/* roulang page: index */
:root {
      --primary: #1A3C5E;
      --primary-light: #2B5A8C;
      --accent: #C49A2B;
      --accent-hover: #A88220;
      --bg: #F7F9FC;
      --white: #FFFFFF;
      --text: #1E2A38;
      --text-secondary: #5A6675;
      --border: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 2px 12px rgba(26, 60, 94, 0.06);
      --shadow-card-hover: 0 8px 30px rgba(26, 60, 94, 0.12);
      --shadow-nav: 0 2px 20px rgba(0,0,0,0.08);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
      --transition: 0.3s ease;
      --container-max: 1280px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      cursor: pointer;
      transition: background var(--transition), color var(--transition), box-shadow var(--transition), transform var(--transition);
      border: 2px solid transparent;
      line-height: 1.2;
    }
    .btn-primary {
      background-color: var(--accent);
      color: var(--white);
      border-color: var(--accent);
      box-shadow: 0 4px 10px rgba(196, 154, 43, 0.25);
    }
    .btn-primary:hover {
      background-color: var(--accent-hover);
      border-color: var(--accent-hover);
      box-shadow: 0 6px 18px rgba(196, 154, 43, 0.35);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border-color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: var(--white);
      border-color: var(--primary);
    }
    .btn-link {
      color: var(--primary);
      text-decoration: underline;
      padding: 0;
      background: none;
      border: none;
      font-weight: 500;
    }
    .btn-link:hover {
      text-decoration: none;
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: var(--white);
      border-bottom: 1px solid var(--border);
      z-index: 100;
      display: flex;
      align-items: center;
      transition: box-shadow var(--transition);
    }
    .nav.scrolled {
      box-shadow: var(--shadow-nav);
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }
    .logo i {
      font-size: 28px;
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      font-weight: 500;
      color: var(--text);
    }
    .nav-links a {
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
    }
    .nav-cta {
      margin-left: 24px;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition);
    }
    /* 板块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    /* Hero */
    .hero {
      margin-top: 72px;
      background: var(--white);
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 1 1 50%;
    }
    .hero-right {
      flex: 1 1 50%;
    }
    .hero h1 {
      font-size: 40px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.3;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 28px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-img {
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 10px 25px rgba(26,60,94,0.15);
    }
    /* 标题 */
    h2 {
      font-size: 32px;
      font-weight: 600;
      letter-spacing: -0.3px;
      color: var(--primary);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-subtitle {
      text-align: center;
      color: var(--text-secondary);
      margin-bottom: 48px;
      font-size: 16px;
    }
    /* 网格卡片 */
    .grid-2x3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .advantage-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      text-align: center;
      border-left: 4px solid transparent;
    }
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
      border-left-color: var(--accent);
    }
    .advantage-icon {
      width: 64px;
      height: 64px;
      background: rgba(26,60,94,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--accent);
      font-size: 28px;
      transition: background var(--transition), color var(--transition);
    }
    .advantage-card:hover .advantage-icon {
      background: var(--primary);
      color: var(--white);
    }
    .advantage-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .advantage-card p {
      font-size: 14px;
      color: var(--text-secondary);
      line-height: 1.6;
    }
    /* 服务瀑布流 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .service-img {
      height: 200px;
      object-fit: cover;
    }
    .service-body {
      padding: 24px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .service-body h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .service-body p {
      font-size: 14px;
      color: var(--text-secondary);
      margin-bottom: 20px;
      flex: 1;
    }
    /* 对比表 */
    .comparison-table {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 32px;
    }
    .plan-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border);
      display: flex;
      flex-direction: column;
      transition: all var(--transition);
      position: relative;
    }
    .plan-card.featured {
      border: 2px solid var(--primary);
      box-shadow: 0 10px 25px rgba(26,60,94,0.1);
    }
    .plan-badge {
      position: absolute;
      top: -12px;
      right: 20px;
      background: var(--accent);
      color: white;
      font-size: 12px;
      font-weight: 600;
      padding: 4px 14px;
      border-radius: 20px;
    }
    .plan-name {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 24px;
    }
    .plan-features {
      list-style: none;
      margin-bottom: 32px;
      flex: 1;
    }
    .plan-features li {
      padding: 12px 0;
      border-bottom: 1px solid var(--border);
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 14px;
    }
    .check {
      color: var(--accent);
      font-weight: bold;
    }
    /* 数据展示 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      text-align: center;
      margin-bottom: 60px;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    .stat-desc {
      font-size: 14px;
      color: var(--text-secondary);
    }
    .case-cards {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      display: flex;
      align-items: center;
    }
    .case-img {
      width: 120px;
      height: 120px;
      object-fit: cover;
    }
    .case-info {
      padding: 20px;
    }
    /* FAQ */
    .faq-group {
      margin-bottom: 40px;
    }
    .faq-group h3 {
      font-size: 20px;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 16px 0;
    }
    .faq-question {
      display: flex;
      align-items: center;
      justify-content: space-between;
      cursor: pointer;
      font-weight: 500;
      font-size: 18px;
      gap: 12px;
    }
    .faq-question h4 {
      font-weight: 500;
      font-size: 18px;
      flex: 1;
    }
    .faq-icon {
      color: var(--accent);
      font-size: 20px;
      transition: transform 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F7F9FC;
      border-radius: 8px;
      margin-top: 12px;
      padding: 0 16px;
      color: var(--text);
      font-size: 16px;
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      padding: 16px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA横幅 */
    .cta-band {
      background: linear-gradient(135deg, #1A3C5E 0%, #234B72 100%);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    .cta-band h2 {
      color: white;
      margin-bottom: 16px;
    }
    .cta-sub {
      color: rgba(255,255,255,0.75);
      margin-bottom: 32px;
    }
    /* 页脚 */
    .footer {
      background: #1A2B3C;
      color: #B0BEC5;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1.5fr 1.5fr;
      gap: 40px;
    }
    .footer-logo {
      font-size: 24px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }
    .footer a {
      color: #B0BEC5;
      transition: color 0.2s;
    }
    .footer a:hover {
      color: white;
    }
    .footer-links {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    @media (max-width: 1024px) {
      .grid-2x3 { grid-template-columns: repeat(2, 1fr); }
      .services-grid { grid-template-columns: repeat(2, 1fr); }
      .comparison-table { grid-template-columns: 1fr; max-width: 500px; margin-left: auto; margin-right: auto; }
    }
    @media (max-width: 768px) {
      .nav-links, .nav-cta { display: none; }
      .hamburger { display: flex; }
      .hero .container { flex-direction: column; }
      .hero-right { order: -1; }
      .hero-img { height: 240px; width: 100%; }
      .hero h1 { font-size: 28px; }
      .grid-2x3 { grid-template-columns: 1fr; }
      .services-grid { grid-template-columns: 1fr; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
      .case-cards { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .comparison-table { grid-template-columns: 1fr; }
    }
    .mobile-menu {
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      box-shadow: var(--shadow-nav);
      display: none;
      flex-direction: column;
      padding: 24px;
      gap: 20px;
      z-index: 99;
    }
    .mobile-menu.active { display: flex; }