/* roulang page: index */
:root {
      --primary: #0A4DA4;
      --primary-dark: #083D82;
      --accent: #00B4D8;
      --bg: #F8FAFC;
      --text: #1E293B;
      --text-soft: #64748B;
      --border: #E2E8F0;
      --white: #FFFFFF;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-card: 0 4px 12px rgba(0,0,0,0.04);
      --radius-md: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --spacing-section: 96px;
      --container-max: 1200px;
      --nav-height: 72px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      font-size: 16px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      height: 48px;
      padding: 0 28px;
      font-size: 1rem;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all 200ms ease;
      cursor: pointer;
      border: none;
      background: transparent;
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      box-shadow: 0 2px 6px rgba(10,77,164,0.25);
    }

    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: translateY(-1px);
      box-shadow: 0 8px 18px rgba(10,77,164,0.3);
    }

    .btn-outline {
      border: 1.5px solid var(--primary);
      color: var(--primary);
      background: transparent;
    }

    .btn-outline:hover {
      background-color: rgba(10,77,164,0.08);
      border-color: var(--primary-dark);
      color: var(--primary-dark);
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: #475569;
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      width: 24px;
      height: 18px;
    }

    .hamburger span {
      display: block;
      height: 2px;
      background: var(--text);
      border-radius: 2px;
      transition: 0.3s;
    }

    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        gap: 24px;
        padding: 32px 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        transform: translateY(-120%);
        opacity: 0;
        transition: 0.3s ease;
        pointer-events: none;
      }

      .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
      }

      .hamburger {
        display: flex;
      }

      .nav-link {
        font-size: 18px;
        border-bottom: none;
      }
    }

    /* 板块通用 */
    section {
      padding-top: var(--spacing-section);
      padding-bottom: var(--spacing-section);
    }

    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text);
      text-align: center;
    }

    .section-subtitle {
      font-size: 18px;
      color: var(--text-soft);
      text-align: center;
      max-width: 680px;
      margin: 0 auto 48px;
    }

    @media (max-width: 768px) {
      :root {
        --spacing-section: 64px;
      }
      .section-title {
        font-size: 28px;
      }
      .section-subtitle {
        font-size: 16px;
      }
    }

    /* Hero */
    .hero {
      padding-top: calc(var(--nav-height) + 56px);
      padding-bottom: 80px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      background-color: #F0F4FA;
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }

    .hero-left h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text);
      margin-bottom: 24px;
    }

    .hero-left .subtitle {
      font-size: 18px;
      color: var(--text-soft);
      margin-bottom: 32px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-right {
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(6px);
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
      display: flex;
      align-items: center;
      justify-content: center;
      aspect-ratio: 1 / 0.8;
    }

    .hero-right img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-left h1 {
        font-size: 32px;
      }
      .hero-buttons {
        justify-content: center;
      }
      .hero-right {
        aspect-ratio: 16/9;
        max-height: 260px;
      }
    }

    /* 服务卡片 4列 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--white);
      border: 1px solid var(--border);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      transition: transform 0.2s, box-shadow 0.2s;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 24px rgba(0,0,0,0.06);
    }

    .service-icon {
      width: 48px;
      height: 48px;
      background: #E6F0FC;
      border-radius: 10px;
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 24px;
    }

    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .service-desc {
      font-size: 14px;
      color: var(--text-soft);
      margin-bottom: 16px;
      line-height: 1.6;
    }

    .service-link {
      color: var(--primary);
      font-weight: 600;
      font-size: 14px;
      transition: color 0.2s;
    }

    .service-link:hover {
      color: var(--primary-dark);
    }

    @media (max-width: 1024px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 520px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 优势数据 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      text-align: center;
    }

    .adv-item {
      padding: 24px;
      border-right: 1px solid var(--border);
    }
    .adv-item:last-child {
      border-right: none;
    }

    .adv-number {
      font-size: 44px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }

    .adv-label {
      font-size: 16px;
      color: var(--text-soft);
      margin-top: 8px;
    }

    @media (max-width: 768px) {
      .advantages-grid {
        grid-template-columns: 1fr;
        gap: 24px;
      }
      .adv-item {
        border-right: none;
        border-bottom: 1px solid var(--border);
        padding-bottom: 24px;
      }
      .adv-item:last-child {
        border-bottom: none;
      }
    }

    /* 案例卡片 3列 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
    }

    .case-card:hover {
      box-shadow: 0 12px 28px rgba(0,0,0,0.08);
    }

    .case-img {
      aspect-ratio: 16 / 9;
      background-color: #E2E8F0;
      overflow: hidden;
    }

    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .case-content {
      padding: 20px;
    }

    .case-title {
      font-weight: 700;
      font-size: 18px;
      margin-bottom: 4px;
    }

    .case-client {
      font-size: 12px;
      color: var(--text-soft);
      margin-bottom: 8px;
    }

    .case-desc {
      font-size: 14px;
      color: var(--text-soft);
      line-height: 1.6;
    }

    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 解决方案步骤 */
    .steps {
      display: flex;
      justify-content: space-between;
      position: relative;
      gap: 24px;
      margin-top: 40px;
    }

    .step {
      flex: 1;
      text-align: center;
      position: relative;
    }

    .step-num {
      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;
      margin: 0 auto 16px;
    }

    .step h3 {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .step p {
      font-size: 14px;
      color: var(--text-soft);
    }

    @media (max-width: 768px) {
      .steps {
        flex-direction: column;
        align-items: flex-start;
      }
      .step {
        display: flex;
        align-items: center;
        gap: 16px;
        text-align: left;
      }
      .step-num {
        margin: 0;
      }
    }

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

    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      padding: 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 18px;
      font-weight: 600;
      color: var(--text);
      cursor: pointer;
      text-align: left;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.2s;
      background: #F1F5F9;
      padding: 0 20px;
      font-size: 16px;
      color: var(--text-soft);
      line-height: 1.75;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px 20px;
    }

    .faq-icon {
      font-size: 24px;
      color: var(--primary);
    }

    /* CTA */
    .cta-band {
      background: #E6F0FC;
      text-align: center;
      padding: 80px 24px;
      border-radius: 24px;
      margin: 0 24px;
    }

    .cta-band h2 {
      font-size: 36px;
      font-weight: 700;
    }

    .cta-band p {
      font-size: 18px;
      color: var(--text-soft);
      margin: 16px 0 32px;
    }

    /* 页脚 */
    .footer {
      background: #0F172A;
      color: #CBD5E1;
      padding: 64px 0 32px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .footer h4 {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .footer-links {
      list-style: none;
    }

    .footer-links li {
      margin-bottom: 10px;
      font-size: 14px;
    }

    .footer-links a:hover {
      color: var(--accent);
    }

    .copyright {
      border-top: 1px solid #1E293B;
      margin-top: 40px;
      padding-top: 24px;
      font-size: 12px;
      text-align: center;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }