/* roulang page: index */
:root {
      --deep-space: #1A0A2E;
      --cosmic-dark: #0A0612;
      --card-bg: #0D0D1A;
      --star-cyan: #00E5FF;
      --star-gold: #FFB347;
      --text-light: #F0F0FF;
      --text-body: #B0B0C8;
      --text-muted: #8888A0;
      --border-dim: rgba(0,229,255,0.15);
      --border-glow: rgba(0,229,255,0.4);
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --shadow-card: 0 8px 32px rgba(0,229,255,0.08);
      --shadow-hover: 0 12px 40px rgba(0,229,255,0.25);
      --transition: all 0.3s ease;
    }

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

    body {
      font-family: "Inter", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      background-color: var(--cosmic-dark);
      color: var(--text-body);
      line-height: 1.75;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    h1, h2, h3, h4 {
      font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      color: var(--text-light);
      font-weight: 700;
      letter-spacing: 0.02em;
    }

    h1 {
      font-size: clamp(2.5rem, 5vw, 4rem);
      font-weight: 800;
      color: #F0F0FF;
      text-shadow: 0 0 20px rgba(0,229,255,0.3);
      animation: textPulse 3s infinite alternate;
    }

    @keyframes textPulse {
      0% { text-shadow: 0 0 18px rgba(0,229,255,0.2); }
      100% { text-shadow: 0 0 28px rgba(0,229,255,0.5); }
    }

    h2 {
      font-size: clamp(1.8rem, 3.5vw, 2.5rem);
      margin-bottom: 2rem;
      position: relative;
      display: inline-block;
    }

    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -10px;
      width: 60px;
      height: 4px;
      background: var(--star-cyan);
      border-radius: 2px;
      box-shadow: 0 0 12px var(--star-cyan);
    }

    h3 {
      font-size: 1.4rem;
      font-weight: 600;
      color: #E0E0F0;
    }

    h4 {
      font-size: 1.1rem;
      font-weight: 600;
      color: #E0E0F0;
    }

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    section {
      padding: 100px 0;
    }

    @media (max-width: 1024px) {
      section {
        padding: 70px 0;
      }
    }

    @media (max-width: 640px) {
      section {
        padding: 50px 0;
      }
    }

    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(10,6,18,0.85);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid var(--border-dim);
      transition: background 0.3s;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 16px 24px;
      max-width: 1200px;
      margin: 0 auto;
    }

    .logo {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--star-cyan);
      letter-spacing: 2px;
      text-shadow: 0 0 10px rgba(0,229,255,0.6);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo-icon {
      width: 24px;
      height: 24px;
      border: 2px solid var(--star-cyan);
      border-radius: 50%;
      box-shadow: 0 0 12px var(--star-cyan);
      background: radial-gradient(circle, rgba(0,229,255,0.4) 0%, transparent 70%);
    }

    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
    }

    .nav-links a {
      color: #B0B0C8;
      font-weight: 500;
      font-size: 0.95rem;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--star-cyan);
      border-bottom-color: var(--star-cyan);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      background: none;
      border: none;
    }

    .hamburger span {
      width: 28px;
      height: 3px;
      background: var(--star-cyan);
      border-radius: 2px;
      transition: 0.3s;
    }

    @media (max-width: 840px) {
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(10,6,18,0.95);
        backdrop-filter: blur(25px);
        padding: 24px;
        gap: 20px;
        border-bottom: 1px solid var(--border-dim);
      }

      .nav-links.active {
        display: flex;
      }

      .hamburger {
        display: flex;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      background: linear-gradient(135deg, #0A0612 0%, #1A0A2E 50%, #0D1B3E 100%);
      position: relative;
      overflow: hidden;
    }

    .stars {
      position: absolute;
      width: 100%;
      height: 100%;
      background: radial-gradient(1px 1px at 20% 30%, rgba(255,255,255,0.4), transparent),
                  radial-gradient(1px 1px at 50% 70%, rgba(255,255,255,0.6), transparent),
                  radial-gradient(1px 1px at 80% 20%, rgba(0,229,255,0.5), transparent);
      background-size: 200px 200px;
      animation: drift 40s linear infinite;
    }

    @keyframes drift {
      0% { transform: translateY(0); }
      100% { transform: translateY(-80px); }
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      padding: 0 20px;
    }

    .hero-subtitle {
      font-size: 1.2rem;
      color: #B0B0C8;
      margin: 20px 0 32px;
    }

    .btn-group {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: var(--star-cyan);
      color: #0A0612;
      font-weight: 700;
      border-radius: var(--radius-md);
      padding: 14px 32px;
      border: none;
      cursor: pointer;
      transition: var(--transition);
      display: inline-block;
    }

    .btn-primary:hover {
      background: #33EAFF;
      box-shadow: 0 0 24px rgba(0,229,255,0.7);
      transform: translateY(-2px);
    }

    .btn-secondary {
      background: transparent;
      color: var(--star-cyan);
      border: 2px solid var(--star-cyan);
      border-radius: var(--radius-md);
      padding: 14px 32px;
      font-weight: 600;
      transition: var(--transition);
      display: inline-block;
    }

    .btn-secondary:hover {
      background: rgba(0,229,255,0.1);
      box-shadow: 0 0 18px rgba(0,229,255,0.3);
    }

    /* 卡片 */
    .glass-card {
      background: rgba(26,10,46,0.6);
      backdrop-filter: blur(12px);
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-lg);
      padding: 28px;
      transition: var(--transition);
      box-shadow: var(--shadow-card);
    }

    .glass-card:hover {
      border-color: var(--border-glow);
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .feature-grid {
      display: grid;
      grid-template-columns: 5fr 4fr 3fr;
      gap: 24px;
    }

    @media (max-width: 1024px) {
      .feature-grid {
        grid-template-columns: 1fr 1fr;
      }
      .feature-grid .card-large {
        grid-column: span 2;
      }
    }

    @media (max-width: 640px) {
      .feature-grid {
        grid-template-columns: 1fr;
      }
      .feature-grid .card-large {
        grid-column: span 1;
      }
    }

    /* 图文交替 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 60px;
    }

    .service-img {
      flex: 1;
      background: rgba(0,229,255,0.05);
      border-radius: var(--radius-lg);
      min-height: 300px;
      display: flex;
      align-items: center;
      justify-content: center;
      border: 1px solid var(--border-dim);
    }

    .service-text {
      flex: 1;
    }

    @media (max-width: 840px) {
      .service-row {
        flex-direction: column;
      }
      .service-row.reverse {
        flex-direction: column-reverse;
      }
    }

    /* 数据 */
    .stats-bar {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 20px;
      background: rgba(26,10,46,0.3);
      padding: 40px 20px;
      border-radius: var(--radius-lg);
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-size: 2.5rem;
      font-weight: 800;
      color: var(--star-gold);
      font-family: "Inter", sans-serif;
    }

    /* 标签切换 */
    .tab-buttons {
      display: flex;
      gap: 8px;
      margin-bottom: 30px;
    }

    .tab-btn {
      padding: 10px 20px;
      background: transparent;
      border: none;
      color: #B0B0C8;
      font-weight: 600;
      cursor: pointer;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }

    .tab-btn.active {
      color: var(--star-cyan);
      border-bottom-color: var(--star-cyan);
    }

    .tab-panel {
      display: none;
    }

    .tab-panel.active {
      display: flex;
      gap: 30px;
      align-items: center;
    }

    @media (max-width: 640px) {
      .tab-panel.active {
        flex-direction: column;
      }
    }

    /* 案例轮播 */
    .carousel-track {
      display: flex;
      gap: 20px;
      overflow-x: auto;
      scroll-snap-type: x mandatory;
      padding-bottom: 20px;
    }

    .case-card {
      min-width: 280px;
      scroll-snap-align: start;
    }

    .badge {
      background: rgba(255,179,71,0.2);
      color: var(--star-gold);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      display: inline-block;
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }

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

    .accordion-item {
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
    }

    .accordion-title {
      padding: 16px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      color: #E0E0F0;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #1A0A2E, #0A2A4A);
      text-align: center;
      padding: 70px 20px;
      border-radius: var(--radius-lg);
    }

    footer {
      background: #0A0612;
      padding: 50px 0 20px;
      border-top: 1px solid var(--border-dim);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 2fr;
      gap: 30px;
    }

    @media (max-width: 840px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 480px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }

    .copyright {
      text-align: center;
      color: #666680;
      margin-top: 30px;
      padding-top: 20px;
      border-top: 1px solid rgba(0,229,255,0.1);
    }