:root {
            --primary: #38bdf8;
            --accent: #a78bfa;
            --bg: #0f172a;
            --text: #e2e8f0;
            --card-bg: #1e293b;
            --radius-lg: 24px;
            --radius-md: 16px;
            --shadow: 0 12px 30px rgba(0, 0, 0, 0.5);
            --shadow-soft: 0 6px 16px rgba(0, 0, 0, 0.3);
        }
        * {
            box-sizing: border-box;
        }
        body {
            background-color: var(--bg);
            color: var(--text);
            font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            font-size: 15px;
            line-height: 1.6;
            font-weight: 400;
            position: relative;
            overflow-x: hidden;
        }
        /* 细微噪点纹理 */
        body::before {
            content: "";
            position: fixed;
            top: 0; left: 0; width: 100%; height: 100%;
            background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="120" height="120"><filter id="n"><feTurbulence type="fractalNoise" baseFrequency="0.9" numOctaves="2" stitchTiles="stitch"/><feColorMatrix type="saturate" values="0"/></filter><rect width="100%25" height="100%25" filter="url(%23n)" opacity="0.03"/></svg>');
            pointer-events: none;
            z-index: 9999;
            opacity: 0.2;
        }

        a {
            text-decoration: none;
            color: var(--primary);
        }

        .navbar-91 {
            background: rgba(15, 23, 42, 0.85);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid rgba(56, 189, 248, 0.15);
            padding: 12px 0;
            transition: all 0.3s;
            z-index: 1000;
            border-radius: 0;
            margin-bottom: 0;
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.4rem;
            color: var(--text) !important;
            letter-spacing: 0.5px;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .navbar-brand i {
            color: var(--primary);
            font-size: 1.8rem;
        }
        .navbar-nav .nav-link {
            color: rgba(226, 232, 240, 0.85) !important;
            font-weight: 500;
            margin: 0 8px;
            transition: 0.2s;
            border-radius: 30px;
            padding: 8px 16px !important;
        }
        .navbar-nav .nav-link:hover {
            color: var(--primary) !important;
            background: rgba(56, 189, 248, 0.08);
        }
        .navbar-toggler {
            border: 1px solid rgba(255,255,255,0.3);
            color: var(--text);
        }

        /* 布局容器 */
        .container-91 {
            max-width: 1280px;
            margin: 0 auto;
            padding-left: 20px;
            padding-right: 20px;
        }

        /* Hero 区 */
        .hero-section {
            padding: 70px 0 50px;
            position: relative;
            background: linear-gradient(145deg, rgba(15,23,42,0.9) 0%, rgba(30,41,59,0.6) 100%);
        }
        .keyword-cloud {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 16px 22px;
            margin-bottom: 28px;
        }
        .keyword-item {
            background: rgba(56, 189, 248, 0.08);
            border: 1px solid rgba(56, 189, 248, 0.2);
            padding: 6px 18px;
            border-radius: 40px;
            font-size: 0.85rem;
            font-weight: 600;
            color: var(--primary);
            letter-spacing: 0.3px;
            backdrop-filter: blur(5px);
            transition: 0.3s;
        }
        .keyword-item:nth-child(2n) {
            border-color: rgba(167, 139, 250, 0.3);
            color: var(--accent);
            background: rgba(167, 139, 250, 0.06);
        }
        .hero-title {
            font-size: 3.2rem;
            font-weight: 900;
            line-height: 1.2;
            margin: 18px 0 20px;
            text-shadow: 0 8px 30px rgba(0,0,0,0.6);
        }
        .hero-title .accent-text {
            color: var(--primary);
        }
        .hero-desc {
            max-width: 700px;
            margin: 0 auto 32px;
            font-size: 1.1rem;
            color: #cbd5e1;
        }
        .btn-91 {
            background: linear-gradient(135deg, var(--primary), var(--accent));
            border: none;
            padding: 12px 28px;
            border-radius: 50px;
            font-weight: 600;
            color: #0f172a;
            transition: 0.3s;
            box-shadow: var(--shadow);
        }
        .btn-91:hover {
            transform: scale(1.02);
            color: #0f172a;
        }

        /* 双色块左右分屏特征 */
        .split-col {
            display: flex;
            align-items: stretch;
            gap: 20px;
            flex-wrap: wrap;
        }
        .split-col > * {
            flex: 1 1 300px;
        }
        .color-panel {
            border-radius: var(--radius-lg);
            padding: 30px 26px;
            background: var(--card-bg);
            box-shadow: var(--shadow-soft);
        }
        .panel-primary {
            border-left: 6px solid var(--primary);
        }
        .panel-accent {
            border-left: 6px solid var(--accent);
        }

        /* 数据统计 */
        .stats-section {
            padding: 60px 0;
        }
        .stat-card {
            background: rgba(30, 41, 59, 0.6);
            backdrop-filter: blur(4px);
            border-radius: var(--radius-lg);
            padding: 24px 16px;
            text-align: center;
            border: 1px solid rgba(255,255,255,0.04);
            transition: 0.3s;
            height: 100%;
        }
        .stat-card:hover {
            transform: scale(1.02);
            border-color: rgba(56, 189, 248, 0.5);
        }
        .stat-number {
            font-size: 2.8rem;
            font-weight: 800;
            color: var(--primary);
        }
        .stat-label {
            font-size: 0.9rem;
            letter-spacing: 1px;
            text-transform: uppercase;
            color: #94a3b8;
        }

        /* 手风琴(使用说明) */
        .accordion-91 .accordion-item {
            background: rgba(30, 41, 59, 0.5);
            border: 1px solid rgba(148, 163, 184, 0.1);
            border-radius: var(--radius-md);
            margin-bottom: 14px;
            overflow: hidden;
        }
        .accordion-button-91 {
            background: transparent;
            color: var(--text);
            font-weight: 600;
            padding: 18px 24px;
            font-size: 1.05rem;
            border: none;
            text-align: left;
            width: 100%;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .accordion-button-91 i {
            color: var(--primary);
            font-size: 1.3rem;
            transition: 0.3s;
        }
        .accordion-content-91 {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.4s ease;
            padding: 0 24px;
            border-top: 1px solid rgba(255,255,255,0.05);
        }
        .accordion-content-91.show {
            max-height: 300px;
            padding-bottom: 20px;
            padding-top: 14px;
        }
        .accordion-content-91 p {
            margin-bottom: 0;
            color: #cbd5e1;
        }

        /* 特色卡片 */
        .feature-card {
            background: var(--card-bg);
            border-radius: var(--radius-lg);
            padding: 28px 20px;
            box-shadow: var(--shadow-soft);
            border: 1px solid transparent;
            transition: 0.3s ease;
            height: 100%;
        }
        .feature-card:hover {
            transform: scale(1.03);
            border-color: var(--primary);
            box-shadow: 0 16px 30px rgba(0,0,0,0.5);
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--accent);
            margin-bottom: 12px;
        }
        .feature-card h5 {
            font-weight: 700;
            margin-bottom: 8px;
        }

        /* CTA */
        .cta-box {
            background: linear-gradient(135deg, rgba(56,189,248,0.1), rgba(167,139,250,0.1));
            border-radius: var(--radius-lg);
            padding: 48px 30px;
            text-align: center;
            border: 1px solid rgba(56,189,248,0.2);
        }

        /* 友情链接 */
        .friend-links {
            background: rgba(30, 41, 59, 0.3);
            border-radius: var(--radius-lg);
            padding: 32px 24px;
            margin: 50px 0 30px;
        }
        .friend-links h5 {
            font-weight: 700;
            margin-bottom: 16px;
            color: var(--text);
        }
        .friend-links .link-item {
            color: #94a3b8;
            font-size: 0.95rem;
        }

        /* 回到顶部 */
        #backTop {
            position: fixed;
            bottom: 30px;
            right: 30px;
            width: 48px;
            height: 48px;
            border-radius: 50%;
            background: var(--primary);
            color: #0f172a;
            border: none;
            font-size: 1.3rem;
            box-shadow: var(--shadow);
            opacity: 0;
            visibility: hidden;
            transition: 0.4s;
            z-index: 9999;
        }
        #backTop.show {
            opacity: 1;
            visibility: visible;
        }

        /* 错落渐显 */
        .reveal {
            opacity: 0;
            transform: translateY(30px);
            transition: opacity 0.6s cubic-bezier(0.23, 1, 0.32, 1), transform 0.6s cubic-bezier(0.23, 1, 0.32, 1);
        }
        .reveal.visible {
            opacity: 1;
            transform: translateY(0);
        }
        .delay-1 { transition-delay: 0.1s; }
        .delay-2 { transition-delay: 0.2s; }
        .delay-3 { transition-delay: 0.3s; }

        footer {
            border-top: 1px solid rgba(255,255,255,0.05);
            padding: 25px 0;
            font-size: 0.9rem;
        }

        h2.section-title {
            font-weight: 800;
            font-size: 2rem;
            margin-bottom: 30px;
            position: relative;
            display: inline-block;
        }
        h2.section-title:after {
            content: "";
            position: absolute;
            bottom: -10px;
            left: 0;
            width: 70px;
            height: 4px;
            background: linear-gradient(to right, var(--primary), var(--accent));
            border-radius: 4px;
        }
        .bg-soft {
            background: rgba(30, 41, 59, 0.2);
        }

        @media (max-width: 992px) {
            .hero-title { font-size: 2.5rem; }
        }

/* --- 子页面追加 --- */
/* 覆盖 Bootstrap 组件默认白底黑字，强制走暗色卡片风格 */
        .card, .card-body, .card-title, .card-text, .card-header, .card-footer,
        .form-control, .form-select, .form-label, .input-group-text,
        .table, .list-group-item, .accordion-item, .accordion-button, .accordion-body,
        .modal-content, .modal-header, .modal-body, .dropdown-menu, .dropdown-item,
        .nav-link, .navbar, .navbar-brand, .btn-light, .btn-outline-* {
            background: var(--card-bg) !important;
            color: var(--text) !important;
            border-color: rgba(255,255,255,0.08) !important;
        }
.accordion-button:not(.collapsed) {
            background: rgba(56, 189, 248, 0.15) !important;
            color: var(--primary) !important;
            box-shadow: none;
        }
.accordion-button::after {
            filter: invert(1) brightness(2);
        }
/* 自定义卡片内链接颜色 */
        .card a, .list-group-item a {
            color: var(--primary);
        }
/* 所有标题保持亮色 */
        h1, h2, h3, h4, h5, h6 {
            color: #f1f5f9;
            letter-spacing: -0.01em;
        }
/* 小卡片图标微调 */
        .feature-icon {
            background: rgba(56, 189, 248, 0.15);
            border-radius: 16px;
        }
/* 确保暗色下 placeholder 可见 */
        .form-control::placeholder {
            color: rgba(226, 232, 240, 0.4);
        }
/* 关于页特有：时间线/里程碑 */
        .milestone-item {
            border-left: 2px solid var(--primary);
            padding-left: 1.25rem;
            position: relative;
            margin-bottom: 1.8rem;
        }
.milestone-item::before {
            content: "";
            position: absolute;
            left: -7px; top: 0.2rem;
            width: 12px; height: 12px;
            background: var(--primary);
            border-radius: 50%;
            box-shadow: 0 0 12px var(--primary);
        }
.milestone-date {
            color: var(--primary);
            font-weight: 600;
            font-size: 0.9rem;
            letter-spacing: 0.5px;
        }
/* 关于页引言区 */
        .quote-block {
            background: rgba(167, 139, 250, 0.08);
            border-left: 4px solid var(--accent);
            padding: 1.5rem 2rem;
            border-radius: 0 var(--radius-md) var(--radius-md) 0;
            margin: 2.5rem 0;
        }
.quote-block p {
            font-size: 1.15rem;
            font-weight: 400;
            color: #cbd5e1;
            font-style: italic;
        }
/* 目录/快速导航 */
        .about-toc {
            background: rgba(30, 41, 59, 0.6);
            border-radius: var(--radius-md);
            padding: 1.5rem 2rem;
            backdrop-filter: blur(4px);
        }
.about-toc a {
            color: var(--text);
            text-decoration: none;
            border-bottom: 1px dashed rgba(56,189,248,0.3);
        }
.about-toc a:hover {
            color: var(--primary);
            border-bottom-color: var(--primary);
        }
/* 按钮风格与首页 btn-91 一致 */
        .btn-91 {
            background: var(--primary);
            color: #0b1220;
            font-weight: 600;
            padding: 0.6rem 1.8rem;
            border-radius: 60px;
            transition: all .2s ease;
        }

/* --- 子页面追加 --- */
.page-hero-91 {
            background: linear-gradient(135deg, var(--bg) 0%, rgba(56, 189, 248, 0.08) 50%, var(--bg) 100%);
            padding: 5rem 0 3rem;
            border-bottom: 1px solid rgba(255,255,255,0.06);
        }
.page-hero-91 h1 {
            font-size: 2.8rem;
            font-weight: 800;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-bottom: 1rem;
        }
.page-hero-91 p {
            color: rgba(226, 232, 240, 0.7);
            font-size: 1.15rem;
            max-width: 700px;
            margin: 0 auto;
        }
.content-section-91 {
            padding: 4rem 0;
        }
.content-section-91 .card-91 {
            background: var(--card-bg);
            border-radius: var(--radius-lg);
            padding: 2.5rem;
            box-shadow: var(--shadow);
            border: 1px solid rgba(255,255,255,0.06);
            margin-bottom: 2rem;
        }
.content-section-91 h2 {
            color: var(--primary);
            font-weight: 700;
            font-size: 1.6rem;
            margin-bottom: 1.5rem;
            display: flex;
            align-items: center;
            gap: 0.75rem;
        }
.content-section-91 h2 i {
            font-size: 1.3rem;
            color: var(--accent);
        }
.content-section-91 h3 {
            color: var(--text);
            font-weight: 600;
            font-size: 1.2rem;
            margin: 1.5rem 0 0.75rem;
        }
.content-section-91 p, .content-section-91 li {
            color: rgba(226, 232, 240, 0.8);
            line-height: 1.8;
            margin-bottom: 0.75rem;
        }
.content-section-91 ul, .content-section-91 ol {
            padding-left: 1.5rem;
            margin-bottom: 1.25rem;
        }
.content-section-91 li {
            margin-bottom: 0.5rem;
        }
.content-section-91 .badge-91 {
            display: inline-block;
            background: rgba(56, 189, 248, 0.1);
            color: var(--primary);
            padding: 0.25rem 0.75rem;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 600;
            margin-right: 0.5rem;
        }
.content-section-91 .callout-91 {
            background: rgba(167, 139, 250, 0.08);
            border-left: 4px solid var(--accent);
            padding: 1.25rem 1.5rem;
            border-radius: 0 var(--radius-md) var(--radius-md) 0;
            margin: 1.5rem 0;
        }
.content-section-91 .callout-91 p {
            margin-bottom: 0;
        }
.content-section-91 .callout-91 i {
            color: var(--accent);
            margin-right: 0.5rem;
        }
.content-section-91 .divider-91 {
            height: 1px;
            background: linear-gradient(90deg, rgba(255,255,255,0.08), rgba(255,255,255,0.02));
            margin: 2rem 0;
        }
.content-section-91 .contact-box-91 {
            background: rgba(56, 189, 248, 0.06);
            border: 1px solid rgba(56, 189, 248, 0.15);
            border-radius: var(--radius-md);
            padding: 1.5rem 2rem;
            margin-top: 1rem;
        }
.content-section-91 .contact-box-91 p {
            margin-bottom: 0.5rem;
        }
.content-section-91 .contact-box-91 a {
            color: var(--primary);
            text-decoration: none;
            font-weight: 500;
            transition: color 0.2s;
        }
.content-section-91 .contact-box-91 a:hover {
            color: var(--accent);
        }
.page-hero-91 h1 {
                font-size: 2rem;
            }
.content-section-91 .card-91 {
                padding: 1.5rem;
            }
.content-section-91 h2 {
                font-size: 1.3rem;
            }

/* --- 子页面追加 --- */
.privacy-hero { padding: 4rem 0 3rem; }
.privacy-title { font-weight: 800; font-size: 2.4rem; margin-bottom: 0.8rem; }
.privacy-subtitle { color: var(--text); opacity: 0.8; font-size: 1.1rem; max-width: 700px; }
.privacy-section { padding: 2.2rem 0; border-bottom: 1px solid rgba(255,255,255,0.08); }
.privacy-section:last-child { border-bottom: none; }
.privacy-heading { font-size: 1.4rem; font-weight: 700; color: var(--primary); margin-bottom: 1rem; }
.privacy-heading i { margin-right: 10px; color: var(--accent); }
.privacy-content { color: var(--text); line-height: 1.75; font-size: 0.98rem; }
.privacy-content p { margin-bottom: 0.9rem; }
.privacy-content strong { color: var(--primary); }
.privacy-content ul, .privacy-content ol { padding-left: 1.4rem; margin-bottom: 1rem; }
.privacy-content li { margin-bottom: 0.45rem; }
.privacy-badge { display: inline-block; background: var(--card-bg); border: 1px solid rgba(56,189,248,0.25); color: var(--primary); padding: 0.25rem 0.85rem; border-radius: 20px; font-size: 0.78rem; font-weight: 600; margin-bottom: 0.5rem; }
.update-info { font-size: 0.85rem; color: var(--text); opacity: 0.7; margin-top: 1.5rem; padding-top: 1rem; border-top: 1px solid rgba(255,255,255,0.08); }
.contact-panel { background: var(--card-bg); border-radius: var(--radius-md); padding: 1.5rem; margin-top: 1rem; box-shadow: var(--shadow-soft); }
.contact-panel h4 { font-size: 1.1rem; font-weight: 700; color: var(--accent); margin-bottom: 0.8rem; }
.contact-panel p { margin-bottom: 0.4rem; font-size: 0.95rem; }
.highlight-box { background: rgba(167,139,250,0.12); border-left: 3px solid var(--accent); border-radius: 0 12px 12px 0; padding: 1rem 1.4rem; margin: 1.2rem 0; }
.highlight-box p { margin-bottom: 0.3rem; }
.privacy-title { font-size: 1.8rem; }
.privacy-heading { font-size: 1.2rem; }
.privacy-section { padding: 1.6rem 0; }