/* roulang page: index */
:root {
      --primary: #0A4D3C;
      --primary-dark: #06382B;
      --primary-light: #0F6B52;
      --accent: #F5A623;
      --accent-dark: #E09510;
      --bg: #FAFAF7;
      --card: #FFFFFF;
      --text: #1E1E1E;
      --text-secondary: #5F6B6A;
      --border: #DDE5E2;
      --radius-card: 16px;
      --radius-btn: 10px;
      --radius-input: 8px;
      --shadow-sm: 0 2px 12px rgba(10,77,60,0.06);
      --shadow-md: 0 8px 28px rgba(10,77,60,0.12);
      --font-body: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "DIN Alternate", "Arial", sans-serif;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, input, textarea {
      font-family: inherit;
      outline: none;
    }
    .container {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* Navigation */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background-color: var(--card);
      border-bottom: 1px solid var(--border);
      transition: box-shadow 0.3s ease;
    }
    .site-header.scrolled {
      box-shadow: 0 4px 20px rgba(10,77,60,0.08);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
      white-space: nowrap;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      margin-right: 10px;
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 18px;
    }
    .desktop-nav {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .desktop-nav a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      transition: color 0.2s;
      position: relative;
      padding: 4px 0;
    }
    .desktop-nav a:hover,
    .desktop-nav a.active {
      color: var(--primary);
    }
    .desktop-nav a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background-color: var(--primary);
      transition: width 0.2s;
    }
    .desktop-nav a:hover::after,
    .desktop-nav a.active::after {
      width: 100%;
    }
    .btn-primary {
      background-color: var(--accent);
      color: white;
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background-color 0.2s, transform 0.2s;
      border: none;
      cursor: pointer;
      white-space: nowrap;
    }
    .btn-primary:hover {
      background-color: var(--accent-dark);
      transform: translateY(-2px);
    }
    .btn-outline {
      background-color: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      transition: all 0.2s;
      cursor: pointer;
    }
    .btn-outline:hover {
      background-color: var(--primary);
      color: white;
      transform: translateY(-2px);
    }
    .btn-white {
      background-color: white;
      color: var(--primary);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      transition: all 0.2s;
      border: none;
      cursor: pointer;
    }
    .btn-white:hover {
      background-color: #FFF8E7;
      transform: scale(1.05);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background-color: var(--primary);
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-color: white;
      z-index: 60;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
    }
    .mobile-menu.active {
      display: flex;
    }
    .mobile-menu a {
      font-size: 22px;
      font-weight: 600;
      color: var(--text);
    }
    .mobile-menu .btn-primary {
      margin-top: 24px;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .hamburger {
        display: flex;
      }
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #F4F8F6 0%, #FAFAF7 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 6fr 4fr;
      gap: 60px;
      align-items: center;
      min-height: 600px;
    }
    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--primary);
      letter-spacing: -0.5px;
    }
    .hero-subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-top: 20px;
      max-width: 480px;
    }
    .hero-actions {
      display: flex;
      align-items: center;
      gap: 24px;
      margin-top: 36px;
    }
    .hero-image {
      position: relative;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    .hero-image::after {
      content: '';
      position: absolute;
      bottom: 0;
      right: 0;
      width: 200px;
      height: 200px;
      background: radial-gradient(circle, rgba(245,166,35,0.2) 0%, transparent 70%);
      pointer-events: none;
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        gap: 32px;
      }
      .hero-content h1 {
        font-size: 32px;
      }
      .hero-image {
        order: -1;
      }
    }

    /* Sections */
    .section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 600;
      color: var(--text);
      margin-bottom: 12px;
    }
    .section-desc {
      font-size: 16px;
      color: var(--text-secondary);
      max-width: 600px;
      margin-bottom: 40px;
    }
    @media (max-width: 768px) {
      .section {
        padding: 48px 0;
      }
      .section-title {
        font-size: 26px;
      }
    }

    /* Cards */
    .card {
      background: var(--card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s, box-shadow 0.3s;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .feature-card {
      padding: 28px;
      text-align: center;
    }
    .feature-icon {
      width: 64px;
      height: 64px;
      background-color: rgba(10,77,60,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary);
    }
    .service-card {
      overflow: hidden;
    }
    .service-img {
      position: relative;
      aspect-ratio: 16/9;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-img::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 30%;
      background: linear-gradient(to top, rgba(0,0,0,0.5), transparent);
    }
    .service-img h3 {
      position: absolute;
      bottom: 16px;
      left: 16px;
      color: white;
      font-size: 20px;
      font-weight: 600;
      z-index: 2;
    }
    .case-card {
      border: 1px solid var(--border);
      background: white;
    }
    .case-card:hover {
      border-color: var(--primary);
    }
    .case-img {
      aspect-ratio: 4/3;
      position: relative;
    }
    .case-tag {
      position: absolute;
      top: 12px;
      left: 12px;
      background: var(--accent);
      color: white;
      font-size: 12px;
      font-weight: 600;
      padding: 4px 12px;
      border-radius: 20px;
    }

    /* Stats */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 56px;
      font-weight: 800;
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .stat-label {
      font-size: 15px;
      color: var(--text-secondary);
      font-weight: 500;
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .stat-number {
        font-size: 40px;
      }
    }

    /* Process */
    .process-steps {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      position: relative;
    }
    .process-step {
      text-align: center;
      position: relative;
    }
    .step-circle {
      width: 56px;
      height: 56px;
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 22px;
      margin: 0 auto 16px;
    }
    .step-line {
      display: none;
    }
    @media (min-width: 769px) {
      .process-steps::before {
        content: '';
        position: absolute;
        top: 28px;
        left: 12%;
        width: 76%;
        height: 2px;
        background: repeating-linear-gradient(90deg, var(--border) 0px, var(--border) 8px, transparent 8px, transparent 16px);
        z-index: 0;
      }
    }
    @media (max-width: 768px) {
      .process-steps {
        grid-template-columns: 1fr;
      }
      .process-step {
        display: flex;
        align-items: flex-start;
        gap: 20px;
        text-align: left;
      }
      .step-circle {
        margin: 0;
        flex-shrink: 0;
      }
    }

    /* FAQ */
    .faq-section {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
      color: white;
    }
    .faq-item {
      background: rgba(255,255,255,0.08);
      border-radius: 8px;
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 18px 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 500;
      font-size: 18px;
    }
    .faq-answer {
      padding: 0 20px 16px;
      font-size: 15px;
      line-height: 1.7;
      opacity: 0.9;
      display: none;
    }
    .faq-item.open .faq-answer {
      display: block;
    }
    .faq-icon {
      transition: transform 0.3s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    /* Footer */
    .site-footer {
      background: #0A2E24;
      color: #B8CCC6;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer-links a {
      display: block;
      color: #B8CCC6;
      margin-bottom: 10px;
      transition: color 0.2s;
    }
    .footer-links a:hover {
      color: var(--accent);
    }
    .social-icons {
      display: flex;
      gap: 16px;
    }
    .social-icon {
      width: 36px;
      height: 36px;
      border: 1px solid #B8CCC6;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: all 0.2s;
    }
    .social-icon:hover {
      background: var(--accent);
      border-color: var(--accent);
      color: white;
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    /* Contact Form */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: start;
    }
    .input-field {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border);
      border-radius: var(--radius-input);
      background: white;
      font-size: 15px;
      margin-bottom: 16px;
      transition: border 0.2s, box-shadow 0.2s;
    }
    .input-field:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(10,77,60,0.1);
    }
    @media (max-width: 768px) {
      .contact-grid {
        grid-template-columns: 1fr;
      }
    }