/* roulang page: index */
:root {
      --charcoal: #1E1E24;
      --champagne: #C6A972;
      --warm-white: #F7F5F0;
      --pure-white: #FFFFFF;
      --body-text: #4A4A55;
      --light-border: #EAE9E4;
      --muted-text: #8C8C96;
      --hover-bg: #2C2C33;
      --radius-card: 8px;
      --radius-btn: 4px;
      --shadow-card: 0 2px 8px rgba(0,0,0,0.04);
      --transition-base: all 0.25s ease;
    }
    
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
      background-color: var(--warm-white);
      color: var(--body-text);
      line-height: 1.8;
      font-weight: 400;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
    }
    
    h1, h2, h3, h4 {
      font-weight: 600;
      color: var(--charcoal);
      margin-bottom: 0.5rem;
    }
    
    h1 {
      font-weight: 700;
      font-size: 3.5rem;
      letter-spacing: 0.02em;
      color: var(--champagne);
      line-height: 1.2;
    }
    
    h2 {
      font-size: 2.25rem;
      font-weight: 600;
    }
    
    h3 {
      font-size: 1.25rem;
      font-weight: 500;
    }
    
    a {
      color: var(--charcoal);
      text-decoration: none;
      transition: var(--transition-base);
    }
    
    a:hover {
      color: var(--champagne);
      text-decoration: none;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    button, input, textarea {
      font-family: inherit;
    }
    
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(247, 245, 240, 0.88);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(234, 233, 228, 0.6);
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0.75rem 1.5rem;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--charcoal);
      letter-spacing: 0.02em;
      text-decoration: none;
    }
    
    .logo i {
      font-size: 2rem;
      color: var(--champagne);
    }
    
    .logo span {
      font-size: 0.9rem;
      font-weight: 400;
      color: var(--muted-text);
      letter-spacing: 0.05em;
      margin-left: 0.25rem;
    }
    
    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
      list-style: none;
    }
    
    .nav-links a {
      font-weight: 500;
      color: var(--charcoal);
      position: relative;
      padding: 0.25rem 0;
      transition: color 0.2s;
    }
    
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--champagne);
      transition: width 0.25s ease;
    }
    
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    
    .menu-toggle {
      display: none;
      background: transparent;
      border: none;
      font-size: 1.8rem;
      color: var(--charcoal);
      cursor: pointer;
    }
    
    @media (max-width: 840px) {
      .menu-toggle {
        display: block;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--pure-white);
        flex-direction: column;
        gap: 1rem;
        padding: 1.5rem;
        box-shadow: 0 12px 24px rgba(0,0,0,0.05);
        border-top: 1px solid var(--light-border);
      }
      .nav-links.active {
        display: flex;
      }
    }
    
    /* Hero */
    #hero {
      background: linear-gradient(90deg, #1E1E24 0%, rgba(30,30,36,0.4) 70%, transparent 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 85vh;
      display: flex;
      align-items: center;
      color: white;
      position: relative;
      margin-top: 0;
    }
    
    .hero-content {
      max-width: 600px;
      padding: 2rem 0;
    }
    
    .hero-content h1 {
      color: var(--champagne);
      margin-bottom: 1.5rem;
    }
    
    .hero-sub {
      font-size: 1.25rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 2.25rem;
      line-height: 1.7;
    }
    
    .btn-primary {
      display: inline-block;
      background: var(--charcoal);
      color: var(--champagne);
      font-weight: 600;
      padding: 0.8rem 2.2rem;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: var(--transition-base);
      text-decoration: none;
      letter-spacing: 0.02em;
    }
    
    .btn-primary:hover {
      background: var(--hover-bg);
      color: var(--champagne);
      transform: translateY(-1px);
    }
    
    .btn-link {
      color: var(--champagne);
      font-weight: 500;
      border-bottom: 1px solid var(--champagne);
      padding-bottom: 2px;
      margin-left: 1.5rem;
      transition: var(--transition-base);
    }
    
    .btn-link:hover {
      color: #fff;
      border-color: #fff;
    }
    
    section {
      padding: 5rem 0;
    }
    
    /* value */
    .value-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    
    .value-text h2 {
      margin-bottom: 1.5rem;
    }
    
    .value-list {
      list-style: none;
      margin-top: 2rem;
    }
    
    .value-list li {
      display: flex;
      gap: 1rem;
      margin-bottom: 2rem;
      align-items: flex-start;
    }
    
    .value-icon {
      font-size: 2rem;
      color: var(--champagne);
      min-width: 2.5rem;
    }
    
    /* capabilities 层叠卡片 */
    .capabilities-wrapper {
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
      margin-top: 2.5rem;
    }
    
    .cap-card {
      background: var(--pure-white);
      border: 1px solid var(--light-border);
      border-radius: var(--radius-card);
      padding: 2rem;
      display: flex;
      gap: 2rem;
      align-items: center;
      box-shadow: var(--shadow-card);
      transition: transform 0.2s;
    }
    
    .cap-card:nth-child(even) {
      transform: translateX(-15px);
      z-index: 2;
      position: relative;
    }
    
    .cap-card img {
      width: 80px;
      height: 80px;
      object-fit: cover;
      border-radius: 8px;
    }
    
    /* scenarios 交替图文 */
    .scenario-block {
      display: flex;
      gap: 3rem;
      align-items: center;
      margin-bottom: 4rem;
    }
    
    .scenario-block.reverse {
      flex-direction: row-reverse;
    }
    
    .scenario-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
    }
    
    .scenario-text {
      flex: 1;
    }
    
    /* cases 时间轴 */
    .timeline {
      position: relative;
      padding-left: 2rem;
      border-left: 2px solid var(--champagne);
      margin-top: 2rem;
    }
    
    .timeline-item {
      margin-bottom: 2.5rem;
      position: relative;
    }
    
    .timeline-item::before {
      content: '';
      position: absolute;
      left: -2.45rem;
      top: 0.3rem;
      width: 12px;
      height: 12px;
      background: var(--champagne);
      border-radius: 50%;
    }
    
    .timeline-year {
      font-weight: 700;
      color: var(--champagne);
    }
    
    /* FAQ */
    .accordion-title {
      background: var(--warm-white);
      border: 1px solid var(--light-border);
      border-radius: 6px;
      padding: 1rem 1.5rem;
      font-weight: 500;
      cursor: pointer;
      transition: var(--transition-base);
      margin-bottom: 0.5rem;
    }
    
    .accordion-title:hover {
      background: var(--pure-white);
    }
    
    .accordion-title.active {
      background: var(--pure-white);
      border-left: 4px solid var(--champagne);
      color: var(--charcoal);
    }
    
    .accordion-content {
      padding: 0 1.5rem 1rem;
      color: var(--body-text);
    }
    
    /* 联系表单 */
    .contact-form input,
    .contact-form textarea {
      background: var(--pure-white);
      border: 1px solid #D1D0CB;
      border-radius: 4px;
      padding: 0.8rem;
      margin-bottom: 1rem;
      width: 100%;
    }
    
    .contact-form input:focus,
    .contact-form textarea:focus {
      border-color: var(--champagne);
      outline: none;
    }
    
    footer {
      background: var(--charcoal);
      color: #ddd;
      padding: 3rem 0 1.5rem;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    
    .footer-bottom {
      border-top: 1px solid var(--champagne);
      margin-top: 2rem;
      padding-top: 1.5rem;
      text-align: center;
      color: #aaa;
    }
    
    @media (max-width: 768px) {
      h1 { font-size: 2.5rem; }
      h2 { font-size: 1.9rem; }
      .value-grid, .scenario-block {
        grid-template-columns: 1fr;
        flex-direction: column;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .cap-card {
        flex-direction: column;
      }
    }