/* roulang page: index */
:root {
      --primary: #0D9488;
      --primary-hover: #0F766E;
      --secondary-slate: #1E293B;
      --bg-page: #F8FAFC;
      --bg-card: #FFFFFF;
      --text-heading: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
      --border-input: #CBD5E1;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.3s ease;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    img { max-width: 100%; height: auto; display: block; }
    a { text-decoration: none; color: inherit; transition: var(--transition); }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .main-nav {
      position: sticky;
      top: 0;
      z-index: 50;
      height: 72px;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(226,232,240,0.6);
      display: flex;
      align-items: center;
      transition: background 0.3s;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
    }
    .nav-links {
      display: flex;
      gap: 40px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      color: #475569;
      font-weight: 500;
      position: relative;
      padding-bottom: 6px;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }
    .nav-links a:hover { color: #1E293B; }
    .nav-links a:hover::after { width: 100%; }
    .nav-links a.active-link::after { width: 100%; }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: #1E293B;
      border-radius: 0;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      padding: 32px 24px;
      flex-direction: column;
      gap: 28px;
      box-shadow: 0 12px 24px rgba(0,0,0,0.05);
      z-index: 45;
      border-top: 1px solid #E2E8F0;
    }
    .mobile-menu a {
      font-size: 18px;
      color: #1E293B;
      font-weight: 500;
    }
    /* 板块通用 */
    section {
      padding: 120px 0;
    }
    @media (max-width: 640px) {
      section { padding: 80px 0; }
    }
    h2 {
      font-size: 32px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-heading);
      margin-bottom: 16px;
    }
    h3 {
      font-size: 20px;
      font-weight: 600;
      color: #0F172A;
    }
    .section-subtitle {
      color: var(--text-muted);
      font-size: 18px;
      max-width: 700px;
      margin: 0 auto 48px;
    }
    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: var(--transition);
      display: inline-block;
      text-align: center;
      cursor: pointer;
      border: 2px solid transparent;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      color: white;
    }
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      transition: var(--transition);
      display: inline-block;
      text-align: center;
      cursor: pointer;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    /* Hero */
    #hero {
      min-height: 90vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #F0F9FF 0%, #F8FAFC 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 55% 45%;
      align-items: center;
      gap: 40px;
    }
    .hero-text h1 {
      font-size: 42px;
      font-weight: 700;
      line-height: 1.2;
      color: #0F172A;
      margin-bottom: 24px;
    }
    .hero-text .sub {
      font-size: 18px;
      color: #475569;
      margin-bottom: 40px;
      max-width: 520px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-image img {
      border-radius: 16px;
      box-shadow: 0 20px 35px rgba(0,0,0,0.08);
      width: 100%;
    }
    /* 痛点卡片 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .problem-card {
      background: var(--bg-card);
      padding: 32px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .problem-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .problem-card i {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 20px;
    }
    /* 解决方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 100px;
    }
    .solution-row.reverse {
      flex-direction: row-reverse;
    }
    .solution-img, .solution-text {
      flex: 1;
    }
    .solution-img img {
      border-radius: 16px;
      box-shadow: 0 12px 24px rgba(0,0,0,0.05);
    }
    .check-list {
      list-style: none;
      margin-top: 20px;
    }
    .check-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 12px;
      color: #334155;
    }
    .check-list i {
      color: var(--primary);
    }
    /* 数据卡片 */
    .stat-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 30px;
      text-align: center;
    }
    .stat-card {
      background: white;
      padding: 32px 16px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
    }
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.1;
    }
    /* 证言滑动 */
    .testimonial-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 12px;
      scroll-snap-type: x mandatory;
    }
    .testimonial-card {
      flex: 0 0 calc(33.333% - 16px);
      min-width: 280px;
      background: #F1F5F9;
      border-left: 4px solid var(--primary);
      padding: 28px;
      border-radius: 12px;
      scroll-snap-align: start;
    }
    .testimonial-avatar {
      width: 48px;
      height: 48px;
      background: #CBD5E1;
      border-radius: 50%;
      margin-bottom: 16px;
    }
    /* FAQ */
    .accordion-title {
      font-size: 18px;
      font-weight: 600;
      background: transparent;
      border-top: 1px solid #E2E8F0;
      padding: 20px 0;
      color: #0F172A;
    }
    .accordion-title::before {
      content: "●";
      color: var(--primary);
      margin-right: 12px;
      font-size: 10px;
    }
    /* CTA */
    #cta {
      background: linear-gradient(135deg, #0D9488 0%, #0F766E 100%);
      color: white;
      text-align: center;
    }
    #cta h2 { color: white; }
    /* 页脚 */
    footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      border-bottom: 1px solid rgba(255,255,255,0.15);
      padding-bottom: 40px;
    }
    .copyright {
      text-align: center;
      margin-top: 30px;
      font-size: 14px;
      color: #94A3B8;
    }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .hero-image { order: -1; }
      .card-grid { grid-template-columns: 1fr; }
      .stat-grid { grid-template-columns: repeat(2,1fr); }
      .solution-row, .solution-row.reverse { flex-direction: column; }
    }
    @media (max-width: 640px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu.active { display: flex; }
      h1 { font-size: 32px !important; }
      h2 { font-size: 26px; }
      .hero-buttons .btn-primary, .hero-buttons .btn-outline { width: 100%; }
      .stat-grid { grid-template-columns: 1fr; }
      .testimonial-card { flex: 0 0 85%; }
      .footer-grid { grid-template-columns: 1fr; }
    }