/* roulang page: index */
:root {
      --primary-cyan: #00E5FF;
      --deep-blue-start: #0A1128;
      --deep-blue-end: #0F1B3D;
      --card-bg: rgba(15, 27, 61, 0.55);
      --glass-border: rgba(255, 255, 255, 0.1);
      --glass-border-light: rgba(255, 255, 255, 0.08);
      --text-white: #FFFFFF;
      --text-light-steel: #B0C4DE;
      --text-muted: #6B7FA3;
      --btn-ghost-border: rgba(0, 229, 255, 0.4);
      --btn-glow: rgba(0, 229, 255, 0.5);
      --radius-card: 16px;
      --radius-btn: 8px;
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.4);
      --shadow-hover: 0 12px 40px rgba(0, 229, 255, 0.15);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "DIN Alternate", "Roboto Mono", monospace;
    }

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

    body {
      font-family: var(--font-sans);
      background: linear-gradient(135deg, var(--deep-blue-start) 0%, var(--deep-blue-end) 100%);
      color: var(--text-light-steel);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button {
      font-family: inherit;
      cursor: pointer;
      border: none;
      background: none;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(10, 17, 40, 0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      z-index: 1000;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: 0.5px;
    }

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

    .nav-links {
      display: flex;
      gap: 28px;
      list-style: none;
    }

    .nav-links a {
      color: var(--text-light-steel);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 4px 0;
      position: relative;
      transition: color 0.2s;
    }

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

    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary-cyan);
      box-shadow: 0 0 8px var(--primary-cyan);
      border-radius: 2px;
    }

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

    .search-icon {
      font-size: 1.2rem;
      color: var(--text-light-steel);
      background: transparent;
      transition: color 0.2s;
    }

    .search-icon:hover {
      color: var(--primary-cyan);
    }

    .btn-ghost {
      border: 1px solid var(--btn-ghost-border);
      color: var(--primary-cyan);
      background: transparent;
      padding: 8px 20px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      transition: all 0.25s ease;
      white-space: nowrap;
    }

    .btn-ghost:hover {
      background: rgba(0, 229, 255, 0.1);
      border-color: var(--primary-cyan);
      box-shadow: 0 0 12px rgba(0, 229, 255, 0.3);
    }

    .btn-primary {
      background: var(--primary-cyan);
      color: var(--deep-blue-start);
      font-weight: 700;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      box-shadow: 0 0 20px var(--btn-glow);
      transition: all 0.25s ease;
      font-size: 0.9rem;
      letter-spacing: 0.3px;
      white-space: nowrap;
    }

    .btn-primary:hover {
      box-shadow: 0 0 36px rgba(0, 229, 255, 0.8);
      filter: brightness(1.1);
    }

    .hamburger {
      display: none;
      font-size: 1.6rem;
      color: var(--text-white);
      background: transparent;
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .nav-actions .btn-ghost {
        display: none;
      }
      .hamburger {
        display: block;
        order: 1;
      }
      .logo {
        order: 0;
      }
      .nav-actions {
        order: 2;
        gap: 12px;
      }
      .nav-container {
        flex-wrap: wrap;
      }
    }

    /* 区块共用 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }

    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      color: var(--text-white);
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }

    .section-sub {
      font-size: 1.1rem;
      color: var(--text-light-steel);
      margin-bottom: 48px;
      max-width: 700px;
    }

    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      background: radial-gradient(circle at 20% 30%, rgba(0,229,255,0.08) 0%, transparent 50%);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }

    .hero h1 {
      font-size: 3rem;
      font-weight: 700;
      color: var(--text-white);
      line-height: 1.2;
      margin-bottom: 20px;
    }

    .hero .subtitle {
      font-size: 1.2rem;
      color: var(--text-light-steel);
      margin-bottom: 32px;
    }

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

    .hero-image img {
      border-radius: 20px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.6);
      border: 1px solid rgba(255,255,255,0.15);
    }

    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero h1 {
        font-size: 2rem;
      }
      .hero-image {
        order: -1;
      }
      .hero-buttons {
        justify-content: center;
      }
    }

    /* 玻璃卡片 */
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--radius-card);
      padding: 28px;
      transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.2s;
    }

    .glass-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(0, 229, 255, 0.25);
    }

    .icon-box {
      width: 64px;
      height: 64px;
      background: rgba(0, 229, 255, 0.1);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary-cyan);
      font-size: 1.8rem;
    }

    .card-title {
      font-size: 1.25rem;
      font-weight: 600;
      color: var(--text-white);
      margin-bottom: 10px;
    }

    /* 三列网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    @media (max-width: 768px) {
      .grid-3 {
        grid-template-columns: 1fr;
      }
    }

    /* 解决方案左文右图 */
    .split-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }

    .split-row img {
      border-radius: 16px;
      box-shadow: 0 15px 30px rgba(0,0,0,0.5);
    }

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

    /* 数据仪表盘 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }

    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--primary-cyan);
      line-height: 1.2;
    }

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

    /* FAQ */
    .faq-item {
      background: rgba(15, 27, 61, 0.4);
      border: 1px solid rgba(255, 255, 255, 0.06);
      border-radius: 12px;
      margin-bottom: 12px;
      overflow: hidden;
    }

    .faq-question {
      padding: 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--text-white);
      cursor: pointer;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      padding: 0 20px;
      color: var(--text-light-steel);
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    .faq-item.open {
      border-color: rgba(0, 229, 255, 0.3);
    }

    /* 页脚 */
    .footer {
      background: #080E1F;
      border-top: 1px solid rgba(255,255,255,0.05);
      padding: 60px 0 30px;
    }

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

    .footer a {
      color: var(--text-muted);
      font-size: 0.9rem;
      display: block;
      margin-bottom: 8px;
    }

    .footer a:hover {
      color: var(--primary-cyan);
    }

    .copyright {
      margin-top: 40px;
      text-align: center;
      color: #4A5A7A;
      font-size: 0.85rem;
    }

    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    /* 动画 */
    @keyframes fadeUp {
      0% { opacity: 0; transform: translateY(20px); }
      100% { opacity: 1; transform: translateY(0); }
    }
    .animate {
      animation: fadeUp 0.7s ease forwards;
    }