/* roulang page: index */
:root {
      --primary: #1B2A4A;
      --secondary: #F15A24;
      --accent: #C9A96E;
      --bg: #F7F5F2;
      --white: #FFFFFF;
      --text: #2E3B4E;
      --text-light: #5F6B7A;
      --border-light: #E2DFDA;
      --shadow-sm: 0 2px 12px rgba(27, 42, 74, 0.06);
      --shadow-md: 0 8px 24px rgba(27, 42, 74, 0.12);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      --transition: 0.2s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      background: var(--white);
      height: 72px;
      display: flex;
      align-items: center;
      z-index: 50;
      box-shadow: 0 1px 0 var(--border-light);
      transition: box-shadow 0.2s;
    }
    .header.scrolled {
      box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--primary);
      letter-spacing: 1px;
    }
    .logo span {
      color: var(--secondary);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text);
      padding: 0.25rem 0;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--secondary);
      border-bottom-color: var(--secondary);
    }
    .btn-primary {
      background: var(--secondary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      border: none;
      cursor: pointer;
      display: inline-block;
      transition: background 0.2s;
      white-space: nowrap;
      border: 2px solid var(--secondary);
    }
    .btn-primary:hover {
      background: #E14A1A;
      border-color: #E14A1A;
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
      transition: 0.2s;
      white-space: nowrap;
    }
    .btn-outline:hover {
      background: rgba(27,42,74,0.05);
    }
    .btn-text {
      color: var(--secondary);
      font-weight: 600;
      background: none;
      border: none;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .btn-text:hover {
      text-decoration: underline;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 26px;
      height: 3px;
      background: var(--primary);
      border-radius: 4px;
    }

    /* Hero */
    .hero {
      padding: 80px 0;
      background: var(--bg);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-content {
      flex: 1;
    }
    .hero-image {
      flex: 1;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    h1 {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 1.25rem;
      color: var(--text-light);
      margin-bottom: 32px;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      text-align: center;
      margin-bottom: 16px;
    }
    .section-desc {
      text-align: center;
      color: var(--text-light);
      max-width: 680px;
      margin: 0 auto 56px;
    }

    /* 服务卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--white);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: 0.25s ease;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(27,42,74,0.08);
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 28px;
    }
    .service-card h3 {
      font-size: 1.25rem;
      margin-bottom: 12px;
      font-weight: 700;
    }

    /* 优势数据 */
    .stats-band {
      background: var(--primary);
      padding: 64px 0;
      color: white;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 24px;
    }
    .stat-number {
      font-size: 42px;
      font-weight: 700;
      color: var(--secondary);
    }
    .stat-label {
      font-size: 0.95rem;
      color: rgba(255,255,255,0.8);
      margin-top: 8px;
    }

    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-img {
      aspect-ratio: 16/9;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-text {
      padding: 20px 24px;
    }

    /* 解决方案 */
    .solution-block {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }
    .solution-block.reverse {
      flex-direction: row-reverse;
    }
    .solution-text {
      flex: 1;
    }
    .solution-img {
      flex: 1;
      border-radius: 20px;
      overflow: hidden;
    }
    .solution-list {
      list-style: none;
      margin-top: 20px;
    }
    .solution-list li {
      margin-bottom: 10px;
      display: flex;
      align-items: baseline;
      gap: 8px;
    }
    .solution-list li::before {
      content: "●";
      color: var(--secondary);
      font-weight: bold;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      padding: 20px 16px;
      font-weight: 700;
      color: var(--primary);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: none;
      border: none;
      width: 100%;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.2s;
      background: #F9F8F6;
      padding: 0 16px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 16px;
    }

    /* CTA 尾屏 */
    .cta-dark {
      background: var(--primary);
      padding: 80px 0;
      text-align: center;
      color: white;
    }

    /* 表单 */
    .contact-form {
      max-width: 560px;
      margin: 0 auto;
    }
    .form-input {
      width: 100%;
      padding: 14px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      margin-bottom: 16px;
      font-size: 1rem;
      background: white;
    }
    .form-input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(27,42,74,0.1);
    }

    /* 页脚 */
    .footer {
      background: #101C2E;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer a {
      color: #CBD5E1;
    }
    .footer a:hover {
      color: white;
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 0.9rem;
    }

    @media (max-width: 1024px) {
      .cards-grid, .case-grid { grid-template-columns: repeat(2, 1fr); }
      .stats-grid { grid-template-columns: repeat(2, 1fr); }
      .hero-grid { flex-direction: column; }
      h1 { font-size: 40px; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .cards-grid, .case-grid, .stats-grid { grid-template-columns: 1fr; }
      .solution-block, .solution-block.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      h1 { font-size: 32px; }
      .section-title { font-size: 28px; }
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: var(--bg);
      flex-direction: column;
      padding: 32px;
      gap: 24px;
      z-index: 40;
      box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    }
    .mobile-menu.active { display: flex; }