/* roulang page: index */
:root {
      --primary: #C8102E;
      --primary-dark: #A00D24;
      --secondary: #1A1A1A;
      --accent: #F5A623;
      --bg: #FAFAFA;
      --card-bg: #FFFFFF;
      --text-main: #1A1A1A;
      --text-muted: #5A5A5A;
      --border-light: #E5E5E5;
      --shadow-card: 0 10px 25px -8px rgba(0,0,0,0.04), 0 4px 10px -6px rgba(0,0,0,0.02);
      --shadow-hover: 0 20px 35px -12px rgba(0,0,0,0.08), 0 8px 16px -8px rgba(0,0,0,0.04);
      --radius-card: 20px;
      --radius-btn: 50px;
      --radius-badge: 40px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --transition: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      font-size: 16px;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.02);
      z-index: 50;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
      transition: var(--transition);
    }

    .logo {
      font-weight: 700;
      font-size: 1.6rem;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
      text-decoration: none;
    }
    .logo i {
      font-size: 1.8rem;
      color: var(--secondary);
    }

    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-main);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--primary);
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 10px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      letter-spacing: 0.5px;
      transition: var(--transition);
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      text-decoration: none;
      box-shadow: 0 8px 18px -6px rgba(200,16,46,0.4);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 14px 24px -8px rgba(160,13,36,0.5);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 10px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition);
      text-decoration: none;
    }
    .btn-outline:hover {
      background: rgba(200,16,46,0.08);
      border-color: var(--primary-dark);
      color: var(--primary-dark);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 25px;
      height: 3px;
      background: var(--secondary);
      border-radius: 3px;
      transition: var(--transition);
    }

    /* Hero */
    .hero-section {
      padding: 140px 0 100px;
      background: linear-gradient(135deg, #C8102E 0%, #1A1A1A 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1 1 400px;
      color: white;
    }
    .hero-text h1 {
      font-size: 3.4rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }
    .hero-text p {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 2.5rem;
    }
    .hero-image {
      flex: 1 1 380px;
      display: flex;
      justify-content: center;
    }
    .hero-image img {
      max-height: 520px;
      filter: drop-shadow(0 30px 35px rgba(0,0,0,0.4));
    }

    section {
      padding: 90px 0;
    }

    h2 {
      font-size: 2.4rem;
      font-weight: 700;
      margin-bottom: 1rem;
      color: var(--secondary);
    }
    .section-sub {
      color: var(--text-muted);
      font-size: 1.1rem;
      margin-bottom: 3rem;
    }

    .card-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 28px;
    }

    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      text-align: center;
    }
    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-hover);
    }

    .badge-accent {
      background: var(--accent);
      color: #1A1A1A;
      font-weight: 700;
      padding: 6px 18px;
      border-radius: var(--radius-badge);
      display: inline-block;
      font-size: 0.9rem;
      margin-top: 15px;
    }

    .testimonial-card {
      background: var(--card-bg);
      border-radius: 18px;
      padding: 30px;
      display: flex;
      gap: 20px;
      align-items: flex-start;
      box-shadow: var(--shadow-card);
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    footer {
      background: #1A1A1A;
      color: #ccc;
      padding: 70px 0 20px;
    }

    @media (max-width: 768px) {
      .navbar {
        padding: 0 20px;
      }
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(20,20,20,0.95);
        flex-direction: column;
        padding: 30px;
        gap: 1.8rem;
        backdrop-filter: blur(20px);
      }
      .nav-links.active {
        display: flex;
      }
      .nav-links a {
        color: white;
        font-size: 1.2rem;
      }
      .hamburger {
        display: flex;
      }
      .hero-text h1 {
        font-size: 2.4rem;
      }
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .testimonial-card {
        flex-direction: column;
      }
    }