/* roulang page: index */
:root {
      --brand-primary: #1A5F7A;
      --brand-primary-hover: #134B61;
      --brand-accent: #C8963E;
      --brand-accent-hover: #B07D2E;
      --bg-main: #FFFFFF;
      --bg-subtle: #F4F7FC;
      --text-primary: #1E293B;
      --text-secondary: #64748B;
      --text-muted: #94A3B8;
      --border-light: #E2E8F0;
      --border-subtle: #CBD5E1;
      --footer-bg: #1E293B;
      --footer-text: #CBD5E1;
      --footer-title: #FFFFFF;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(26,95,122,0.12);
      --shadow-lg: 0 12px 40px rgba(0,0,0,0.08);
      --radius-sm: 4px;
      --radius-md: 8px;
      --radius-lg: 12px;
      --font-heading: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-body: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "Segoe UI", sans-serif;
      --transition-base: 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-body);
      color: var(--text-primary);
      background-color: var(--bg-main);
      line-height: 1.8;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    h1, h2, h3, h4, h5, h6 {
      font-family: var(--font-heading);
      font-weight: 700;
      line-height: 1.3;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: color var(--transition-base);
    }

    a:hover {
      color: var(--brand-primary);
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button, .btn {
      transition: all var(--transition-base);
    }

    input, textarea {
      font-family: var(--font-body);
    }

    .container-custom {
      max-width: 1140px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 12px;
      padding-right: 12px;
    }

    /* 导航系统 */
    .navbar-brand-line {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 56px;
      background: #fff;
      border-bottom: 1px solid var(--border-light);
    }

    .logo-text {
      font-size: 20px;
      font-weight: 700;
      color: var(--brand-primary);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo-icon {
      font-size: 22px;
      color: var(--brand-accent);
    }

    .nav-cta-btn {
      background: var(--brand-primary);
      color: #fff;
      border: none;
      padding: 8px 18px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 14px;
      white-space: nowrap;
      text-decoration: none;
      transition: background var(--transition-base), box-shadow var(--transition-base);
    }

    .nav-cta-btn:hover {
      background: var(--brand-primary-hover);
      box-shadow: var(--shadow-md);
      color: #fff;
    }

    .channel-row {
      height: 44px;
      background: #F8FAFC;
      border-bottom: 1px solid var(--border-light);
      display: flex;
      align-items: center;
    }

    .channel-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .channel-links a {
      font-size: 15px;
      color: var(--text-secondary);
      font-weight: 500;
      position: relative;
      padding: 4px 0;
      transition: color var(--transition-base);
    }

    .channel-links a.active,
    .channel-links a:hover {
      color: var(--brand-primary);
    }

    .channel-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--brand-primary);
      transition: width var(--transition-base);
    }

    .channel-links a.active::after,
    .channel-links a:hover::after {
      width: 100%;
    }

    .navbar-toggler-custom {
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-primary);
      padding: 4px 8px;
    }

    .mobile-menu-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(255,255,255,0.98);
      z-index: 1050;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 24px;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }

    .mobile-menu-overlay.show {
      transform: translateX(0);
    }

    .mobile-menu-overlay a {
      font-size: 20px;
      font-weight: 500;
      color: var(--text-primary);
    }

    /* Hero */
    .hero-section {
      background: linear-gradient(135deg, #FFFFFF 0%, #F4F7FC 100%);
      padding: 60px 0;
    }

    .hero-title {
      font-size: 32px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-primary);
      margin-bottom: 16px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 28px;
    }

    .hero-img {
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-lg);
      width: 100%;
      height: auto;
    }

    .btn-primary-brand {
      background: var(--brand-primary);
      color: #fff;
      border: none;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 16px;
    }

    .btn-primary-brand:hover {
      background: var(--brand-primary-hover);
      box-shadow: var(--shadow-md);
      color: #fff;
    }

    .btn-outline-brand {
      background: transparent;
      color: var(--brand-primary);
      border: 1.5px solid var(--brand-primary);
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 16px;
    }

    .btn-outline-brand:hover {
      background: var(--brand-primary);
      color: #fff;
    }

    .btn-accent-lg {
      background: var(--brand-accent);
      color: #fff;
      border: none;
      padding: 16px 40px;
      border-radius: var(--radius-md);
      font-weight: 700;
      font-size: 18px;
    }

    .btn-accent-lg:hover {
      background: var(--brand-accent-hover);
      box-shadow: var(--shadow-md);
      color: #fff;
    }

    /* 区块通用 */
    .section-padding {
      padding: 80px 0;
    }

    .section-title {
      font-size: 26px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-primary);
    }

    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 40px;
    }

    /* 卡片 */
    .feature-card {
      background: #fff;
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition-base);
      height: 100%;
      border-bottom: 3px solid var(--brand-primary);
    }

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .feature-icon {
      font-size: 28px;
      color: var(--brand-accent);
      margin-bottom: 12px;
    }

    /* 解决方案图文行 */
    .solution-img {
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      width: 100%;
      height: auto;
    }

    .solution-text {
      font-size: 16px;
      line-height: 1.8;
      color: var(--text-primary);
    }

    /* 数据卡片 */
    .stat-card {
      background: #fff;
      border-radius: var(--radius-md);
      padding: 24px;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 32px;
      font-weight: 700;
      color: var(--brand-primary);
    }

    .stat-label {
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 4px;
    }

    /* 证言卡片 */
    .testimonial-card {
      background: #fff;
      border-radius: var(--radius-md);
      padding: 20px;
      box-shadow: var(--shadow-sm);
      border-left: 4px solid var(--brand-primary);
      min-width: 280px;
      margin-right: 16px;
      flex-shrink: 0;
    }

    .testimonial-text {
      font-style: italic;
      font-size: 15px;
      color: #555;
      margin-bottom: 12px;
    }

    .testimonial-author {
      font-weight: 600;
      font-size: 14px;
      color: var(--text-primary);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      font-size: 17px;
      font-weight: 700;
      padding: 16px 0;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-primary);
    }

    .faq-answer {
      font-size: 15px;
      color: #666;
      padding-bottom: 16px;
      display: none;
    }

    .faq-icon {
      font-size: 20px;
      font-weight: bold;
      opacity: 0.6;
    }

    /* CTA 尾屏 */
    .cta-section {
      background: linear-gradient(135deg, var(--brand-primary) 0%, #0F4357 100%);
      color: #fff;
    }

    /* 页脚 */
    .footer {
      background: var(--footer-bg);
      color: var(--footer-text);
      padding: 48px 0 24px;
    }

    .footer a {
      color: var(--footer-text);
    }

    .footer a:hover {
      color: #fff;
    }

    .footer-title {
      color: var(--footer-title);
      font-weight: 700;
      margin-bottom: 16px;
    }

    .footer-bottom {
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 20px;
      margin-top: 30px;
      font-size: 14px;
      text-align: center;
    }

    @media (max-width: 768px) {
      .hero-title {
        font-size: 26px;
      }
      .section-title {
        font-size: 22px;
      }
      .section-padding {
        padding: 48px 0;
      }
      .channel-row {
        display: none;
      }
      .feature-card, .stat-card {
        margin-bottom: 16px;
      }
      .testimonial-scroll {
        flex-wrap: nowrap;
        overflow-x: auto;
        display: flex;
      }
      .solution-row-reverse {
        flex-direction: column-reverse;
      }
      .footer .col-md-3 {
        margin-bottom: 24px;
      }
    }