/* roulang page: index */
:root {
      --primary-deep: #2C3E6B;
      --primary-soft: #3D5290;
      --primary-light-bg: #EBEFF6;
      --accent-gold: #C49A6C;
      --accent-gold-hover: #D4B185;
      --bg-page: #F8F9FB;
      --white: #FFFFFF;
      --text-body: #4A5568;
      --text-muted: #5A6D8A;
      --text-light: #8899B4;
      --border-light: #E9ECF2;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 2px 12px rgba(44, 62, 107, 0.06);
      --shadow-hover: 0 8px 24px rgba(44, 62, 107, 0.12);
      --transition: 0.25s ease;
      --nav-width: 240px;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.8;
      font-size: 16px;
      display: flex;
      min-height: 100vh;
    }
    a { text-decoration: none; color: inherit; transition: var(--transition); }
    img { max-width: 100%; height: auto; display: block; }
    h1, h2, h3, h4 { color: var(--primary-deep); font-weight: 600; }
    h1 { font-size: 44px; font-weight: 700; line-height: 1.2; letter-spacing: -0.5px; }
    h2 { font-size: 32px; font-weight: 600; line-height: 1.3; margin-bottom: 1rem; position: relative; }
    h2::after {
      content: '';
      display: block;
      width: 40px;
      height: 3px;
      background: var(--accent-gold);
      margin-top: 12px;
      border-radius: 2px;
    }
    h3 { font-size: 20px; font-weight: 600; line-height: 1.4; }
    .container-main {
      margin-left: var(--nav-width);
      width: 100%;
      max-width: 1440px;
    }
    /* 左侧导航 */
    .side-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: var(--nav-width);
      height: 100vh;
      background: var(--white);
      box-shadow: 1px 0 0 rgba(0,0,0,0.04);
      display: flex;
      flex-direction: column;
      padding: 28px 20px;
      z-index: 50;
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
      margin-bottom: 40px;
    }
    .logo-icon {
      width: 36px;
      height: 36px;
      background: var(--primary-deep);
      border-radius: 10px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 20px;
      position: relative;
    }
    .logo-icon span { position: relative; z-index: 1; }
    .logo-text {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary-deep);
      letter-spacing: 1px;
    }
    .nav-links {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .nav-links a {
      display: block;
      padding: 12px 16px;
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
      border-radius: 8px;
      position: relative;
      transition: var(--transition);
      border-left: 3px solid transparent;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-deep);
      background: #F5F7FA;
      border-left-color: var(--accent-gold);
    }
    .nav-cta {
      margin-top: auto;
    }
    .btn-nav {
      display: block;
      text-align: center;
      background: var(--primary-deep);
      color: white;
      padding: 12px 16px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
    }
    .btn-nav:hover { background: var(--primary-soft); color: white; }
    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      background: var(--white);
      padding: 12px 20px;
      align-items: center;
      justify-content: space-between;
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
      position: sticky;
      top: 0;
      z-index: 60;
    }
    .mobile-logo { display: flex; align-items: center; gap: 8px; }
    .hamburger { font-size: 24px; color: var(--primary-deep); background: none; border: none; }
    .mobile-menu {
      display: none;
      flex-direction: column;
      background: white;
      position: absolute;
      top: 60px;
      left: 0;
      width: 100%;
      box-shadow: 0 8px 20px rgba(0,0,0,0.08);
      padding: 12px 20px;
    }
    .mobile-menu a {
      padding: 14px 0;
      border-bottom: 1px solid var(--border-light);
      font-weight: 500;
      color: var(--text-muted);
    }
    /* 主内容区 */
    .section {
      padding: 100px 60px;
      max-width: 1200px;
      margin: 0 auto;
    }
    .hero-section {
      display: flex;
      align-items: center;
      gap: 60px;
      padding: 80px 60px;
      background-image: radial-gradient(circle at 20% 30%, rgba(44,62,107,0.02) 0%, transparent 30%);
    }
    .hero-left { flex: 0 0 55%; }
    .hero-right { flex: 1; }
    .hero-right img {
      border-radius: 20px;
      box-shadow: var(--shadow-card);
      width: 100%;
      aspect-ratio: 4/3;
      object-fit: cover;
    }
    .hero-subtitle {
      font-size: 18px;
      color: var(--text-muted);
      margin: 20px 0 32px;
      max-width: 480px;
    }
    .btn-group { display: flex; gap: 16px; flex-wrap: wrap; }
    .btn-primary {
      background: var(--primary-deep);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      border: none;
    }
    .btn-primary:hover { background: var(--primary-soft); color: white; }
    .btn-secondary {
      background: transparent;
      color: var(--primary-deep);
      border: 1px solid var(--primary-deep);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
    }
    .btn-secondary:hover { background: var(--primary-light-bg); }
    .btn-gold {
      background: var(--accent-gold);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
    }
    .btn-gold:hover { background: var(--accent-gold-hover); color: white; }
    .grid-2x2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
      margin-top: 40px;
    }
    .highlight-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      border-bottom: 3px solid var(--primary-deep);
      transition: var(--transition);
    }
    .highlight-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
    .highlight-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--accent-gold);
      margin-bottom: 12px;
    }
    .cases-grid {
      column-count: 3;
      column-gap: 24px;
      margin-top: 40px;
    }
    .case-card {
      break-inside: avoid;
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      margin-bottom: 24px;
      overflow: hidden;
      transition: var(--transition);
    }
    .case-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
    .case-img { width: 100%; aspect-ratio: 16/10; object-fit: cover; transition: transform 0.3s; }
    .case-card:hover .case-img { transform: scale(1.03); }
    .case-content { padding: 20px; }
    .case-tag {
      display: inline-block;
      background: rgba(196,154,108,0.15);
      color: var(--accent-gold);
      font-size: 12px;
      padding: 4px 10px;
      border-radius: 20px;
      margin-bottom: 8px;
    }
    .pricing-row {
      display: flex;
      gap: 24px;
      margin-top: 40px;
    }
    .pricing-card {
      flex: 1;
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 36px 28px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-light);
      text-align: center;
    }
    .pricing-card.recommend {
      border: 2px solid var(--accent-gold);
      position: relative;
    }
    .recommend-badge {
      position: absolute;
      top: -12px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--accent-gold);
      color: white;
      padding: 6px 18px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
    }
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin-top: 40px;
    }
    .accordion-item {
      background: var(--white);
      border-radius: var(--radius-card);
      border: 1px solid var(--border-light);
      overflow: hidden;
    }
    .accordion-title {
      padding: 18px 24px;
      font-weight: 600;
      font-size: 17px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--primary-deep);
      background: white;
    }
    .accordion-content {
      padding: 0 24px 20px;
      color: var(--text-muted);
      font-size: 15px;
      display: none;
    }
    .accordion-item.active .accordion-content { display: block; }
    .cta-banner {
      background: linear-gradient(135deg, #2C3E6B 0%, #1A2744 100%);
      color: white;
      text-align: center;
      padding: 80px 40px;
      margin: 0;
    }
    .cta-banner h2 { color: white; }
    .cta-banner h2::after { background: var(--accent-gold); margin: 16px auto 0; }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
      background: #1A2744;
      color: var(--text-light);
      padding: 60px 60px 30px;
      max-width: 1200px;
      margin: 0 auto;
    }
    .copyright {
      text-align: center;
      font-size: 13px;
      color: var(--text-light);
      padding: 20px 0;
      border-top: 1px solid rgba(255,255,255,0.1);
    }
    @media (max-width: 1024px) {
      .container-main { margin-left: 0; }
      .side-nav { display: none; }
      .mobile-header { display: flex; }
      .section { padding: 60px 24px; }
      .hero-section { flex-direction: column; padding: 40px 24px; }
      .cases-grid { column-count: 2; }
      .grid-2x2 { grid-template-columns: 1fr; }
      .faq-grid { grid-template-columns: 1fr; }
      .pricing-row { flex-direction: column; }
    }
    @media (max-width: 640px) {
      h1 { font-size: 32px; }
      .cases-grid { column-count: 1; }
      .footer-grid { grid-template-columns: 1fr; }
    }