding: 0 16px; }
            .knowledge-category-grid { grid-template-columns: 1fr; }
            .risk-grid { grid-template-columns: 1fr; }
            .footer-grid { grid-template-columns: 1fr; text-align: center; }
            .footer-brand .logo { justify-content: center; }
            .principle-section, .best-practice-section { margin: 0 12px 30px; padding: 40px 16px; }
        }