/* roulang page: index */
:root {
      --primary: #0A4B6E;
      --primary-dark: #083B54;
      --accent: #E8A838;
      --accent-light: #F7E5C2;
      --bg: #F7F9FC;
      --card-bg: #FFFFFF;
      --text: #1E2B3C;
      --text-secondary: #5F6B7A;
      --border-light: #E1E8EE;
      --shadow-sm: 0 2px 12px rgba(10, 75, 110, 0.08);
      --shadow-hover: 0 8px 24px rgba(10, 75, 110, 0.15);
      --radius-card: 12px;
      --radius-btn: 30px;
      --transition: 0.25s ease;
      --footer-bg: #0A3A52;
      --footer-text: #B0C4D1;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'Poppins', 'Segoe UI', 'Source Han Sans CN', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
      background-color: var(--bg);
      color: var(--text);
      font-size: 16px;
      line-height: 1.6;
      margin: 0;
      padding: 0;
      overflow-x: hidden;
    }

    h1, h2, h3, h4 {
      font-weight: 600;
      letter-spacing: -0.02em;
      color: var(--text);
    }

    h1 { font-size: 44px; font-weight: 700; }
    h2 { font-size: 32px; }
    h3 { font-size: 24px; }
    h4 { font-size: 20px; }

    .container {
      max-width: 1140px;
      margin: 0 auto;
      padding-left: 15px;
      padding-right: 15px;
    }

    section {
      padding: 100px 0;
    }

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

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

    /* 导航栏风格：分屏Hero联动，紧凑高度 */
    .navbar-custom {
      position: sticky;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1020;
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid rgba(10, 75, 110, 0.08);
      padding: 0 15px;
      height: 48px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo-text {
      font-weight: 700;
      font-size: 1.25rem;
      color: var(--primary);
      letter-spacing: -0.5px;
      white-space: nowrap;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 1.8rem;
      list-style: none;
      margin: 0;
      padding: 0;
    }
    .nav-links a {
      color: var(--text-secondary);
      font-weight: 500;
      font-size: 0.9rem;
      position: relative;
      padding: 0.2rem 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s ease;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-nav-cta {
      background: var(--primary);
      color: white;
      border-radius: 30px;
      padding: 0.4rem 1.2rem;
      font-size: 0.85rem;
      font-weight: 600;
      border: none;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-nav-cta:hover {
      background: var(--primary-dark);
      box-shadow: var(--shadow-hover);
      color: white;
    }
    .navbar-toggler {
      border: none;
      color: var(--primary);
      font-size: 1.4rem;
      padding: 0.2rem;
    }
    .navbar-toggler:focus {
      box-shadow: none;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .navbar-custom {
        justify-content: space-between;
      }
    }

    /* Hero 分屏布局 */
    .hero-section {
      padding: 60px 0 80px;
      background: var(--bg);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .hero-left {
      flex: 0 0 45%;
    }
    .hero-right {
      flex: 0 0 55%;
    }
    .hero-image-card {
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 15px 35px rgba(10, 75, 110, 0.18);
      background: white;
    }
    .hero-image-card img {
      width: 100%;
      height: auto;
      object-fit: cover;
      display: block;
    }
    .hero-title {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text);
      margin-bottom: 1.2rem;
    }
    .hero-sub {
      font-size: 1.1rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
      max-width: 90%;
    }
    .btn-primary-custom {
      background: var(--primary);
      border: none;
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
      font-weight: 600;
      color: white;
      transition: var(--transition);
      box-shadow: 0 4px 10px rgba(10,75,110,0.2);
      margin-right: 1rem;
    }
    .btn-primary-custom:hover {
      background: var(--primary-dark);
      box-shadow: var(--shadow-hover);
      color: white;
    }
    .btn-outline-custom {
      border: 1.5px solid var(--primary);
      background: transparent;
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 0.7rem 2rem;
      font-weight: 600;
      transition: var(--transition);
    }
    .btn-outline-custom:hover {
      background: rgba(10,75,110,0.05);
      border-color: var(--primary-dark);
      color: var(--primary-dark);
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-left, .hero-right {
        flex: 1 1 auto;
        width: 100%;
      }
      .hero-title {
        font-size: 2.5rem;
      }
      .hero-right {
        margin-top: 2rem;
      }
    }

    /* 标签式卡片 (优势) */
    .feature-tag-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 1.5rem;
      display: flex;
      gap: 1rem;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      border-left: 4px solid var(--primary);
      margin-bottom: 1.8rem;
    }
    .feature-tag-card:hover {
      border-left-width: 6px;
      box-shadow: var(--shadow-hover);
      transform: translateY(-2px);
    }
    .feature-icon {
      font-size: 2rem;
      color: var(--accent);
      min-width: 40px;
    }
    .feature-content h4 {
      margin-bottom: 0.4rem;
    }
    .feature-content p {
      color: var(--text-secondary);
      margin: 0;
      font-size: 0.95rem;
    }

    /* 亮点网格 */
    .highlight-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 1.5rem;
    }
    .highlight-item {
      background: linear-gradient(135deg, #e9f2f8 0%, #d4e3f0 100%);
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      text-align: center;
      position: relative;
      overflow: hidden;
      background-image: repeating-linear-gradient(45deg, rgba(255,255,255,0.05) 0px, rgba(255,255,255,0.05) 2px, transparent 2px, transparent 8px);
    }
    .highlight-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }
    .highlight-desc {
      color: var(--text);
      font-weight: 500;
      margin-top: 0.5rem;
    }

    /* 案例瀑布流 */
    .case-masonry {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 1.8rem;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 220px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s ease;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-info {
      padding: 1.3rem;
    }
    .case-tag {
      background: var(--accent-light);
      color: #b3741a;
      font-size: 0.75rem;
      font-weight: 600;
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 0.6rem;
    }
    .case-title {
      font-weight: 600;
      font-size: 1.2rem;
      margin-bottom: 0.4rem;
    }
    .case-desc {
      color: var(--text-secondary);
      font-size: 0.9rem;
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

    /* 方案对比表 */
    .solution-table {
      display: flex;
      gap: 1.5rem;
      flex-wrap: wrap;
    }
    .solution-col {
      flex: 1;
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 1.8rem;
      border: 1px solid var(--border-light);
      transition: var(--transition);
    }
    .solution-col.recommended {
      border: 2px solid var(--primary);
      background: #f6fafd;
      position: relative;
    }
    .badge-recommend {
      background: var(--accent);
      color: white;
      font-size: 0.75rem;
      font-weight: 700;
      padding: 0.25rem 1rem;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      left: 20px;
    }
    .solution-header {
      font-weight: 700;
      font-size: 1.5rem;
      margin-bottom: 1.5rem;
      color: var(--primary);
    }
    .solution-feature {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      padding: 0.7rem 0;
      border-bottom: 1px solid #ecf0f4;
    }
    .solution-feature i {
      color: var(--accent);
      font-size: 1rem;
    }

    /* FAQ */
    .accordion-custom .accordion-button {
      background: white;
      border: 1px solid var(--border-light);
      border-radius: 8px;
      font-weight: 600;
      color: var(--text);
      box-shadow: none;
      padding: 1rem 1.5rem;
      transition: var(--transition);
    }
    .accordion-custom .accordion-button:not(.collapsed) {
      background: white;
      border-left: 4px solid var(--primary);
      border-color: var(--primary);
      color: var(--primary);
    }
    .accordion-custom .accordion-body {
      background: #F7F9FC;
      border-radius: 0 0 8px 8px;
      color: var(--text-secondary);
    }

    /* 联系表单 */
    .input-underline {
      border: none;
      border-bottom: 2px solid #D1D9E0;
      border-radius: 0;
      padding: 0.8rem 0.5rem;
      background: transparent;
      transition: border 0.2s;
      width: 100%;
    }
    .input-underline:focus {
      outline: none;
      border-bottom: 2px solid var(--primary);
      box-shadow: none;
    }
    .btn-submit {
      background: var(--accent);
      border: none;
      border-radius: 30px;
      padding: 0.8rem 2.5rem;
      font-weight: 600;
      color: white;
      transition: var(--transition);
      box-shadow: 0 4px 12px rgba(232,168,56,0.3);
    }
    .btn-submit:hover {
      background: #cd9227;
      box-shadow: 0 8px 20px rgba(232,168,56,0.4);
    }

    /* 页脚 */
    .footer-bg {
      background: var(--footer-bg);
      color: var(--footer-text);
      padding: 3rem 0 1.5rem;
    }
    .footer-links a {
      color: var(--footer-text);
      font-size: 0.9rem;
      display: block;
      margin-bottom: 0.4rem;
    }
    .footer-links a:hover {
      color: var(--accent);
    }
    .social-icons i {
      font-size: 1.3rem;
      margin-right: 1rem;
      color: var(--footer-text);
      transition: var(--transition);
    }
    .social-icons i:hover {
      color: var(--accent);
    }

    @media (max-width: 768px) {
      section { padding: 60px 0; }
      .highlight-grid, .case-masonry { grid-template-columns: 1fr; }
      .solution-table { flex-direction: column; }
    }