/* roulang page: index */
:root {
      --color-primary: #0A8F4A;
      --color-primary-dark: #077A3D;
      --color-secondary: #1E2A38;
      --color-accent: #F15A24;
      --color-bg: #FAFBF7;
      --color-card: #FFFFFF;
      --color-border: #E8EDE4;
      --color-text: #1E2A38;
      --color-text-light: #5A6A7E;
      --color-muted: #B0B8C1;
      --font-heading: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
      --font-body: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 32px rgba(10,143,74,0.12);
      --radius-lg: 12px;
      --radius-md: 8px;
      --transition: 0.2s ease-out;
      --max-width: 1200px;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--color-bg);
      color: var(--color-text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-heading);
      font-weight: 600;
      border: none;
      outline: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      border-radius: var(--radius-md);
    }

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

    /* 导航栏 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(250, 251, 247, 0.96);
      backdrop-filter: blur(10px);
      border-bottom: 1px solid var(--color-border);
      transition: box-shadow 0.3s ease;
      height: 72px;
      display: flex;
      align-items: center;
    }

    .site-header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--color-primary);
      letter-spacing: -0.02em;
      transition: var(--transition);
    }

    .logo:hover {
      color: var(--color-primary-dark);
    }

    .logo-icon {
      width: 36px;
      height: 36px;
      background: var(--color-primary);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm-1 15l-4-4 1.41-1.41L11 14.17l6.59-6.59L19 9l-8 8z"/></svg>') no-repeat center;
      background: var(--color-primary);
      display: inline-block;
      border-radius: 50%;
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      list-style: none;
      align-items: center;
    }

    .nav-menu a {
      font-weight: 500;
      color: var(--color-secondary);
      position: relative;
      padding: 4px 0;
      font-size: 1rem;
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--color-primary);
      transition: width 0.25s ease;
    }

    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--color-primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-weight: 600;
      transition: background 0.2s, transform 0.2s;
    }

    .btn-primary:hover {
      background: var(--color-primary-dark);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--color-primary);
      color: var(--color-primary);
      padding: 10px 26px;
      border-radius: var(--radius-md);
      font-weight: 600;
    }

    .btn-outline:hover {
      background: rgba(10,143,74,0.06);
    }

    .btn-accent {
      background: var(--color-accent);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-md);
      font-weight: 700;
      transition: 0.2s;
    }

    .btn-accent:hover {
      background: #D94A1A;
      transform: translateY(-2px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 4px;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--color-secondary);
      transition: 0.2s;
    }

    /* 英雄区 */
    .hero {
      padding: 160px 0 100px;
      background: linear-gradient(135deg, #FAFBF7 0%, #EFF6EE 100%);
      position: relative;
      overflow: hidden;
    }

    .hero::before {
      content: "";
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 200px;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200" opacity="0.06"><circle cx="40" cy="40" r="30" fill="none" stroke="%230A8F4A" stroke-width="2"/><circle cx="160" cy="120" r="50" fill="none" stroke="%230A8F4A" stroke-width="1.5"/><path d="M20 80 L180 80" stroke="%230A8F4A" stroke-width="0.5" stroke-dasharray="4 4"/></svg>') repeat;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      position: relative;
      z-index: 2;
    }

    .hero-left {
      flex: 1;
    }

    .hero-left h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--color-secondary);
      margin-bottom: 24px;
    }

    .hero-left .subtitle {
      font-size: 18px;
      color: #4A5B6B;
      margin-bottom: 36px;
      max-width: 500px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
      position: relative;
    }

    .hero-image {
      width: 100%;
      max-width: 500px;
      border-radius: 16px;
      box-shadow: 0 20px 40px rgba(10,143,74,0.18);
      transition: transform 0.3s;
    }

    .scroll-indicator {
      position: absolute;
      bottom: 20px;
      left: 50%;
      transform: translateX(-50%);
      color: var(--color-primary);
      font-size: 2rem;
      opacity: 0.8;
      animation: bounce 2s infinite;
    }

    @keyframes bounce {
      0%, 100% { transform: translateX(-50%) translateY(0); }
      50% { transform: translateX(-50%) translateY(8px); }
    }

    /* 通用板块 */
    .section {
      padding: 100px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 16px;
      font-size: 36px;
      font-weight: 700;
      color: var(--color-secondary);
      letter-spacing: -0.02em;
    }

    .section-sub {
      text-align: center;
      color: var(--color-text-light);
      max-width: 600px;
      margin: 0 auto 60px;
      font-size: 1.1rem;
    }

    /* 核心优势 */
    .advantage-grid {
      display: flex;
      gap: 40px;
      justify-content: center;
      flex-wrap: wrap;
    }

    .adv-card {
      background: var(--color-card);
      padding: 40px 28px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
      flex: 1 1 280px;
      text-align: center;
      border: 1px solid var(--color-border);
      transition: all 0.25s;
    }

    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: var(--color-primary);
    }

    .adv-icon {
      font-size: 2.5rem;
      margin-bottom: 20px;
      color: var(--color-primary);
    }

    /* 功能分组 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
      flex-wrap: wrap;
    }

    .feature-row.reverse {
      flex-direction: row-reverse;
    }

    .feature-img {
      flex: 1 1 400px;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

    .feature-text {
      flex: 1 1 300px;
    }

    .feature-text h3 {
      font-size: 28px;
      margin-bottom: 20px;
      color: var(--color-secondary);
    }

    .feature-list {
      list-style: none;
    }

    .feature-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 12px;
      color: var(--color-text-light);
    }

    .feature-list li::before {
      content: "●";
      color: var(--color-primary);
      font-size: 1.2rem;
    }

    /* 使用场景 */
    .scenes-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 30px;
    }

    .scene-card {
      background: var(--color-card);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.25s;
      border: 1px solid var(--color-border);
    }

    .scene-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .scene-img {
      height: 200px;
      object-fit: cover;
      border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    }

    .scene-tag {
      background: rgba(10,143,74,0.12);
      color: var(--color-primary);
      padding: 4px 14px;
      border-radius: 20px;
      font-weight: 600;
      font-size: 0.8rem;
      display: inline-block;
      margin: 20px 20px 0;
    }

    .scene-card h4 {
      margin: 12px 20px 8px;
      font-size: 1.3rem;
    }

    .scene-card p {
      margin: 0 20px 20px;
      color: var(--color-text-light);
      font-size: 0.95rem;
    }

    /* 案例区 */
    .case-slider {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding: 10px 0 20px;
      scroll-snap-type: x mandatory;
    }

    .case-card {
      flex: 0 0 280px;
      background: #F4F7F2;
      border-radius: var(--radius-lg);
      padding: 28px;
      scroll-snap-align: start;
      border: 1px solid var(--color-border);
      transition: 0.2s;
    }

    .case-number {
      font-size: 42px;
      font-weight: 800;
      color: var(--color-accent);
      margin-bottom: 12px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--color-border);
    }

    .faq-question {
      width: 100%;
      background: white;
      padding: 20px 10px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      border: none;
      cursor: pointer;
      text-align: left;
      transition: 0.2s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      background: #FAFBF7;
      padding: 0 20px;
      color: var(--color-text-light);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 20px;
      border-left: 3px solid var(--color-primary);
    }

    /* CTA */
    .cta-band {
      background: linear-gradient(135deg, #0A8F4A, #066B35);
      padding: 100px 0;
      text-align: center;
      color: white;
    }

    .footer {
      background: #1E2A38;
      color: #B0B8C1;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
      margin-bottom: 40px;
    }

    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .feature-row { flex-direction: column; }
    }

    @media (max-width: 768px) {
      .hamburger { display: flex; }
      .nav-menu { display: none; position: fixed; top: 72px; right: 0; background: #FAFBF7; width: 80vw; height: 100vh; flex-direction: column; padding: 30px; gap: 25px; }
      .nav-menu.active { display: flex; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .hero-left h1 { font-size: 36px; }
    }