/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CE4;
      --primary-light: #EBF0FF;
      --accent: #00C9A7;
      --accent-light: #E6F9F5;
      --warning: #FF9F0A;
      --error: #FA5151;
      --bg: #F5F6FA;
      --card-bg: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --text-on-primary: #FFFFFF;
      --border-light: #E5E8EF;
      --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.08);
      --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
      --radius-xs: 8px;
      --radius-sm: 12px;
      --radius-md: 16px;
      --radius-lg: 20px;
      --radius-pill: 50px;
      --font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.25s cubic-bezier(0.2, 0.0, 0, 1.0);
      --container-padding: 24px;
      --section-gap: 80px;
    }

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

    body {
      font-family: var(--font-family);
      background-color: var(--bg);
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 var(--container-padding);
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      outline: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
      font-weight: 500;
    }

    h1, h2, h3, h4 {
      line-height: 1.3;
      font-weight: 700;
    }

    h1 { font-size: 36px; }
    h2 { font-size: 28px; margin-bottom: 12px; position: relative; display: inline-block; }
    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 48px;
      height: 4px;
      background: var(--primary);
      border-radius: 2px;
    }
    h3 { font-size: 20px; }
    h4 { font-size: 18px; }

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

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      transition: background 0.3s, box-shadow 0.3s;
      border-bottom: 1px solid transparent;
    }
    .header.scrolled {
      background: rgba(255,255,255,0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 16px 0;
      flex-wrap: wrap;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--accent);
      font-size: 18px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-primary);
      transition: color 0.2s;
      font-size: 16px;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--primary);
      color: var(--text-on-primary);
      padding: 10px 24px;
      border-radius: var(--radius-pill);
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(78,110,242,0.3);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 18px rgba(78,110,242,0.4);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 10px 24px;
      border-radius: var(--radius-pill);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }
    .btn-large {
      padding: 14px 36px;
      font-size: 18px;
    }
    .hamburger {
      display: none;
      background: none;
      font-size: 24px;
      color: var(--text-primary);
    }

    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: linear-gradient(135deg, #F0F2FF 0%, #F5F6FA 100%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
      align-items: center;
    }
    .hero-left h1 {
      margin-bottom: 20px;
      font-weight: 700;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      align-items: center;
      flex-wrap: wrap;
    }
    .trust-badge {
      margin-top: 24px;
      font-size: 14px;
      color: var(--text-secondary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .hero-right img {
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-lg);
      width: 100%;
      object-fit: cover;
    }

    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .highlight-card {
      background: var(--card-bg);
      padding: 32px 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      text-align: center;
    }
    .highlight-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .highlight-icon {
      font-size: 36px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .highlight-card h3 {
      margin-bottom: 8px;
    }
    .highlight-card p {
      color: var(--text-secondary);
      font-size: 14px;
    }

    /* 案例瀑布 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-md);
    }
    .case-img {
      position: relative;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 220px;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-overlay {
      position: absolute;
      inset: 0;
      background: rgba(78,110,242,0.7);
      display: flex;
      align-items: center;
      justify-content: center;
      opacity: 0;
      transition: 0.3s;
      color: white;
      font-size: 24px;
    }
    .case-card:hover .case-overlay {
      opacity: 1;
    }
    .case-content {
      padding: 18px;
    }
    .case-tags {
      display: flex;
      gap: 8px;
      margin: 10px 0;
    }
    .tag {
      background: #F0F2FF;
      color: var(--primary);
      padding: 4px 12px;
      border-radius: var(--radius-lg);
      font-size: 12px;
      font-weight: 500;
    }
    .case-desc {
      font-size: 14px;
      color: var(--text-secondary);
    }

    /* 对比表 */
    .compare-table {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 0;
      background: var(--card-bg);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
    }
    .compare-col {
      padding: 32px 20px;
      text-align: center;
      border-right: 1px solid var(--border-light);
    }
    .compare-col:last-child { border-right: none; }
    .compare-col.featured {
      background: var(--primary-light);
      border-radius: 0;
    }
    .compare-header {
      font-weight: 700;
      font-size: 20px;
      margin-bottom: 16px;
    }
    .compare-price {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
      margin: 16px 0;
    }
    .compare-list {
      list-style: none;
      text-align: left;
      margin: 24px 0;
    }
    .compare-list li {
      padding: 8px 0;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--text-secondary);
    }
    .compare-list i.fa-check {
      color: var(--accent);
    }
    .compare-list i.fa-minus {
      color: #ccc;
    }

    /* FAQ */
    .faq-item {
      background: var(--card-bg);
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: none;
      width: 100%;
      font-size: 18px;
      color: var(--text-primary);
      transition: 0.2s;
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-answer {
      padding: 0 24px 18px;
      color: var(--text-secondary);
      display: none;
      font-size: 15px;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #4E6EF2 0%, #3A5CE4 100%);
      border-radius: var(--radius-md);
      padding: 64px 24px;
      text-align: center;
      color: white;
    }
    .cta-banner h2 {
      color: white;
      margin-bottom: 16px;
    }
    .cta-banner h2::after { display: none; }
    .cta-btn {
      background: white;
      color: var(--primary);
      padding: 16px 42px;
      border-radius: var(--radius-pill);
      font-weight: 700;
      font-size: 18px;
      margin-top: 24px;
      transition: 0.2s;
    }
    .cta-btn:hover {
      transform: scale(1.02);
      box-shadow: 0 8px 24px rgba(0,0,0,0.15);
    }

    /* 页脚 */
    .footer {
      background: #1F2329;
      color: #fff;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
    }
    .footer-col h4 {
      color: white;
      margin-bottom: 16px;
    }
    .footer-links {
      list-style: none;
    }
    .footer-links li {
      margin-bottom: 10px;
    }
    .footer-links a {
      color: #86909C;
      font-size: 14px;
    }
    .footer-links a:hover {
      color: white;
    }
    .subscribe-input {
      display: flex;
      margin-top: 12px;
    }
    .subscribe-input input {
      flex:1;
      padding: 10px 16px;
      border-radius: var(--radius-pill) 0 0 var(--radius-pill);
      border: none;
      background: #2E333B;
      color: white;
    }
    .subscribe-input button {
      background: var(--primary);
      border-radius: 0 var(--radius-pill) var(--radius-pill) 0;
      padding: 10px 20px;
      color: white;
    }
    .copyright {
      margin-top: 40px;
      text-align: center;
      color: #86909C;
      font-size: 14px;
      border-top: 1px solid #2E333B;
      padding-top: 20px;
    }

    @media (max-width: 768px) {
      :root {
        --section-gap: 60px;
      }
      h1 { font-size: 30px; }
      h2 { font-size: 24px; }
      .nav-links {
        display: none;
        flex-direction: column;
        width: 100%;
        background: white;
        padding: 20px;
        margin-top: 16px;
        border-radius: var(--radius-sm);
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: block;
      }
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .highlights-grid {
        grid-template-columns: 1fr;
      }
      .cases-grid {
        grid-template-columns: 1fr;
      }
      .compare-table {
        grid-template-columns: 1fr;
        overflow-x: auto;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }