/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --accent: #0D9488;
      --accent-hover: #0F766E;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-main: #1E293B;
      --text-secondary: #64748B;
      --text-body: #475569;
      --border-light: #E2E8F0;
      --border-input: #CBD5E1;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.1);
      --radius-card: 12px;
      --radius-btn: 30px;
      --radius-input: 8px;
      --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.2s ease;
    }

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

    body {
      font-family: var(--font-stack);
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    h1, h2, h3, h4 {
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 0.75rem;
    }

    h1 {
      font-size: 2.75rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
    }

    h2 {
      font-size: 2rem;
      color: var(--primary);
      text-align: center;
      position: relative;
      margin-bottom: 2.5rem;
      font-weight: 600;
    }

    h2::after {
      content: '';
      display: block;
      width: 60px;
      height: 3px;
      background: var(--accent);
      margin: 0.75rem auto 0;
      border-radius: 2px;
    }

    h3 {
      font-size: 1.25rem;
      font-weight: 600;
      color: var(--text-main);
    }

    .text-accent {
      color: var(--accent);
    }

    .text-primary {
      color: var(--primary);
    }

    .text-secondary {
      color: var(--text-secondary);
    }

    a {
      color: var(--primary);
      text-decoration: none;
      transition: color var(--transition), text-decoration var(--transition);
    }

    a:hover {
      color: var(--accent-hover);
      text-decoration: underline;
    }

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

    .btn {
      display: inline-block;
      font-weight: 600;
      font-size: 1rem;
      border-radius: var(--radius-btn);
      padding: 0.75rem 2rem;
      text-align: center;
      transition: all var(--transition);
      cursor: pointer;
      border: none;
      text-decoration: none;
    }

    .btn-primary {
      background-color: var(--accent);
      color: #FFFFFF;
      box-shadow: 0 4px 10px rgba(13,148,136,0.25);
    }

    .btn-primary:hover {
      background-color: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(13,148,136,0.3);
      color: #FFFFFF;
      text-decoration: none;
    }

    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 1px solid var(--primary);
    }

    .btn-outline:hover {
      background: rgba(26,95,122,0.05);
      color: var(--primary);
      text-decoration: none;
    }

    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition), transform var(--transition);
      height: 100%;
      display: flex;
      flex-direction: column;
    }

    .card:hover {
      box-shadow: var(--shadow-hover), 0 0 0 1px var(--accent);
      transform: translateY(-4px);
    }

    /* 导航栏悬浮胶囊 */
    .nav-capsule {
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(10px);
      border-radius: 40px;
      max-width: 1100px;
      margin: 1rem auto 0;
      padding: 0.5rem 1.5rem;
      box-shadow: 0 8px 20px rgba(0,0,0,0.04);
      display: flex;
      align-items: center;
      justify-content: space-between;
      position: sticky;
      top: 1rem;
      z-index: 100;
      border: 1px solid rgba(226,232,240,0.6);
    }

    .logo {
      font-weight: 700;
      font-size: 1.25rem;
      color: var(--primary);
      white-space: nowrap;
    }

    .nav-links {
      display: flex;
      gap: 1.8rem;
      align-items: center;
    }

    .nav-links a {
      color: var(--text-secondary);
      font-weight: 500;
      font-size: 0.95rem;
      transition: color var(--transition);
      text-decoration: none;
    }

    .nav-links a:hover {
      color: var(--primary);
      text-decoration: none;
    }

    .nav-cta {
      background: var(--accent);
      color: #fff !important;
      padding: 0.5rem 1.4rem;
      border-radius: 30px;
      font-weight: 600;
    }

    .nav-cta:hover {
      background: var(--accent-hover);
      color: #fff !important;
      text-decoration: none;
    }

    .hamburger {
      display: none;
      font-size: 1.5rem;
      color: var(--primary);
      cursor: pointer;
    }

    /* Hero */
    .hero {
      padding: 5rem 0 4rem;
    }

    .hero-image {
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 15px 30px rgba(0,0,0,0.1);
    }

    .stat-badge {
      background: #E6F0F3;
      color: var(--primary);
      border-radius: 20px;
      padding: 0.2rem 1rem;
      font-size: 0.85rem;
      font-weight: 600;
      display: inline-block;
    }

    .section {
      padding: 5rem 0;
    }

    .icon-circle {
      width: 50px;
      height: 50px;
      background: rgba(13,148,136,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 1.5rem;
      margin-bottom: 1.2rem;
    }

    .scenario-block {
      display: flex;
      align-items: center;
      gap: 2rem;
      margin-bottom: 3rem;
    }

    .scenario-block.reverse {
      flex-direction: row-reverse;
    }

    .case-highlight {
      font-size: 2rem;
      font-weight: 700;
      color: var(--accent);
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1rem 0;
      cursor: pointer;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--text-main);
      font-size: 1.1rem;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: var(--text-body);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 0.8rem;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    .footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 3rem 0 1.5rem;
    }

    .footer a {
      color: #CBD5E1;
      text-decoration: none;
    }

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

    input, textarea {
      border: 1px solid var(--border-input);
      border-radius: var(--radius-input);
      padding: 0.75rem;
      width: 100%;
      transition: border var(--transition), box-shadow var(--transition);
    }

    input:focus, textarea:focus {
      outline: none;
      border-color: var(--accent);
      box-shadow: 0 0 0 3px rgba(13,148,136,0.2);
    }

    @media (max-width: 1024px) {
      h1 { font-size: 2.2rem; }
      .nav-links { gap: 1.2rem; }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 1rem;
        right: 1rem;
        background: white;
        flex-direction: column;
        border-radius: 20px;
        padding: 1.5rem;
        box-shadow: 0 10px 25px rgba(0,0,0,0.1);
      }
      .nav-links.show {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .hero .grid-x {
        flex-direction: column-reverse;
      }
      .scenario-block, .scenario-block.reverse {
        flex-direction: column;
      }
      h1 { font-size: 2rem; }
      h2 { font-size: 1.6rem; }
    }