/* roulang page: index */
:root {
      --primary: #0A2E4D;
      --secondary: #E85D04;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --border: #E2E8F0;
      --text-main: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --white: #FFFFFF;
      --footer-bg: #0A2E4D;
      --footer-dark: #051D33;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-pill: 50px;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 24px rgba(0,0,0,0.08);
      --transition: 0.25s ease;
      --container: 1200px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "Roboto", sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: var(--transition);
      border: none;
      outline: none;
    }
    h1, h2, h3, h4 {
      color: var(--text-main);
    }
    h1 {
      font-size: 3rem;
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    h2 {
      font-size: 2.25rem;
      font-weight: 600;
      margin-bottom: 1rem;
      position: relative;
      display: inline-block;
    }
    .section-title {
      text-align: center;
      margin-bottom: 3rem;
    }
    .section-title h2::after {
      content: '';
      display: block;
      width: 60px;
      height: 4px;
      background: var(--secondary);
      margin: 12px auto 0;
      border-radius: 2px;
    }
    .bg-light {
      background-color: #F1F5F9;
    }
    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--white);
      border-bottom: 1px solid rgba(0,0,0,0.05);
      height: 72px;
      display: flex;
      align-items: center;
    }
    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 1.7rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--secondary);
    }
    .nav-links {
      display: flex;
      gap: 2.5rem;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-body);
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 3px;
      background: var(--primary);
      border-radius: 2px;
    }
    .btn-primary {
      background: var(--secondary);
      color: white;
      border-radius: var(--radius-pill);
      padding: 10px 28px;
      font-weight: 600;
      box-shadow: 0 8px 16px rgba(232,93,4,0.25);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: #C94D00;
      box-shadow: 0 12px 20px rgba(232,93,4,0.35);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-pill);
      padding: 10px 28px;
      font-weight: 600;
    }
    .btn-outline:hover {
      background: #E8F0F8;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: var(--primary);
      border-radius: 2px;
      transition: 0.3s;
    }
    /* hero */
    .hero {
      padding: 80px 0 100px;
      background: linear-gradient(180deg, #FFFFFF 0%, #F8FAFC 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-text h1 {
      margin-bottom: 1.5rem;
      line-height: 1.3;
    }
    .hero-text p {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 2rem;
      max-width: 90%;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .hero-image {
      background-image: url('/assets/images/coverpic/hero-app.webp');
      background-size: contain;
      background-repeat: no-repeat;
      background-position: center;
      min-height: 380px;
      position: relative;
    }
    .hero-image::before {
      content: '';
      position: absolute;
      width: 300px;
      height: 300px;
      background: rgba(10,46,77,0.04);
      border-radius: 50%;
      top: 20%;
      left: 10%;
      z-index: 0;
    }
    /* 卡片系统 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border);
      transition: var(--transition);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .icon-placeholder {
      width: 64px;
      height: 64px;
      background: #E8F0F8;
      border-radius: 16px;
      margin-bottom: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 32px;
    }
    .card h3 {
      font-size: 1.25rem;
      margin-bottom: 0.75rem;
    }
    /* 数据面板 */
    .stats-panel {
      background: #F1F5F9;
      padding: 70px 0;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 2rem;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--text-muted);
      margin-top: 8px;
    }
    /* 服务矩阵 2x3 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .service-card {
      display: flex;
      background: white;
      border-radius: var(--radius-card);
      padding: 24px;
      border: 1px solid var(--border);
      align-items: center;
      gap: 24px;
      transition: var(--transition);
    }
    .service-card:hover {
      box-shadow: var(--shadow-md);
      border-color: #CBD5E1;
    }
    .service-img {
      width: 120px;
      height: 120px;
      background: #F1F5F9;
      border-radius: 12px;
      flex-shrink: 0;
      overflow: hidden;
    }
    .service-content h3 {
      margin-bottom: 8px;
    }
    .learn-more {
      color: var(--secondary);
      font-weight: 600;
      margin-top: 12px;
      display: inline-block;
    }
    .learn-more:hover {
      text-decoration: underline;
    }
    /* logo 墙 */
    .brand-wall {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 2.5rem;
      align-items: center;
      padding: 40px 0;
    }
    .brand-item {
      filter: grayscale(1);
      opacity: 0.7;
      transition: 0.3s;
      font-weight: 600;
      color: var(--text-muted);
      font-size: 1.25rem;
    }
    .brand-item:hover {
      filter: grayscale(0);
      opacity: 1;
      color: var(--primary);
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: transparent;
      transition: background 0.2s;
    }
    .faq-question:hover {
      background: #F8FAFC;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      background: #F0F4F8;
      padding: 0 20px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 20px;
    }
    .faq-item.active .faq-question {
      background: #F0F4F8;
    }
    .faq-icon {
      font-size: 1.5rem;
      font-weight: 300;
      color: var(--secondary);
    }
    /* CTA 横幅 */
    .cta-banner {
      background: linear-gradient(135deg, #0A2E4D 0%, #0F3B5C 100%);
      padding: 80px 0;
      text-align: center;
      color: white;
    }
    .cta-banner h2 {
      color: white;
      font-size: 2.5rem;
    }
    .cta-banner p {
      color: #CBD5E1;
      margin: 1rem 0 2rem;
    }
    .btn-large {
      background: var(--secondary);
      padding: 16px 48px;
      font-size: 1.2rem;
      border-radius: 50px;
      color: white;
      font-weight: 700;
    }
    /* footer */
    .footer {
      background: var(--footer-bg);
      color: #CBD5E1;
      padding: 60px 0 0;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    .footer-logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }
    .social-icons {
      display: flex;
      gap: 16px;
      margin-top: 16px;
    }
    .social-circle {
      width: 40px;
      height: 40px;
      background: #1E3B54;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: 0.2s;
    }
    .social-circle:hover {
      background: var(--secondary);
    }
    .copyright {
      background: var(--footer-dark);
      text-align: center;
      padding: 20px;
      font-size: 0.9rem;
      margin-top: 40px;
    }
    @media (max-width: 1024px) {
      .cards-grid { grid-template-columns: repeat(2, 1fr); }
      .stats-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      h1 { font-size: 2.4rem; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-grid { grid-template-columns: 1fr; }
      .hero-image { min-height: 280px; margin-top: 2rem; }
      .cards-grid, .service-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 520px) {
      .container { padding: 0 16px; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero-buttons .btn { width: 100%; }
    }