/* roulang page: index */
:root {
      --deep-space: #0A0E27;
      --cyan-glow: #00F0FF;
      --competitive-red: #FF4655;
      --bg-light: #F4F6FA;
      --white: #FFFFFF;
      --text-primary: #2D3748;
      --text-secondary: #718096;
      --card-shadow: 0 2px 12px rgba(10, 14, 39, 0.06);
      --card-shadow-hover: 0 8px 24px rgba(10, 14, 39, 0.12);
      --radius-lg: 16px;
      --radius-md: 8px;
      --transition: all 0.25s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-mono: "Inter", "Roboto Mono", monospace;
      --container-max: 1200px;
      --nav-height: 72px;
    }

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

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

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--white);
      height: var(--nav-height);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: box-shadow 0.3s;
    }

    .main-header.scrolled {
      box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    }

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

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.4rem;
      color: var(--deep-space);
    }

    .logo-icon {
      color: var(--cyan-glow);
      font-size: 1.8rem;
    }

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

    .nav-links a {
      color: var(--text-primary);
      font-weight: 500;
      transition: var(--transition);
    }

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

    .btn-primary {
      background: var(--cyan-glow);
      color: var(--deep-space);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-md);
      border: none;
      transition: var(--transition);
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      background: var(--competitive-red);
      color: white;
      box-shadow: 0 0 20px rgba(255, 70, 85, 0.4);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--cyan-glow);
      color: var(--cyan-glow);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      transition: var(--transition);
    }

    .btn-outline:hover {
      background: var(--cyan-glow);
      color: var(--deep-space);
    }

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

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--deep-space);
      border-radius: 2px;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: rgba(0, 240, 255, 0.95);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 32px;
        backdrop-filter: blur(8px);
        z-index: 999;
      }

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

      .hamburger {
        display: flex;
        z-index: 1001;
      }

      .nav-links a {
        font-size: 1.8rem;
        color: var(--deep-space);
      }
    }

    /* Hero */
    .hero {
      background: var(--deep-space);
      padding: 120px 0 80px;
      position: relative;
      overflow: hidden;
      color: white;
    }

    .hero::before {
      content: "";
      position: absolute;
      top: -20%;
      left: -10%;
      width: 60%;
      height: 140%;
      background: radial-gradient(circle at 30% 30%, rgba(0, 240, 255, 0.12), transparent 70%);
      pointer-events: none;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
    }

    .hero-text {
      flex: 1;
    }

    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero-sub {
      font-size: 18px;
      color: #CBD5E0;
      margin-bottom: 32px;
    }

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

    .hero-visual {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .data-badge {
      background: rgba(255, 255, 255, 0.08);
      backdrop-filter: blur(4px);
      border-radius: var(--radius-lg);
      padding: 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: white;
    }

    .badge-number {
      font-family: var(--font-mono);
      font-size: 2rem;
      font-weight: 700;
      color: var(--cyan-glow);
    }

    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero h1 {
        font-size: 36px;
      }
    }

    /* 板块通用 */
    .section {
      padding: 80px 0;
    }

    .section-title {
      text-align: center;
      font-size: 36px;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--deep-space);
    }

    .section-sub {
      text-align: center;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

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

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

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

    .icon-cyan {
      color: var(--cyan-glow);
      font-size: 2rem;
      margin-bottom: 16px;
    }

    /* 功能Tab */
    .tabs {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 40px;
    }

    .tab-btn {
      background: transparent;
      border: 1px solid var(--text-secondary);
      padding: 8px 24px;
      border-radius: 20px;
      font-weight: 500;
      transition: var(--transition);
    }

    .tab-btn.active {
      background: var(--cyan-glow);
      border-color: var(--cyan-glow);
      color: var(--deep-space);
    }

    .feature-cards {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 20px;
    }

    .feature-item {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
      border: 1px solid transparent;
    }

    .feature-item:hover {
      border-color: var(--cyan-glow);
      transform: translateY(-4px);
    }

    /* 场景卡片 */
    .scene-card {
      background: #F4F6FA;
      border-radius: var(--radius-lg);
      padding: 40px;
      display: flex;
      gap: 32px;
      align-items: center;
      margin-bottom: 24px;
    }

    .scene-img {
      width: 180px;
      height: 180px;
      object-fit: cover;
      border-radius: var(--radius-md);
    }

    /* 数据背书 */
    .stats-row {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      margin-bottom: 48px;
    }

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

    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--competitive-red);
    }

    /* 价格卡片 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .price-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--card-shadow);
      text-align: center;
      position: relative;
    }

    .price-card.popular {
      border: 2px solid var(--cyan-glow);
    }

    .badge {
      background: var(--competitive-red);
      color: white;
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 12px;
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
    }

    .price {
      font-family: var(--font-mono);
      font-size: 36px;
      font-weight: 700;
    }

    /* FAQ */
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      box-shadow: var(--card-shadow);
    }

    .faq-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    .faq-answer {
      padding: 0 20px 20px;
      display: none;
    }

    .faq-item.open .faq-answer {
      display: block;
    }

    /* 最终CTA */
    .cta-dark {
      background: var(--deep-space);
      color: white;
      text-align: center;
      padding: 80px 0;
    }

    .footer {
      background: var(--deep-space);
      color: #A0AEC0;
      padding: 48px 0 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    @media (max-width: 768px) {
      .grid-3, .pricing-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .scene-card {
        flex-direction: column;
      }
    }

    @media (max-width: 576px) {
      .hero h1 {
        font-size: 32px;
      }
    }