/* roulang page: index */
:root {
      --primary: #0EA5E9;
      --primary-dark: #0284C7;
      --accent: #7C3AED;
      --bg-page: #F8FAFC;
      --bg-white: #FFFFFF;
      --text-heading: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --text-light: #CBD5E1;
      --success: #10B981;
      --warning: #F59E0B;
      --border: #E2E8F0;
      --radius-lg: 16px;
      --radius-md: 12px;
      --radius-sm: 8px;
      --radius-pill: 50px;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.03);
      --shadow-hover: 0 4px 8px rgba(0,0,0,0.06), 0 12px 32px rgba(0,0,0,0.06);
      --shadow-image: 0 20px 40px rgba(14,165,233,0.12);
      --font-stack: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
      --transition: 0.3s ease;
    }
    * { box-sizing: border-box; }
    body {
      font-family: var(--font-stack);
      font-size: 16px;
      font-weight: 400;
      line-height: 1.7;
      background-color: var(--bg-page);
      color: var(--text-body);
      margin: 0;
      padding: 0;
    }
    h1, h2, h3, h4 { font-weight: 700; letter-spacing: -0.02em; line-height: 1.2; color: var(--text-heading); }
    h1 { font-size: 3rem; font-weight: 800; }
    h2 { font-size: 2.25rem; margin-bottom: 1.5rem; position: relative; }
    h3 { font-size: 1.25rem; font-weight: 600; }
    a { color: var(--primary); text-decoration: none; transition: var(--transition); }
    a:hover { color: var(--accent); text-decoration: underline 1px; }
    .section-padding { padding: 6rem 0; }
    .container-lg { max-width: 1140px; margin: 0 auto; padding: 0 1.5rem; }
    img { max-width: 100%; height: auto; display: block; }
    .decorative-line {
      width: 48px; height: 4px; background: var(--accent); margin-top: 0.5rem; margin-bottom: 1.5rem;
    }

    /* 按钮系统 */
    .btn-primary-custom {
      background: var(--primary); color: #FFFFFF; border-radius: var(--radius-pill);
      padding: 0.75rem 2rem; font-weight: 600; border: none; transition: var(--transition);
      display: inline-block; box-shadow: 0 2px 8px rgba(14,165,233,0.2);
    }
    .btn-primary-custom:hover {
      background: var(--primary-dark); color: #FFFFFF; text-decoration: none;
      box-shadow: 0 0 20px rgba(14,165,233,0.3); transform: translateY(-1px);
    }
    .btn-outline-custom {
      background: transparent; border: 2px solid var(--primary); color: var(--primary);
      border-radius: var(--radius-pill); padding: 0.75rem 2rem; font-weight: 600;
      transition: var(--transition); display: inline-block;
    }
    .btn-outline-custom:hover {
      background: var(--primary); color: #FFFFFF; text-decoration: none; transform: translateY(-1px);
    }
    .btn-large {
      font-size: 1.125rem; padding: 1rem 2.5rem; border-radius: var(--radius-pill);
    }

    /* 导航栏 */
    .navbar {
      background: var(--bg-white); border-bottom: 1px solid var(--border);
      box-shadow: none; padding: 0.5rem 1.5rem;
    }
    .navbar-brand {
      font-size: 1.5rem; font-weight: 800; color: var(--primary) !important;
      letter-spacing: -0.5px;
    }
    .navbar-brand span.dot { color: var(--accent); font-size: 2rem; line-height: 0; margin-left: 2px; }
    .nav-link {
      color: var(--text-body) !important; font-weight: 500; margin: 0 0.75rem;
      transition: var(--transition); position: relative;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--primary) !important;
    }
    .nav-link.active::after {
      content: ''; position: absolute; bottom: -1px; left: 0; width: 100%;
      height: 2px; background: var(--primary);
    }
    .navbar-toggler { border: none; color: var(--primary); }
    .navbar-toggler:focus { box-shadow: none; }
    @media (max-width: 991px) {
      .navbar-collapse { background: var(--bg-white); padding: 1rem 0; }
    }

    /* Hero */
    .hero-section {
      background: linear-gradient(135deg, #F0F9FF 0%, #F8FAFC 100%);
      padding: 4rem 0 6rem;
    }
    .hero-img {
      border-radius: var(--radius-lg); box-shadow: var(--shadow-image); width: 100%; height: auto;
    }
    .hero-subtitle {
      font-size: 1.125rem; color: var(--text-muted); margin: 1.5rem 0;
    }

    /* 亮点网格 */
    .highlight-item {
      text-align: center; padding: 2rem 1rem; background: transparent;
      border-bottom: 2px solid var(--primary);
    }
    .highlight-number {
      font-size: 3rem; font-weight: 800; color: var(--accent); line-height: 1.2;
    }
    .highlight-label {
      font-size: 1rem; color: var(--text-body); margin-top: 0.5rem;
    }

    /* 卡片通用 */
    .custom-card {
      background: var(--bg-white); border-radius: var(--radius-lg); box-shadow: var(--shadow-card);
      transition: var(--transition); border: none;
    }
    .custom-card:hover {
      box-shadow: var(--shadow-hover); transform: translateY(-4px);
    }
    .card-tag {
      font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.05em;
      color: var(--accent); font-weight: 600; margin-bottom: 0.5rem;
    }
    .card-text-muted { color: var(--text-muted); font-size: 0.95rem; }

    /* 标签要点 */
    .tag-pill {
      display: inline-block; background: #F0F9FF; color: var(--primary);
      border-radius: var(--radius-pill); padding: 0.25rem 0.75rem; font-size: 0.85rem;
      margin: 0.25rem 0.5rem 0.25rem 0; font-weight: 500;
    }

    /* 案例特殊 */
    .case-wide .case-img { aspect-ratio: 16 / 9; }
    .case-square .case-img { aspect-ratio: 1 / 1; }

    /* 对比表 */
    .compare-card {
      background: var(--bg-white); border-radius: var(--radius-lg); box-shadow: var(--shadow-card);
      padding: 2rem; height: 100%;
    }
    .compare-header-blue { border-top: 6px solid var(--primary); }
    .compare-header-purple { border-top: 6px solid var(--accent); }
    .compare-item { padding: 0.75rem 0; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; }
    .check { color: var(--success); font-weight: bold; }
    .cross { color: #CBD5E1; }

    /* FAQ */
    .accordion-faq .accordion-item {
      background: var(--bg-white); border: none; border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card); margin-bottom: 1rem;
    }
    .accordion-faq .accordion-button {
      font-weight: 600; font-size: 1rem; color: var(--text-heading); background: transparent;
      box-shadow: none; border-radius: var(--radius-lg); padding: 1.25rem 1.5rem;
    }
    .accordion-faq .accordion-button:not(.collapsed) {
      background: #F8FAFC; border-left: 3px solid var(--primary); color: var(--primary);
    }
    .accordion-faq .accordion-body { padding: 1.25rem 1.5rem; color: var(--text-body); }

    /* CTA */
    .cta-gradient {
      background: linear-gradient(135deg, #F0F9FF 0%, #EDE9FE 100%);
      border-radius: var(--radius-lg); padding: 4rem 2rem;
    }

    /* Footer */
    .footer-dark {
      background: #0F172A; color: var(--text-light); padding: 4rem 0 2rem;
    }
    .footer-dark a { color: var(--text-light); }
    .footer-dark a:hover { color: var(--primary); text-decoration: none; }
    .social-icon {
      display: inline-flex; align-items: center; justify-content: center;
      width: 40px; height: 40px; border-radius: 50%; background: rgba(255,255,255,0.1);
      color: white; margin-right: 0.5rem; transition: var(--transition);
    }
    .social-icon:hover { background: var(--primary); color: white; }

    @media (max-width: 768px) {
      h1 { font-size: 2rem; }
      h2 { font-size: 1.75rem; }
      .section-padding { padding: 3rem 0; }
      .hero-section { padding: 2rem 0 3rem; }
      .navbar-brand { font-size: 1.25rem; }
    }