/* roulang page: index */
:root {
      --primary-red: #E12B1F;
      --dark-bg: #1A1A2E;
      --gold-accent: #FFB800;
      --text-dark: #333333;
      --text-gray: #6B7280;
      --bg-light: #F8F9FA;
      --card-bg: #FFFFFF;
      --border-light: #E5E7EB;
      --shadow-sm: 0 8px 24px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.1);
      --radius-lg: 16px;
      --radius-btn: 40px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.7;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }
    a, button, input {
      font-family: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: white;
      box-shadow: 0 4px 12px rgba(0,0,0,0.03);
      z-index: 1000;
      padding: 0 20px;
      height: 72px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo-text {
      font-size: 1.5rem;
      font-weight: 800;
      color: var(--primary-red);
      letter-spacing: 1px;
      white-space: nowrap;
      text-decoration: none;
    }
    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--text-dark);
      font-weight: 500;
      font-size: 1rem;
      transition: color 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover {
      color: var(--primary-red);
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--text-dark);
      cursor: pointer;
      padding: 6px;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: var(--dark-bg);
      flex-direction: column;
      padding: 2rem 1.5rem;
      gap: 1.8rem;
      z-index: 999;
    }
    .mobile-menu a {
      color: white;
      font-size: 1.3rem;
      font-weight: 600;
      text-decoration: none;
      border-bottom: 1px solid rgba(255,255,255,0.15);
      padding-bottom: 0.8rem;
    }
    /* Hero */
    .hero-section {
      background: linear-gradient(135deg, #1A1A2E 0%, #0F0F1A 100%);
      padding: 140px 0 90px;
      margin-top: 72px;
      position: relative;
      overflow: hidden;
      text-align: center;
    }
    .hero-bg-pattern {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.2;
      pointer-events: none;
    }
    .hero-content {
      position: relative;
      z-index: 2;
    }
    .hero-title {
      font-size: 3.8rem;
      font-weight: 800;
      color: white;
      line-height: 1.2;
      margin-bottom: 1.2rem;
      letter-spacing: 2px;
    }
    .hero-sub {
      font-size: 1.4rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 2.5rem;
    }
    .badge-row {
      display: flex;
      justify-content: center;
      gap: 2rem;
      flex-wrap: wrap;
      margin-bottom: 3rem;
    }
    .data-badge {
      background: rgba(225,43,31,0.2);
      backdrop-filter: blur(4px);
      border-radius: 20px;
      padding: 1.2rem 2rem;
      color: var(--gold-accent);
      font-weight: 700;
      font-size: 2.2rem;
      font-family: 'DIN Alternate', 'Helvetica Neue', sans-serif;
      box-shadow: 0 8px 18px rgba(225,43,31,0.3);
      min-width: 130px;
    }
    .btn-primary {
      display: inline-block;
      background: var(--primary-red);
      color: white;
      font-weight: 700;
      padding: 0.9rem 2.8rem;
      border-radius: var(--radius-btn);
      text-decoration: none;
      transition: 0.3s ease;
      border: none;
      cursor: pointer;
      font-size: 1.1rem;
    }
    .btn-primary:hover {
      background: #C11712;
      transform: translateY(-2px);
      box-shadow: 0 10px 20px rgba(225,43,31,0.4);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-red);
      color: var(--primary-red);
      font-weight: 700;
      padding: 0.8rem 2.5rem;
      border-radius: var(--radius-btn);
      transition: 0.3s;
      text-decoration: none;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(225,43,31,0.08);
    }
    /* 功能卡片 2x2 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 2rem;
      margin: 5rem 0 4rem;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: 2rem;
      box-shadow: var(--shadow-sm);
      display: flex;
      gap: 1.5rem;
      align-items: flex-start;
      border: 1px solid var(--border-light);
      transition: all 0.25s ease;
    }
    .feature-card:hover {
      border-color: var(--primary-red);
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .feature-icon {
      width: 60px;
      height: 60px;
      background: #FFF0F0;
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 2rem;
      color: var(--primary-red);
    }
    .feature-text h3 {
      font-weight: 700;
      font-size: 1.4rem;
      margin-bottom: 0.5rem;
    }
    /* 数据优势区 */
    .stats-section {
      background: var(--dark-bg);
      border-radius: 32px;
      padding: 4rem 2rem;
      margin: 5rem 0;
      color: white;
      display: flex;
      flex-wrap: wrap;
      gap: 2rem;
      align-items: center;
      justify-content: space-between;
    }
    .big-number {
      font-size: 3.5rem;
      font-weight: 800;
      color: var(--gold-accent);
      font-family: 'DIN Alternate', sans-serif;
    }
    .chart-placeholder {
      background: rgba(255,255,255,0.1);
      border-radius: 20px;
      padding: 2rem;
      width: 280px;
      height: 180px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.2rem;
      color: #ccc;
    }
    /* 时间线 */
    .timeline {
      display: flex;
      justify-content: space-between;
      gap: 1rem;
      margin: 4rem 0;
      flex-wrap: wrap;
    }
    .timeline-step {
      flex: 1;
      min-width: 140px;
      background: white;
      border-radius: 20px;
      padding: 1.8rem 1rem;
      text-align: center;
      box-shadow: var(--shadow-sm);
      border-top: 5px solid var(--primary-red);
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 1rem;
    }
    .faq-question {
      background: white;
      padding: 1.4rem 1rem;
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 0.8rem;
      cursor: pointer;
      border-radius: 12px;
      transition: background 0.2s;
    }
    .faq-question.active {
      background: #FFF5F5;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      padding: 0 1rem 0 2.5rem;
      color: #4B5563;
    }
    .faq-answer.open {
      max-height: 200px;
      padding-bottom: 1.2rem;
    }
    .q-mark {
      color: var(--primary-red);
      font-weight: 800;
      font-size: 1.4rem;
    }
    /* CTA */
    .cta-block {
      background: var(--dark-bg);
      border-radius: 28px;
      padding: 4rem 2rem;
      text-align: center;
      color: white;
      margin: 5rem 0 3rem;
    }
    /* Footer */
    .site-footer {
      background: #0F0F1A;
      color: #9CA3AF;
      padding: 3rem 2rem;
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 2rem;
      font-size: 0.95rem;
    }
    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-links {
        display: none;
      }
      .hero-title {
        font-size: 2.4rem;
      }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .badge-row {
        flex-direction: column;
        align-items: center;
      }
      .stats-section {
        flex-direction: column;
      }
      .timeline {
        flex-direction: column;
      }
      .site-footer {
        grid-template-columns: 1fr;
        text-align: center;
      }
    }