/* roulang page: index */
/* 基础设计变量与重置 */
    :root {
      --primary-green: #38A169;
      --primary-green-deep: #2E8B57;
      --deep-navy: #1A202C;
      --warm-gold: #D69E2E;
      --bg-light-mint: #F0FFF4;
      --bg-warm-gray: #F7FAFC;
      --text-dark: #1A202C;
      --text-body: #4A5568;
      --text-muted: #718096;
      --border-light: #E2E8F0;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: 'Inter', 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      --transition-base: 0.2s ease;
      --max-width: 1200px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      line-height: 1.7;
      color: var(--text-body);
      background-color: #fff;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition-base);
    }
    ul {
      list-style: none;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all var(--transition-base);
      cursor: pointer;
      border: 2px solid transparent;
      padding: 0.75rem 1.8rem;
      font-size: 1rem;
      letter-spacing: 0.3px;
    }
    .btn-primary {
      background-color: var(--primary-green);
      color: white;
      border-color: var(--primary-green);
      box-shadow: 0 4px 10px rgba(56,161,105,0.2);
    }
    .btn-primary:hover {
      background-color: var(--primary-green-deep);
      border-color: var(--primary-green-deep);
      box-shadow: 0 8px 18px rgba(56,161,105,0.35);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      color: var(--primary-green);
      border-color: var(--primary-green);
    }
    .btn-outline:hover {
      background-color: rgba(56,161,105,0.06);
      border-color: var(--primary-green-deep);
      color: var(--primary-green-deep);
    }
    .btn-gold {
      background-color: var(--warm-gold);
      color: var(--deep-navy);
      border-color: var(--warm-gold);
      font-weight: 700;
      padding: 0.9rem 2.5rem;
      font-size: 1.1rem;
      box-shadow: 0 6px 14px rgba(214,158,46,0.25);
    }
    .btn-gold:hover {
      background-color: #c98d1e;
      border-color: #c98d1e;
      box-shadow: 0 10px 20px rgba(214,158,46,0.4);
      transform: translateY(-2px);
    }
    .btn-white {
      background: white;
      color: var(--deep-navy);
      border-color: white;
      font-weight: 700;
    }
    .btn-white:hover {
      background: #f0f0f0;
      border-color: #f0f0f0;
      box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    }

    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(226,232,240,0.7);
      z-index: 100;
      transition: background 0.3s;
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--deep-navy);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--primary-green);
    }
    .nav-links {
      display: flex;
      gap: 2.5rem;
      font-weight: 500;
      color: var(--text-body);
    }
    .nav-links a {
      position: relative;
      padding: 5px 0;
      font-size: 1rem;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-green);
      transition: width var(--transition-base);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-green);
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 4px;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: var(--deep-navy);
      border-radius: 2px;
      transition: 0.2s;
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        align-items: center;
        gap: 2rem;
        padding: 2.5rem;
        transform: translateY(-150%);
        transition: transform 0.3s ease;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      .nav-links.open {
        transform: translateY(0);
      }
      .hamburger {
        display: flex;
      }
    }

    /* 通用板块样式 */
    .section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      color: var(--deep-navy);
      margin-bottom: 1rem;
      letter-spacing: -0.5px;
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 1.15rem;
      max-width: 700px;
      margin: 0 auto 3rem;
    }
    .text-center {
      text-align: center;
    }

    /* Hero 双栏 */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
      background: #F7FAFC;
    }
    .hero-left h1 {
      font-size: 3.8rem;
      font-weight: 800;
      line-height: 1.15;
      color: var(--deep-navy);
      margin-bottom: 1.5rem;
    }
    .hero-left .highlight {
      color: var(--primary-green);
    }
    .hero-desc {
      font-size: 1.2rem;
      color: var(--text-body);
      margin-bottom: 2rem;
    }
    .hero-stats {
      display: flex;
      gap: 2rem;
      margin-bottom: 2.2rem;
    }
    .stat-item h3 {
      font-size: 2rem;
      font-weight: 700;
      color: var(--primary-green);
    }
    .stat-item p {
      color: var(--text-muted);
      font-size: 0.9rem;
    }
    .hero-right img {
      border-radius: 24px 8px 24px 8px;
      box-shadow: 0 20px 30px rgba(0,0,0,0.08);
      width: 100%;
      height: auto;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-left h1 {
        font-size: 2.8rem;
      }
      .hero-stats {
        justify-content: center;
      }
      .hero-right {
        order: -1;
      }
    }

    /* 优势卡片网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    .feature-card {
      background: #fff;
      padding: 2rem 1.5rem;
      border-bottom: 3px solid var(--border-light);
      transition: all var(--transition-base);
    }
    .feature-card:hover {
      border-bottom-color: var(--primary-green);
      transform: translateY(-4px);
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--primary-green);
      margin-bottom: 1.2rem;
    }
    .feature-card h3 {
      font-size: 1.5rem;
      font-weight: 650;
      color: var(--deep-navy);
      margin-bottom: 0.8rem;
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 服务瀑布流 (masonry) */
    .services-masonry {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-5px);
    }
    .service-img {
      width: 100%;
      aspect-ratio: 16 / 9;
      object-fit: cover;
      border-radius: 8px 8px 0 0;
    }
    .service-body {
      padding: 1.4rem;
      flex: 1;
      display: flex;
      flex-direction: column;
    }
    .service-tag {
      background: var(--primary-green);
      color: white;
      font-size: 0.75rem;
      font-weight: 600;
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      display: inline-block;
      width: fit-content;
      margin-bottom: 0.8rem;
    }
    .service-title {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--deep-navy);
      margin-bottom: 0.5rem;
    }
    .service-desc {
      font-size: 0.95rem;
      color: var(--text-body);
      margin-bottom: 1rem;
      flex: 1;
    }
    .service-meta {
      display: flex;
      justify-content: space-between;
      color: var(--text-muted);
      font-size: 0.85rem;
      border-top: 1px solid #edf2f7;
      padding-top: 0.8rem;
    }
    @media (max-width: 1024px) {
      .services-masonry {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 520px) {
      .services-masonry {
        grid-template-columns: 1fr;
      }
    }

    /* 数据条 */
    .stats-bar {
      background: #F0FFF4;
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      text-align: center;
      padding: 3rem 1rem;
    }
    .stat-count {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--primary-green);
    }
    .stat-label {
      color: var(--text-muted);
      font-weight: 500;
    }

    /* 方案对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .plan-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      border-top: 5px solid transparent;
    }
    .plan-card.recommended {
      border-top-color: var(--primary-green);
      box-shadow: 0 10px 25px rgba(0,0,0,0.06);
    }
    .plan-name {
      font-size: 1.5rem;
      font-weight: 700;
    }
    .plan-price {
      font-size: 2rem;
      font-weight: 800;
      color: var(--deep-navy);
    }
    @media (max-width: 768px) {
      .compare-grid {
        grid-template-columns: 1fr;
      }
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.4rem 0;
    }
    .faq-question {
      font-weight: 650;
      font-size: 1.1rem;
      display: flex;
      align-items: center;
      gap: 1rem;
      cursor: pointer;
      color: var(--deep-navy);
    }
    .faq-question::before {
      content: '';
      width: 4px;
      height: 20px;
      background: #CBD5E0;
      border-radius: 2px;
      transition: 0.2s;
    }
    .faq-item.open .faq-question::before {
      background: var(--primary-green);
      height: 28px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding-left: 1.8rem;
      color: var(--text-body);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      margin-top: 0.8rem;
    }

    /* CTA 深色背景 */
    .cta-dark {
      background: linear-gradient(135deg, #1A202C 0%, #2d3748 100%);
      color: white;
      text-align: center;
    }
    .footer {
      background: #0f1419;
      color: #cbd5e0;
      padding: 3rem 0;
    }
    .footer a:hover {
      color: white;
    }