/* roulang page: index */
:root {
      --primary: #3B5FE2;
      --primary-hover: #2A48C0;
      --primary-light: #EEF1FD;
      --green: #00B578;
      --orange: #FF9F0A;
      --red: #FA5151;
      --text-main: #1F2329;
      --text-secondary: #86909C;
      --bg-page: #F5F6FA;
      --bg-white: #FFFFFF;
      --border-light: #E5E8EF;
      --shadow-card: 0 2px 12px rgba(31, 35, 41, 0.06);
      --shadow-card-hover: 0 6px 20px rgba(31, 35, 41, 0.10);
      --radius-card: 16px;
      --radius-btn: 12px;
      --radius-img: 24px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", system-ui, -apple-system, sans-serif;
      --header-height: 72px;
      --max-width: 1200px;
      --transition: 200ms ease-out;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      padding-top: var(--header-height);
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 40px;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 1px 6px rgba(0,0,0,0.02);
      z-index: 100;
      display: flex;
      align-items: center;
      transition: background 0.3s;
    }
    .header.scrolled {
      background: rgba(255, 255, 255, 0.96);
      backdrop-filter: blur(16px);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 40px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 18px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-main);
      transition: color var(--transition);
      position: relative;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition);
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      font-weight: 600;
      font-size: 16px;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: background var(--transition), box-shadow var(--transition);
      display: inline-block;
      text-align: center;
      line-height: 1.2;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 4px 14px rgba(59,95,226,0.30);
    }
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
      font-weight: 600;
      font-size: 16px;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: background var(--transition), color var(--transition);
      display: inline-block;
      text-align: center;
    }
    .btn-secondary:hover {
      background: var(--primary-light);
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--text-main);
      cursor: pointer;
    }
    /* 移动端导航 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--header-height);
      left: 0;
      width: 100%;
      background: white;
      box-shadow: 0 10px 25px rgba(0,0,0,0.05);
      padding: 20px 24px;
      flex-direction: column;
      gap: 24px;
      z-index: 99;
      backdrop-filter: blur(8px);
    }
    .mobile-menu a {
      font-size: 20px;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      border-bottom: 1px solid var(--border-light);
    }
    /* 区块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 32px;
      font-weight: 600;
      line-height: 1.4;
      color: var(--text-main);
      margin-bottom: 16px;
      text-align: center;
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-secondary);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
    }
    /* Hero */
    .hero {
      display: flex;
      align-items: center;
      min-height: 80vh;
      background: var(--bg-page);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-main);
      margin-bottom: 20px;
    }
    .hero-left .sub {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-right {
      background: linear-gradient(135deg, rgba(59,95,226,0.08) 0%, rgba(59,95,226,0.02) 100%);
      border-radius: var(--radius-img);
      overflow: hidden;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      height: 420px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      box-shadow: var(--shadow-card);
    }
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: rgba(59,95,226,0.12);
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-stat {
      background: rgba(255,255,255,0.9);
      backdrop-filter: blur(6px);
      border-radius: 20px;
      padding: 24px 32px;
      text-align: center;
      color: var(--primary);
      font-weight: 700;
      font-size: 36px;
      z-index: 2;
    }
    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
      transition: all 250ms ease-out;
      height: 100%;
    }
    .card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    .icon-bg {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: var(--primary);
      font-size: 24px;
    }
    .card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .card p {
      color: var(--text-secondary);
      font-size: 16px;
    }
    /* 场景卡片 */
    .scene-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all 250ms ease-out;
    }
    .scene-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    .scene-img {
      height: 200px;
      background-color: #E5E8EF;
      background-size: cover;
      background-position: center;
      border-radius: 12px 12px 0 0;
    }
    .scene-content {
      padding: 24px;
    }
    /* 数据统计 */
    .stat-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 4px;
    }
    .stat-label {
      color: var(--text-secondary);
      font-size: 14px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      background: white;
      border-radius: 12px;
      padding: 20px 24px;
      box-shadow: var(--shadow-card);
      cursor: pointer;
      transition: all 300ms ease-out;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
    }
    .faq-icon {
      font-size: 24px;
      color: var(--primary);
      transition: transform 0.3s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out;
      color: var(--text-secondary);
      line-height: 1.6;
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary-light);
      text-align: center;
      padding: 80px 20px;
    }
    /* 页脚 */
    .footer {
      background: #1F2329;
      color: white;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: #ccc;
      transition: color 0.2s;
    }
    .footer a:hover {
      color: var(--primary);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      color: #aaa;
      font-size: 14px;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .container { padding: 0 24px; }
      .nav-container { padding: 0 24px; }
      .hero-grid { grid-template-columns: 1fr; gap: 40px; }
      .hero-right { height: 300px; }
      .grid-3 { grid-template-columns: repeat(2,1fr); }
      .grid-4 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      :root { --header-height: 60px; }
      .nav-links { display: none; }
      .mobile-toggle { display: block; }
      .mobile-menu.active { display: flex; }
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
      .hero-left h1 { font-size: 32px; }
      .section-title { font-size: 24px; }
      .footer-grid { grid-template-columns: 1fr; }
      section { padding: 60px 0; }
    }