:root {
    --primary: #38bdf8;
    --accent: #a78bfa;
    --bg: #0f172a;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --card-bg: #1e293b;
    --border: #334155;
    --shadow: 6px 6px 0px rgba(56, 189, 248, 0.2);
  }

  * { border-radius: 0 !important; }

  body {
    background-color: var(--bg);
    color: var(--text);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    font-weight: 400;
    letter-spacing: 0.01em;
    overflow-x: hidden;
  }

  h1, h2, h3, h4, .font-serif {
    font-family: 'Source Han Serif SC', 'Noto Serif SC', 'Songti SC', serif;
    font-weight: 900;
    color: #fff;
  }

  .font-sans { font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif; }

  /* 直角硬朗 + 粗边框 + 硬阴影 */
  .brutal-card {
    background: var(--card-bg);
    border: 2px solid var(--border);
    box-shadow: 6px 6px 0px rgba(0,0,0,0.45);
    transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
  }
  .brutal-card:hover {
    transform: scale(1.015);
    border-color: var(--primary);
    box-shadow: 8px 8px 0px rgba(56,189,248,0.15);
  }

  .btn-brutal {
    border: 2px solid var(--primary);
    background: var(--primary);
    color: #0f172a;
    font-weight: 700;
    padding: 10px 20px;
    box-shadow: 4px 4px 0px #000;
    transition: all 0.12s;
  }
  .btn-brutal:hover {
    background: var(--accent);
    border-color: var(--accent);
    transform: translate(2px, 2px);
    box-shadow: 2px 2px 0px #000;
  }

  /* 渐变光晕/模糊光斑 */
  .glow-spot {
    position: fixed;
    width: 340px; height: 340px;
    background: radial-gradient(circle, rgba(167,139,250,0.15) 0%, transparent 70%);
    top: 10%; left: -5%; z-index: 0; pointer-events: none;
  }
  .glow-spot-2 {
    position: fixed;
    width: 420px; height: 420px;
    background: radial-gradient(circle, rgba(56,189,248,0.12) 0%, transparent 70%);
    bottom: 5%; right: -10%; z-index: 0; pointer-events: none;
  }

  /* 懒加载占位渐显 */
  img.lazy {
    background: linear-gradient(110deg, #1e293b 8%, #2d3a4f 18%, #1e293b 33%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    min-height: 80px;
    opacity: 0.9;
    transition: opacity 0.5s;
  }
  img.lazy-loaded { opacity: 1; animation: none; }
  @keyframes shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

  /* 回到顶部按钮 */
  #backToTop {
    position: fixed;
    bottom: 30px; right: 30px;
    width: 48px; height: 48px;
    background: var(--primary);
    border: 2px solid #0f172a;
    box-shadow: 4px 4px 0px rgba(0,0,0,0.5);
    color: #0f172a;
    font-size: 1.5rem;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    cursor: pointer;
    transition: 0.2s;
  }
  #backToTop.show { display: flex; }
  #backToTop:hover { background: var(--accent); transform: translateY(-2px); }

  /* 导航 */
  .navbar-51 {
    background: rgba(15,23,42,0.9);
    backdrop-filter: blur(8px);
    border-bottom: 2px solid var(--border);
    padding: 0.5rem 0;
    z-index: 2000;
  }
  .navbar-brand { font-weight: 900; font-size: 1.6rem; }
  .nav-link-custom { font-weight: 600; color: var(--text) !important; margin: 0 1rem; }
  .nav-link-custom:hover { color: var(--primary) !important; }

  /* hero 大数字 */
  .hero-stat {
    font-size: 5.5rem;
    font-weight: 900;
    line-height: 1;
    letter-spacing: -2px;
    color: var(--primary);
    font-family: 'Inter', sans-serif;
  }

  /* 对比表格 */
  .compare-table {
    border-collapse: collapse;
    width: 100%;
    border: 2px solid var(--border);
  }
  .compare-table th, .compare-table td {
    padding: 1rem;
    border: 2px solid var(--border);
    background: var(--card-bg);
    text-align: center;
    font-weight: 500;
  }
  .compare-table th { background: #25344a; font-weight: 800; }

  /* 编号清单 */
  .num-list {
    counter-reset: step;
    list-style: none;
    padding-left: 0;
  }
  .num-list li {
    counter-increment: step;
    margin-bottom: 1.2rem;
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    font-weight: 500;
  }
  .num-list li::before {
    content: counter(step) ".";
    font-size: 2rem;
    font-weight: 900;
    color: var(--accent);
    font-family: serif;
    min-width: 2.2rem;
    line-height: 1;
  }

  /* 友情链接 */
  .friend-links a {
    color: var(--text-muted);
    text-decoration: none;
    margin-right: 1rem;
    border-bottom: 1px dotted var(--border);
  }
  .friend-links a:hover { color: var(--primary); }

  /* 锚点滚动 */
  html { scroll-behavior: smooth; }

  section { position: relative; z-index: 5; }
  .container { max-width: 1280px; }
  .bg-grid { 
    background-image: linear-gradient(rgba(148,163,184,0.03) 1px, transparent 1px),
      linear-gradient(90deg, rgba(148,163,184,0.03) 1px, transparent 1px);
    background-size: 30px 30px;
  }

/* --- 子页面追加 --- */
/* 覆盖 Bootstrap 潜在的白底冲突，确保与 dark 主题融合 */
        .navbar-51 .navbar-brand,
        .navbar-51 .nav-link-custom {
            color: var(--text) !important;
        }
.navbar-51 .nav-link-custom.active {
            color: var(--primary) !important;
        }
.navbar-51 .nav-link-custom:hover {
            color: var(--primary) !important;
        }
.about-hero {
            background: radial-gradient(circle at 20% 30%, rgba(56,189,248,0.15), transparent 40%), radial-gradient(circle at 80% 70%, rgba(167,139,250,0.1), transparent 40%);
            border-bottom: 1px solid var(--border);
        }
.section-title-51 {
            font-weight: 800;
            letter-spacing: -0.02em;
            position: relative;
            display: inline-block;
            margin-bottom: 1.5rem;
        }
.section-title-51::after {
            content: '';
            position: absolute;
            bottom: -6px;
            left: 0;
            width: 60%;
            height: 4px;
            background: var(--primary);
            border-radius: 2px;
        }
.icon-list i {
            color: var(--primary);
            width: 1.8rem;
        }
.footer-link-51 a {
            color: var(--text-muted);
            text-decoration: none;
            margin-right: 1.5rem;
            transition: color .15s;
        }
.footer-link-51 a:hover {
            color: var(--primary);
        }

/* --- 子页面追加 --- */
/* 确保 Bootstrap 组件不破坏深色风格 (仅栅格与工具类之外，此处覆盖常见组件) */
    body {
      background-color: var(--bg);
      color: var(--text);
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    }
/* 防白底组件 */
    .card, .card-body, .card-header, .card-footer,
    .list-group-item, .accordion-item, .accordion-button,
    .form-control, .form-select, .modal-content, .modal-header, .modal-body {
      background-color: var(--card-bg) !important;
      color: var(--text) !important;
      border-color: var(--border) !important;
    }
.accordion-button:not(.collapsed) {
      background-color: rgba(56, 189, 248, 0.1) !important;
      color: var(--primary) !important;
    }
/* 自定义高亮下划线 */
    .disclaimer-section {
      border-left: 4px solid var(--primary);
      padding-left: 1.5rem;
    }
.text-glow {
      color: var(--primary);
    }
hr {
      border-top: 1px solid var(--border);
      opacity: .5;
    }

/* --- 子页面追加 --- */
/* 保证任何bootstrap组件都不露白 */
        .card, .card-body, .card-header, .card-footer, .form-control, .list-group-item {
            background: var(--card-bg) !important;
            color: var(--text) !important;
            border-color: var(--border) !important;
        }
.accordion-item, .accordion-button, .accordion-body {
            background: var(--card-bg) !important;
            color: var(--text) !important;
            border-color: var(--border) !important;
        }
.modal-content {
            background: var(--card-bg) !important;
            color: var(--text) !important;
            border: 1px solid var(--border);
        }
.dropdown-menu {
            background: var(--card-bg) !important;
            border-color: var(--border) !important;
        }
.dropdown-item {
            color: var(--text) !important;
        }
.dropdown-item:hover {
            background: rgba(56, 189, 248, 0.15);
            color: #fff;
        }
/* 隐私政策内容特定修饰 */
        .privacy-section-title {
            border-left: 4px solid var(--accent);
            padding-left: 0.75rem;
            margin-bottom: 1.2rem;
            font-weight: 700;
            color: var(--text);
        }
.privacy-content p {
            color: var(--text-muted);
            line-height: 1.8;
        }
.privacy-content strong {
            color: var(--primary);
        }
.privacy-card {
            background: var(--card-bg);
            border: 1px solid var(--border);
            box-shadow: var(--shadow);
            padding: 1.5rem;
            border-radius: 12px;
            margin-bottom: 1.5rem;
            transition: transform 0.2s;
        }
.privacy-card:hover {
            transform: translateY(-3px);
        }