/* roulang page: index */
/* 设计变量与重置 */
    :root {
      --primary: #0A66C2;
      --primary-dark: #084E9E;
      --accent: #F5A623;
      --bg-light: #F4F7FC;
      --bg-white: #FFFFFF;
      --text-dark: #1E293B;
      --text-mid: #64748B;
      --text-light: #CBD5E1;
      --border-color: #E2E8F0;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition: 0.2s ease;
      --max-width: 1200px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      transition: var(--transition);
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 基础排版 */
    h1 { font-size: clamp(2rem, 5vw, 3rem); font-weight: 700; line-height: 1.2; }
    h2 { font-size: clamp(1.5rem, 3.5vw, 2rem); font-weight: 600; }
    h3 { font-size: 1.25rem; font-weight: 600; }
    p { color: var(--text-mid); }
    section { padding: 80px 0; }
    @media (max-width: 768px) {
      section { padding: 60px 0; }
      .container { padding: 0 20px; }
    }
    /* 导航栏 */
    .main-header {
      background: var(--bg-white);
      border-bottom: 1px solid var(--border-color);
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      height: 72px;
      display: flex;
      align-items: center;
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }
    .nav-links a {
      color: var(--text-mid);
      font-weight: 500;
      font-size: 0.95rem;
      padding-bottom: 4px;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .mobile-menu-btn {
      display: none;
      font-size: 1.8rem;
      color: var(--text-dark);
      background: none;
      border: none;
      line-height: 1;
    }
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: var(--bg-white);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        box-shadow: var(--shadow-md);
        border-bottom: 1px solid var(--border-color);
      }
      .nav-links.open {
        display: flex;
      }
      .mobile-menu-btn {
        display: block;
      }
    }
    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      text-align: center;
      box-shadow: 0 4px 10px rgba(10,102,194,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-1px);
      box-shadow: 0 6px 14px rgba(10,102,194,0.3);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      padding: 10px 30px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
    }
    .btn-outline:hover {
      background: rgba(10,102,194,0.05);
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, rgba(10,102,194,0.85) 0%, rgba(10,102,194,0.6) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      color: white;
      padding: 120px 0 100px;
      margin-top: 72px;
      text-align: center;
    }
    .hero h1 {
      color: white;
      margin-bottom: 16px;
    }
    .hero p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.9);
      max-width: 700px;
      margin: 0 auto 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .live-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: var(--accent);
      color: #1E293B;
      padding: 8px 20px;
      border-radius: 40px;
      font-weight: 700;
      margin-bottom: 20px;
      font-size: 0.9rem;
    }
    /* 卡片基础 */
    .card {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 28px;
      transition: var(--transition);
      border: 1px solid var(--border-color);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-2px);
    }
    .grid-2, .grid-3, .grid-4 {
      display: grid;
      gap: 24px;
    }
    .grid-2 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(3, 1fr); }
    .grid-4 { grid-template-columns: repeat(4, 1fr); }
    @media (max-width: 992px) {
      .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 640px) {
      .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    }
    /* 区块标题 */
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      color: var(--text-dark);
      margin-bottom: 12px;
    }
    .section-title p {
      font-size: 1.1rem;
      max-width: 600px;
      margin: 0 auto;
    }
    /* 痛点卡片 */
    .pain-card {
      display: flex;
      gap: 20px;
      align-items: flex-start;
    }
    .icon-circle {
      width: 52px;
      height: 52px;
      background: var(--bg-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
      color: var(--primary);
      font-size: 1.6rem;
      font-weight: 700;
    }
    /* 解决方案卡片 */
    .solution-img {
      width: 100%;
      height: 180px;
      object-fit: cover;
      background: var(--border-color);
      border-radius: 8px 8px 0 0;
    }
    .solution-card .card-body {
      padding: 20px 0 0;
    }
    /* 数据统计 */
    .stat-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent);
      line-height: 1;
    }
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    @media (max-width: 768px) {
      .data-grid { grid-template-columns: repeat(2, 1fr); }
    }
    /* 证言 */
    .testimonial-card {
      background: #F8FAFC;
      border-radius: var(--radius-card);
      padding: 24px;
    }
    .avatar-placeholder {
      width: 48px;
      height: 48px;
      background: #CBD5E1;
      border-radius: 50%;
      margin-bottom: 12px;
    }
    blockquote {
      font-style: italic;
      margin: 12px 0;
      color: var(--text-dark);
    }
    /* FAQ */
    .faq-item {
      background: var(--bg-white);
      border-radius: var(--radius-card);
      padding: 20px 24px;
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-mid);
      margin-top: 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(120deg, #F4F7FC 0%, #E8F0FE 100%);
      text-align: center;
      border-radius: 24px;
      margin: 40px 20px;
      padding: 60px 20px;
    }
    @media (max-width: 640px) {
      .cta-section { margin: 20px; }
    }
    /* 页脚 */
    .footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 32px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }
    .footer a:hover {
      color: white;
    }
    .copyright {
      border-top: 1px solid #334155;
      margin-top: 32px;
      padding-top: 20px;
      text-align: center;
      font-size: 0.9rem;
    }