/* roulang page: index */
:root {
      --primary: #4A6B8A;
      --primary-hover: #3A5670;
      --primary-light: rgba(74, 107, 138, 0.05);
      --bg-warm: #F4F6F9;
      --card-bg: #FFFFFF;
      --card-border: #E2E6EB;
      --text-main: #1E2A36;
      --text-secondary: #5F6B7A;
      --accent-gold: #C9A96E;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 24px rgba(0,0,0,0.08);
      --spacing-section: 80px;
      --container-max: 1200px;
      --font-hero: 2.25rem;
      --font-section-title: 1.75rem;
      --font-card-title: 1.25rem;
      --font-body: 1rem;
      --font-small: 0.875rem;
      --line-height-body: 1.625;
      --transition-smooth: 0.25s ease;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: var(--line-height-body);
      font-size: var(--font-body);
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      color: var(--primary);
      text-decoration: none;
      transition: color 0.2s;
    }

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

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 40;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(8px);
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
      padding: 0.75rem 0;
      transition: box-shadow 0.3s;
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .brand {
      font-size: 1.375rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      white-space: nowrap;
    }

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

    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-links {
      display: flex;
      gap: 1.75rem;
      list-style: none;
      margin: 0;
    }

    .nav-links a {
      color: var(--text-secondary);
      font-weight: 500;
      font-size: var(--font-body);
      text-decoration: none;
      transition: color 0.2s;
    }

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

    .nav-cta-group {
      display: flex;
      gap: 0.75rem;
      margin-left: 0.5rem;
    }

    .btn {
      display: inline-block;
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 0.75rem 1.8rem;
      font-size: var(--font-body);
      transition: all var(--transition-smooth);
      text-align: center;
      line-height: 1.4;
      border: 2px solid transparent;
      cursor: pointer;
      white-space: nowrap;
    }

    .btn-primary {
      background: var(--primary);
      color: #fff;
      border-color: var(--primary);
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      border-color: var(--primary-hover);
      color: #fff;
      transform: translateY(-1px);
      text-decoration: none;
    }

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

    .btn-outline:hover {
      background: rgba(74,107,138,0.1);
      color: var(--primary-hover);
      transform: translateY(-1px);
      text-decoration: none;
    }

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

    /* Hero */
    .hero {
      padding: 3rem 0 4rem;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }

    .hero-left {
      flex: 0 0 55%;
    }

    .hero-right {
      flex: 0 0 45%;
    }

    .hero h1 {
      font-size: var(--font-hero);
      font-weight: 700;
      line-height: 1.3;
      letter-spacing: -0.5px;
      color: var(--text-main);
      margin-bottom: 1.5rem;
    }

    .hero-sub {
      font-size: 1.125rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
      max-width: 90%;
    }

    .hero-image {
      width: 100%;
      border-radius: 16px;
      box-shadow: 0 12px 28px rgba(0,0,0,0.05);
      object-fit: cover;
      aspect-ratio: 4/3;
    }

    /* 通用板块标题 */
    .section {
      padding: var(--spacing-section) 0;
    }

    .section-title {
      font-size: var(--font-section-title);
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 2.5rem;
      letter-spacing: 0.3px;
    }

    /* 核心亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }

    .highlight-card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      padding: 2rem 1.8rem;
      box-shadow: var(--shadow-card);
      transition: all var(--transition-smooth);
    }

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

    .highlight-icon {
      font-size: 2.2rem;
      color: var(--primary);
      margin-bottom: 1.2rem;
    }

    .highlight-card h3 {
      font-size: var(--font-card-title);
      font-weight: 600;
      margin-bottom: 0.75rem;
    }

    .highlight-card p {
      color: var(--text-secondary);
      font-size: var(--font-body);
    }

    /* 案例瀑布流 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }

    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all var(--transition-smooth);
      border: 1px solid var(--card-border);
      display: flex;
      flex-direction: column;
    }

    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-card-hover);
    }

    .case-img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
    }

    .case-content {
      padding: 1.4rem 1.5rem 1.8rem;
    }

    .case-tag {
      display: inline-block;
      background: rgba(201,169,110,0.15);
      color: var(--text-main);
      font-size: 0.8rem;
      font-weight: 600;
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      margin-bottom: 0.6rem;
      letter-spacing: 0.3px;
    }

    .case-card h4 {
      font-size: 1.2rem;
      font-weight: 600;
      margin-bottom: 0.5rem;
    }

    .case-summary {
      font-size: var(--font-small);
      color: var(--text-secondary);
    }

    /* 方案对比 */
    .compare-panel {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }

    .compare-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 2rem;
      border: 1px solid var(--card-border);
    }

    .compare-card.highlight {
      border: 2px solid var(--primary);
      background: #fff;
    }

    .compare-card h4 {
      font-size: 1.3rem;
      font-weight: 600;
      margin-bottom: 1.5rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .compare-list {
      list-style: none;
    }

    .compare-list li {
      margin-bottom: 1rem;
      font-size: var(--font-body);
      display: flex;
      align-items: baseline;
      gap: 0.5rem;
      color: var(--text-secondary);
    }

    .compare-list i {
      color: var(--primary);
      width: 1.2rem;
    }

    /* FAQ */
    .accordion {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      border: 1px solid var(--card-border);
      box-shadow: var(--shadow-card);
    }

    .accordion-item {
      border-bottom: 1px solid var(--card-border);
    }

    .accordion-item:last-child {
      border-bottom: none;
    }

    .accordion-title {
      font-size: 1.1rem;
      font-weight: 600;
      padding: 1.2rem 1.8rem;
      background: transparent;
      color: var(--text-main);
      border: none;
      width: 100%;
      text-align: left;
      position: relative;
      cursor: pointer;
    }

    .accordion-title::after {
      content: '\f107';
      font-family: 'Font Awesome 6 Free';
      font-weight: 900;
      position: absolute;
      right: 1.5rem;
      color: var(--primary);
    }

    .accordion-content {
      padding: 0 1.8rem 1.5rem;
      color: var(--text-secondary);
    }

    /* 全局 CTA */
    .cta-banner {
      background: var(--primary-light);
      border-radius: var(--radius-card);
      padding: 4rem 2rem;
      text-align: center;
      margin: var(--spacing-section) 0;
    }

    .cta-banner h2 {
      font-size: 2rem;
      font-weight: 700;
      margin-bottom: 1rem;
    }

    .cta-banner p {
      font-size: 1.1rem;
      color: var(--text-secondary);
      margin-bottom: 2rem;
    }

    /* 页脚 */
    .site-footer {
      background: var(--primary);
      color: #fff;
      padding: 3.5rem 0 2rem;
      margin-top: 2rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.2fr;
      gap: 2.5rem;
    }

    .footer-brand p {
      color: rgba(255,255,255,0.8);
      font-size: var(--font-small);
      margin-top: 0.8rem;
    }

    .footer-links h5, .footer-contact h5, .footer-social h5 {
      font-weight: 600;
      margin-bottom: 1.2rem;
      font-size: 1rem;
    }

    .footer-links ul {
      list-style: none;
    }

    .footer-links li {
      margin-bottom: 0.5rem;
    }

    .footer-links a {
      color: rgba(255,255,255,0.8);
      font-size: var(--font-small);
    }

    .footer-links a:hover {
      color: var(--accent-gold);
      text-decoration: none;
    }

    .footer-contact p {
      color: rgba(255,255,255,0.8);
      font-size: var(--font-small);
    }

    .social-icons {
      display: flex;
      gap: 1rem;
    }

    .social-icons a {
      color: #fff;
      background: rgba(255,255,255,0.15);
      width: 36px;
      height: 36px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      transition: background 0.2s;
    }

    .social-icons a:hover {
      background: var(--accent-gold);
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.2);
      margin-top: 2.5rem;
      padding-top: 1.5rem;
      text-align: center;
      font-size: 0.85rem;
      color: rgba(255,255,255,0.7);
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-left, .hero-right {
        flex: auto;
        width: 100%;
      }
      .hero-sub {
        max-width: 100%;
        margin-left: auto;
        margin-right: auto;
      }
      .highlights-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-menu {
        display: none;
        flex-direction: column;
        background: white;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        padding: 1rem 1.5rem;
        box-shadow: 0 12px 24px rgba(0,0,0,0.05);
      }
      .mobile-menu.active {
        display: flex;
      }
      .case-grid, .highlights-grid {
        grid-template-columns: 1fr;
      }
      .compare-panel {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 520px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .btn {
        width: 100%;
        display: block;
      }
      .nav-cta-group {
        flex-wrap: wrap;
      }
    }