/* roulang page: index */
:root {
      --deep-blue: #0B1A2F;
      --cyan: #00E5FF;
      --amber: #FFB300;
      --bg-dark: #0D1117;
      --glass-bg: rgba(20, 30, 50, 0.7);
      --glass-border: rgba(0, 229, 255, 0.2);
      --text-light: #f0f4f8;
      --text-muted: #a0b4cc;
      --card-radius: 20px;
      --btn-radius: 12px;
      --section-gap: 100px;
    }

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

    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      background-color: var(--bg-dark);
      color: var(--text-light);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 导航 */
    .navbar {
      background-color: var(--deep-blue);
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 229, 255, 0.15);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    .logo {
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: 1px;
      color: var(--cyan);
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--amber);
      font-size: 0.9rem;
      background: rgba(255,179,0,0.15);
      padding: 2px 8px;
      border-radius: 20px;
      margin-left: 4px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      color: #cbd5e1;
      text-decoration: none;
      font-weight: 500;
      position: relative;
      transition: color 0.2s;
      font-size: 0.95rem;
    }
    .nav-links a:hover {
      color: var(--cyan);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--cyan);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--amber);
      color: #0B1A2F;
      font-weight: 700;
      padding: 0.7rem 1.8rem;
      border-radius: var(--btn-radius);
      text-decoration: none;
      transition: box-shadow 0.25s, transform 0.2s;
      box-shadow: 0 0 12px rgba(255,179,0,0.4);
      font-size: 0.95rem;
      display: inline-block;
      border: none;
      cursor: pointer;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      box-shadow: 0 0 22px rgba(255,179,0,0.7);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--cyan);
      color: var(--cyan);
      font-weight: 600;
      padding: 0.7rem 1.8rem;
      border-radius: var(--btn-radius);
      text-decoration: none;
      transition: 0.25s;
      display: inline-block;
      cursor: pointer;
    }
    .btn-outline:hover {
      background: var(--cyan);
      color: #0B1A2F;
      box-shadow: 0 0 18px rgba(0,229,255,0.6);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--cyan);
      border-radius: 2px;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: var(--deep-blue);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        border-bottom: 1px solid rgba(0,229,255,0.2);
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 20% 30%, rgba(0,229,255,0.08) 0%, transparent 50%);
      position: relative;
      padding-top: 80px;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      background: linear-gradient(to right, #ffffff, #00E5FF);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero p {
      color: #cbd5e1;
      font-size: 1.15rem;
      margin-bottom: 2rem;
      max-width: 90%;
    }
    .stat-card {
      background: rgba(20,30,50,0.6);
      backdrop-filter: blur(16px);
      border: 1px solid var(--glass-border);
      border-radius: var(--card-radius);
      padding: 1.8rem;
      box-shadow: 0 8px 32px rgba(0,0,0,0.4);
    }
    .stat-item {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
      margin-bottom: 1rem;
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding-bottom: 0.8rem;
    }
    .stat-value {
      color: var(--amber);
      font-weight: 700;
      font-size: 2rem;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero h1 {
        font-size: 2.4rem;
      }
    }

    /* 功能卡片不对称 */
    .feature-card {
      background: var(--glass-bg);
      backdrop-filter: blur(14px);
      border: 1px solid var(--glass-border);
      border-radius: var(--card-radius);
      padding: 2rem 2rem 2rem 2.5rem;
      position: relative;
      transition: transform 0.25s, box-shadow 0.3s;
      display: flex;
      gap: 1.5rem;
      align-items: flex-start;
      box-shadow: 0 8px 28px rgba(0,0,0,0.35);
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 18px 40px rgba(0,229,255,0.15);
    }
    .feature-left-line {
      width: 4px;
      height: 100%;
      min-height: 80px;
      background: var(--cyan);
      border-radius: 4px;
      transition: width 0.2s;
      flex-shrink: 0;
    }
    .feature-card:hover .feature-left-line {
      width: 8px;
      box-shadow: 0 0 16px var(--cyan);
    }
    .feature-number {
      color: rgba(255,179,0,0.25);
      font-size: 2.5rem;
      font-weight: 700;
      position: absolute;
      top: 16px;
      right: 20px;
    }
    .feature-content h3 {
      font-size: 1.5rem;
      font-weight: 600;
      margin-bottom: 0.5rem;
      text-align: right;
    }
    .feature-content p {
      color: #b0c4d8;
      text-align: right;
    }

    /* 场景交替 */
    .scene-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 4rem;
    }
    .scene-text ul {
      list-style: none;
      padding-left: 0;
    }
    .scene-text li::before {
      content: "◆";
      color: var(--cyan);
      margin-right: 10px;
    }
    .img-placeholder {
      background: rgba(11,26,47,0.7);
      border: 1px solid var(--glass-border);
      border-radius: var(--card-radius);
      overflow: hidden;
      box-shadow: 0 0 18px rgba(0,229,255,0.2);
    }
    .img-placeholder img {
      width: 100%;
      height: auto;
      display: block;
      object-fit: cover;
    }

    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 1.8rem;
    }
    .case-card {
      background: rgba(15,25,40,0.8);
      border: 1px solid rgba(255,179,0,0.15);
      border-radius: 20px;
      padding: 1.8rem;
      backdrop-filter: blur(8px);
    }
    .case-highlight {
      color: var(--amber);
      font-size: 2.2rem;
      font-weight: 700;
    }

    /* 价格卡 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 1.8rem;
    }
    .pricing-card {
      background: var(--glass-bg);
      border: 1px solid var(--glass-border);
      border-radius: 24px;
      padding: 2rem;
      backdrop-filter: blur(14px);
      text-align: center;
    }
    .pricing-card.featured {
      border: 2px solid var(--amber);
      box-shadow: 0 0 24px rgba(255,179,0,0.3);
    }
    .price-num {
      color: var(--amber);
      font-size: 2.8rem;
      font-weight: 700;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(0,229,255,0.25);
      padding: 1.2rem 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: #b0c4d8;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 0.8rem;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--deep-blue);
      padding: 4rem 1rem;
      text-align: center;
      border-top: 1px solid rgba(0,229,255,0.2);
    }

    footer {
      background: #0B1A2F;
      padding: 3rem 1rem 1.5rem;
      color: #b0c4d8;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 2rem;
    }
    .footer-col h4 {
      color: var(--amber);
      margin-bottom: 1rem;
    }
    @media (max-width: 768px) {
      .footer-grid, .pricing-grid, .case-grid {
        grid-template-columns: 1fr;
      }
      .scene-row {
        flex-direction: column;
      }
    }