/* roulang page: index */
:root {
      --primary: #1A5F2A;
      --primary-dark: #0F3D1C;
      --accent: #F5A623;
      --accent-hover: #F7B84E;
      --bg-light: #FAFBF7;
      --bg-section: #F4F7F2;
      --white: #FFFFFF;
      --text-main: #1E2A1E;
      --text-secondary: #5A6B5A;
      --border-light: #DCE5D8;
      --card-shadow: 0 2px 12px rgba(26, 95, 42, 0.06);
      --card-shadow-hover: 0 8px 24px rgba(26, 95, 42, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, sans-serif;
      --container-max: 1200px;
      --nav-height-desktop: 72px;
      --nav-height-mobile: 60px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.6;
      -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(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 var(--border-light);
      z-index: 100;
      height: var(--nav-height-desktop);
      display: flex;
      align-items: center;
      transition: box-shadow 0.3s ease;
    }

    .site-header.scrolled {
      box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    }

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

    .logo {
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }
    .logo i {
      font-size: 1.8rem;
      color: var(--accent);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }

    .nav-menu a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-main);
      position: relative;
      padding: 4px 0;
    }

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

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

    .btn-nav {
      background: var(--primary);
      color: white;
      padding: 10px 20px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      transition: background 0.2s, transform 0.2s;
      margin-left: 8px;
    }
    .btn-nav:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary);
      cursor: pointer;
    }

    @media (max-width: 1024px) {
      .nav-menu {
        gap: 18px;
      }
      .nav-menu a {
        font-size: 0.9rem;
      }
    }

    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-menu {
        position: fixed;
        top: var(--nav-height-mobile);
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        align-items: flex-start;
        padding: 24px;
        gap: 20px;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        box-shadow: 0 12px 24px rgba(0,0,0,0.1);
        border-top: 1px solid var(--border-light);
      }
      .nav-menu.active {
        transform: translateX(0);
      }
      .btn-nav {
        margin-left: 0;
        width: 100%;
        text-align: center;
      }
      .site-header {
        height: var(--nav-height-mobile);
      }
    }

    /* 板块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 640px) {
      section {
        padding: 64px 0;
      }
    }

    h2 {
      font-size: 2.2rem;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .section-subtitle {
      color: var(--text-secondary);
      font-size: 1.1rem;
      max-width: 620px;
      margin-bottom: 48px;
    }

    /* 按钮 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: all 0.2s ease;
      cursor: pointer;
      border: none;
      gap: 8px;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      font-size: 1rem;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 6px 14px rgba(26,95,42,0.25);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 30px;
    }
    .btn-outline:hover {
      background: rgba(26,95,42,0.06);
      transform: translateY(-2px);
    }
    .btn-accent {
      background: var(--accent);
      color: #1E2A1E;
      padding: 16px 36px;
      font-weight: 700;
      font-size: 1.1rem;
      box-shadow: 0 4px 12px rgba(245,166,35,0.3);
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
    }

    /* 卡片 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
      padding: 28px;
      transition: transform 0.25s, box-shadow 0.25s;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--card-shadow-hover);
    }

    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(180deg, #FAFBF7 0%, #F4F7F2 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      flex: 1;
      text-align: right;
    }
    .hero-image img {
      max-height: 440px;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    }

    @media (max-width: 768px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-content {
        order: 1;
      }
      .hero-image {
        order: 0;
        text-align: center;
        margin-bottom: 24px;
      }
      .hero h1 {
        font-size: 2.4rem;
      }
      .hero-buttons {
        justify-content: center;
      }
    }

    /* 优势 2x2 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 24px;
      margin-top: 32px;
    }
    .adv-card {
      display: flex;
      gap: 20px;
      background: var(--white);
      padding: 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--card-shadow);
    }
    .adv-icon {
      font-size: 2.4rem;
      color: var(--accent);
      width: 50px;
      text-align: center;
    }
    @media (max-width: 640px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 服务矩阵 非对称 */
    .services-flex {
      display: flex;
      gap: 24px;
      margin-top: 24px;
    }
    .service-card-large {
      flex: 2;
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px;
    }
    .service-card-small {
      flex: 1;
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 28px;
    }
    @media (max-width: 768px) {
      .services-flex {
        flex-direction: column;
      }
    }

    /* 统计 */
    .stats-row {
      display: flex;
      justify-content: space-around;
      text-align: center;
      margin-top: 40px;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--accent);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background: var(--bg-section);
      border-radius: 8px;
      margin-top: 8px;
      padding: 0 20px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 20px;
    }

    footer {
      background: var(--primary-dark);
      color: #CCD6CC;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .stats-row {
        flex-wrap: wrap;
        gap: 20px;
      }
    }