/* roulang page: index */
:root {
      --primary: #0B1D3A;
      --accent: #00F0FF;
      --cta: #FF6B35;
      --surface-glass: rgba(15, 30, 60, 0.55);
      --surface-border: rgba(0, 240, 255, 0.25);
      --text-primary: #E0E8F0;
      --text-secondary: #8A9BB5;
      --text-white: #FFFFFF;
      --glass-blur: blur(16px) saturate(180%);
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
      --shadow-glow: 0 0 20px rgba(0, 240, 255, 0.5);
      --radius-card: 16px;
      --transition: all 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'SF Pro Text', -apple-system, 'Microsoft YaHei', sans-serif;
      background-color: #050f1f;
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.02'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      color: var(--text-white);
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }
    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(11, 29, 58, 0.85);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0, 240, 255, 0.3);
      transition: background 0.3s, box-shadow 0.3s;
    }
    .header.scrolled {
      background: rgba(11, 29, 58, 0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.6rem;
      letter-spacing: -0.5px;
      color: white;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--accent);
      filter: drop-shadow(0 0 6px rgba(0,240,255,0.6));
    }
    .nav-links {
      display: flex;
      gap: 2.2rem;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-secondary);
      padding: 6px 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--text-white);
      border-bottom-color: var(--accent);
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: white;
      background: none;
      border: none;
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: clamp(2rem, 4vw, 2.8rem);
      font-weight: 700;
      margin-bottom: 16px;
      color: white;
      position: relative;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 60px;
      height: 3px;
      background: var(--accent);
      margin-top: 12px;
    }
    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: radial-gradient(circle at 30% 40%, rgba(0,240,255,0.08) 0%, transparent 60%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-right img {
      max-height: 420px;
      filter: drop-shadow(0 15px 30px rgba(0,240,255,0.2));
      animation: float 6s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-18px); }
      100% { transform: translateY(0px); }
    }
    h1 {
      font-size: clamp(2.5rem, 5vw, 4rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 1.2rem;
      color: white;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--cta);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 600;
      letter-spacing: 0.05em;
      text-transform: uppercase;
      font-size: 0.9rem;
      transition: 0.2s;
      box-shadow: 0 4px 12px rgba(255,107,53,0.4);
    }
    .btn-primary:hover {
      box-shadow: 0 0 25px rgba(255,107,53,0.7);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent);
      color: var(--accent);
      padding: 14px 32px;
      border-radius: 40px;
      font-weight: 600;
      letter-spacing: 0.05em;
      text-transform: uppercase;
      font-size: 0.9rem;
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.1);
      box-shadow: 0 0 15px rgba(0,240,255,0.4);
      color: white;
    }
    /* 玻璃卡片基础 */
    .glass-card {
      background: var(--surface-glass);
      backdrop-filter: var(--glass-blur);
      border: 1px solid var(--surface-border);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .glass-card:hover {
      border-color: rgba(0,240,255,0.6);
      box-shadow: 0 0 24px rgba(0,240,255,0.35);
      transform: translateY(-8px);
    }
    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
      margin-top: 40px;
    }
    .highlight-card {
      padding: 32px 24px;
      text-align: center;
    }
    .highlight-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--cta);
      display: block;
      margin-bottom: 8px;
    }
    .highlight-card h3 {
      color: var(--accent);
      margin: 12px 0 8px;
    }
    /* 案例瀑布流 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
      gap: 24px;
      margin-top: 40px;
    }
    .case-card {
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }
    .case-img {
      height: 180px;
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .case-img::after {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(0,240,255,0.25);
      transition: 0.3s;
    }
    .case-card:hover .case-img::after {
      background: rgba(0,240,255,0.05);
    }
    .case-content {
      padding: 24px;
    }
    .case-tag {
      display: inline-block;
      background: rgba(0,240,255,0.15);
      color: var(--accent);
      font-size: 0.75rem;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 12px;
    }
    /* 方案对比 */
    .solutions-row {
      display: flex;
      gap: 0;
      margin-top: 40px;
      border-radius: 24px;
      overflow: hidden;
      background: rgba(15,30,60,0.5);
      backdrop-filter: blur(10px);
      border: 1px solid rgba(0,240,255,0.2);
    }
    .solution-col {
      flex: 1;
      padding: 40px 32px;
      position: relative;
    }
    .solution-col.recommended {
      background: rgba(0,240,255,0.05);
    }
    .badge {
      background: var(--cta);
      color: white;
      font-size: 0.8rem;
      padding: 4px 14px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 16px;
    }
    .solution-list {
      list-style: none;
      margin: 24px 0;
    }
    .solution-list li {
      margin-bottom: 14px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .solution-list i {
      color: var(--accent);
    }
    .divider {
      width: 1px;
      background: linear-gradient(to bottom, transparent, var(--accent), transparent);
    }
    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 16px;
      margin-top: 30px;
    }
    .faq-item {
      padding: 20px 24px;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: white;
      cursor: pointer;
    }
    .faq-icon {
      font-size: 1.3rem;
      color: var(--accent);
      transition: 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 16px;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA 横幅 */
    .cta-banner {
      background: #0B1D3A;
      text-align: center;
      padding: 80px 24px;
      background-image: radial-gradient(circle at 50% 20%, rgba(0,240,255,0.1), transparent);
    }
    .cta-banner h2 {
      margin-bottom: 20px;
    }
    .cta-small {
      color: var(--text-secondary);
      margin-top: 16px;
    }
    /* 页脚 */
    .footer {
      background: #0a1525;
      padding: 60px 0 20px;
      border-top: 1px solid rgba(255,255,255,0.05);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-links a {
      display: block;
      color: var(--text-secondary);
      margin-bottom: 10px;
    }
    .footer-links a:hover {
      color: var(--accent);
    }
    .copyright {
      text-align: center;
      color: var(--text-secondary);
      font-size: 0.9rem;
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 24px;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-sub {
        margin-left: auto;
        margin-right: auto;
      }
      .btn-group {
        justify-content: center;
      }
      .highlights-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .solutions-row {
        flex-direction: column;
      }
      .divider {
        width: 100%;
        height: 1px;
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(11,29,58,0.96);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 32px 24px;
        gap: 24px;
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .highlights-grid {
        grid-template-columns: 1fr;
      }
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }
    @media (max-width: 520px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }