/* roulang page: index */
:root {
      --primary: #2B5C8F;
      --primary-light: #4A90A4;
      --accent: #C8A96E;
      --accent-hover: #D4B87A;
      --bg-warm: #FAF9F6;
      --card-white: #FFFFFF;
      --dark-bg: #1E3A52;
      --text-main: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-on-dark: #FFFFFF;
      --text-muted: #B0B0B0;
      --border-soft: #E5E2DC;
      --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.06);
      --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.10);
      --shadow-nav: 0 1px 8px rgba(0, 0, 0, 0.08);
      --shadow-btn: 0 4px 12px rgba(43, 92, 143, 0.25);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-badge: 4px;
      --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.3s ease;
    }

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

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

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

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      transition: var(--transition);
    }

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

    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.97);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-soft);
      box-shadow: var(--shadow-nav);
    }

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

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      white-space: nowrap;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }

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

    .nav-cta {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.4px;
      white-space: nowrap;
      transition: var(--transition);
    }

    .nav-cta:hover {
      background: var(--primary-light);
      box-shadow: var(--shadow-btn);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      justify-content: space-between;
      width: 26px;
      height: 20px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 0;
    }

    .hamburger span {
      display: block;
      height: 2px;
      background: var(--text-main);
      border-radius: 2px;
      transition: var(--transition);
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      border-bottom: 1px solid var(--border-soft);
      padding: 24px 0;
      flex-direction: column;
      gap: 20px;
      align-items: center;
      box-shadow: var(--shadow-md);
      z-index: 999;
    }

    .mobile-menu a {
      font-size: 18px;
      font-weight: 500;
      color: var(--text-main);
    }

    /* 通用区块间距 */
    .section {
      padding: 80px 0;
    }

    .section-title {
      text-align: center;
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-main);
    }

    .section-subtitle {
      text-align: center;
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      gap: 48px;
      padding: 72px 0;
    }

    .hero-content {
      flex: 1 1 45%;
    }

    .hero-content h1 {
      font-size: 46px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: var(--text-main);
    }

    .hero-subtitle {
      font-size: 19px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }

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

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    }

    .btn-primary:hover {
      background: var(--primary-light);
      box-shadow: var(--shadow-btn);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
    }

    .btn-outline:hover {
      background: rgba(43,92,143,0.05);
    }

    .hero-image {
      flex: 1 1 55%;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
      position: relative;
    }

    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      border-radius: 16px;
    }

    /* 优势卡片 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .advantage-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      text-align: center;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .icon-circle {
      width: 72px;
      height: 72px;
      background: rgba(74,144,164,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary-light);
      font-size: 36px;
    }

    .advantage-card h3 {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 12px;
    }

    /* 案例瀑布流 */
    .case-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }

    .case-row.reverse {
      flex-direction: row-reverse;
    }

    .case-img {
      flex: 1 1 50%;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .case-text {
      flex: 1 1 50%;
    }

    .badge {
      display: inline-block;
      background: rgba(200,169,110,0.15);
      color: var(--accent);
      font-size: 13px;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: var(--radius-badge);
      margin-bottom: 12px;
    }

    .case-text h3 {
      font-size: 24px;
      font-weight: 700;
      margin-bottom: 16px;
    }

    .stat-num {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
      margin-right: 8px;
    }

    /* 对比卡 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      align-items: start;
    }

    .compare-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

    .compare-card.recommended {
      border: 2px solid var(--accent);
      position: relative;
    }

    .recommend-tag {
      position: absolute;
      top: -12px;
      right: 24px;
      background: var(--accent);
      color: white;
      font-size: 13px;
      font-weight: 600;
      padding: 4px 16px;
      border-radius: 20px;
    }

    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-soft);
      padding: 20px 0;
    }

    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      color: var(--text-main);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
      font-size: 15px;
      line-height: 1.8;
    }

    .faq-answer.open {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA横幅 */
    .cta-banner {
      background: var(--dark-bg);
      color: white;
      text-align: center;
      padding: 80px 24px;
    }

    .cta-banner h2 {
      font-size: 32px;
      margin-bottom: 16px;
    }

    .btn-accent {
      background: var(--accent);
      color: white;
      padding: 16px 48px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 18px;
      margin-top: 24px;
      display: inline-block;
    }

    .btn-accent:hover {
      background: var(--accent-hover);
    }

    .trust-row {
      margin-top: 24px;
      font-size: 14px;
      color: rgba(255,255,255,0.7);
    }

    /* 页脚 */
    .footer {
      background: var(--dark-bg);
      color: white;
      padding: 64px 0 24px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .footer a {
      color: rgba(255,255,255,0.8);
      font-size: 15px;
    }

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

    .copyright {
      text-align: center;
      padding-top: 32px;
      border-top: 1px solid rgba(255,255,255,0.15);
      margin-top: 32px;
      font-size: 14px;
      color: rgba(255,255,255,0.6);
    }

    @media (max-width: 992px) {
      .hero {
        flex-direction: column;
      }
      .advantages-grid {
        grid-template-columns: repeat(2,1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu.active { display: flex; }
      .hero-content h1 { font-size: 34px; }
      .case-row, .case-row.reverse {
        flex-direction: column;
      }
      .compare-grid {
        grid-template-columns: 1fr;
      }
      .advantages-grid {
        grid-template-columns: 1fr;
      }
    }