/* roulang page: index */
:root {
      --primary: #0A7EA4;
      --primary-dark: #065A75;
      --accent: #F85C2B;
      --accent-hover: #d94a1f;
      --bg-light: #EFF4F7;
      --dark: #1A1D22;
      --text: #2C3E50;
      --text-light: #5A6C7D;
      --white: #FFFFFF;
      --border: #e9edf2;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-title: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-body: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --transition: 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-body);
      background: var(--white);
      color: var(--text);
      line-height: 1.75;
      font-size: 16px;
      margin: 0;
      padding: 0;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }

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

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

    button, .btn {
      font-family: var(--font-body);
      font-weight: 600;
      transition: var(--transition);
      border-radius: var(--radius-btn);
    }

    h1, h2, h3, h4 {
      font-family: var(--font-title);
      font-weight: 700;
      color: var(--dark);
      margin-top: 0;
    }

    h1 {
      font-size: 44px;
      line-height: 1.2;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: 32px;
      line-height: 1.3;
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
      line-height: 1.4;
    }

    .container-main {
      display: flex;
      flex: 1;
    }

    /* 左侧竖向导航 */
    .side-nav {
      width: 260px;
      min-height: 100vh;
      background: var(--dark);
      color: rgba(255,255,255,0.85);
      display: flex;
      flex-direction: column;
      position: fixed;
      left: 0;
      top: 0;
      bottom: 0;
      z-index: 1030;
      padding: 0;
      box-shadow: 2px 0 15px rgba(0,0,0,0.05);
    }

    .brand-wrap {
      padding: 28px 24px 20px;
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    .logo-text {
      font-size: 24px;
      font-weight: 700;
      color: white;
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo-text i {
      color: var(--accent);
      font-size: 28px;
    }

    .nav-menu {
      list-style: none;
      padding: 24px 0;
      margin: 0;
      flex: 1;
    }

    .nav-item {
      margin: 0;
    }

    .nav-link {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 14px 24px;
      color: rgba(255,255,255,0.8);
      font-size: 16px;
      font-weight: 500;
      border-left: 3px solid transparent;
      transition: var(--transition);
      letter-spacing: 0.5px;
      background: transparent;
      width: 100%;
    }

    .nav-link i {
      width: 20px;
      font-size: 18px;
    }

    .nav-link:hover {
      background: rgba(255,255,255,0.05);
      color: white;
      border-left-color: var(--accent);
    }

    .nav-link.active {
      background: rgba(255,255,255,0.08);
      color: white;
      border-left-color: var(--accent);
      font-weight: 600;
    }

    /* 右侧内容区 */
    .main-content {
      margin-left: 260px;
      width: calc(100% - 260px);
      background: var(--white);
    }

    /* 移动端顶部导航 */
    .mobile-nav {
      display: none;
      background: var(--dark);
      height: 64px;
      align-items: center;
      padding: 0 20px;
      position: fixed;
      top: 0;
      width: 100%;
      z-index: 1040;
      justify-content: space-between;
    }

    .mobile-brand {
      font-size: 22px;
      font-weight: 700;
      color: white;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .hamburger {
      background: transparent;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }

    .mobile-menu {
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background: var(--dark);
      flex-direction: column;
      padding: 16px 0;
      display: none;
      z-index: 1050;
    }

    .mobile-menu.open {
      display: flex;
    }

    .mobile-menu .nav-link {
      border-left: none;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }

    /* Hero */
    .hero-section {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      padding: 100px 0;
      display: flex;
      align-items: center;
      min-height: 600px;
    }

    .hero-overlay {
      position: absolute;
      top: 0; left: 0; right: 0; bottom: 0;
      background: linear-gradient(135deg, rgba(10,126,164,0.3) 0%, rgba(255,255,255,0.85) 70%);
    }

    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 60px;
      padding: 0 40px;
    }

    .hero-text {
      flex: 1;
    }

    .hero-text h1 {
      color: var(--dark);
      margin-bottom: 20px;
    }

    .hero-sub {
      font-size: 20px;
      color: var(--text-light);
      margin-bottom: 24px;
    }

    .hero-desc {
      font-size: 18px;
      color: var(--text);
      margin-bottom: 32px;
      max-width: 90%;
    }

    .hero-image {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(10,126,164,0.25);
      border: 2px solid rgba(10,126,164,0.2);
    }

    .btn-primary-custom {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border: none;
      border-radius: var(--radius-btn);
      font-weight: 600;
      letter-spacing: 0.5px;
    }

    .btn-primary-custom:hover {
      background: var(--primary-dark);
      color: white;
    }

    .btn-outline-custom {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 12px 30px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }

    .btn-outline-custom:hover {
      background: var(--primary);
      color: white;
    }

    .btn-accent {
      background: var(--accent);
      color: white;
      border: none;
    }

    .btn-accent:hover {
      background: var(--accent-hover);
      color: white;
    }

    section {
      padding: 100px 0;
    }

    .bg-light-gray {
      background: var(--bg-light);
    }

    .section-title {
      margin-bottom: 48px;
    }

    .section-title h2 {
      display: inline-block;
      position: relative;
    }

    .section-title h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 60px;
      height: 4px;
      background: var(--accent);
    }

    /* 服务卡片 左对齐图文水平 */
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      align-items: flex-start;
      gap: 20px;
      transition: var(--transition);
      border: 1px solid var(--border);
      height: 100%;
    }

    .service-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
      border-color: var(--primary);
    }

    .service-icon {
      font-size: 42px;
      color: var(--primary);
      flex-shrink: 0;
    }

    /* 数据大字 */
    .stat-block {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 16px;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }

    .stat-number {
      font-size: 56px;
      font-weight: 800;
      color: var(--accent);
      line-height: 1.1;
    }

    .stat-label {
      font-size: 16px;
      font-weight: 600;
      color: var(--dark);
      margin-top: 8px;
    }

    /* 案例卡片 */
    .case-card {
      border-radius: var(--radius-card);
      overflow: hidden;
      background: white;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-md);
    }

    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      position: relative;
    }

    .case-img::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 60px;
      background: linear-gradient(transparent, rgba(0,0,0,0.4));
    }

    .case-body {
      padding: 20px;
    }

    /* 解决方案流程 */
    .step-item {
      display: flex;
      gap: 20px;
      margin-bottom: 32px;
    }

    .step-number {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 20px;
      flex-shrink: 0;
    }

    /* FAQ */
    .accordion-button {
      font-weight: 600;
      font-size: 18px;
      color: var(--dark);
      background: transparent;
      box-shadow: none;
      border-bottom: 1px solid var(--border);
      padding: 20px 0;
    }

    .accordion-button:not(.collapsed) {
      background: var(--bg-light);
      color: var(--primary);
      box-shadow: none;
    }

    .accordion-item {
      border: none;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, var(--primary) 0%, #065A75 100%);
      color: white;
      border-radius: var(--radius-card);
      padding: 60px;
    }

    /* Footer */
    .footer {
      background: var(--dark);
      color: rgba(255,255,255,0.7);
      padding: 60px 0 20px;
    }

    @media (max-width: 991.98px) {
      .side-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 64px;
      }
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      .hero-content {
        flex-direction: column;
        padding: 0 20px;
      }
      section {
        padding: 60px 0;
      }
      .stat-number {
        font-size: 40px;
      }
    }

    @media (min-width: 992px) {
      .mobile-nav, .mobile-menu {
        display: none !important;
      }
    }