/* roulang page: index */
:root {
      --primary: #E63946;
      --primary-light: #FF6B6B;
      --secondary-bg: #1D1D2C;
      --card-bg: #F1FAEE;
      --accent: #00B4D8;
      --text-dark: #1D1D2C;
      --text-soft: #4a4a5a;
      --text-light: #7c7c8a;
      --border-light: rgba(29,29,44,0.08);
      --shadow-card: 0 4px 20px rgba(29,29,44,0.08);
      --shadow-hover: 0 12px 32px rgba(230,57,70,0.15);
      --radius-card: 12px;
      --radius-btn: 8px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: 'Noto Sans SC', 'Inter', system-ui, -apple-system, sans-serif;
      background-color: var(--secondary-bg);
      color: #2a2a35;
      line-height: 1.75;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .font-inter {
      font-family: 'Inter', system-ui, sans-serif;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s ease;
      padding: 1rem 0;
    }
    .navbar.scrolled {
      background: rgba(29,29,44,0.92);
      backdrop-filter: blur(16px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    }
    .logo-text {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .logo-dot {
      display: inline-block;
      width: 8px;
      height: 8px;
      background: var(--accent);
      border-radius: 50%;
      margin-left: 2px;
      box-shadow: 0 0 8px var(--accent);
    }
    .nav-link {
      font-weight: 500;
      color: #e0e0e0;
      transition: color 0.2s;
      padding: 0.5rem 0.8rem;
      font-size: 0.95rem;
      position: relative;
      white-space: nowrap;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0.8rem;
      right: 0.8rem;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }
    .btn-primary {
      background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
      color: white;
      font-weight: 700;
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-btn);
      transition: all 0.2s ease;
      box-shadow: 0 4px 12px rgba(230,57,70,0.3);
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 20px rgba(230,57,70,0.45);
      background: linear-gradient(135deg, #d62839 0%, #ff5a5a 100%);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 700;
      padding: 0.6rem 1.8rem;
      border-radius: var(--radius-btn);
      transition: all 0.2s;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(230,57,70,0.08);
      border-color: #ff5a5a;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 2.5rem;
      display: flex;
      align-items: center;
      gap: 1rem;
      color: var(--text-dark);
    }
    .section-title::before {
      content: '';
      display: inline-block;
      width: 4px;
      height: 32px;
      background: var(--primary);
      border-radius: 4px;
      flex-shrink: 0;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 1.8rem;
      box-shadow: var(--shadow-card);
      transition: box-shadow 0.25s ease, transform 0.2s;
      height: 100%;
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    @media (max-width: 768px) {
      .section-title {
        font-size: 1.8rem;
      }
      .container {
        padding-left: 1rem;
        padding-right: 1rem;
      }
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: white;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .hamburger {
        display: block;
      }
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 70%;
      max-width: 280px;
      height: 100vh;
      background: #1D1D2C;
      backdrop-filter: blur(20px);
      padding: 2rem;
      transition: right 0.3s ease;
      z-index: 100;
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      color: #ddd;
      font-size: 1.3rem;
      font-weight: 500;
      padding-left: 0.5rem;
      border-left: 4px solid transparent;
    }
    .mobile-menu a:hover, .mobile-menu a.active {
      color: var(--primary);
      border-left-color: var(--primary);
    }