/* roulang page: index */
/* ----- GLOBAL RESET & DESIGN TOKENS ----- */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    :root {
      --primary: #1B7A3D;
      --primary-hover: #145E2E;
      --accent: #F27A33;
      --accent-hover: #D9651E;
      --bg-page: #F7F5F0;
      --bg-card: #FFFFFF;
      --bg-dark: #1E2B1F;
      --text-primary: #1E2B1F;
      --text-secondary: #5C6B5E;
      --text-on-dark: #E8EDE4;
      --border: #DDE3D8;
      --success: #2E9E5A;
      --warning: #F5A623;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-sm: 0 2px 12px rgba(27, 122, 61, 0.06);
      --shadow-hover: 0 8px 24px rgba(27, 122, 61, 0.12);
      --font-title: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --font-body: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
      --max-width: 1200px;
      --section-gap: 80px;
      --nav-height: 64px;
    }

    html {
      scroll-behavior: smooth;
      font-size: 16px;
      background-color: var(--bg-page);
    }

    body {
      font-family: var(--font-body);
      line-height: 1.7;
      color: var(--text-primary);
      background-color: var(--bg-page);
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
      border-radius: var(--radius-card);
    }

    a {
      text-decoration: none;
      color: inherit;
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: all 0.2s ease;
      font-weight: 600;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }

    /* ----- COMPONENTS ----- */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      padding: 14px 28px;
      border-radius: var(--radius-btn);
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: scale(1.03);
    }

    .btn-accent {
      background-color: var(--accent);
      color: white;
      padding: 16px 36px;
      border-radius: var(--radius-btn);
      animation: subtle-pulse 2.5s infinite;
    }
    .btn-accent:hover {
      background-color: var(--accent-hover);
      box-shadow: 0 0 12px rgba(242,122,51,0.5);
    }

    .btn-outline {
      border: 1px solid var(--primary);
      color: var(--primary);
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      background: transparent;
    }
    .btn-outline:hover {
      background-color: rgba(27,122,61,0.07);
    }

    @keyframes subtle-pulse {
      0% { box-shadow: 0 0 0 0 rgba(242,122,51,0.3); }
      70% { box-shadow: 0 0 0 10px rgba(242,122,51,0); }
      100% { box-shadow: 0 0 0 0 rgba(242,122,51,0); }
    }

    /* ----- NAVIGATION ----- */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.03);
      z-index: 999;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-family: var(--font-title);
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo svg {
      width: 26px;
      height: 26px;
      stroke: var(--primary);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-link {
      font-weight: 500;
      color: var(--text-primary);
      transition: color 0.2s;
      position: relative;
      font-size: 0.95rem;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      padding: 4px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: 0.2s;
    }

    /* Mobile Nav */
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: var(--primary);
        flex-direction: column;
        align-items: flex-start;
        padding: 32px 24px;
        gap: 24px;
        transform: translateY(-150%);
        transition: 0.3s ease;
        box-shadow: 0 8px 20px rgba(0,0,0,0.15);
      }
      .nav-menu.active {
        transform: translateY(0);
      }
      .nav-link {
        color: white;
        font-size: 1.1rem;
      }
      .hamburger {
        display: flex;
      }
    }

    /* ----- SECTIONS ----- */
    section {
      padding: var(--section-gap) 0;
    }

    .section-title {
      font-family: var(--font-title);
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-primary);
      letter-spacing: -0.2px;
    }
    .section-subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 40px;
    }

    /* Hero */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .hero-left h1 {
      font-family: var(--font-title);
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-primary);
    }
    .hero-metrics {
      display: flex;
      gap: 20px;
      margin-top: 24px;
    }
    .metric-card {
      background: var(--bg-card);
      box-shadow: var(--shadow-sm);
      border-radius: var(--radius-card);
      padding: 16px 18px;
      text-align: center;
      flex: 1;
    }
    .metric-number {
      font-size: 2rem;
      font-weight: 700;
      color: var(--accent);
    }

    /* Data Cards Grid */
    .grid-4, .grid-3 {
      display: grid;
      gap: 24px;
    }
    .grid-4 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }
    .grid-3 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }

    .card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border);
      padding: 24px;
      transition: transform 0.2s, box-shadow 0.2s;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .icon-circle {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: rgba(27,122,61,0.1);
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 16px;
    }

    /* Comparison */
    .comparison-wrapper {
      background: var(--bg-dark);
      color: var(--text-on-dark);
      border-radius: var(--radius-card);
      padding: 40px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .team-col { flex: 1; }
    .vs-circle {
      background: var(--accent);
      width: 60px;
      height: 60px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      font-size: 1.5rem;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 18px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s ease;
      color: var(--text-secondary);
    }
    .faq-item.open .faq-answer {
      max-height: 180px;
      margin-top: 12px;
    }

    /* Footer */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      color: var(--text-on-dark);
    }