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

        :root {
            --purple-950: #1a0a2e;
            --purple-900: #220c3d;
            --purple-800: #2d1065;
            --purple-700: #3b1578;
            --purple-600: #5b1eb8;
            --purple-500: #6d28d9;
            --purple-400: #7c3aed;
            --purple-350: #8b5cf6;
            --purple-300: #a78bfa;
            --purple-200: #c4b5fd;
            --purple-150: #dcd0fe;
            --purple-100: #ede9fe;
            --purple-50: #f5f0ff;
            --purple-25: #faf7ff;
            --gray-bg: #f9fafc;
            --gray-100: #f3f4f6;
            --gray-200: #e5e7eb;
            --gray-300: #d1d5db;
            --gray-400: #9ca3af;
            --gray-500: #6b7280;
            --text-primary: #111827;
            --text-secondary: #1f2937;
            --text-tertiary: #374151;
            --text-muted: #4b5563;
            --white: #ffffff;
            --shadow-xs: 0 1px 2px rgba(0,0,0,0.04);
            --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
            --shadow-md: 0 4px 20px rgba(0,0,0,0.07);
            --shadow-lg: 0 20px 40px -12px rgba(109,40,217,0.18);
            --shadow-card: 0 2px 6px rgba(0,0,0,0.03), 0 10px 28px rgba(0,0,0,0.06);
            --shadow-card-hover: 0 4px 12px rgba(0,0,0,0.05), 0 18px 40px rgba(109,40,217,0.12);
            --radius-sm: 16px;
            --radius-md: 20px;
            --radius-lg: 28px;
            --radius-xl: 40px;
            --radius-full: 50%;
            --font-mono: 'SF Mono', 'Cascadia Code', 'Fira Code', 'JetBrains Mono', 'Consolas', monospace;
            --transition-fast: 0.15s ease;
            --transition-smooth: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }

        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }

        body {
            font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
            background-color: var(--white);
            color: var(--text-primary);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            text-rendering: optimizeLegibility;
            overflow-x: hidden;
        }

        .container {
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 24px;
        }
        .container-narrow {
            max-width: 880px;
            margin: 0 auto;
            padding: 0 24px;
        }
        .container-wide {
            max-width: 1040px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* ===== HEADER (与首页一致) ===== */
        .header {
            position: sticky;
            top: 0;
            z-index: 100;
            background: rgba(255,255,255,0.94);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            box-shadow: 0 0 0 1px rgba(0,0,0,0.04), var(--shadow-xs);
        }
        .header.scrolled {
            box-shadow: 0 0 0 1px rgba(0,0,0,0.06), var(--shadow-sm);
        }
        .nav-bar {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            padding: 14px 0;
            gap: 12px;
        }
        .logo-area {
            display: flex;
            align-items: center;
            gap: 8px;
            flex-shrink: 0;
            text-decoration: none;
        }
        .logo-icon {
            width: 36px;
            height: 36px;
            background: linear-gradient(135deg, #5b1eb8 0%, #7c3aed 50%, #8b5cf6 100%);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: 800;
            font-size: 1.1rem;
            letter-spacing: -0.5px;
            box-shadow: 0 4px 12px rgba(109,40,217,0.3);
        }
        .logo-text {
            font-size: 1.5rem;
            font-weight: 700;
            letter-spacing: -0.4px;
            color: var(--purple-700);
            text-decoration: none;
        }
        .logo-dot {
            display: inline-block;
            width: 6px;
            height: 6px;
            background: #8b5cf6;
            border-radius: var(--radius-full);
            margin-left: 1px;
            animation: pulse-dot 2.4s ease-in-out infinite;
        }
        @keyframes pulse-dot {
            0%,100%{opacity:0.5;transform:scale(1);}
            50%{opacity:1;transform:scale(1.8);}
        }
        .nav-links {
            display: flex;
            gap: 22px;
            list-style: none;
            font-weight: 500;
            align-items: center;
            flex-wrap: wrap;
        }
        .nav-links a {
            text-decoration: none;
            color: var(--text-secondary);
            transition: color var(--transition-fast);
            font-size: 0.9rem;
            position: relative;
            padding: 5px 0;
            white-space: nowrap;
        }
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -1px;
            left: 0;
            width: 0;
            height: 2.5px;
            background: var(--purple-500);
            border-radius: 2px;
            transition: width var(--transition-smooth);
        }
        .nav-links a:hover,
        .nav-links a.active {
            color: var(--purple-600);
        }
        .nav-links a:hover::after,
        .nav-links a.active::after {
            width: 100%;
        }
        .nav-cta {
            background: var(--purple-600);
            color: white !important;
            padding: 8px 18px !important;
            border-radius: 24px;
            font-weight: 600;
            font-size: 0.84rem !important;
            transition: all var(--transition-smooth) !important;
            text-decoration: none;
            box-shadow: 0 4px 14px rgba(109,40,217,0.28);
            letter-spacing: 0.01em;
        }
        .nav-cta:hover {
            background: var(--purple-700) !important;
            box-shadow: 0 6px 20px rgba(109,40,217,0.38);
            transform: translateY(-1px);
            color: white !important;
        }
        .nav-cta::after {
            display: none !important;
        }

        /* ===== PAGE HERO ===== */
        .page-hero {
            background: linear-gradient(170deg, #faf7ff 0%, #f5f0ff 25%, #ede9fe 55%, #f9fafc 100%);
            padding: 44px 0 38px;
            border-bottom: 1px solid #e8e0f8;
            text-align: center;
        }
        .page-hero h1 {
            font-size: 2.4rem;
            font-weight: 800;
            color: var(--purple-900);
            letter-spacing: -0.02em;
            margin-bottom: 12px;
        }
        .page-hero .highlight {
            background: linear-gradient(135deg, #5b1eb8 0%, #7c3aed 50%, #8b5cf6 100%);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
        }
        .page-hero p {
            color: var(--text-tertiary);
            max-width: 640px;
            margin: 0 auto;
            font-size: 1.05rem;
            line-height: 1.6;
        }
        .page-badge {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            background: var(--purple-100);
            color: var(--purple-700);
            padding: 5px 15px;
            border-radius: 24px;
            font-size: 0.76rem;
            font-weight: 600;
            margin-bottom: 16px;
            border: 1px solid rgba(109,40,217,0.12);
        }

        /* ===== SECTION COMMON ===== */
        .section {
            padding: 64px 0;
        }
        .section-alt {
            background: #faf9fc;
        }
        .section-tight {
            padding: 40px 0;
        }
        .section-header {
            text-align: center;
            margin-bottom: 40px;
        }
        .section-tag {
            display: inline-block;
            font-size: 0.76rem;
            font-weight: 650;
            color: var(--purple-500);
            text-transform: uppercase;
            letter-spacing: 0.07em;
            margin-bottom: 8px;
            background: var(--purple-50);
            padding: 4px 14px;
            border-radius: 20px;
        }
        .section-title {
            text-align: center;
            font-size: 1.9rem;
            font-weight: 750;
            margin-bottom: 8px;
            color: var(--purple-900);
            letter-spacing: -0.015em;
        }
        .section-sub {
            text-align: center;
            color: var(--text-muted);
            max-width: 580px;
            margin: 0 auto;
            font-size: 0.98rem;
            line-height: 1.6;
        }

        /* ===== ENCRYPTION ILLUSTRATION (创意视觉) ===== */
        .encrypt-visual {
            display: flex;
            flex-wrap: wrap;
            gap: 24px;
            justify-content: center;
            margin: 32px 0 20px;
        }
        .encrypt-step {
            flex: 1 1 200px;
            background: var(--white);
            border-radius: var(--radius-lg);
            padding: 28px 20px;
            text-align: center;
            border: 1px solid #ece6f8;
            box-shadow: var(--shadow-card);
            transition: all var(--transition-smooth);
            position: relative;
        }
        .encrypt-step:hover {
            transform: translateY(-3px);
            border-color: var(--purple-350);
            box-shadow: var(--shadow-card-hover);
        }
        .encrypt-step .step-num {
            display: inline-block;
            width: 36px;
            height: 36px;
            line-height: 36px;
            background: var(--purple-600);
            color: white;
            font-weight: 700;
            border-radius: var(--radius-full);
            margin-bottom: 12px;
            font-size: 0.9rem;
        }
        .encrypt-step h4 {
            color: var(--purple-800);
            margin-bottom: 6px;
            font-weight: 650;
        }
        .encrypt-step p {
            font-size: 0.85rem;
            color: var(--text-tertiary);
            line-height: 1.5;
        }
        .encrypt-arrow {
            display: flex;
            align-items: center;
            font-size: 1.8rem;
            color: var(--purple-400);
            flex-shrink: 0;
            margin: 0 -8px;
        }

        /* ===== COMPARISON TABLE ===== */
        .compare-table-wrap {
            overflow-x: auto;
            -webkit-overflow-scrolling: touch;
            margin-top: 16px;
        }
        .compare-table {
            width: 100%;
            border-collapse: collapse;
            font-size: 0.9rem;
            min-width: 580px;
        }
        .compare-table th {
            background: var(--purple-50);
            color: var(--purple-800);
            padding: 14px 16px;
            text-align: left;
            font-weight: 650;
            border-bottom: 2px solid #d4c8f0;
            font-size: 0.85rem;
            letter-spacing: 0.02em;
        }
        .compare-table th:first-child {
            border-radius: var(--radius-sm) 0 0 0;
        }
        .compare-table th:last-child {
            border-radius: 0 var(--radius-sm) 0 0;
        }
        .compare-table td {
            padding: 13px 16px;
            border-bottom: 1px solid #f0ebf8;
            color: var(--text-tertiary);
        }
        .compare-table tr:hover td {
            background: #fdfbff;
        }
        .compare-table .check {
            color: var(--purple-500);
            font-weight: 700;
        }
        .compare-table .cross {
            color: #d1d5db;
        }

        /* ===== SEO CONTENT ===== */
        .seo-content {
            padding: 48px 0;
            background: var(--white);
        }
        .seo-content h2 {
            font-size: 1.65rem;
            font-weight: 700;
            color: var(--purple-900);
            margin-bottom: 14px;
            letter-spacing: -0.01em;
        }
        .seo-content h3 {
            font-size: 1.2rem;
            font-weight: 650;
            color: var(--purple-700);
            margin: 22px 0 8px;
        }
        .seo-content p {
            color: var(--text-tertiary);
            line-height: 1.8;
            margin-bottom: 12px;
            font-size: 0.93rem;
        }
        .seo-content ul {
            color: var(--text-tertiary);
            line-height: 1.8;
            margin: 6px 0 16px 20px;
            font-size: 0.9rem;
        }
        .seo-content li {
            margin-bottom: 6px;
        }
        .seo-content strong {
            color: var(--purple-700);
            font-weight: 650;
        }
        .seo-content a {
            color: var(--purple-500);
            text-decoration: underline;
            text-underline-offset: 3px;
            font-weight: 500;
        }
        .seo-content a:hover {
            color: var(--purple-700);
        }
        .code-block {
            background: #1e1035;
            color: #c4b5fd;
            padding: 16px 20px;
            border-radius: var(--radius-md);
            font-family: var(--font-mono);
            font-size: 0.8rem;
            overflow-x: auto;
            margin: 16px 0;
            line-height: 1.6;
            border: 1px solid #3d2670;
        }

        /* ===== DOWNLOAD CTA ROW ===== */
        .cta-row {
            display: flex;
            flex-wrap: wrap;
            gap: 14px;
            justify-content: center;
            align-items: center;
            margin-top: 20px;
        }
        .btn-primary {
            background: var(--purple-600);
            color: white;
            border: none;
            padding: 13px 28px;
            border-radius: 28px;
            font-weight: 600;
            font-size: 0.95rem;
            cursor: pointer;
            transition: all var(--transition-smooth);
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            gap: 7px;
            box-shadow: 0 6px 18px rgba(109,40,217,0.28);
            letter-spacing: 0.01em;
        }
        .btn-primary:hover {
            background: var(--purple-700);
            box-shadow: 0 8px 26px rgba(109,40,217,0.38);
            transform: translateY(-2px);
        }
        .btn-outline {
            background: transparent;
            border: 1.5px solid var(--purple-500);
            color: var(--purple-600);
            padding: 12px 26px;
            border-radius: 28px;
            font-weight: 600;
            font-size: 0.95rem;
            text-decoration: none;
            transition: all var(--transition-smooth);
            display: inline-flex;
            align-items: center;
            gap: 6px;
        }
        .btn-outline:hover {
            background: var(--purple-50);
            border-color: var(--purple-400);
            color: var(--purple-700);
            transform: translateY(-2px);
        }

        /* ===== FOOTER (与首页一致) ===== */
        .footer {
            background: var(--purple-950);
            color: #d4c8f0;
            padding: 48px 0 24px;
        }
        .footer-grid {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 32px;
            margin-bottom: 36px;
        }
        .footer-col {
            min-width: 130px;
        }
        .footer-col h4 {
            color: white;
            margin-bottom: 14px;
            font-weight: 600;
            font-size: 0.84rem;
            letter-spacing: 0.04em;
            text-transform: uppercase;
        }
        .footer-col ul {
            list-style: none;
        }
        .footer-col li {
            margin-bottom: 9px;
        }
        .footer-col a {
            color: #c4b5fd;
            text-decoration: none;
            transition: color var(--transition-fast);
            font-size: 0.84rem;
        }
        .footer-col a:hover {
            color: white;
        }
        .footer-brand {
            font-size: 1.3rem;
            font-weight: 700;
            color: white;
            margin-bottom: 8px;
            letter-spacing: -0.3px;
        }
        .footer-brand-dot {
            display: inline-block;
            width: 5px;
            height: 5px;
            background: #8b5cf6;
            border-radius: var(--radius-full);
            margin-left: 2px;
            vertical-align: middle;
        }
        .copyright {
            text-align: center;
            border-top: 1px solid #3d2670;
            padding-top: 22px;
            font-size: 0.78rem;
            color: #9a8ac0;
        }
        .copyright a {
            color: #c4b5fd;
            text-decoration: none;
        }
        .copyright a:hover {
            color: white;
        }

        /* ===== RESPONSIVE ===== */
        @media (max-width: 960px) {
            .page-hero h1 {
                font-size: 1.9rem;
            }
            .section-title {
                font-size: 1.5rem;
            }
            .encrypt-arrow {
                display: none;
            }
        }
        @media (max-width: 680px) {
            .page-hero h1 {
                font-size: 1.6rem;
            }
            .container {
                padding: 0 16px;
            }
            .nav-links {
                gap: 10px;
                font-size: 0.76rem;
            }
            .nav-cta {
                padding: 6px 14px !important;
                font-size: 0.76rem !important;
            }
            .encrypt-visual {
                flex-direction: column;
                align-items: center;
            }
            .encrypt-step {
                max-width: 320px;
                width: 100%;
            }
            .seo-content {
                padding: 32px 0;
            }
            .seo-content h2 {
                font-size: 1.35rem;
            }
        }