/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-dark: #3b5ad4;
      --secondary: #00B578;
      --warning: #FF9F0A;
      --danger: #FA5151;
      --bg: #F5F6FA;
      --card: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E8ECF1;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
      --radius-card: 12px;
      --radius-btn: 24px;
      --radius-input: 24px;
      --transition: 200ms ease-out;
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

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

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: transparent;
      transition: background 200ms ease, box-shadow 200ms ease;
      height: 64px;
      display: flex;
      align-items: center;
    }

    .header.scrolled {
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(8px);
      box-shadow: var(--shadow-sm);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo .highlight {
      color: var(--primary);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      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;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-size: 15px;
      display: inline-block;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
      border: none;
      cursor: pointer;
      text-align: center;
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-size: 15px;
      display: inline-block;
      transition: all var(--transition);
      cursor: pointer;
    }
    .btn-outline:hover {
      background: rgba(78,110,242,0.05);
      transform: translateY(-2px);
      box-shadow: var(--shadow-sm);
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text);
      cursor: pointer;
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .menu-toggle {
        display: block;
      }
      .header {
        height: 56px;
        background: white;
      }
      .header.scrolled {
        background: rgba(255,255,255,0.98);
      }
      .mobile-menu {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: 56px;
        left: 0;
        width: 100%;
        background: white;
        padding: 20px 24px;
        gap: 20px;
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all 300ms ease;
      }
      .mobile-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
      }
    }

    /* Hero */
    .hero {
      padding: 140px 0 80px;
      background: linear-gradient(180deg, #FFFFFF 0%, var(--bg) 100%);
      min-height: 85vh;
      display: flex;
      align-items: center;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-text {
      flex: 1;
    }
    .hero-text h1 {
      font-size: 52px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text);
      margin-bottom: 20px;
    }
    .hero-text .sub {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-image {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    @media (max-width: 768px) {
      .hero {
        padding: 100px 0 60px;
        min-height: auto;
      }
      .hero-grid {
        flex-direction: column;
        gap: 40px;
      }
      .hero-text h1 {
        font-size: 34px;
      }
    }

    /* 通用板块 */
    section {
      padding: 90px 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 60px 0;
      }
    }
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      font-size: 34px;
      font-weight: 600;
      color: var(--text);
      margin-bottom: 12px;
    }
    .section-title .desc {
      font-size: 16px;
      color: var(--text-secondary);
    }

    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    @media (max-width: 1024px) and (min-width: 769px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
    }

    .card {
      background: var(--card);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: transform 250ms ease, box-shadow 250ms ease;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .feature-icon {
      width: 64px;
      height: 64px;
      background: #f0f3ff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
    }
    .feature-icon i {
      font-size: 28px;
      color: var(--primary);
    }
    .card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .card p {
      font-size: 15px;
      color: var(--text-secondary);
      line-height: 1.5;
    }

    /* 服务卡片图片 */
    .service-img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
      border-radius: var(--radius-card) var(--radius-card) 0 0;
      margin-bottom: 16px;
    }
    .tag {
      background: #FFF1E0;
      color: #E67E00;
      font-size: 12px;
      font-weight: 500;
      padding: 4px 10px;
      border-radius: 20px;
      display: inline-block;
      margin-top: 10px;
    }
    .link-blue {
      color: var(--primary);
      font-weight: 500;
      margin-top: 14px;
      display: inline-block;
    }

    /* 场景交替 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .scenario-row.reverse {
      flex-direction: row-reverse;
    }
    .scenario-img {
      flex: 1;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .scenario-text {
      flex: 1;
    }
    .scenario-text h3 {
      font-size: 28px;
      margin-bottom: 16px;
    }
    .big-number {
      font-size: 36px;
      font-weight: 700;
      color: var(--secondary);
    }

    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse {
        flex-direction: column;
        gap: 24px;
        margin-bottom: 48px;
      }
    }

    /* 数据亮点 */
    .stats {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
      gap: 24px;
    }
    .stat-item .number {
      font-size: 38px;
      font-weight: 700;
      color: var(--primary);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--card);
      border-radius: var(--radius-card);
      padding: 20px 24px;
      margin-bottom: 12px;
      cursor: pointer;
      box-shadow: var(--shadow-sm);
      transition: all 200ms;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 300ms ease;
      color: var(--text-secondary);
      margin-top: 0;
    }
    .faq-item.active {
      border-left: 3px solid var(--primary);
    }
    .faq-item.active .faq-answer {
      max-height: 150px;
      margin-top: 12px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary);
      padding: 80px 0;
      text-align: center;
      color: white;
      border-radius: 0;
    }
    .cta-banner h2 {
      font-size: 36px;
      margin-bottom: 12px;
    }
    .cta-banner .sub {
      font-size: 18px;
      opacity: 0.9;
      margin-bottom: 28px;
    }
    .btn-white {
      background: white;
      color: var(--primary);
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: all 200ms;
    }
    .btn-white:hover {
      transform: scale(1.03);
      box-shadow: 0 8px 20px rgba(0,0,0,0.2);
    }

    /* Footer */
    .footer {
      background: #1F2329;
      color: #86909C;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer a {
      color: #B0B5BE;
      transition: color 150ms;
    }
    .footer a:hover {
      color: white;
    }
    .footer .copyright {
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid #2E3238;
      font-size: 14px;
      color: #5A5F66;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }