/* roulang page: index */
/* ----- 设计变量 ----- */
    :root {
      --primary: #0A1F3F;
      --primary-light: #15315A;
      --accent: #FF6B2B;
      --accent-hover: #E55A1F;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-main: #0A1F3F;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --shadow-sm: 0px 4px 20px rgba(10,31,63,0.06);
      --shadow-md: 0px 8px 30px rgba(10,31,63,0.10);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-input: 8px;
      --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
      --transition: 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

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

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      border-radius: var(--radius-btn);
      transition: background 0.2s, color 0.2s, box-shadow 0.2s, transform 0.2s;
      cursor: pointer;
      border: none;
      font-size: 16px;
      padding: 14px 32px;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.02);
      box-shadow: 0 8px 18px rgba(255,107,43,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
    }
    .btn-white-outline {
      background: transparent;
      border: 2px solid white;
      color: white;
    }
    .btn-white-outline:hover {
      background: white;
      color: var(--primary);
    }
    .btn:focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      height: 72px;
      border-bottom: 1px solid var(--border-light);
      z-index: 50;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      letter-spacing: -0.3px;
    }
    .logo span {
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-body);
      font-size: 16px;
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width 0.2s;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .menu-toggle {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }
    .menu-toggle span {
      width: 25px;
      height: 2.5px;
      background: var(--primary);
      border-radius: 4px;
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
    }

    /* 区块通用 */
    section {
      padding: 120px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 16px;
    }
    .section-sub {
      font-size: 18px;
      color: var(--text-muted);
      max-width: 700px;
      margin-bottom: 48px;
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0A1F3F 0%, #15315A 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      color: white;
    }
    .hero::before {
      content: "";
      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: 0.25;
      mix-blend-mode: overlay;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 48px;
      flex-wrap: wrap;
    }
    .hero-text {
      flex: 1 1 500px;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.15;
      margin-bottom: 24px;
    }
    .hero p {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 32px;
      max-width: 550px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 0 0 360px;
      background: rgba(255,255,255,0.05);
      border-radius: 32px;
      padding: 24px;
      backdrop-filter: blur(8px);
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-visual img {
      border-radius: 24px;
      opacity: 0.9;
    }

    /* 优势 - 不对称列表 */
    .advantages-list {
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .adv-item {
      display: flex;
      gap: 40px;
      align-items: flex-start;
      padding-bottom: 28px;
      border-bottom: 1px solid var(--border-light);
    }
    .adv-icon {
      font-size: 36px;
      color: var(--accent);
      flex-shrink: 0;
    }
    .adv-text h3 {
      font-size: 24px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 8px;
    }

    /* 服务网格 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    .service-card {
      background: var(--card-bg);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: 0.25s;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .service-icon {
      font-size: 32px;
      color: var(--accent);
      margin-bottom: 20px;
    }

    /* 场景交替 */
    .scenario-row {
      display: flex;
      gap: 60px;
      align-items: center;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .scenario-text {
      flex: 1;
    }

    /* 案例横向滚动 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scroll-snap-type: x mandatory;
    }
    .case-card {
      min-width: 260px;
      background: #F1F5F9;
      border-radius: 20px;
      padding: 24px;
      scroll-snap-align: start;
    }
    .case-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--accent);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-body);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }

    /* CTA */
    .cta-section {
      background: var(--primary);
      color: white;
      text-align: center;
    }

    /* 页脚 */
    .footer {
      background: var(--primary);
      color: rgba(255,255,255,0.8);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .hero h1 { font-size: 40px; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .menu-toggle { display: flex; }
      .mobile-menu.active { display: flex; }
      section { padding: 80px 0; }
      .hero { min-height: auto; padding: 120px 0 80px; }
      .hero-content { flex-direction: column; }
      .scenario-row, .scenario-row.reverse { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
    }