/* roulang page: index */
:root {
      --primary-blue: #1A5FBA;
      --accent-teal: #0EA5A0;
      --bg-light: #F8FAFC;
      --card-white: #FFFFFF;
      --bg-subtle: #EEF2F6;
      --text-title: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --cta-orange: #F97316;
      --cta-orange-hover: #EA580C;
      --border-light: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 8px 24px rgba(26,95,186,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --transition-smooth: 0.25s ease;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      margin: 0;
      background-color: var(--bg-light);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4, h5, h6 {
      color: var(--text-title);
      font-weight: 600;
      letter-spacing: -0.3px;
    }
    h1 {
      font-size: 2.5rem;
      line-height: 1.2;
      font-weight: 700;
      letter-spacing: -0.5px;
    }
    h2 {
      font-size: 2rem;
      line-height: 1.3;
      font-weight: 600;
    }
    h3 {
      font-size: 1.25rem;
      line-height: 1.4;
      font-weight: 600;
    }
    p {
      max-width: 38rem;
    }
    a {
      color: var(--primary-blue);
      text-decoration: none;
      transition: color 0.2s;
    }
    a:hover {
      text-decoration: underline;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }
    /* 导航 */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      padding: 0.75rem 0;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }
    .logo {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary-blue);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 0.5rem;
      white-space: nowrap;
    }
    .logo-icon {
      display: inline-flex;
      width: 36px;
      height: 36px;
      background: linear-gradient(135deg, var(--primary-blue), var(--accent-teal));
      border-radius: 50%;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 1.1rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    .nav-links a {
      color: var(--text-body);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 0.5rem 0;
      border-bottom: 3px solid transparent;
      transition: all 0.2s;
      white-space: nowrap;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-blue);
      border-bottom-color: var(--primary-blue);
      font-weight: 600;
    }
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--text-title);
      padding: 0.25rem;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 280px;
      height: 100vh;
      background: white;
      box-shadow: -8px 0 24px rgba(0,0,0,0.1);
      padding: 2rem 1.5rem;
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
      transition: right 0.3s ease;
      z-index: 55;
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      font-size: 1.2rem;
      font-weight: 500;
      color: var(--text-title);
      padding: 0.5rem 0;
      border-bottom: 1px solid var(--border-light);
    }
    .close-drawer {
      align-self: flex-end;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--text-title);
    }
    .btn-primary {
      background: var(--cta-orange);
      color: white;
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 10px rgba(249,115,22,0.3);
      transition: background 0.2s, box-shadow 0.2s, transform 0.1s;
      border: none;
      white-space: nowrap;
    }
    .btn-primary:hover {
      background: var(--cta-orange-hover);
      box-shadow: 0 8px 16px rgba(249,115,22,0.35);
      text-decoration: none;
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--primary-blue);
      color: var(--primary-blue);
      padding: 0.65rem 1.8rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s;
    }
    .btn-secondary:hover {
      background: var(--primary-blue);
      color: white;
      text-decoration: none;
    }
    /* 板块间距 */
    section {
      padding: 6rem 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 3rem;
    }
    .card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 1.75rem;
      transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
      height: 100%;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    /* 瀑布流 */
    .masonry {
      column-count: 3;
      column-gap: 1.5rem;
    }
    .masonry-item {
      break-inside: avoid;
      margin-bottom: 1.5rem;
      background: white;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      transition: var(--transition-smooth);
    }
    .masonry-item:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-hover);
    }
    /* 表格 */
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .compare-table th {
      background: var(--primary-blue);
      color: white;
      font-weight: 600;
      padding: 1rem;
      text-align: left;
    }
    .compare-table td, .compare-table th {
      padding: 1rem;
      border-bottom: 1px solid var(--border-light);
    }
    .highlight-col {
      border-left: 4px solid var(--accent-teal);
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.2rem 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-title);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: #475569;
      background: #F8FAFC;
      padding: 0 1rem;
      border-radius: 0.5rem;
      margin-top: 0.5rem;
    }
    .faq-item.open .faq-answer {
      max-height: 300px;
      padding: 1rem;
    }
    .faq-icon {
      font-size: 1.5rem;
      font-weight: 300;
      transition: transform 0.2s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .masonry {
        column-count: 2;
      }
    }
    @media (max-width: 768px) {
      h1 { font-size: 2rem; }
      h2 { font-size: 1.7rem; }
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero-container {
        flex-direction: column-reverse;
      }
      .masonry {
        column-count: 1;
      }
      .compare-wrapper {
        overflow-x: auto;
      }
    }
    @media (max-width: 640px) {
      section { padding: 4rem 0; }
      .card-grid {
        grid-template-columns: 1fr;
      }
    }
    .hero-container { display: flex; align-items: center; gap: 2.5rem; }
    .card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }