/* roulang page: index */
:root {
      --primary-green: #2E7D32;
      --primary-green-dark: #1B5E20;
      --deep-blue: #0D1B2A;
      --bg-light: #F4F7FA;
      --white: #FFFFFF;
      --text-primary: #0D1B2A;
      --text-body: #374151;
      --text-muted: #6B7280;
      --accent-orange: #F57C00;
      --border-light: #E5E7EB;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04), 0 4px 16px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.1);
      --max-width: 1200px;
      --gap-section: 100px;
      --gap-md: 80px;
      --body-line-height: 1.7;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-body);
      font-size: 16px;
      line-height: var(--body-line-height);
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 导航 */
    .main-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--white);
      box-shadow: 0 1px 0 rgba(0,0,0,0.04);
      transition: box-shadow 0.2s;
    }
    .header-shadow {
      box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 68px;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 22px;
      letter-spacing: -0.3px;
      color: var(--deep-blue);
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: linear-gradient(135deg, var(--primary-green), #1e5631);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 18px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-primary);
      font-size: 15px;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-green);
      border-bottom-color: var(--primary-green);
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--deep-blue);
    }

    /* 按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all 0.25s ease;
      font-size: 15px;
      letter-spacing: 0.3px;
      cursor: pointer;
      border: 2px solid transparent;
      text-align: center;
    }
    .btn-primary {
      background: var(--primary-green);
      color: white;
      border-color: var(--primary-green);
    }
    .btn-primary:hover {
      background: var(--primary-green-dark);
      border-color: var(--primary-green-dark);
      transform: translateY(-1px);
      box-shadow: 0 4px 12px rgba(46,125,50,0.3);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary-green);
      border-color: var(--primary-green);
    }
    .btn-outline:hover {
      background: var(--primary-green);
      color: white;
      border-color: var(--primary-green);
    }
    .btn-white {
      background: white;
      color: var(--deep-blue);
      border-color: white;
    }
    .btn-white:hover {
      background: #f0f2f5;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, rgba(13,27,42,0.82) 0%, rgba(13,27,42,0.78) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      padding: 100px 20px 120px;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      position: relative;
      overflow: hidden;
      min-height: 550px;
    }
    .hero-content {
      max-width: 900px;
      color: white;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
    }
    .hero p {
      font-size: 18px;
      opacity: 0.9;
      margin-bottom: 36px;
      max-width: 700px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }

    /* 板块标题 */
    .section-title {
      font-size: 34px;
      font-weight: 600;
      color: var(--deep-blue);
      margin-bottom: 16px;
      letter-spacing: -0.4px;
    }
    .section-subtitle {
      color: var(--text-muted);
      font-size: 17px;
      max-width: 650px;
      margin: 0 auto 48px;
    }

    /* 通用块 */
    section {
      padding: var(--gap-md) 20px;
    }
    .bg-white-section {
      background: var(--white);
    }

    .grid-3, .grid-4 {
      display: grid;
      gap: 28px;
    }
    .grid-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-4 { grid-template-columns: repeat(4, 1fr); }

    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-card);
      transition: transform 0.2s, box-shadow 0.2s;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .icon-box {
      width: 50px;
      height: 50px;
      background: rgba(46,125,50,0.08);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary-green);
      font-size: 24px;
      margin-bottom: 18px;
    }
    .card h3 {
      font-size: 20px;
      color: var(--deep-blue);
      margin-bottom: 10px;
    }

    .alt-row {
      display: flex;
      gap: 48px;
      align-items: center;
      margin-bottom: 64px;
    }
    .alt-row.reverse {
      flex-direction: row-reverse;
    }
    .alt-text {
      flex: 1;
    }
    .alt-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      background: #eef1f5;
    }

    .scenario-card img {
      border-radius: 12px 12px 0 0;
      height: 200px;
      object-fit: cover;
      width: 100%;
      transition: transform 0.4s;
    }
    .scenario-card:hover img {
      transform: scale(1.03);
    }

    .case-block {
      background: #edf2f8;
      border-radius: 16px;
      padding: 32px;
      display: flex;
      gap: 32px;
      align-items: center;
      margin-bottom: 24px;
    }
    .case-number {
      font-size: 38px;
      font-weight: 700;
      color: var(--primary-green);
    }

    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      align-items: start;
    }
    .pricing-card {
      background: white;
      border-radius: 16px;
      padding: 36px 24px;
      box-shadow: var(--shadow-card);
      border: 2px solid transparent;
    }
    .pricing-card.featured {
      border-color: var(--primary-green);
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      position: relative;
    }
    .price {
      font-size: 40px;
      font-weight: 700;
      color: var(--deep-blue);
      margin: 18px 0;
    }

    .faq-item {
      background: white;
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 17px;
      color: var(--deep-blue);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      color: var(--text-body);
      margin-top: 10px;
      display: none;
      padding-left: 8px;
    }
    .faq-item.open .faq-answer {
      display: block;
    }

    .cta-banner {
      background: #e6f0e9;
      border-radius: 20px;
      padding: 56px 28px;
      text-align: center;
      margin: 40px 20px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 36px;
      padding: 50px 20px 30px;
    }
    .footer-bottom {
      border-top: 1px solid var(--border-light);
      padding: 20px 20px;
      color: #9CA3AF;
      font-size: 14px;
      text-align: center;
    }

    @media (max-width: 1024px) {
      .grid-3, .pricing-grid { grid-template-columns: 1fr 1fr; }
      .alt-row { flex-direction: column; }
      .alt-row.reverse { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-toggle { display: block; }
      .mobile-menu {
        display: flex;
        flex-direction: column;
        background: rgba(13,27,42,0.96);
        position: fixed;
        top: 68px;
        left: 0;
        right: 0;
        bottom: 0;
        padding: 32px;
        gap: 28px;
        font-size: 22px;
      }
      .mobile-menu a { color: white; }
      .hero h1 { font-size: 36px; }
    }
    @media (max-width: 520px) {
      .grid-3, .grid-4, .pricing-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .case-block { flex-direction: column; }
    }