/* roulang page: index */
/* :root 设计变量 —— 有机科技视觉系统 */
    :root {
      --primary-dark: #2D1B3E;
      --primary-light: #3D2556;
      --secondary-green: #3A6B4C;
      --bg-warm: #FAF7F2;
      --white: #FFFFFF;
      --text-dark: #1A0F26;
      --text-body: #3A3640;
      --text-warm: #7A7281;
      --border-light: rgba(45,27,62,0.08);
      --shadow-card: 0 2px 12px rgba(45,27,62,0.06);
      --shadow-hover: 0 8px 24px rgba(45,27,62,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-search: 24px;
      --font-serif: 'Noto Serif SC', 'Times New Roman', '宋体', SimSun, 'Georgia', serif;
      --font-sans: 'PingFang SC', 'Inter', 'Helvetica Neue', 'Microsoft YaHei', sans-serif;
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      --section-gap: 100px;
      --container-max: 1280px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.7;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-serif);
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--text-dark);
    }

    h1 { font-size: 3.2rem; }
    h2 { font-size: 2.2rem; }
    h3 { font-size: 1.5rem; }
    h4 { font-size: 1.25rem; }

    p, li {
      font-family: var(--font-sans);
      color: var(--text-body);
      font-weight: 400;
    }

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

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      text-decoration: none;
      transition: all 0.25s ease;
      cursor: pointer;
      border: 1.5px solid transparent;
      font-size: 1rem;
      letter-spacing: 0.3px;
    }

    .btn-primary {
      background-color: var(--primary-dark);
      color: white;
      border-color: var(--primary-dark);
    }

    .btn-primary:hover {
      background-color: var(--primary-light);
      transform: scale(1.03);
      color: white;
      border-color: var(--primary-light);
    }

    .btn-outline {
      background: transparent;
      color: var(--secondary-green);
      border: 1.5px solid var(--secondary-green);
    }

    .btn-outline:hover {
      background-color: rgba(58,107,76,0.1);
      border-color: var(--secondary-green);
      color: var(--secondary-green);
    }

    .btn-lg {
      padding: 14px 36px;
      font-size: 1.1rem;
    }

    /* 导航栏 */
    .site-header {
      background: var(--bg-warm);
      padding: 16px 0;
      position: sticky;
      top: 0;
      z-index: 50;
      transition: box-shadow 0.3s;
      border-bottom: 1px solid transparent;
    }

    .site-header.scrolled {
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      border-bottom: 1px solid var(--border-light);
    }

    .nav-grid {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }

    .logo {
      font-family: var(--font-serif);
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--primary-dark);
      text-decoration: none;
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
    }

    .logo i {
      color: var(--secondary-green);
      margin-right: 6px;
      font-size: 1.6rem;
    }

    .search-box {
      display: flex;
      align-items: center;
      background: white;
      border-radius: var(--radius-search);
      padding: 8px 18px;
      width: 360px;
      max-width: 100%;
      box-shadow: inset 0 1px 4px rgba(0,0,0,0.02);
      border: 1px solid transparent;
      transition: border 0.2s;
      margin: 0 20px;
    }

    .search-box i {
      color: var(--secondary-green);
      margin-right: 8px;
      font-size: 1rem;
    }

    .search-box input {
      border: none;
      outline: none;
      width: 100%;
      font-family: var(--font-sans);
      font-size: 0.95rem;
      color: var(--text-body);
      background: transparent;
    }

    .search-box input::placeholder {
      color: var(--text-warm);
    }

    .search-box:focus-within {
      border-color: var(--secondary-green);
    }

    .nav-links {
      display: flex;
      gap: 24px;
      align-items: center;
    }

    .nav-links a {
      color: var(--text-body);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
    }

    .nav-links a:hover {
      color: var(--secondary-green);
    }

    /* 汉堡菜单 (纯CSS) */
    #menu-toggle {
      display: none;
    }

    .menu-icon {
      display: none;
      font-size: 1.5rem;
      color: var(--primary-dark);
      cursor: pointer;
    }

    /* Hero */
    #hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      padding: 40px 0;
    }

    .hero-content {
      display: flex;
      align-items: center;
      gap: 60px;
      flex-wrap: wrap;
    }

    .hero-text {
      flex: 1 1 50%;
    }

    .hero-text h1 {
      margin-bottom: 24px;
      line-height: 1.2;
    }

    .hero-text p {
      font-size: 1.1rem;
      color: var(--text-warm);
      margin-bottom: 32px;
      max-width: 500px;
    }

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

    .hero-image {
      flex: 1 1 45%;
      position: relative;
    }

    .hero-image img {
      width: 100%;
      height: auto;
      border-radius: 16px;
      box-shadow: var(--shadow-card);
      aspect-ratio: 16 / 10;
      object-fit: cover;
    }

    /* 通用板块 */
    section {
      padding: var(--section-gap) 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }

    .section-title h2 {
      margin-bottom: 12px;
    }

    .section-title p {
      color: var(--text-warm);
      max-width: 600px;
      margin: 0 auto;
    }

    /* 功能矩阵 2x3 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
    }

    .feature-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }

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

    .feature-icon {
      width: 48px;
      height: 48px;
      background: #E8F0EB;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--secondary-green);
      font-size: 1.4rem;
    }

    .feature-card h3 {
      margin-bottom: 8px;
      font-size: 1.3rem;
    }

    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }

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

    .scenario-img {
      flex: 1 1 45%;
    }

    .scenario-img img {
      width: 100%;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      aspect-ratio: 4/3;
      object-fit: cover;
    }

    .scenario-text {
      flex: 1 1 50%;
    }

    /* 案例卡片 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 12px;
      scrollbar-width: thin;
    }

    .case-card {
      min-width: 220px;
      background: #F3EEF6;
      border-radius: var(--radius-card);
      padding: 28px 24px;
      text-align: center;
      flex-shrink: 0;
    }

    .case-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--secondary-green);
      line-height: 1;
    }

    /* 价格卡 */
    .pricing-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .pricing-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 36px 28px;
      box-shadow: var(--shadow-card);
      text-align: center;
      transition: var(--transition-smooth);
    }

    .pricing-card.featured {
      border: 2px solid var(--primary-dark);
      box-shadow: var(--shadow-hover);
      transform: scale(1.02);
    }

    .pricing-card ul {
      list-style: none;
      text-align: left;
      margin: 24px 0;
    }

    .pricing-card li i {
      color: var(--secondary-green);
      margin-right: 8px;
    }

    /* FAQ */
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      overflow: hidden;
    }

    .faq-question {
      background: var(--bg-warm);
      padding: 18px 24px;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: background 0.2s;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: white;
      padding: 0 24px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 18px 24px;
    }

    /* CTA 尾板 */
    .cta-full {
      background: var(--primary-dark);
      padding: 80px 0;
      text-align: center;
      color: white;
    }

    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    footer {
      background: #1A0F26;
      color: #B8A9C2;
      padding: 60px 0 30px;
    }

    footer a {
      color: #B8A9C2;
      text-decoration: none;
    }

    footer a:hover {
      color: var(--secondary-green);
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      h1 { font-size: 2.8rem; }
      .features-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 640px) {
      :root { --section-gap: 64px; }
      h1 { font-size: 2.4rem; }
      h2 { font-size: 1.9rem; }
      .nav-links { display: none; }
      .search-box { width: 100%; margin: 10px 0; order: 3; }
      .menu-icon { display: block; }
      #menu-toggle:checked ~ .nav-links {
        display: flex;
        flex-direction: column;
        width: 100%;
        background: var(--bg-warm);
        padding: 16px;
      }
      .hero-content { flex-direction: column; }
      .features-grid, .pricing-grid { grid-template-columns: 1fr; }
      .scenario-row, .scenario-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
    }