/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-dark: #0F3B4F;
      --accent: #F39C12;
      --accent-dark: #e67e22;
      --ice-bg: #E8F4F8;
      --white: #FFFFFF;
      --bg-light: #F7F9FC;
      --text: #2C3E50;
      --text-light: #7F8C8D;
      --border-light: #D5E8EF;
      --shadow-sm: 0 4px 12px rgba(26,95,122,0.06);
      --shadow-card: 0 4px 20px rgba(26,95,122,0.08);
      --shadow-hover: 0 12px 32px rgba(26,95,122,0.15);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: 0.3s ease;
      --max-width: 1200px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background: var(--white);
      color: var(--text);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3 {
      font-weight: 700;
      line-height: 1.3;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
    }
    /* 导航 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: var(--white);
      height: var(--nav-height);
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0,0,0,0.04);
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }
    .nav-links a:hover {
      color: var(--primary);
      border-bottom-color: var(--accent);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--primary);
      cursor: pointer;
      line-height: 1;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        box-shadow: var(--shadow-card);
        border-top: 1px solid var(--border-light);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links a {
        font-size: 18px;
        border-bottom: none;
      }
      .menu-toggle {
        display: block;
      }
    }
    /* Hero */
    .hero {
      padding: 80px 0;
      background: var(--white);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 55% 45%;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 36px;
      color: var(--primary);
      margin-bottom: 16px;
      letter-spacing: 1px;
    }
    .hero-content .subtitle {
      font-size: 18px;
      color: var(--text-light);
      margin-bottom: 32px;
      line-height: 1.7;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-block;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      text-align: center;
      transition: var(--transition);
      cursor: pointer;
      border: none;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--ice-bg);
    }
    .btn-accent {
      background: var(--accent);
      color: white;
    }
    .btn-accent:hover {
      background: var(--accent-dark);
    }
    .hero-image img {
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 32px;
      }
      .hero-content h1 {
        font-size: 28px;
      }
      .hero-image {
        order: -1;
      }
    }
    /* 通用板块 */
    .section {
      padding: 100px 0;
    }
    .section-alt {
      background: var(--bg-light);
    }
    .section-title {
      text-align: center;
      font-size: 30px;
      color: var(--primary-dark);
      margin-bottom: 16px;
      position: relative;
      display: flex;
      flex-direction: column;
      align-items: center;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 60px;
      height: 4px;
      background: var(--accent);
      margin-top: 16px;
      border-radius: 2px;
    }
    /* 核心优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 48px;
    }
    .advantage-card {
      background: var(--white);
      padding: 32px 16px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      text-align: center;
      transition: var(--transition);
    }
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .advantage-icon {
      font-size: 40px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .advantage-card h3 {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text);
    }
    .advantage-card p {
      font-size: 14px;
      color: var(--text-light);
      line-height: 1.6;
    }
    @media (max-width: 768px) {
      .advantages-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 520px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 48px;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-img {
      height: 200px;
      object-fit: cover;
      width: 100%;
    }
    .service-body {
      padding: 20px;
      display: flex;
      flex-direction: column;
      flex: 1;
    }
    .service-body h3 {
      font-size: 20px;
      margin-bottom: 10px;
    }
    .service-body p {
      font-size: 15px;
      color: var(--text-light);
      margin-bottom: 16px;
      flex: 1;
    }
    .service-link {
      font-weight: 600;
      color: var(--primary);
      display: inline-block;
      transition: var(--transition);
    }
    .service-link:hover {
      transform: translateX(4px);
    }
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      margin-top: 48px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      display: flex;
      overflow: hidden;
      transition: var(--transition);
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      width: 120px;
      height: 120px;
      object-fit: cover;
      flex-shrink: 0;
    }
    .case-info {
      padding: 16px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .case-info h3 {
      font-size: 18px;
      margin-bottom: 8px;
    }
    .case-tag {
      display: inline-block;
      background: var(--ice-bg);
      color: var(--primary);
      font-size: 12px;
      padding: 4px 10px;
      border-radius: 20px;
      margin-bottom: 6px;
      width: fit-content;
    }
    .case-desc {
      font-size: 14px;
      color: var(--text-light);
    }
    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
      .case-card {
        flex-direction: column;
      }
      .case-img {
        width: 100%;
        height: 180px;
      }
    }
    /* 对比表 */
    .comparison-table {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      margin-top: 48px;
    }
    .plan-card {
      background: var(--white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      overflow: hidden;
    }
    .plan-header {
      padding: 24px;
      color: white;
      font-size: 22px;
      font-weight: 700;
    }
    .plan-basic .plan-header {
      background: var(--primary);
    }
    .plan-pro .plan-header {
      background: var(--primary-dark);
    }
    .plan-body {
      padding: 20px;
    }
    .plan-item {
      display: flex;
      align-items: center;
      gap: 12px;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .plan-icon {
      font-size: 18px;
    }
    .check { color: #27ae60; }
    .cross { color: #bdc3c7; }
    .plan-footer {
      padding: 20px;
      text-align: center;
    }
    @media (max-width: 768px) {
      .comparison-table {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-list {
      margin-top: 40px;
    }
    .faq-item {
      background: var(--white);
      border-bottom: 1px solid var(--ice-bg);
    }
    .faq-question {
      padding: 16px;
      font-size: 18px;
      font-weight: 500;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      color: var(--text);
    }
    .faq-answer {
      padding: 0 16px 16px;
      font-size: 16px;
      color: var(--text-light);
      background: var(--bg-light);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    .faq-icon {
      font-size: 24px;
      color: var(--primary);
    }
    /* CTA */
    .cta-section {
      background: var(--ice-bg);
    }
    .cta-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: start;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 12px;
      margin-bottom: 16px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      background: white;
    }
    .contact-form input:focus, .contact-form textarea:focus {
      outline: none;
      border-color: var(--primary);
    }
    .contact-info {
      background: white;
      padding: 24px;
      border-radius: var(--radius-md);
    }
    @media (max-width: 768px) {
      .cta-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 页脚 */
    .site-footer {
      background: var(--primary-dark);
      color: var(--ice-bg);
      padding: 60px 0 0;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-col h4 {
      color: white;
      margin-bottom: 16px;
    }
    .footer-col a, .footer-col p {
      font-size: 14px;
      color: var(--ice-bg);
      opacity: 0.8;
      display: block;
      margin-bottom: 8px;
    }
    .copyright {
      background: #0A2A38;
      text-align: center;
      padding: 16px;
      font-size: 12px;
      margin-top: 40px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 520px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }