/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-light: #2B7A9C;
      --primary-dark: #0F455A;
      --accent: #F0A500;
      --accent-hover: #E09500;
      --bg: #F8FAFC;
      --surface: #FFFFFF;
      --text: #1E293B;
      --text-secondary: #64748B;
      --border: #E2E8F0;
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 16px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04), 0 1px 3px rgba(0,0,0,0.03);
      --shadow-hover: 0 12px 32px rgba(26,95,122,0.08);
      --transition: all 0.25s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
      --font-number: "Inter", "Segoe UI", system-ui, sans-serif;
      --container: 1200px;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-sans);
      background: var(--bg);
      color: var(--text);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    a { text-decoration: none; color: inherit; }
    img { max-width: 100%; height: auto; display: block; }
    button, .btn { cursor: pointer; font-family: inherit; }
    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border);
      height: 72px;
      display: flex;
      align-items: center;
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 1.7rem;
      font-weight: 700;
      letter-spacing: 0.5px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
      white-space: nowrap;
    }
    .logo i { color: var(--accent); font-size: 1.8rem; }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
      color: var(--text);
    }
    .nav-links a {
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--accent);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--text);
      border-radius: 2px;
      transition: var(--transition);
    }
    /* 按钮 */
    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      border-radius: var(--radius-sm);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      gap: 8px;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      box-shadow: 0 10px 22px rgba(240,165,0,0.28);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-sm);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 16px;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
      transform: translateY(-2px);
    }
    /* 区块 */
    section {
      padding: 90px 0;
    }
    .section-title {
      font-size: 2.3rem;
      font-weight: 650;
      letter-spacing: -0.3px;
      margin-bottom: 16px;
      color: var(--text);
    }
    .section-sub {
      font-size: 1.1rem;
      color: var(--text-secondary);
      margin-bottom: 56px;
      max-width: 680px;
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #F8FAFC 0%, #E2E8F0 100%);
      min-height: 85vh;
      display: flex;
      align-items: center;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .hero-content h1 {
      font-size: 3.1rem;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--text);
      margin-bottom: 20px;
    }
    .hero-content .highlight {
      color: var(--primary);
      border-bottom: 4px solid var(--accent);
    }
    .hero-desc {
      font-size: 1.15rem;
      color: var(--text-secondary);
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: var(--radius-lg);
      min-height: 360px;
      box-shadow: var(--shadow-card);
    }
    /* 卡片网格 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .card {
      background: var(--surface);
      border-radius: var(--radius);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      border: 1px solid transparent;
    }
    .card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--border);
    }
    .card-icon {
      width: 56px;
      height: 56px;
      background: rgba(26,95,122,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 1.7rem;
    }
    .card h3 {
      font-size: 1.4rem;
      font-weight: 650;
      margin-bottom: 12px;
    }
    .card p {
      color: var(--text-secondary);
      font-size: 0.95rem;
    }
    /* 优势数据 */
    .stats-row {
      display: flex;
      gap: 48px;
      justify-content: center;
      flex-wrap: wrap;
      text-align: center;
    }
    .stat-item h4 {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary);
      font-family: var(--font-number);
    }
    .stat-item span {
      display: block;
      color: var(--text-secondary);
      font-weight: 500;
    }
    /* 案例卡片 */
    .case-card {
      background: var(--surface);
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid var(--border);
      transition: var(--transition);
    }
    .case-card:hover {
      border-color: var(--primary);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .case-body {
      padding: 24px;
    }
    .case-stat {
      font-size: 2rem;
      font-weight: 700;
      color: var(--primary);
    }
    /* 证言 */
    .testimonial-card {
      background: #F1F5F9;
      border-radius: var(--radius);
      padding: 32px;
      font-style: italic;
    }
    .testimonial-user {
      display: flex;
      align-items: center;
      gap: 14px;
      margin-top: 20px;
    }
    .avatar {
      width: 48px;
      height: 48px;
      background: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      padding: 20px 0;
      font-weight: 650;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding-bottom: 20px;
    }
    /* CTA 区块 */
    .cta-section {
      background: var(--primary);
      color: white;
      text-align: center;
      border-radius: 0;
    }
    .cta-section h5 {
      font-size: 2.2rem;
      font-weight: 700;
    }
    .footer {
      background: #0F172A;
      color: #CBD5E1;
      padding: 60px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 36px;
    }
    .footer a { color: #CBD5E1; transition: color 0.2s; }
    .footer a:hover { color: white; }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .hero-image { min-height: 280px; }
      .cards-grid { grid-template-columns: repeat(2,1fr); }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-content h1 { font-size: 2.3rem; }
      .section-title { font-size: 1.9rem; }
      .cards-grid { grid-template-columns: 1fr; }
      .stats-row { gap: 32px; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-image { min-height: 240px; }
    }