/* roulang page: index */
:root {
      --primary: #1A5F7A;
      --primary-light: #0EA5E9;
      --accent: #F97316;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-dark: #1E293B;
      --text-medium: #64748B;
      --text-light: #94A3B8;
      --border: #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --radius-search: 24px;
      --shadow-default: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --transition: 0.25s ease;
      --font-cn: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-en: "Inter", "Segoe UI", system-ui, sans-serif;
      --max-width: 1200px;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; font-size: 16px; }
    body {
      font-family: var(--font-cn);
      background: var(--bg);
      color: var(--text-dark);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    img { max-width: 100%; height: auto; display: block; }
    a { text-decoration: none; color: inherit; transition: color var(--transition); }
    button, input { font-family: inherit; outline: none; border: none; }
    .container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
    @media (max-width: 768px) {
      .container { padding: 0 16px; }
    }

    /* 导航栏 */
    .header {
      position: sticky; top: 0; z-index: 50;
      background: rgba(255,255,255,0.85); backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border);
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
      transition: box-shadow 0.3s;
    }
    .header.scrolled { box-shadow: 0 4px 15px rgba(0,0,0,0.06); }
    .nav-container {
      display: flex; align-items: center; justify-content: space-between;
      padding: 12px 24px; max-width: var(--max-width); margin: 0 auto;
      gap: 24px;
    }
    .logo {
      font-size: 20px; font-weight: 700; color: var(--primary);
      white-space: nowrap; letter-spacing: 0.5px;
      display: flex; align-items: center; gap: 6px;
    }
    .logo i { font-size: 24px; color: var(--accent); }
    .search-box {
      flex: 1; max-width: 420px; position: relative;
      display: flex; align-items: center;
    }
    .search-box input {
      width: 100%; padding: 10px 18px 10px 42px;
      border-radius: var(--radius-search); border: 1px solid var(--border);
      background: white; font-size: 14px; color: var(--text-dark);
      transition: border 0.2s, box-shadow 0.2s;
    }
    .search-box input:focus {
      border-color: var(--primary-light);
      box-shadow: 0 0 0 3px rgba(14,165,233,0.2);
    }
    .search-box .search-icon {
      position: absolute; left: 16px; color: var(--text-light); font-size: 16px;
    }
    .nav-links {
      display: flex; align-items: center; gap: 28px;
      font-size: 15px; font-weight: 500;
    }
    .nav-links a { color: var(--text-medium); }
    .nav-links a:hover { color: var(--primary); }
    .hamburger { display: none; background: none; font-size: 24px; cursor: pointer; color: var(--text-dark); }

    @media (max-width: 1024px) {
      .nav-links { gap: 18px; font-size: 14px; }
      .search-box { max-width: 280px; }
    }
    @media (max-width: 768px) {
      .nav-container { flex-wrap: wrap; gap: 12px; }
      .logo { order: 1; }
      .hamburger { display: block; order: 2; }
      .search-box { order: 3; width: 100%; max-width: 100%; flex: auto; }
      .nav-links {
        display: none; order: 4; width: 100%;
        flex-direction: column; align-items: flex-start; gap: 12px;
        background: white; padding: 16px; border-radius: var(--radius-card);
        box-shadow: var(--shadow-default);
      }
      .nav-links.active { display: flex; }
    }

    /* 通用板块 */
    .section { padding: 80px 0; }
    @media (max-width: 768px) { .section { padding: 60px 0; } }
    .section-title {
      font-size: 32px; font-weight: 600; color: var(--text-dark);
      text-align: center; margin-bottom: 16px;
    }
    .section-subtitle {
      font-size: 17px; color: var(--text-medium); text-align: center;
      margin-bottom: 48px; max-width: 680px; margin-left: auto; margin-right: auto;
    }
    @media (max-width: 768px) {
      .section-title { font-size: 26px; }
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #f0f6fa 0%, #f8fafc 100%);
      padding: 60px 0 80px;
    }
    .hero-grid {
      display: flex; align-items: center; gap: 60px;
      max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
    }
    .hero-text { flex: 1; }
    .hero-text h1 {
      font-size: 48px; font-weight: 700; color: var(--text-dark);
      line-height: 1.3; margin-bottom: 20px;
    }
    .hero-text p {
      font-size: 18px; color: var(--text-medium); margin-bottom: 32px;
      max-width: 540px;
    }
    .hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }
    .btn {
      display: inline-flex; align-items: center; justify-content: center;
      padding: 12px 28px; border-radius: var(--radius-btn); font-weight: 600;
      font-size: 15px; cursor: pointer; transition: all 0.2s ease;
    }
    .btn-primary {
      background: var(--accent); color: white; box-shadow: 0 2px 8px rgba(249,115,22,0.25);
    }
    .btn-primary:hover { background: #EA580C; box-shadow: 0 4px 12px rgba(249,115,22,0.35); }
    .btn-outline {
      border: 2px solid var(--primary); color: var(--primary); background: transparent;
    }
    .btn-outline:hover { background: var(--primary); color: white; }
    .hero-image {
      flex: 1; background: white; border-radius: var(--radius-card);
      box-shadow: var(--shadow-default); overflow: hidden;
      aspect-ratio: 16 / 10;
    }
    .hero-image img { width: 100%; height: 100%; object-fit: cover; }
    @media (max-width: 768px) {
      .hero-grid { flex-direction: column; gap: 40px; }
      .hero-text h1 { font-size: 34px; }
      .hero-text p { font-size: 16px; }
    }

    /* 功能卡片网格 2x3 */
    .features-grid {
      display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px;
      margin-top: 20px;
    }
    .feature-card {
      background: var(--card-bg); border-radius: var(--radius-card);
      padding: 32px 24px; box-shadow: var(--shadow-default);
      text-align: center; transition: all var(--transition);
      display: flex; flex-direction: column; align-items: center; gap: 16px;
    }
    .feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
    .feature-icon {
      width: 56px; height: 56px; border-radius: 16px; background: #f0f6fa;
      display: flex; align-items: center; justify-content: center;
      font-size: 28px; color: var(--primary);
    }
    .feature-card h3 { font-size: 20px; font-weight: 600; color: var(--text-dark); }
    .feature-card p { color: var(--text-medium); font-size: 15px; line-height: 1.6; }
    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 520px) {
      .features-grid { grid-template-columns: 1fr; }
    }

    /* 场景交替 */
    .scenario-row {
      display: flex; align-items: center; gap: 50px; margin-bottom: 80px;
    }
    .scenario-row.reverse { flex-direction: row-reverse; }
    .scenario-text { flex: 1; }
    .scenario-text h2 { font-size: 28px; font-weight: 600; margin-bottom: 16px; }
    .scenario-text p { color: var(--text-medium); font-size: 16px; max-width: 480px; }
    .scenario-img {
      flex: 1; border-radius: var(--radius-card); overflow: hidden;
      box-shadow: var(--shadow-default); aspect-ratio: 16 / 9;
    }
    .scenario-img img { width: 100%; height: 100%; object-fit: cover; }
    @media (max-width: 768px) {
      .scenario-row, .scenario-row.reverse { flex-direction: column; }
      .scenario-text h2 { font-size: 24px; }
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px;
    }
    .case-card {
      background: #f8fafc; border-radius: var(--radius-card); padding: 28px 24px;
      display: flex; flex-direction: column; gap: 18px;
    }
    .case-logo { height: 40px; width: auto; opacity: 0.7; filter: grayscale(1); }
    .case-quote { font-style: italic; color: var(--text-medium); font-size: 15px; }
    .case-stat { font-size: 32px; font-weight: 700; color: var(--accent); }
    .case-label { font-size: 14px; color: var(--text-light); }
    @media (max-width: 1024px) { .cases-grid { grid-template-columns: repeat(2, 1fr); } }
    @media (max-width: 520px) { .cases-grid { grid-template-columns: 1fr; } }

    /* 价格 */
    .pricing-grid {
      display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; align-items: start;
    }
    .pricing-card {
      background: white; border-radius: var(--radius-card); padding: 36px 24px;
      box-shadow: var(--shadow-default); text-align: center;
      transition: transform 0.25s; position: relative;
    }
    .pricing-card.featured {
      border: 2px solid var(--primary); transform: scale(1.03);
      box-shadow: var(--shadow-hover);
    }
    .badge {
      position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
      background: var(--primary); color: white; font-size: 12px; padding: 4px 16px;
      border-radius: 4px; font-weight: 600;
    }
    .plan-price { font-size: 42px; font-weight: 700; color: var(--text-dark); margin: 20px 0 12px; }
    .plan-features { list-style: none; text-align: left; margin: 24px 0; }
    .plan-features li { padding: 8px 0; color: var(--text-medium); font-size: 15px; display: flex; align-items: center; gap: 8px; }
    .plan-features li i { color: var(--primary); }
    @media (max-width: 768px) {
      .pricing-grid { grid-template-columns: 1fr; }
      .pricing-card.featured { transform: none; }
    }

    /* FAQ */
    .faq-list { max-width: 768px; margin: 0 auto; }
    .faq-item { border-bottom: 1px solid var(--border); background: white; margin-bottom: 8px; border-radius: 6px; overflow: hidden; }
    .faq-question {
      width: 100%; padding: 20px; background: white; display: flex; justify-content: space-between; align-items: center;
      font-weight: 600; font-size: 18px; cursor: pointer; color: var(--text-dark);
      transition: background 0.2s;
    }
    .faq-question:hover { background: #f8fafc; }
    .faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease, padding 0.3s ease; background: #f8fafc; }
    .faq-item.open .faq-answer { max-height: 300px; padding: 20px; color: var(--text-medium); }
    .faq-icon { font-size: 20px; transition: 0.2s; }

    /* CTA 尾屏 */
    .cta-tail {
      background: linear-gradient(135deg, rgba(26,95,122,0.04), rgba(14,165,233,0.06));
      text-align: center; padding: 80px 20px;
    }
    .cta-tail h2 { font-size: 32px; font-weight: 600; margin-bottom: 12px; }
    .cta-tail p { color: var(--text-medium); margin-bottom: 32px; }

    /* Footer */
    .footer {
      background: white; border-top: 1px solid var(--border); padding: 60px 0 30px;
      color: var(--text-medium);
    }
    .footer-grid {
      display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px;
      max-width: var(--max-width); margin: 0 auto; padding: 0 24px;
    }
    .footer-col h4 { font-weight: 600; color: var(--text-dark); margin-bottom: 20px; }
    .footer-col p, .footer-col a { font-size: 14px; color: var(--text-medium); display: block; margin-bottom: 10px; }
    .footer-col a:hover { color: var(--primary); }
    .copyright {
      text-align: center; padding-top: 30px; margin-top: 30px;
      border-top: 1px solid var(--border); font-size: 14px; color: var(--text-light);
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 480px) {
      .footer-grid { grid-template-columns: 1fr; }
    }
    .social-icons { display: flex; gap: 12px; margin-top: 12px; color: var(--primary); }