/* roulang page: index */
:root {
      --primary-orange: #E8453C;
      --primary-orange-deep: #C0392B;
      --primary-orange-light: #FFF0ED;
      --accent-gold: #F0A500;
      --dark-charcoal: #1E1E1E;
      --bg-light: #F7F8FA;
      --card-white: #FFFFFF;
      --text-body: #4A4A4A;
      --text-secondary: #7A7A7A;
      --success-green: #2E7D32;
      --border-light: #E5E7EB;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 6px 24px rgba(0,0,0,0.08);
      --radius-lg: 12px;
      --radius-md: 8px;
      --transition: 0.2s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
      --font-mono: "Inter", "SF Mono", monospace;
    }
    
    * {
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }
    
    h1, h2, h3, h4, h5, h6 {
      color: var(--dark-charcoal);
      font-weight: 600;
    }
    
    h1 {
      font-size: 36px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }
    
    h2 {
      font-size: 28px;
      font-weight: 600;
      letter-spacing: 0;
      line-height: 1.3;
    }
    
    h3 {
      font-size: 20px;
      font-weight: 500;
      line-height: 1.4;
    }
    
    .section-subtitle {
      font-size: 1rem;
      color: var(--text-secondary);
      font-weight: 400;
    }
    
    a {
      text-decoration: none;
      color: inherit;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    /* 容器微调 */
    .container-custom {
      max-width: 1140px;
      margin: 0 auto;
      padding-left: 15px;
      padding-right: 15px;
    }
    
    /* 区块间距 */
    section {
      padding: 80px 0;
    }
    
    @media (max-width: 991px) {
      section {
        padding: 60px 0;
      }
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 26px;
      }
    }
    
    @media (max-width: 767px) {
      section {
        padding: 48px 0;
      }
      h1 {
        font-size: 28px;
      }
      h2 {
        font-size: 24px;
      }
    }
    
    /* 按钮系统 */
    .btn-primary-custom {
      background-color: var(--primary-orange);
      border: none;
      color: white;
      font-weight: 600;
      border-radius: var(--radius-md);
      padding: 12px 28px;
      transition: background-color var(--transition), transform var(--transition), box-shadow var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      line-height: 1.2;
    }
    .btn-primary-custom:hover {
      background-color: var(--primary-orange-deep);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
      color: white;
    }
    
    .btn-outline-custom {
      background: transparent;
      border: 2px solid var(--primary-orange);
      color: var(--primary-orange);
      font-weight: 600;
      border-radius: var(--radius-md);
      padding: 12px 28px;
      transition: background-color var(--transition), color var(--transition), transform var(--transition);
    }
    .btn-outline-custom:hover {
      background-color: var(--primary-orange-light);
      border-color: var(--primary-orange);
      color: var(--primary-orange);
      transform: translateY(-2px);
    }
    
    .btn-cta {
      padding: 16px 36px;
      font-size: 18px;
      background-color: var(--primary-orange);
      border: none;
      color: white;
      font-weight: 600;
      border-radius: var(--radius-md);
      transition: all 0.2s ease;
    }
    .btn-cta:hover {
      background-color: var(--primary-orange-deep);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
      color: white;
    }
    
    .btn-nav-cta {
      background-color: var(--primary-orange);
      border: none;
      color: white !important;
      font-weight: 600;
      border-radius: var(--radius-md);
      padding: 10px 24px;
      transition: background-color var(--transition);
      white-space: nowrap;
    }
    .btn-nav-cta:hover {
      background-color: var(--primary-orange-deep);
      color: white;
    }
    
    /* 卡片导航样式 */
    .navbar-custom {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      padding: 12px 24px;
      margin: 20px auto 0;
      max-width: 1140px;
      position: sticky;
      top: 15px;
      z-index: 1020;
      backdrop-filter: blur(4px);
      border: 1px solid rgba(0,0,0,0.02);
    }
    
    .nav-card-item {
      background: var(--bg-light);
      border-radius: var(--radius-md);
      padding: 8px 16px;
      transition: background var(--transition), color var(--transition);
      font-weight: 500;
      color: var(--text-body);
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 0.95rem;
    }
    
    .nav-card-item:hover, .nav-card-item.active {
      background: var(--primary-orange-light);
      color: var(--primary-orange);
    }
    
    .navbar-brand-custom {
      font-weight: 700;
      font-size: 1.4rem;
      color: var(--dark-charcoal);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .navbar-brand-custom i {
      font-size: 1.8rem;
      color: var(--primary-orange);
    }
    
    @media (max-width: 767px) {
      .navbar-custom {
        padding: 10px 16px;
        margin: 10px;
        border-radius: 12px;
      }
      .mobile-nav-stack {
        display: flex;
        flex-direction: column;
        gap: 6px;
        margin-top: 12px;
      }
      .nav-card-item {
        justify-content: center;
      }
    }
    
    /* 卡片通用 */
    .card-custom {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      padding: 24px;
      transition: transform 0.25s ease, box-shadow 0.25s ease;
      border: none;
      height: 100%;
    }
    .card-custom:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    
    .icon-circle {
      width: 56px;
      height: 56px;
      background: var(--primary-orange-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary-orange);
      font-size: 24px;
      margin-bottom: 16px;
    }
    
    /* 数据看板数字 */
    .metric-number {
      font-family: var(--font-mono);
      font-size: 32px;
      font-weight: 700;
      color: var(--primary-orange);
      line-height: 1.2;
    }
    .metric-label {
      font-size: 13px;
      color: var(--text-secondary);
      letter-spacing: 0.2px;
      margin-top: 4px;
    }
    
    /* 对比表格 */
    .comparison-card-left {
      background: #f3f4f6;
      border-radius: var(--radius-lg);
      padding: 28px;
    }
    .comparison-card-right {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      padding: 28px;
      border-left: 4px solid var(--primary-orange);
    }
    .text-strikethrough {
      text-decoration: line-through;
      color: #9ca3af;
    }
    .check-green {
      color: var(--success-green);
      font-weight: 600;
    }
    
    /* FAQ 手风琴 */
    .accordion-button:not(.collapsed) {
      background-color: var(--primary-orange-light);
      color: var(--dark-charcoal);
      box-shadow: none;
      font-weight: 600;
    }
    .accordion-button:focus {
      border-color: var(--primary-orange);
      box-shadow: 0 0 0 0.15rem rgba(232, 69, 60, 0.25);
    }
    .accordion-item {
      border: none;
      margin-bottom: 12px;
      border-radius: var(--radius-md) !important;
      overflow: hidden;
    }
    
    /* 表单样式 */
    .form-control-custom {
      border-radius: var(--radius-md);
      border: 1px solid #D1D5DB;
      padding: 12px 16px;
      transition: border-color var(--transition);
    }
    .form-control-custom:focus {
      border-color: var(--primary-orange);
      box-shadow: 0 0 0 0.15rem rgba(232, 69, 60, 0.2);
    }
    
    footer {
      background: var(--dark-charcoal);
      color: #ccc;
    }
    footer a {
      color: #ddd;
      transition: color 0.2s;
    }
    footer a:hover {
      color: var(--accent-gold);
    }
    .footer-divider {
      border-top: 1px solid var(--accent-gold);
      opacity: 0.5;
    }
    
    /* Hero 图片 */
    .hero-img {
      border-radius: 16px;
      box-shadow: var(--shadow-md);
      width: 100%;
      height: auto;
    }