/* roulang page: index */
:root {
      --primary: #5B2D8E;
      --secondary: #00E5CC;
      --accent: #FF6B35;
      --bg-dark: #0F0A1A;
      --bg-secondary: #1A1425;
      --text-primary: #F0EBF5;
      --text-secondary: #A89BB5;
      --text-dark: #E4D9F0;
      --border-light: rgba(0, 229, 204, 0.15);
      --border-glow: rgba(0, 229, 204, 0.4);
      --shadow-card: 0 4px 24px rgba(91, 45, 142, 0.25);
      --shadow-hover: 0 8px 40px rgba(0, 229, 204, 0.3);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --transition: all 0.25s ease;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --container-max: 1280px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-dark);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 15px;
      -webkit-font-smoothing: antialiased;
    }

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

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

    img {
      max-width: 100%;
      display: block;
      height: auto;
      border-radius: var(--radius-md);
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      font-weight: 600;
      border: none;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border-radius: var(--radius-sm);
      font-size: 15px;
      letter-spacing: 0.3px;
    }

    /* 导航栏 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(15, 10, 26, 0.8);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 229, 204, 0.25);
      transition: background 0.3s ease;
    }

    #header.scrolled {
      background: rgba(15, 10, 26, 0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      padding: 0 24px;
      max-width: var(--container-max);
      margin: 0 auto;
    }

    .logo {
      font-weight: 800;
      font-size: 28px;
      letter-spacing: -0.5px;
      color: white;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .logo i {
      color: var(--secondary);
      font-size: 32px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      font-weight: 500;
      color: var(--text-secondary);
    }

    .nav-links a {
      font-size: 15px;
      padding: 6px 0;
      position: relative;
      color: var(--text-secondary);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: white;
    }

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

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

    .nav-actions {
      display: flex;
      align-items: center;
      gap: 16px;
    }

    .search-icon {
      color: var(--text-secondary);
      font-size: 20px;
      cursor: pointer;
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--secondary);
      color: var(--secondary);
      padding: 10px 22px;
      border-radius: var(--radius-sm);
    }

    .btn-outline:hover {
      background: rgba(0, 229, 204, 0.1);
    }

    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 10px 24px;
      font-weight: 700;
      border-radius: var(--radius-sm);
      box-shadow: 0 4px 12px rgba(255, 107, 53, 0.35);
    }

    .btn-primary:hover {
      background: #ff7f55;
      transform: scale(1.03);
      box-shadow: 0 8px 20px rgba(255, 107, 53, 0.5);
    }

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

    @media (max-width: 1024px) {
      .nav-links, .nav-actions .search-icon, .nav-actions .btn-outline {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .nav-actions .btn-primary {
        display: inline-flex;
      }
    }

    .mobile-menu {
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(15, 10, 26, 0.98);
      backdrop-filter: blur(20px);
      flex-direction: column;
      padding: 32px 24px;
      gap: 24px;
      display: none;
      border-bottom: 1px solid var(--border-light);
    }

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

    .mobile-menu a {
      font-size: 18px;
      font-weight: 600;
      color: var(--text-primary);
    }

    /* Hero */
    #hero {
      padding: 140px 0 100px;
      min-height: 90vh;
      display: flex;
      align-items: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }

    #hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(15,10,26,0.9) 0%, rgba(15,10,26,0.6) 70%);
    }

    .hero-content {
      position: relative;
      display: flex;
      align-items: center;
      gap: 40px;
    }

    .hero-text {
      flex: 1 1 55%;
    }

    .hero-text h1 {
      font-size: clamp(38px, 5vw, 56px);
      font-weight: 800;
      line-height: 1.2;
      margin-bottom: 24px;
      color: white;
    }

    .hero-text .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 36px;
      max-width: 500px;
    }

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

    .btn-lg {
      padding: 14px 32px;
      font-size: 17px;
    }

    .hero-visual {
      flex: 1 1 45%;
      position: relative;
      display: flex;
      justify-content: center;
    }

    .abstract-graphic {
      width: 100%;
      max-width: 480px;
      height: 360px;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,204,0.2) 0%, rgba(91,45,142,0.3) 80%);
      border-radius: 50%;
      filter: blur(30px);
      position: absolute;
    }

    .node-lines {
      width: 400px;
      height: 300px;
      border: 2px dashed var(--secondary);
      opacity: 0.4;
      border-radius: 50%;
      position: relative;
    }

    @media (max-width: 768px) {
      .hero-content {
        flex-direction: column;
        text-align: center;
      }
      .hero-text .subtitle {
        max-width: 100%;
      }
    }

    /* 通用区块 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 16px;
      color: white;
    }

    .section-desc {
      color: var(--text-secondary);
      max-width: 600px;
      margin-bottom: 48px;
      font-size: 16px;
    }

    /* 功能卡片网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .feature-card {
      background: rgba(26, 20, 37, 0.85);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 28px;
      transition: var(--transition);
    }

    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      border-color: var(--border-glow);
    }

    .feature-icon {
      font-size: 40px;
      color: var(--secondary);
      margin-bottom: 20px;
    }

    .feature-card h3 {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .feature-list {
      list-style: none;
      color: var(--text-secondary);
      font-size: 14px;
    }

    .feature-list li {
      margin-bottom: 10px;
      display: flex;
      align-items: baseline;
      gap: 8px;
    }

    .feature-list li i {
      color: var(--secondary);
      font-size: 12px;
    }

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

    @media (max-width: 640px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }

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

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

    .scenario-img {
      flex: 1;
    }

    .scenario-img img {
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
    }

    .scenario-text {
      flex: 1;
    }

    .scenario-text h3 {
      font-size: 26px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    .tags {
      display: flex;
      gap: 10px;
      margin-top: 16px;
      flex-wrap: wrap;
    }

    .pill {
      background: rgba(0,229,204,0.15);
      color: var(--secondary);
      padding: 4px 14px;
      border-radius: 20px;
      font-size: 13px;
    }

    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
      }
    }

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

    .case-card {
      background: rgba(26, 20, 37, 0.9);
      border-left: 4px solid var(--secondary);
      padding: 24px;
      border-radius: var(--radius-sm);
    }

    .case-quote {
      font-style: italic;
      margin-bottom: 12px;
    }

    .case-meta {
      color: var(--secondary);
      font-weight: 600;
    }

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

    /* 价格卡片 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .pricing-card {
      background: rgba(26, 20, 37, 0.9);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      text-align: center;
      position: relative;
    }

    .pricing-card.featured {
      border-color: var(--secondary);
      box-shadow: 0 0 28px rgba(0,229,204,0.25);
    }

    .badge {
      background: var(--secondary);
      color: var(--bg-dark);
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
    }

    .price {
      font-size: 44px;
      font-weight: 800;
      color: white;
      margin: 16px 0;
    }

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

    @media (max-width: 640px) {
      .pricing-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 16px 0;
    }

    .faq-question {
      font-weight: 700;
      font-size: 16px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }

    /* CTA */
    #cta {
      background: linear-gradient(135deg, #1A1425 0%, #0F0A1A 100%);
      text-align: center;
      padding: 80px 0;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      color: var(--text-secondary);
    }

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