/* roulang page: index */
:root {
      --primary: #0A66C2;
      --primary-deep: #084E96;
      --soft-blue: #F0F6FF;
      --accent: #FF6B35;
      --accent-hover: #E55A2B;
      --neutral-dark: #1A1A2E;
      --neutral-mid: #5C5C7A;
      --bg-light: #F5F6FA;
      --border: #E2E6EF;
      --success: #10B981;
      --white: #FFFFFF;
      --card-shadow: 0 2px 12px rgba(26,26,46,0.06);
      --card-hover-shadow: 0 8px 28px rgba(26,26,46,0.10);
      --transition: 0.25s ease;
      --radius-card: 12px;
      --radius-btn: 8px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-number: "Inter", "Segoe UI", system-ui, sans-serif;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: var(--font-sans);
      background: var(--bg-light);
      color: var(--neutral-dark);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }
    img { max-width: 100%; height: auto; display: block; }
    a { text-decoration: none; color: inherit; }
    button { cursor: pointer; font-family: inherit; }

    /* 导航 */
    #nav {
      position: fixed; top: 0; left: 0; width: 100%; height: 72px;
      background: rgba(255,255,255,0.92); backdrop-filter: blur(12px);
      z-index: 1000; display: flex; align-items: center;
      border-bottom: 1px solid transparent; transition: box-shadow 0.3s, border-color 0.3s;
    }
    #nav.scrolled { box-shadow: 0 4px 20px rgba(0,0,0,0.06); border-color: var(--border); }
    .nav-container {
      display: flex; justify-content: space-between; align-items: center;
      width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 20px;
    }
    .logo {
      font-size: 24px; font-weight: 700; color: var(--neutral-dark);
      letter-spacing: 1px; display: flex; align-items: center;
    }
    .logo span { color: var(--primary); margin-left: 4px; }
    .nav-menu {
      display: flex; gap: 32px; align-items: center; list-style: none;
    }
    .nav-menu a {
      font-size: 15px; font-weight: 500; color: var(--neutral-mid);
      padding: 8px 0; position: relative; transition: color 0.2s;
    }
    .nav-menu a:hover, .nav-menu a.active { color: var(--primary); }
    .nav-menu a.active::after {
      content: ''; position: absolute; bottom: 0; left: 0; width: 100%;
      height: 3px; background: var(--primary); border-radius: 2px;
    }
    .nav-cta {
      background: var(--primary); color: white; padding: 12px 28px;
      border-radius: var(--radius-btn); font-weight: 600; font-size: 15px;
      transition: background 0.2s, transform 0.2s; white-space: nowrap;
    }
    .nav-cta:hover { background: var(--primary-deep); transform: translateY(-1px); }
    .hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; z-index: 1001; }
    .hamburger span { width: 26px; height: 2.5px; background: var(--neutral-dark); border-radius: 2px; transition: 0.3s; }
    .mobile-menu {
      display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
      background: rgba(255,255,255,0.98); backdrop-filter: blur(20px);
      flex-direction: column; align-items: center; justify-content: center;
      gap: 28px; z-index: 999; opacity: 0; pointer-events: none; transition: opacity 0.3s;
    }
    .mobile-menu.open { opacity: 1; pointer-events: auto; }
    .mobile-menu a { font-size: 22px; font-weight: 600; color: var(--neutral-dark); }

    /* Hero */
    #hero {
      padding: 140px 0 100px; background: linear-gradient(135deg, #FFFFFF 0%, #F0F6FF 100%);
      position: relative; overflow: hidden;
    }
    .hero-grid {
      display: flex; align-items: center; gap: 60px;
    }
    .hero-text { flex: 0 0 55%; }
    .hero-text h1 {
      font-size: 46px; line-height: 1.2; font-weight: 700; color: var(--neutral-dark);
      margin-bottom: 20px;
    }
    .hero-subtitle {
      font-size: 18px; color: var(--neutral-mid); margin-bottom: 32px; max-width: 500px;
    }
    .hero-buttons { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; margin-bottom: 40px; }
    .btn-primary {
      background: var(--primary); color: white; padding: 14px 32px;
      border-radius: var(--radius-btn); font-weight: 600; font-size: 16px;
      transition: 0.2s; border: none; display: inline-block;
    }
    .btn-primary:hover { background: var(--primary-deep); transform: translateY(-2px); box-shadow: 0 8px 16px rgba(10,102,194,0.2); }
    .btn-outline {
      background: transparent; border: 1.5px solid var(--primary); color: var(--primary);
      padding: 14px 32px; border-radius: var(--radius-btn); font-weight: 600; font-size: 16px;
      transition: 0.2s;
    }
    .btn-outline:hover { background: var(--soft-blue); }
    .trust-badges { display: flex; gap: 24px; flex-wrap: wrap; }
    .badge-item { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--neutral-mid); }
    .badge-item svg { width: 20px; height: 20px; color: var(--primary); }
    .hero-image {
      flex: 0 0 40%; background: #E8ECF1; border-radius: 20px;
      overflow: hidden; box-shadow: 0 20px 30px rgba(0,0,0,0.08);
    }
    .hero-image img { width: 100%; height: auto; object-fit: cover; }

    /* 区块通用 */
    section { padding: 100px 0; }
    .section-title {
      font-size: 32px; font-weight: 700; margin-bottom: 16px; color: var(--neutral-dark);
    }
    .section-desc { font-size: 16px; color: var(--neutral-mid); margin-bottom: 48px; max-width: 700px; }

    /* 卡片网格 */
    .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
    .grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
    .card {
      background: white; border-radius: var(--radius-card); padding: 32px;
      box-shadow: var(--card-shadow); border: 1px solid var(--border);
      transition: 0.25s ease; display: flex; flex-direction: column;
    }
    .card:hover { box-shadow: var(--card-hover-shadow); transform: translateY(-4px); }
    .feature-icon { width: 48px; height: 48px; color: var(--primary); margin-bottom: 20px; }
    .card h3 { font-size: 20px; font-weight: 600; margin-bottom: 12px; }
    .card p { font-size: 14px; color: var(--neutral-mid); line-height: 1.6; }

    /* 服务交替布局 */
    .service-row { display: flex; align-items: center; gap: 60px; margin-bottom: 80px; }
    .service-img { flex: 0 0 45%; border-radius: 12px; overflow: hidden; background: #E8ECF1; }
    .service-content { flex: 1; }
    .service-content h3 { font-size: 24px; margin-bottom: 16px; }
    .check-list { list-style: none; margin-bottom: 24px; }
    .check-list li { display: flex; align-items: center; gap: 8px; margin-bottom: 10px; color: var(--neutral-mid); }
    .check-list svg { color: var(--success); width: 20px; }
    .text-cta { color: var(--primary); font-weight: 600; display: inline-flex; align-items: center; gap: 4px; transition: 0.2s; }
    .text-cta:hover { text-decoration: underline; color: var(--primary-deep); }

    /* 案例卡片 */
    .case-card { text-align: center; padding: 28px; }
    .case-logo {
      width: 80px; height: 80px; background: #f0f2f5; border-radius: 50%;
      margin: 0 auto 20px; display: flex; align-items: center; justify-content: center;
      color: var(--neutral-mid); font-size: 14px;
    }
    .case-quote { font-style: italic; margin-bottom: 16px; color: var(--neutral-dark); }
    .case-stat { font-size: 30px; font-weight: 700; color: var(--accent); margin-bottom: 4px; }

    /* 价格卡片 */
    .pricing-card {
      background: white; border-radius: var(--radius-card); padding: 32px;
      border: 1px solid var(--border); text-align: center; position: relative;
    }
    .pricing-card.featured { border: 2px solid var(--primary); }
    .badge {
      background: var(--accent); color: white; padding: 4px 16px; border-radius: 20px;
      font-size: 13px; position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
      white-space: nowrap;
    }
    .price { font-size: 44px; font-weight: 700; color: var(--primary); margin: 20px 0 12px; }
    .price small { font-size: 16px; font-weight: 400; }
    .feature-list { list-style: none; text-align: left; margin: 24px 0; }
    .feature-list li { padding: 8px 0; display: flex; align-items: center; gap: 8px; color: var(--neutral-mid); }
    .btn-accent { background: var(--accent); color: white; border: none; padding: 14px 28px; border-radius: var(--radius-btn); font-weight: 600; width: 100%; }
    .btn-accent:hover { background: var(--accent-hover); }

    /* FAQ */
    .faq-item { border-bottom: 1px solid var(--border); }
    .faq-question {
      width: 100%; background: none; border: none; font-size: 18px; font-weight: 600;
      padding: 20px 0; display: flex; justify-content: space-between; align-items: center;
      text-align: left; color: var(--neutral-dark);
    }
    .faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; color: var(--neutral-mid); padding: 0 0; }
    .faq-item.open .faq-answer { max-height: 200px; padding-bottom: 20px; }
    .faq-icon { transition: transform 0.2s; }
    .faq-item.open .faq-icon { transform: rotate(45deg); }

    /* CTA 横幅 */
    #cta {
      background: var(--primary); padding: 80px 0; text-align: center; color: white;
    }
    #cta h2 { color: white; margin-bottom: 16px; }
    #cta .btn-white {
      background: white; color: var(--primary); padding: 14px 36px; border-radius: var(--radius-btn);
      font-weight: 700; margin-top: 24px; display: inline-block;
    }

    /* Footer */
    #footer { background: #1A1A2E; color: #B0B0C0; padding: 60px 0 30px; }
    .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 40px; }
    .footer-logo { font-size: 24px; font-weight: 700; color: white; margin-bottom: 12px; }
    .footer-desc { font-size: 14px; margin-bottom: 16px; }
    .footer-title { color: white; font-weight: 600; margin-bottom: 16px; }
    .footer-links li { list-style: none; margin-bottom: 10px; font-size: 14px; }
    .footer-links a:hover { color: white; }
    .copyright { border-top: 1px solid #2A2A3E; margin-top: 40px; padding-top: 20px; text-align: center; font-size: 13px; }

    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .hero-image { width: 100%; }
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-menu, .nav-cta { display: none; }
      .hamburger { display: flex; }
      #hero { padding: 100px 0 60px; }
      .hero-text h1 { font-size: 32px; }
      .service-row { flex-direction: column; }
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
    }