/* roulang page: index */
:root {
      --primary-deep: #0A0E27;
      --accent-cyan: #00F0FF;
      --accent-cyan-hover: #33F5FF;
      --bg-light: #FAFAFC;
      --bg-subtle: #F0F2F8;
      --text-body: #3A3D4F;
      --text-heading: #0A0E27;
      --text-muted: #6B6F82;
      --text-on-dark: #B0B5CC;
      --white: #ffffff;
      --border-light: #DDE1EC;
      --shadow-card: 0 4px 20px rgba(10, 14, 39, 0.06);
      --shadow-card-hover: 0 12px 32px rgba(0, 240, 255, 0.12);
      --radius-sm: 8px;
      --radius-md: 16px;
      --radius-pill: 20px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      --font-display: 'Space Grotesk', 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --max-width: 1280px;
      --nav-height: 72px;
      --space-section: 100px;
      --space-mobile-section: 60px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, input {
      font-family: inherit;
      font-size: inherit;
      border: none;
      outline: none;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: var(--white);
      box-shadow: 0 1px 0 rgba(10, 14, 39, 0.08);
      z-index: 1000;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    .logo {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 22px;
      letter-spacing: -0.3px;
      color: var(--primary-deep);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo span {
      color: var(--accent-cyan);
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-body);
      padding: 8px 0;
      position: relative;
      transition: color 0.2s;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.25s ease;
    }

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

    .nav-links a:hover::after {
      width: 100%;
    }

    .nav-cta {
      background: var(--accent-cyan);
      color: var(--primary-deep);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-sm);
      transition: background 0.25s, box-shadow 0.25s;
      font-size: 15px;
      white-space: nowrap;
    }

    .nav-cta:hover {
      background: var(--accent-cyan-hover);
      box-shadow: 0 0 16px rgba(0, 240, 255, 0.5);
      color: var(--primary-deep);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary-deep);
      border-radius: 4px;
      transition: 0.3s;
    }

    /* 首屏 Hero */
    .hero {
      padding-top: var(--nav-height);
      background: var(--bg-light);
      display: flex;
      align-items: center;
      min-height: 90vh;
      position: relative;
      overflow: hidden;
    }

    .hero .container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      width: 100%;
    }

    .hero-content {
      z-index: 2;
    }

    .hero h1 {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 48px;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--primary-deep);
      margin-bottom: 18px;
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 480px;
    }

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

    .btn-primary {
      background: var(--accent-cyan);
      color: var(--primary-deep);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      transition: 0.25s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: 1.5px solid transparent;
    }

    .btn-primary:hover {
      background: var(--accent-cyan-hover);
      box-shadow: 0 0 20px rgba(0, 240, 255, 0.6);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary-deep);
      color: var(--primary-deep);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      transition: 0.25s;
    }

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

    .hero-visual {
      position: relative;
      width: 100%;
      height: 400px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      overflow: hidden;
    }

    .hero-visual::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(0, 240, 255, 0.18) 0%, rgba(10, 14, 39, 0.3) 100%);
    }

    /* 通用板块 */
    .section {
      padding: var(--space-section) 0;
    }

    .section-alt {
      background: var(--bg-subtle);
    }

    .section-header {
      text-align: center;
      max-width: 700px;
      margin: 0 auto 60px;
    }

    .section-header h2 {
      font-family: var(--font-display);
      font-weight: 600;
      font-size: 36px;
      color: var(--primary-deep);
      margin-bottom: 12px;
    }

    .section-header p {
      color: var(--text-muted);
      font-size: 17px;
    }

    /* 优势 非对称 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1.2fr 1fr 1fr;
      gap: 28px;
    }

    .advantage-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: 0.25s ease;
    }

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

    .advantage-icon {
      font-size: 36px;
      color: var(--accent-cyan);
      margin-bottom: 16px;
    }

    .advantage-card h3 {
      font-weight: 600;
      font-size: 20px;
      color: var(--primary-deep);
      margin-bottom: 10px;
    }

    /* 服务卡片 2x3 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .service-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: 0.25s;
    }

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

    .service-img {
      width: 100%;
      height: 140px;
      object-fit: cover;
      border-radius: var(--radius-sm);
      margin-bottom: 20px;
    }

    .service-card h3 {
      font-weight: 600;
      font-size: 20px;
      color: var(--primary-deep);
      margin-bottom: 8px;
    }

    /* 场景交错 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

    .scenario-row.reverse {
      flex-direction: row-reverse;
    }

    .scenario-text {
      flex: 1;
    }

    .scenario-text h3 {
      font-weight: 600;
      font-size: 26px;
      color: var(--primary-deep);
      margin-bottom: 16px;
    }

    .scenario-img {
      flex: 1;
      height: 300px;
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-md);
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: 0.25s;
    }

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

    .case-img {
      height: 160px;
      background-size: cover;
    }

    .case-info {
      padding: 20px;
    }

    .case-stat {
      font-family: var(--font-display);
      font-weight: 700;
      font-size: 28px;
      color: var(--accent-cyan);
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }

    .faq-item {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 18px 24px;
      box-shadow: var(--shadow-card);
      cursor: pointer;
    }

    .faq-question {
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--primary-deep);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, margin 0.3s;
      color: var(--text-body);
      font-size: 15px;
    }

    .faq-item.active .faq-answer {
      max-height: 150px;
      margin-top: 12px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary-deep);
      color: white;
      text-align: center;
      padding: 80px 20px;
    }

    .cta-banner h2 {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
    }

    /* 页脚 */
    .footer {
      background: var(--primary-deep);
      color: var(--text-on-dark);
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
    }

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

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

    @media (max-width: 1024px) {
      .hero .container { grid-template-columns: 1fr; gap: 40px; }
      .advantages-grid { grid-template-columns: 1fr 1fr; }
      .services-grid, .cases-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 32px; }
      .section-header h2 { font-size: 28px; }
      .advantages-grid, .services-grid, .cases-grid { grid-template-columns: 1fr; }
      .scenario-row, .scenario-row.reverse { flex-direction: column; }
      .faq-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }