/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-dark: #0F3D94;
      --accent: #F5A623;
      --accent-hover: #E09510;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --card-hover: #EEF2F9;
      --text-main: #1E293B;
      --text-secondary: #475569;
      --text-muted: #64748B;
      --border: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-tag: 4px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 10px 25px -5px rgba(0,0,0,0.08), 0 4px 10px -6px rgba(0,0,0,0.04);
      --font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --max-width: 1280px;
      --header-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-family);
      background: var(--bg);
      color: var(--text-main);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: #fff;
      box-shadow: 0 1px 4px rgba(0,0,0,0.04);
      z-index: 50;
      display: flex;
      align-items: center;
    }
    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo img {
      width: 32px;
      height: 32px;
      border-radius: 6px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      color: var(--text-secondary);
      font-weight: 500;
      font-size: 15px;
      transition: color 0.2s;
      position: relative;
      padding: 8px 0;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }
    .btn-primary {
      background: var(--primary);
      color: #fff;
      border: none;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 15px;
      letter-spacing: 0.3px;
      cursor: pointer;
      transition: background 0.2s, box-shadow 0.2s;
      box-shadow: 0 2px 8px rgba(26,95,220,0.2);
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 4px 12px rgba(15,61,148,0.25);
    }
    .btn-accent {
      background: var(--accent);
      color: #fff;
      box-shadow: 0 4px 12px rgba(245,166,35,0.25);
    }
    .btn-accent:hover {
      background: var(--accent-hover);
      box-shadow: 0 6px 16px rgba(245,166,35,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.2s;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: #fff;
    }
    .btn-large {
      padding: 18px 48px;
      font-size: 17px;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2.5px;
      background: var(--text-main);
      border-radius: 2px;
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--header-height);
      left: 0;
      width: 100%;
      background: #fff;
      flex-direction: column;
      padding: 24px;
      box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      z-index: 49;
      gap: 16px;
    }
    .mobile-menu a {
      font-size: 18px;
      color: var(--text-main);
      padding: 12px 0;
      border-bottom: 1px solid var(--border);
    }
    /* Hero */
    .hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: linear-gradient(105deg, rgba(248,250,252,0.92) 0%, rgba(238,242,249,0.8) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      padding-top: var(--header-height);
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 55%;
    }
    .hero-content h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--text-main);
      margin-bottom: 20px;
    }
    .hero-content .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      align-items: center;
      gap: 20px;
      flex-wrap: wrap;
    }
    .text-link {
      color: var(--primary);
      font-weight: 500;
      transition: 0.15s;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .text-link:hover {
      text-decoration: underline;
    }
    .hero-image {
      flex: 1 1 40%;
      text-align: center;
    }
    .hero-image img {
      max-height: 380px;
      margin: 0 auto;
      filter: drop-shadow(0 20px 25px rgba(0,0,0,0.08));
    }
    /* 通用区块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--text-main);
      text-align: center;
    }
    .section-sub {
      color: var(--text-muted);
      text-align: center;
      max-width: 600px;
      margin: 0 auto 48px;
    }
    /* 痛点 */
    .pain-grid {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
    }
    .pain-card {
      flex: 1 1 280px;
      background: var(--card-bg);
      padding: 28px 24px;
      border-radius: var(--radius-card);
      border-left: 4px solid var(--border);
      display: flex;
      gap: 16px;
      align-items: flex-start;
      transition: 0.2s;
    }
    .pain-card:hover {
      border-left-color: var(--primary);
      box-shadow: var(--shadow-hover);
    }
    .pain-icon {
      font-size: 28px;
      color: var(--accent);
    }
    /* 解决方案卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 24px;
    }
    .solution-card {
      background: var(--card-bg);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: 0.25s;
      text-align: center;
    }
    .solution-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      background: var(--card-hover);
    }
    .solution-card img {
      width: 64px;
      height: 64px;
      margin: 0 auto 20px;
      border-radius: 16px;
    }
    /* 数据区 */
    .stats-grid {
      display: flex;
      justify-content: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
    }
    /* 证言 */
    .testimonials-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 24px;
    }
    .testimonial {
      background: #F1F5F9;
      padding: 24px;
      border-radius: 12px;
      display: flex;
      gap: 16px;
      align-items: flex-start;
    }
    .testimonial img {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      object-fit: cover;
    }
    /* FAQ */
    .faq-item {
      background: #fff;
      border-bottom: 1px solid var(--border);
      margin-bottom: 8px;
      border-radius: 8px;
    }
    .faq-question {
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      transition: 0.2s;
    }
    .faq-answer {
      padding: 0 20px 20px;
      color: var(--text-secondary);
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(135deg, #EEF2F9 0%, #F8FAFC 100%);
      text-align: center;
    }
    /* 页脚 */
    .footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
      gap: 32px;
    }
    .footer a {
      color: #CBD5E1;
      transition: 0.2s;
    }
    .footer a:hover {
      color: #fff;
    }
    .copyright {
      background: #0F172A;
      text-align: center;
      padding: 16px 0;
      color: #64748B;
      margin-top: 40px;
    }
    @media (max-width: 1024px) {
      .hero-content h1 {
        font-size: 38px;
      }
      section {
        padding: 70px 0;
      }
    }
    @media (max-width: 768px) {
      .nav-links, .header .btn-primary {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu.active {
        display: flex;
      }
      .hero .container {
        flex-direction: column;
        text-align: center;
      }
      .hero-content h1 {
        font-size: 32px;
      }
      .hero-buttons {
        justify-content: center;
      }
      .pain-grid, .stats-grid {
        flex-direction: column;
        align-items: center;
      }
      .section-title {
        font-size: 28px;
      }
    }