/* roulang page: index */
:root {
      --primary: #0A2540;
      --primary-hover: #1A3A5C;
      --accent: #F6B83D;
      --accent-glow: rgba(246, 184, 61, 0.18);
      --bg-page: #FAFBFD;
      --bg-card: #FFFFFF;
      --bg-footer: #F0F2F5;
      --text-heading: #0A2540;
      --text-body: #3A4A5C;
      --text-muted: #6B7B8D;
      --border-light: #E9EDF2;
      --border-input: #D1D9E0;
      --shadow-card: 0 4px 16px rgba(10, 37, 64, 0.06);
      --shadow-card-hover: 0 8px 24px rgba(10, 37, 64, 0.10);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --transition: 0.25s ease;
      --max-width: 1200px;
      --nav-height: 64px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", system-ui, -apple-system, sans-serif;
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.6;
      font-weight: 400;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input {
      font-family: inherit;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(10,37,64,0.08);
      z-index: 100;
      display: flex;
      align-items: center;
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 1.4rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      white-space: nowrap;
    }
    .logo i {
      color: var(--accent);
      margin-right: 6px;
      font-size: 1.5rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-body);
      transition: color var(--transition);
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-right {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .search-box {
      display: flex;
      align-items: center;
      background: #F8FAFB;
      border: 1px solid var(--border-light);
      border-radius: 20px;
      padding: 6px 14px;
      color: var(--text-muted);
      font-size: 0.9rem;
      gap: 6px;
    }
    .search-box input {
      border: none;
      background: transparent;
      outline: none;
      width: 140px;
      font-size: 0.9rem;
    }
    .search-box i {
      color: var(--text-muted);
    }
    .icon-btn {
      background: transparent;
      border: none;
      color: var(--text-body);
      font-size: 1.2rem;
      cursor: pointer;
      transition: color var(--transition);
    }
    .icon-btn:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      transition: background var(--transition), box-shadow var(--transition);
      white-space: nowrap;
      letter-spacing: 0.3px;
      box-shadow: 0 2px 8px rgba(10,37,64,0.08);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 12px rgba(10,37,64,0.15);
    }
    .btn-accent {
      background: var(--accent);
      color: #0A2540;
      font-weight: 700;
      box-shadow: 0 2px 10px var(--accent-glow);
    }
    .btn-accent:hover {
      background: #e5a82f;
      box-shadow: 0 6px 18px rgba(246,184,61,0.25);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary);
      cursor: pointer;
    }
    @media (max-width: 1024px) {
      .nav-links {
        gap: 18px;
      }
      .search-box input {
        width: 100px;
      }
    }
    @media (max-width: 768px) {
      .nav-links, .nav-right .search-box, .nav-right .icon-btn {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .nav-right {
        gap: 8px;
      }
      .mobile-menu {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(16px);
        border-bottom: 1px solid var(--border-light);
        flex-direction: column;
        padding: 20px 24px;
        gap: 18px;
        box-shadow: var(--shadow-card);
      }
      .mobile-menu.active {
        display: flex;
      }
      .mobile-menu a {
        font-weight: 600;
        color: var(--text-body);
        font-size: 1.1rem;
        padding: 8px 0;
      }
    }
    /* Hero */
    .hero {
      padding: 120px 0 80px;
      background: linear-gradient(180deg, #FFFFFF 0%, var(--bg-page) 100%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero-content h1 {
      font-size: 3rem;
      font-weight: 700;
      color: var(--text-heading);
      line-height: 1.25;
      margin-bottom: 20px;
    }
    .hero-content h1 span {
      color: var(--accent);
      border-bottom: 2px solid rgba(246,184,61,0.4);
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-btns {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: all var(--transition);
    }
    .btn-outline:hover {
      background: rgba(10,37,64,0.04);
    }
    .hero-image {
      flex: 1;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      min-height: 340px;
      box-shadow: 0 20px 35px rgba(10,37,64,0.1);
    }
    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        gap: 40px;
      }
      .hero-content h1 {
        font-size: 2.4rem;
      }
      .hero-image {
        width: 100%;
        min-height: 240px;
      }
    }
    /* 通用区块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-heading);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-sub {
      color: var(--text-muted);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .service-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      border-top: 4px solid transparent;
      position: relative;
    }
    .service-card:nth-child(1) { border-top-color: var(--accent); }
    .service-card:nth-child(3) { border-top-color: var(--accent); }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .service-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .service-card h3 {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 12px;
    }
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 优势数据 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      text-align: center;
      padding: 20px 0;
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
      flex-wrap: wrap;
    }
    .stat-item {
      padding: 20px;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent);
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 1rem;
      margin-top: 6px;
    }
    @media (max-width: 520px) {
      .stats-grid {
        flex-direction: column;
        gap: 20px;
      }
    }
    /* 案例卡片水平布局 */
    .case-row {
      display: flex;
      gap: 32px;
      align-items: center;
      margin-bottom: 40px;
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .case-img {
      width: 280px;
      min-height: 200px;
      background-size: cover;
      background-position: center;
    }
    .case-info {
      padding: 28px;
      flex: 1;
    }
    .case-tag {
      background: rgba(10,37,64,0.06);
      color: var(--primary);
      font-weight: 600;
      font-size: 0.85rem;
      padding: 4px 12px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 10px;
    }
    @media (max-width: 768px) {
      .case-row {
        flex-direction: column;
      }
      .case-img {
        width: 100%;
        height: 200px;
      }
    }
    /* 解决方案图文交替 */
    .solution-alt {
      display: flex;
      gap: 40px;
      align-items: center;
      margin-bottom: 60px;
    }
    .solution-alt.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-img {
      flex: 1;
      background-size: cover;
      background-position: center;
      border-radius: 16px;
      min-height: 240px;
    }
    @media (max-width: 768px) {
      .solution-alt, .solution-alt.reverse {
        flex-direction: column;
      }
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-heading);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-body);
    }
    .faq-answer.open {
      max-height: 200px;
      padding-top: 12px;
    }
    /* CTA banner */
    .cta-banner {
      background: #F0F4F8;
      text-align: center;
      padding: 64px 24px;
      border-radius: 24px;
      margin: 40px 0;
    }
    .cta-banner h2 {
      font-size: 2rem;
      font-weight: 700;
    }
    /* Footer */
    .footer {
      background: var(--bg-footer);
      padding: 40px 0;
      text-align: center;
      color: var(--text-muted);
    }
    .footer-links {
      display: flex;
      justify-content: center;
      gap: 28px;
      margin: 16px 0;
      font-size: 0.9rem;
    }