/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #E8452D;
      --primary-hover: #C0392B;
      --secondary: #2E2E2E;
      --accent: #00D2A0;
      --bg-dark: #1A1A1A;
      --bg-warm: #F5F4EF;
      --text-white: #FFFFFF;
      --text-light: #C2C2C2;
      --text-gray: #9A9A9A;
      --border-light: rgba(255,255,255,0.08);
      --shadow-card: 0 8px 30px rgba(0,0,0,0.45), 0 2px 6px rgba(0,0,0,0.5);
      --shadow-button: 0 4px 14px rgba(232,69,45,0.4);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --transition-default: 0.3s ease;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    html {
      scroll-behavior: smooth;
      background-color: var(--bg-dark);
    }
    
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-dark);
      color: var(--text-light);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-default);
    }
    
    button, input, textarea {
      font-family: inherit;
    }
    
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    
    /* 导航栏自定义 */
    .navbar-blur {
      background: rgba(26,26,26,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.06);
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      transition: background 0.3s;
    }
    
    .nav-link {
      color: var(--text-light);
      font-size: 0.95rem;
      font-weight: 500;
      padding: 0.5rem 0;
      position: relative;
      transition: color 0.2s;
    }
    
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease, left 0.25s ease;
    }
    
    .nav-link:hover {
      color: var(--primary);
    }
    
    .nav-link:hover::after {
      width: 100%;
      left: 0;
    }
    
    /* 按钮样式 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      font-weight: 600;
      padding: 0.85rem 2.2rem;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s ease;
      box-shadow: 0 4px 12px rgba(232,69,45,0.35);
      border: none;
      cursor: pointer;
      letter-spacing: 0.5px;
    }
    
    .btn-primary:hover {
      background-color: var(--primary-hover);
      box-shadow: 0 6px 20px rgba(232,69,45,0.55);
      transform: translateY(-1px);
    }
    
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 0.85rem 2.2rem;
      border-radius: var(--radius-btn);
      transition: all 0.25s ease;
      cursor: pointer;
      letter-spacing: 0.5px;
    }
    
    .btn-outline:hover {
      background-color: var(--primary);
      color: white;
    }
    
    /* 卡片悬停效果 */
    .card-hover {
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    
    .card-hover:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 35px rgba(0,0,0,0.6);
    }
    
    .card-hover:hover .card-img {
      transform: scale(1.03);
    }
    
    .card-img {
      transition: transform 0.4s ease;
    }
    
    /* FAQ动画 */
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), padding 0.3s;
    }
    
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding-top: 12px;
    }
    
    .faq-item.active .faq-question {
      color: var(--primary);
    }
    
    .faq-icon {
      transition: transform 0.3s ease;
      color: var(--accent);
    }
    
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    
    /* 表单焦点 */
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(232,69,45,0.3);
    }
    
    /* 移动端菜单 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 70px;
      left: 0;
      width: 100%;
      background: rgba(26,26,26,0.98);
      backdrop-filter: blur(20px);
      flex-direction: column;
      align-items: center;
      padding: 2rem 0;
      z-index: 40;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    
    .mobile-menu.active {
      display: flex;
    }
    
    /* 渐变遮罩 Hero */
    .hero-overlay {
      background: linear-gradient(to right, rgba(26,26,26,0.9) 0%, rgba(26,26,26,0.5) 60%, rgba(26,26,26,0.2) 100%);
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      z-index: 2;
    }
    
    @media (max-width: 768px) {
      .container-custom {
        padding-left: 16px;
        padding-right: 16px;
      }
      .hero-overlay {
        background: linear-gradient(to bottom, rgba(26,26,26,0.2) 0%, rgba(26,26,26,0.8) 70%);
      }
    }