/* roulang page: index */
:root {
      --primary-bg: #1E2B24;
      --accent-lime: #C8FF00;
      --accent-lime-hover: #B3E600;
      --neutral-warm: #F4F5F0;
      --text-dark: #2E3A33;
      --text-muted: #5A6B60;
      --white: #ffffff;
      --card-shadow: 0 4px 12px rgba(0,0,0,0.03);
      --card-hover-shadow: 0 8px 24px rgba(0,0,0,0.08);
      --border-radius-card: 12px;
      --border-radius-btn: 8px;
      --border-radius-capsule: 40px;
      --transition: all 0.25s ease;
      --font-family: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --max-width: 1200px;
      --spacing-section: 5rem;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: var(--font-family);
      background-color: var(--white);
      color: var(--text-dark);
      line-height: 1.7;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    
    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.5px;
    }
    
    h1 {
      font-size: 48px;
      line-height: 1.2;
    }
    
    h2 {
      font-size: 36px;
      margin-bottom: 0.75rem;
    }
    
    h3 {
      font-size: 22px;
    }
    
    .section-subtitle {
      color: var(--text-muted);
      font-size: 16px;
      max-width: 680px;
      margin: 0 auto 2.5rem;
    }
    
    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      border-radius: var(--border-radius-btn);
      padding: 12px 28px;
      text-decoration: none;
      transition: var(--transition);
      cursor: pointer;
      border: 2px solid transparent;
      font-size: 16px;
      letter-spacing: 0.3px;
      background: transparent;
      line-height: 1.2;
    }
    
    .btn-primary {
      background-color: var(--accent-lime);
      color: var(--primary-bg);
      border-color: var(--accent-lime);
    }
    
    .btn-primary:hover {
      background-color: var(--accent-lime-hover);
      border-color: var(--accent-lime-hover);
      box-shadow: 0 8px 18px rgba(200, 255, 0, 0.25);
      transform: translateY(-1px);
    }
    
    .btn-secondary {
      background: transparent;
      color: var(--accent-lime);
      border-color: var(--accent-lime);
    }
    
    .btn-secondary:hover {
      background: rgba(200, 255, 0, 0.1);
      border-color: var(--accent-lime-hover);
      color: var(--accent-lime-hover);
    }
    
    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      transition: background 0.3s, backdrop-filter 0.3s;
    }
    
    .header-scrolled {
      background: rgba(30, 43, 36, 0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.2);
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 1rem 1.5rem;
      max-width: var(--max-width);
      margin: 0 auto;
    }
    
    .logo {
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--accent-lime);
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: 0.5px;
    }
    
    .logo span {
      font-size: 0.7rem;
      font-weight: 400;
      background: rgba(200,255,0,0.2);
      padding: 2px 8px;
      border-radius: 20px;
      color: var(--accent-lime);
      margin-left: 4px;
    }
    
    .nav-links {
      display: flex;
      gap: 2.2rem;
      list-style: none;
    }
    
    .nav-links a {
      color: var(--neutral-warm);
      text-decoration: none;
      font-weight: 400;
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
      font-size: 15px;
    }
    
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--accent-lime);
      transition: width 0.3s ease, left 0.3s ease;
    }
    
    .nav-links a:hover {
      color: var(--accent-lime);
    }
    
    .nav-links a:hover::after {
      width: 100%;
      left: 0;
    }
    
    /* 移动端底部导航 */
    .mobile-bottom-nav {
      display: none;
    }
    
    /* 区块通用 */
    section {
      padding: var(--spacing-section) 0;
    }
    
    .section-title {
      text-align: center;
      margin-bottom: 2.5rem;
      color: var(--primary-bg);
    }
    
    /* Hero */
    #hero {
      background: linear-gradient(135deg, #1E2B24 0%, #0f1a14 100%);
      color: var(--white);
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    
    .hero-content h1 {
      color: white;
      margin-bottom: 1.5rem;
    }
    
    .hero-content h1 .highlight {
      color: var(--accent-lime);
    }
    
    .hero-content p {
      color: rgba(244, 245, 240, 0.8);
      font-size: 16px;
      max-width: 480px;
      margin-bottom: 2rem;
    }
    
    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    
    .hero-visual {
      position: relative;
      height: 400px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: 24px;
      overflow: hidden;
    }
    
    .hero-visual::after {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(30,43,36,0.4);
      backdrop-filter: blur(0px);
      border-radius: 24px;
    }
    
    .geometric-overlay {
      position: absolute;
      top: 20%;
      left: 15%;
      width: 70%;
      height: 60%;
      border: 2px solid rgba(200,255,0,0.2);
      border-radius: 50%;
      z-index: 2;
      animation: pulse 4s infinite;
    }
    
    @keyframes pulse {
      0% { transform: scale(0.95); opacity: 0.5; }
      50% { transform: scale(1.05); opacity: 0.8; }
      100% { transform: scale(0.95); opacity: 0.5; }
    }
    
    /* 服务卡片 错落栅格 */
    .services-grid {
      display: grid;
      grid-template-columns: 5fr 3fr 3fr;
      gap: 24px;
      margin-top: 2rem;
    }
    
    .service-card {
      background: var(--neutral-warm);
      border-radius: var(--border-radius-card);
      padding: 2rem 1.8rem;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }
    
    .service-card:first-child {
      grid-row: span 2;
    }
    
    .service-card:hover {
      box-shadow: var(--card-hover-shadow);
      transform: translateY(-4px);
    }
    
    .service-icon {
      font-size: 32px;
      color: var(--accent-lime);
      margin-bottom: 1.5rem;
      background: rgba(30,43,36,0.05);
      width: 56px;
      height: 56px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 12px;
    }
    
    .service-card h3 {
      margin-bottom: 0.75rem;
      color: var(--primary-bg);
    }
    
    .service-card p {
      color: var(--text-muted);
      font-size: 14px;
      line-height: 1.6;
    }
    
    /* 优势数据 */
    #advantages {
      background: var(--primary-bg);
      color: white;
    }
    
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
      margin-top: 2rem;
    }
    
    .stat-item {
      background: rgba(255,255,255,0.03);
      padding: 2rem 1rem;
      border-radius: 16px;
      backdrop-filter: blur(4px);
    }
    
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent-lime);
      font-feature-settings: "tnum";
      letter-spacing: 0;
    }
    
    .stat-label {
      color: var(--neutral-warm);
      font-size: 14px;
      margin-top: 0.5rem;
    }
    
    /* 案例横向滚动 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding: 1rem 0 2rem;
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
      scrollbar-width: thin;
      scrollbar-color: var(--accent-lime) transparent;
    }
    
    .case-card {
      flex: 0 0 calc(40% - 12px);
      min-width: 280px;
      scroll-snap-align: start;
      background: white;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--card-shadow);
      transition: var(--transition);
    }
    
    .case-card:hover {
      transform: scale(1.02);
      box-shadow: var(--card-hover-shadow);
    }
    
    .case-img {
      height: 180px;
      background-size: cover;
      background-position: center;
      position: relative;
    }
    
    .case-tag {
      position: absolute;
      top: 12px;
      left: 12px;
      background: var(--accent-lime);
      color: var(--primary-bg);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 700;
    }
    
    .case-info {
      padding: 1.2rem;
    }
    
    /* 时间轴 */
    .timeline {
      position: relative;
      padding-left: 3rem;
    }
    
    .timeline-item {
      display: flex;
      gap: 2rem;
      margin-bottom: 2.5rem;
      position: relative;
    }
    
    .timeline-marker {
      width: 40px;
      height: 40px;
      background: var(--accent-lime);
      color: var(--primary-bg);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      flex-shrink: 0;
      position: absolute;
      left: 0;
    }
    
    .timeline-content {
      margin-left: 4rem;
    }
    
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(0,0,0,0.05);
      margin-bottom: 0.5rem;
    }
    
    .faq-question {
      font-weight: 500;
      padding: 1.2rem 0;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--primary-bg);
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: var(--neutral-warm);
      border-left: 4px solid var(--accent-lime);
      padding: 0 1.5rem;
      margin-bottom: 0.8rem;
      border-radius: 0 8px 8px 0;
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem 1.5rem;
    }
    
    /* 联系表单 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
    }
    
    .form-group input, .form-group textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid #ddd;
      border-radius: 8px;
      font-family: inherit;
      transition: 0.2s;
      background: white;
    }
    
    .form-group input:focus, .form-group textarea:focus {
      outline: none;
      border-color: var(--accent-lime);
    }
    
    /* 页脚 */
    footer {
      background: var(--primary-bg);
      color: var(--neutral-warm);
      padding: 3rem 0 1.5rem;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1.5fr 1fr;
      gap: 2rem;
    }
    
    @media (max-width: 992px) {
      h1 { font-size: 38px; }
      .hero-grid { grid-template-columns: 1fr; }
      .services-grid { grid-template-columns: 1fr 1fr; }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .case-card { flex: 0 0 60%; }
    }
    
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-bottom-nav {
        display: flex;
        justify-content: space-around;
        position: fixed;
        bottom: 0;
        left: 0;
        width: 100%;
        background: var(--primary-bg);
        border-radius: 40px 40px 0 0;
        padding: 10px 0;
        z-index: 99;
      }
      .mobile-bottom-nav a {
        color: var(--neutral-warm);
        text-decoration: none;
        font-size: 12px;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 4px;
      }
      .services-grid { grid-template-columns: 1fr; }
      .contact-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .hero-visual { height: 250px; }
    }