/* roulang page: index */
:root {
      --primary: #0A6E6E;
      --primary-dark: #085858;
      --secondary: #F26722;
      --secondary-dark: #D95A1A;
      --bg-light: #FAFBFB;
      --bg-card: #FFFFFF;
      --bg-dark: #0C4A4A;
      --bg-footer: #0C2F2F;
      --text-title: #1A202C;
      --text-body: #2D3748;
      --text-muted: #718096;
      --text-on-dark: #FFFFFF;
      --text-on-dark-muted: #A0C4C4;
      --border-light: #E2E8F0;
      --success: #2F855A;
      --warning: #C05621;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-hover: 0 10px 25px rgba(10,110,110,0.12), 0 4px 10px rgba(0,0,0,0.05);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-container: 16px;
      --font-cn: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
      --font-number: "Inter", "SF Pro Display", system-ui, sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-cn);
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 15px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      transition: box-shadow 0.3s;
    }
    .nav.scrolled {
      box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
    }
    .logo i {
      font-size: 26px;
      color: var(--secondary);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-body);
      transition: color 0.2s;
      font-size: 15px;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .btn-primary {
      background: var(--secondary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.25s;
      border: none;
      cursor: pointer;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--secondary-dark);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(242,103,34,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.25s;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .hamburger {
      display: none;
      font-size: 26px;
      background: none;
      border: none;
      color: var(--text-title);
      cursor: pointer;
    }
    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(10px);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 36px;
      z-index: 999;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    .mobile-menu.active {
      transform: translateX(0);
    }
    .mobile-menu a {
      font-size: 22px;
      font-weight: 600;
      color: var(--text-title);
    }
    .close-menu {
      position: absolute;
      top: 24px;
      right: 28px;
      font-size: 32px;
      background: none;
      border: none;
      color: var(--text-title);
    }
    /* Hero */
    .hero {
      padding: 120px 0 80px;
      background: linear-gradient(180deg, #FAFBFB 0%, #E6F2F2 100%);
      position: relative;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .hero-left {
      flex: 1 1 55%;
    }
    .hero-right {
      flex: 1 1 45%;
      animation: float 4s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-10px); }
      100% { transform: translateY(0); }
    }
    .badge {
      display: inline-block;
      background: rgba(10,110,110,0.1);
      color: var(--primary);
      padding: 6px 16px;
      border-radius: 40px;
      font-size: 14px;
      font-weight: 500;
      margin-bottom: 20px;
    }
    h1 {
      font-size: 44px;
      font-weight: 700;
      color: var(--text-title);
      line-height: 1.2;
      margin-bottom: 16px;
    }
    .hero-desc {
      font-size: 16px;
      color: #4A5568;
      max-width: 480px;
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    /* 指标看板 */
    .stats-board {
      margin-top: -40px;
      padding-bottom: 60px;
      position: relative;
      z-index: 2;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      text-align: center;
      transition: all 0.25s;
    }
    .stat-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-hover);
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
    }
    .stat-label {
      color: var(--text-muted);
      font-size: 14px;
      margin-top: 8px;
    }
    /* 通用板块 */
    section {
      padding: 80px 0;
    }
    h2 {
      font-size: 32px;
      font-weight: 600;
      color: var(--text-title);
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }
    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 60px;
      height: 3px;
      background: var(--secondary);
      border-radius: 3px;
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 48px;
      max-width: 620px;
    }
    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      border: 1px solid var(--border-light);
      transition: all 0.3s;
      text-align: center;
    }
    .feature-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      width: 64px;
      height: 64px;
      background: rgba(10,110,110,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      font-size: 28px;
      color: var(--primary);
      transition: 0.3s;
    }
    .feature-card:hover .feature-icon {
      background: var(--primary);
      color: white;
    }
    h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    /* 服务矩阵 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 60px;
      background: var(--bg-card);
      border-radius: var(--radius-container);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1 1 45%;
      min-height: 280px;
      background-size: cover;
      background-position: center;
    }
    .service-text {
      flex: 1 1 55%;
      padding: 40px;
    }
    .service-list {
      list-style: none;
      margin: 20px 0;
    }
    .service-list li {
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .service-list i {
      color: var(--success);
    }
    /* 对比区 */
    .comparison-container {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 24px;
    }
    .compare-panel {
      flex: 1;
      padding: 32px;
      border-radius: var(--radius-card);
      background: white;
    }
    .compare-before {
      background: rgba(245,225,225,0.8);
      border: 1px solid #e0c0c0;
    }
    .compare-after {
      background: rgba(225,245,235,0.8);
      border: 1px solid #b0d6c0;
    }
    .vs-badge {
      background: var(--primary);
      color: white;
      font-weight: 700;
      font-size: 22px;
      width: 56px;
      height: 56px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--bg-card);
      border: 1px solid var(--border-light);
      border-radius: 8px;
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 16px 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: white;
    }
    .faq-answer {
      padding: 0 20px 16px;
      color: var(--text-muted);
      display: none;
      background: #F7FAFA;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-item.open {
      border-color: var(--primary);
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #0C4A4A 0%, #0A6E6E 100%);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    .cta-section h2 {
      color: white;
    }
    .cta-section h2::after {
      background: var(--secondary);
    }
    /* Footer */
    .footer {
      background: var(--bg-footer);
      color: var(--text-on-dark-muted);
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
      margin-bottom: 40px;
    }
    .footer-brand .logo {
      color: white;
      margin-bottom: 12px;
    }
    .copyright {
      text-align: center;
      font-size: 13px;
      color: #6B8A8A;
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 20px;
    }
    @media (max-width: 1024px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero .container { flex-direction: column; }
      .features-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      h1 { font-size: 36px; }
      .stats-grid, .features-grid { grid-template-columns: 1fr; }
      .service-row, .service-row.reverse { flex-direction: column; }
      .comparison-container { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }