/* roulang page: index */
:root {
      --primary-cyan: #0AE0E0;
      --primary-dark: #0AC8C8;
      --bg-dark: #1A1D29;
      --bg-gray: #F7F8FA;
      --white: #FFFFFF;
      --accent-orange: #FF6B35;
      --accent-dark: #E55A2B;
      --text-dark: #1E293B;
      --text-mid: #64748B;
      --text-light: #94A3B8;
      --border-light: #E2E8F0;
      --shadow-sm: 0 2px 12px rgba(26,29,41,0.06);
      --shadow-hover: 0 8px 24px rgba(10,224,224,0.15);
      --radius-md: 12px;
      --radius-sm: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", "Segoe UI", sans-serif;
      --container-max: 1280px;
      --section-gap: 80px;
    }

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

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

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

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

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

    button, input, textarea {
      font-family: inherit;
    }

    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: 42px;
      letter-spacing: -0.5px;
      margin-bottom: 16px;
      color: #0F172A;
    }

    h2 {
      font-size: 32px;
      margin-bottom: 16px;
      color: #1E293B;
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
      color: #1E293B;
    }

    .section {
      padding: var(--section-gap) 0;
    }

    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      z-index: 1000;
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      transition: box-shadow 0.3s ease;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      font-weight: 700;
      font-size: 24px;
      color: #0F172A;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      color: var(--primary-cyan);
      font-weight: 800;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-menu a {
      font-weight: 500;
      color: var(--text-mid);
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }

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

    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary-cyan);
      border-radius: 2px;
    }

    .btn-primary {
      background: var(--accent-orange);
      color: white;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      border: none;
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-block;
      text-align: center;
      box-shadow: 0 4px 10px rgba(255,107,53,0.2);
    }

    .btn-primary:hover {
      background: var(--accent-dark);
      transform: scale(1.03);
      box-shadow: 0 8px 18px rgba(229,90,43,0.3);
      color: white;
    }

    .btn-secondary {
      background: transparent;
      border: 1px solid var(--primary-cyan);
      color: var(--primary-cyan);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-block;
      text-align: center;
    }

    .btn-secondary:hover {
      background: #E6FCFC;
      border-color: #0AC8C8;
      color: #0AC8C8;
    }

    .btn-cyan {
      background: var(--primary-cyan);
      color: #0F172A;
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-md);
      border: none;
      cursor: pointer;
      transition: all 0.2s ease;
      display: inline-block;
      box-shadow: 0 4px 10px rgba(10,224,224,0.2);
    }

    .btn-cyan:hover {
      background: var(--primary-dark);
      box-shadow: 0 8px 18px rgba(10,200,200,0.3);
      color: #0F172A;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: #1E293B;
      border-radius: 2px;
      transition: 0.3s;
    }

    /* Hero */
    #hero {
      padding: 140px 0 80px;
      background: var(--white);
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }

    .hero-left {
      flex: 1 1 50%;
    }
    .hero-right {
      flex: 1 1 50%;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 20px 35px rgba(0,0,0,0.05);
    }
    .hero-right img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
      background: #E8EAEF;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      margin-top: 32px;
      flex-wrap: wrap;
    }

    .subtitle {
      font-size: 18px;
      color: var(--text-mid);
      margin-bottom: 8px;
    }

    /* 卡片基础 */
    .card {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      border: 1px solid transparent;
    }

    .card:hover {
      box-shadow: var(--shadow-hover);
      border-color: var(--primary-cyan);
    }

    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(10,224,224,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary-cyan);
      font-size: 24px;
    }

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

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

    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all 0.3s ease;
      border: 1px solid transparent;
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
      border-color: var(--primary-cyan);
    }
    .case-img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
      background: #E8EAEF;
      transition: transform 0.3s ease;
    }
    .case-card:hover .case-img {
      transform: scale(1.05);
    }
    .case-content {
      padding: 20px;
    }
    .tag {
      display: inline-block;
      background: #F1F5F9;
      color: var(--text-mid);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: 20px;
      margin-right: 8px;
      margin-bottom: 8px;
    }

    /* 对比 */
    .comparison-row {
      display: flex;
      gap: 24px;
      align-items: stretch;
    }
    .compare-card {
      flex: 1;
      background: white;
      border-radius: var(--radius-md);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
    }
    .compare-card.right {
      border: 2px solid var(--primary-cyan);
      background: rgba(10,224,224,0.02);
      box-shadow: 0 12px 30px rgba(10,224,224,0.1);
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
      font-size: 16px;
    }

    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
      overflow: hidden;
    }
    .faq-question {
      background: white;
      padding: 20px 24px;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: background 0.2s;
    }
    .faq-question:hover {
      background: #F8FAFC;
    }
    .faq-answer {
      padding: 0 24px 20px;
      display: none;
      color: var(--text-mid);
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-item.open .faq-question {
      color: var(--primary-cyan);
    }

    /* CTA */
    .cta-block {
      background: var(--bg-dark);
      color: white;
      text-align: center;
    }
    .cta-form {
      display: flex;
      gap: 16px;
      margin-top: 32px;
      flex-wrap: wrap;
      justify-content: center;
    }
    .cta-form input,
    .cta-form textarea {
      background: white;
      border: 1px solid #E2E8F0;
      border-radius: var(--radius-sm);
      padding: 12px 16px;
      font-size: 16px;
      color: #1E293B;
      outline: none;
      transition: border 0.2s;
    }
    .cta-form input:focus,
    .cta-form textarea:focus {
      border-color: var(--primary-cyan);
    }

    /* Footer */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
      color: #CBD5E1;
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      color: #94A3B8;
      font-size: 13px;
    }

    @media (max-width: 1024px) {
      .grid-3, .cases-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .hero-grid {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: repeat(3, 1fr);
      }
    }

    @media (max-width: 768px) {
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      .nav-menu.open {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .grid-3, .cases-grid {
        grid-template-columns: 1fr;
      }
      .comparison-row {
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .cta-form {
        flex-direction: column;
        align-items: stretch;
      }
    }