/* roulang page: index */
:root {
      --primary: #E6392C;
      --primary-dark: #C1121F;
      --secondary: #1D1D1F;
      --accent: #F4A261;
      --light-bg: #F8F9FA;
      --text-main: #1D1D1F;
      --text-muted: #5A5A5E;
      --border-light: #E5E7EB;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 24px rgba(0,0,0,0.08);
      --transition: all 0.25s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: #ffffff;
      color: var(--text-main);
      line-height: 1.75;
      margin: 0;
      padding: 0;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding-left: 16px;
        padding-right: 16px;
      }
      body {
        font-size: 15px;
      }
      h1 {
        font-size: 2.4rem !important;
      }
      h2 {
        font-size: 1.9rem !important;
      }
      h3 {
        font-size: 1.4rem !important;
      }
    }

    /* 导航栏 */
    .top-bar {
      background-color: #0f0f10;
      color: #cccccc;
      font-size: 0.85rem;
      height: 38px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .main-nav {
      background-color: rgba(255,255,255,0.96);
      backdrop-filter: blur(6px);
      position: sticky;
      top: 0;
      z-index: 50;
      border-bottom: 1px solid var(--border-light);
      transition: var(--transition);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 68px;
    }
    .logo-text {
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: var(--primary);
      display: flex;
      align-items: baseline;
    }
    .logo-text span {
      font-weight: 600;
      font-size: 0.9rem;
      margin-left: 4px;
      color: var(--secondary);
    }
    .nav-links a {
      margin-left: 2rem;
      font-weight: 500;
      color: var(--secondary);
      position: relative;
      padding-bottom: 6px;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .hamburger-btn {
      display: none;
      font-size: 1.6rem;
      background: none;
      border: none;
      color: var(--secondary);
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 68px;
        left: 0;
        width: 100%;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(12px);
        flex-direction: column;
        padding: 1.5rem 1rem;
        box-shadow: var(--shadow-md);
        border-bottom: 1px solid var(--border-light);
      }
      .nav-links.open {
        display: flex;
      }
      .nav-links a {
        margin: 0.8rem 0;
        font-size: 1.1rem;
      }
      .hamburger-btn {
        display: block;
      }
      .main-nav .container {
        padding-left: 16px;
        padding-right: 16px;
      }
    }

    /* 按钮 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.7rem 1.8rem;
      font-weight: 600;
      display: inline-block;
      transition: var(--transition);
      border: none;
      box-shadow: 0 4px 10px rgba(230,57,44,0.25);
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: scale(1.02);
      box-shadow: 0 8px 18px rgba(193,18,31,0.3);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      border-radius: var(--radius-btn);
      padding: 0.7rem 1.8rem;
      font-weight: 600;
      display: inline-block;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background-color: rgba(230,57,44,0.06);
      border-color: var(--primary-dark);
      color: var(--primary-dark);
    }

    /* 卡片与区块 */
    .section-padding {
      padding: 5rem 0;
    }
    .card {
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .highlight-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }
    .accent-badge {
      background-color: var(--accent);
      color: #1D1D1F;
      padding: 0.2rem 0.9rem;
      border-radius: 20px;
      font-weight: 600;
      font-size: 0.8rem;
      display: inline-block;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
    }
    .faq-question {
      font-weight: 700;
      font-size: 1.2rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-muted);
      line-height: 1.8;
      margin-top: 0;
    }
    .faq-answer.open {
      max-height: 300px;
      margin-top: 0.8rem;
    }
    .comparison-col.highlight {
      background-color: #fff5f4;
      border-left: 4px solid var(--primary);
    }
    footer {
      background-color: #0f0f10;
      color: #e0e0e0;
      padding: 4rem 0 1.5rem;
    }
    footer a:hover {
      color: var(--primary);
    }