/* roulang page: index */
:root {
      --primary-burgundy: #7A0D2C;
      --primary-deep: #5E0A22;
      --secondary-steel: #2C3E50;
      --accent-gold: #C9A96E;
      --bg-warm: #F9F7F4;
      --card-bg: #FFFFFF;
      --text-dark: #1A1A1A;
      --text-muted: #5F6B7A;
      --border-light: rgba(0,0,0,0.05);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 32px rgba(122,13,44,0.08);
      --radius-md: 12px;
      --radius-btn: 8px;
      --transition: 0.25s ease;
      --font-heading: 'Noto Sans SC', 'Inter', system-ui, sans-serif;
      --font-body: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --font-mono: 'Inter', 'DIN Alternate', monospace;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--bg-warm);
      color: var(--text-dark);
      line-height: 1.7;
      margin: 0;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4 {
      font-family: var(--font-heading);
      letter-spacing: -0.02em;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 2rem;
      padding-right: 2rem;
    }
    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: transparent;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      padding: 1rem 0;
    }
    .navbar.scrolled {
      background: rgba(249,247,244,0.92);
      backdrop-filter: blur(8px);
      box-shadow: 0 1px 8px rgba(0,0,0,0.05);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }
    .logo-text {
      font-family: var(--font-heading);
      font-weight: 800;
      font-size: 1.75rem;
      color: var(--primary-burgundy);
      line-height: 1.2;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .logo-sub {
      font-size: 0.8rem;
      font-weight: 500;
      color: var(--secondary-steel);
      display: block;
      letter-spacing: 0.02em;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--secondary-steel);
      text-decoration: none;
      position: relative;
      padding: 0.25rem 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--primary-burgundy);
      transition: width 0.25s ease, left 0.25s ease;
    }
    .nav-links a:hover {
      color: var(--primary-burgundy);
    }
    .nav-links a:hover::after {
      width: 100%;
      left: 0;
    }
    .btn-primary {
      background: var(--primary-burgundy);
      color: white;
      font-weight: 600;
      padding: 0.75rem 1.8rem;
      border-radius: var(--radius-btn);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      transition: background 0.2s, transform 0.1s;
      border: none;
      cursor: pointer;
      font-family: var(--font-body);
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      box-shadow: inset 0 1px 4px rgba(0,0,0,0.2);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--secondary-steel);
      color: var(--secondary-steel);
      font-weight: 600;
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-btn);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 0.4rem;
      transition: all 0.2s;
    }
    .btn-outline:hover {
      background: rgba(44,62,80,0.08);
    }
    .btn-gold {
      background: var(--primary-burgundy);
      color: white;
      border: 2px solid var(--accent-gold);
      font-weight: 700;
      padding: 0.9rem 2.5rem;
      border-radius: var(--radius-btn);
      transition: all 0.25s;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
    }
    .btn-gold:hover {
      transform: scale(1.03);
      background: var(--primary-deep);
      border-color: #b48b4b;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--text-dark);
    }
    .section-spacing {
      margin-top: 6rem;
      margin-bottom: 6rem;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-light);
      transition: var(--transition);
      height: 100%;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-color: rgba(122,13,44,0.2);
    }
    /* 移动菜单 */
    .mobile-menu {
      display: none;
      flex-direction: column;
      background: white;
      position: absolute;
      top: 70px;
      left: 0;
      width: 100%;
      box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      padding: 1.5rem 2rem;
      gap: 1.2rem;
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: var(--secondary-steel);
      background: none;
      border: none;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .container {
        padding-left: 1.5rem;
        padding-right: 1.5rem;
      }
      .section-spacing {
        margin-top: 4rem;
        margin-bottom: 4rem;
      }
      .section-title {
        font-size: 2rem;
      }
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .mobile-menu.active {
        display: flex;
      }
    }
    @media (max-width: 640px) {
      .section-spacing {
        margin-top: 2.5rem;
        margin-bottom: 2.5rem;
      }
    }
    .fade-up {
      animation: fadeUp 0.6s ease-out forwards;
    }
    @keyframes fadeUp {
      from { opacity: 0; transform: translateY(20px); }
      to { opacity: 1; transform: translateY(0); }
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
    }
    .faq-item.open .faq-answer {
      max-height: 150px;
    }
    .faq-icon {
      transition: transform 0.3s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(180deg);
    }