/* roulang page: index */
:root {
      --primary: #0F766E;
      --primary-dark: #115E59;
      --primary-light: #CCFBF1;
      --accent: #F97316;
      --accent-hover: #EA580C;
      --accent-green: #10B981;
      --dark: #0F172A;
      --dark-card: #1E293B;
      --text: #0F172A;
      --text-muted: #334155;
      --text-light: #64748B;
      --bg-light: #F8FAFC;
      --bg-white: #FFFFFF;
      --border: #E2E8F0;
      --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
      --shadow-md: 0 4px 20px -2px rgba(15, 23, 42, 0.06);
      --shadow-lg: 0 12px 32px -4px rgba(15, 23, 42, 0.12);
      --radius: 14px;
      --transition: all 0.25s ease-in-out;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; font-size: 16px; }
    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      line-height: 1.75;
      color: var(--text-muted);
      background-color: var(--bg-white);
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    a { color: inherit; text-decoration: none; transition: var(--transition); }
    img { max-width: 100%; height: auto; display: block; }
    button, input, select, textarea { font: inherit; }

    .container { width: 100%; max-width: 1280px; margin: 0 auto; padding: 0 24px; }
    .section-title-wrap { text-align: center; max-width: 820px; margin: 0 auto 52px; }
    .section-tag { display: inline-flex; align-items: center; gap: 6px; padding: 5px 14px; background: var(--primary-light); color: var(--primary); font-size: 0.875rem; font-weight: 600; border-radius: 9999px; margin-bottom: 14px; }
    .section-title { font-size: 2.15rem; font-weight: 800; color: var(--text); line-height: 1.35; margin-bottom: 14px; letter-spacing: -0.02em; }
    .section-desc { font-size: 1.05rem; color: var(--text-light); line-height: 1.8; }
    .btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-weight: 600; padding: 13px 26px; border-radius: 10px; border: 1px solid transparent; cursor: pointer; transition: var(--transition); font-size: 1rem; text-decoration: none; }
    .btn-primary { background: var(--accent); color: #fff; }
    .btn-primary:hover { background: var(--accent-hover); box-shadow: 0 6px 18px rgba(249, 115, 22, 0.35); transform: translateY(-2px); }
    .btn-teal { background: var(--primary); color: #fff; }
    .btn-teal:hover { background: var(--primary-dark); box-shadow: 0 6px 18px rgba(15, 118, 110, 0.35); transform: translateY(-2px); }
    .btn-outline { background: transparent; color: #fff; border-color: rgba(255, 255, 255, 0.4); }
    .btn-outline:hover { background: rgba(255, 255, 255, 0.15); border-color: #fff; }
    .btn-outline-teal { background: transparent; color: var(--primary); border-color: var(--primary); }
    .btn-outline-teal:hover { background: var(--primary-light); }

    /* Top bar */
    .topbar { background: #F1F5F9; border-bottom: 1px solid var(--border); font-size: 0.85rem; color: var(--text-light); padding: 8px 0; }
    .topbar-content { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
    .topbar-left { display: flex; align-items: center; gap: 20px; }
    .topbar-item { display: inline-flex; align-items: center; gap: 6px; }

    /* Nav Header */
    .header { position: sticky; top: 0; z-index: 100; background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); }
    .nav-content { display: flex; justify-content: space-between; align-items: center; height: 74px; }
    .brand-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }
    .logo-badge { width: 44px; height: 44px; border-radius: 12px; background: linear-gradient(135deg, var(--primary), #14B8A6); display: flex; align-items: center; justify-content: center; color: #fff; font-size: 1.25rem; font-weight: 800; box-shadow: 0 4px 12px rgba(15, 118, 110, 0.25); }
    .brand-title { font-size: 1.25rem; font-weight: 800; color: var(--text); letter-spacing: -0.01em; display: flex; flex-direction: column; }
    .brand-subtitle { font-size: 0.725rem; color: var(--text-light); font-weight: 500; letter-spacing: 0.05em; text-transform: uppercase; }
    .nav-links { display: flex; align-items: center; gap: 28px; list-style: none; }
    .nav-links a { font-size: 0.95rem; font-weight: 600; color: var(--text-muted); padding: 6px 0; position: relative; }
    .nav-links a:hover, .nav-links a.active { color: var(--primary); }
    .nav-links a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--primary); transition: width 0.2s ease; }
    .nav-links a:hover::after { width: 100%; }
    .mobile-menu-btn { display: none; background: none; border: none; font-size: 1.5rem; color: var(--text); cursor: pointer; }

    /* Sections Shared */
    section { padding: 88px 0; position: relative; }
    .section-light { background: var(--bg-light); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
    .section-white { background: var(--bg-white); }
    .section-dark { background: var(--dark); color: #F1F5F9; }

    /* 1. Hero */
    .hero-section {
      padding: 120px 0 100px;
      min-height: 84vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(15, 23, 42, 0.88), rgba(15, 118, 110, 0.85)), url('/assets/images/55b893a5a0921820.png') center/cover no-repeat;
      color: #fff;
      text-align: center;
    }
    .hero-content { max-width: 960px; margin: 0 auto; }
    .hero-badge { display: inline-flex; align-items: center; gap: 8px; background: rgba(255, 255, 255, 0.15); border: 1px solid rgba(255, 255, 255, 0.3); padding: 6px 18px; border-radius: 9999px; font-size: 0.875rem; font-weight: 500; margin-bottom: 24px; }
    .hero-title { font-size: 3.2rem; font-weight: 900; line-height: 1.25; margin-bottom: 22px; letter-spacing: -0.02em; }
    .hero-title span { color: #5EEAD4; }
    .hero-description { font-size: 1.2rem; line-height: 1.85; color: #E2E8F0; margin-bottom: 38px; max-width: 820px; margin-left: auto; margin-right: auto; }
    .hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin-bottom: 50px; }
    .hero-preview-box { max-width: 860px; margin: 0 auto; background: rgba(255, 255, 255, 0.08); border: 1px solid rgba(255, 255, 255, 0.2); backdrop-filter: blur(8px); border-radius: 18px; padding: 18px; box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4); }
    .hero-preview-box img { width: 100%; border-radius: 12px; height: 380px; object-fit: cover; }
    .hero-metrics-bar { display: flex; justify-content: space-around; flex-wrap: wrap; gap: 20px; margin-top: 36px; padding-top: 28px; border-top: 1px solid rgba(255, 255, 255, 0.15); }
    .metric-hero-item { text-align: center; }
    .metric-hero-val { font-size: 1.9rem; font-weight: 800; color: #5EEAD4; }
    .metric-hero-lbl { font-size: 0.85rem; color: #CBD5E1; }

    /* 2. Problem Statement */
    .problem-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; }
    .problem-card { background: #FFF; border: 1px solid var(--border); border-radius: var(--radius); padding: 30px 24px; box-shadow: var(--shadow-sm); transition: var(--transition); border-top: 4px solid #CBD5E1; }
    .problem-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-top-color: var(--accent); }
    .problem-icon { width: 48px; height: 48px; border-radius: 10px; background: #FEF3C7; color: #D97706; display: flex; align-items: center; justify-content: center; font-size: 1.4rem; margin-bottom: 18px; }
    .problem-card h3 { font-size: 1.2rem; color: var(--text); margin-bottom: 10px; font-weight: 700; }
    .problem-card p { font-size: 0.95rem; color: var(--text-light); line-height: 1.7; }

    /* 3. Demo / Workflow */
    .demo-showcase { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
    .demo-media { position: relative; border-radius: 18px; overflow: hidden; box-shadow: var(--shadow-lg); border: 1px solid var(--border); }
    .demo-media img { width: 100%; height: 440px; object-fit: cover; }
    .demo-badge-float { position: absolute; bottom: 20px; left: 20px; right: 20px; background: rgba(15, 23, 42, 0.85); backdrop-filter: blur(6px); color: #fff; padding: 14px 18px; border-radius: 12px; font-size: 0.875rem; border: 1px solid rgba(255, 255, 255, 0.15); }
    .demo-step-list { display: flex; flex-direction: column; gap: 20px; }
    .demo-step-item { display: flex; gap: 18px; background: #fff; border: 1px solid var(--border); padding: 20px; border-radius: 12px; transition: var(--transition); }
    .demo-step-item:hover { border-color: var(--primary); box-shadow: var(--shadow-md); }
    .demo-step-num { width: 38px; height: 38px; border-radius: 8px; background: var(--primary-light); color: var(--primary); font-weight: 800; display: flex; align-items: center; justify-content: center; flex-shrink: 0; font-size: 1.1rem; }
    .demo-step-text h4 { font-size: 1.1rem; color: var(--text); margin-bottom: 6px; font-weight: 700; }
    .demo-step-text p { font-size: 0.925rem; color: var(--text-light); line-height: 1.65; }

    /* 4. Results Preview */
    .results-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
    .result-card { background: #fff; border-radius: var(--radius); border: 1px solid var(--border); padding: 26px; box-shadow: var(--shadow-sm); }
    .result-tag { font-size: 0.8rem; font-weight: 700; color: var(--accent-green); text-transform: uppercase; margin-bottom: 8px; }
    .result-stat { font-size: 2.25rem; font-weight: 800; color: var(--text); margin-bottom: 6px; font-feature-settings: "tnum"; }
    .result-title { font-size: 1.05rem; font-weight: 700; color: var(--text); margin-bottom: 8px; }
    .result-desc { font-size: 0.9rem; color: var(--text-light); line-height: 1.65; }

    /* 5. Pain Points / Bottlenecks Resolved */
    .bottleneck-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
    .bottleneck-box { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; }
    .bottleneck-header { display: flex; align-items: center; gap: 12px; margin-bottom: 20px; padding-bottom: 14px; border-bottom: 1px solid var(--border); }
    .bottleneck-header h3 { font-size: 1.25rem; color: var(--text); font-weight: 700; }
    .bottleneck-list { list-style: none; display: flex; flex-direction: column; gap: 16px; }
    .bottleneck-item { display: flex; align-items: flex-start; gap: 12px; font-size: 0.95rem; }
    .b-icon-cross { color: #EF4444; font-weight: bold; font-size: 1.1rem; line-height: 1; margin-top: 3px; }
    .b-icon-check { color: var(--accent-green); font-weight: bold; font-size: 1.1rem; line-height: 1; margin-top: 3px; }

    /* 6. Success Roadmap */
    .roadmap-timeline { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; position: relative; margin-top: 30px; }
    .roadmap-node { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; position: relative; }
    .roadmap-node-index { font-size: 0.8rem; font-weight: 800; color: var(--primary); background: var(--primary-light); display: inline-block; padding: 3px 10px; border-radius: 9999px; margin-bottom: 12px; }
    .roadmap-node h4 { font-size: 1.1rem; color: var(--text); margin-bottom: 8px; font-weight: 700; }
    .roadmap-node p { font-size: 0.9rem; color: var(--text-light); line-height: 1.6; }

    /* 7. Product Hardware & Software Suite */
    .products-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
    .product-card { background: #fff; border-radius: var(--radius); border: 1px solid var(--border); overflow: hidden; box-shadow: var(--shadow-sm); transition: var(--transition); display: flex; flex-direction: column; }
    .product-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
    .product-img-box { position: relative; height: 210px; overflow: hidden; }
    .product-img-box img { width: 100%; height: 100%; object-fit: cover; }
    .product-tag-pill { position: absolute; top: 14px; right: 14px; background: rgba(15, 23, 42, 0.75); color: #fff; font-size: 0.75rem; padding: 4px 10px; border-radius: 9999px; }
    .product-body { padding: 24px; flex-grow: 1; display: flex; flex-direction: column; }
    .product-title { font-size: 1.25rem; color: var(--text); margin-bottom: 8px; font-weight: 700; }
    .product-desc { font-size: 0.925rem; color: var(--text-light); margin-bottom: 18px; line-height: 1.65; flex-grow: 1; }
    .product-specs { background: var(--bg-light); border-radius: 8px; padding: 12px 14px; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 18px; }
    .product-specs-row { display: flex; justify-content: space-between; padding: 4px 0; border-bottom: 1px dashed var(--border); }
    .product-specs-row:last-child { border-bottom: none; }

    /* 8. Full Scenarios */
    .scenarios-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }
    .scenario-box { display: flex; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); }
    .scenario-thumb { width: 42%; position: relative; }
    .scenario-thumb img { width: 100%; height: 100%; object-fit: cover; }
    .scenario-info { width: 58%; padding: 26px; display: flex; flex-direction: column; justify-content: center; }
    .scenario-info h3 { font-size: 1.2rem; color: var(--text); margin-bottom: 10px; font-weight: 700; }
    .scenario-info p { font-size: 0.9rem; color: var(--text-light); line-height: 1.65; margin-bottom: 14px; }
    .scenario-bullets { list-style: none; font-size: 0.85rem; color: var(--primary); font-weight: 600; display: flex; flex-direction: column; gap: 6px; }

    /* 9. Tech & Algorithms (Dark Section) */
    .tech-showcase { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
    .tech-item-list { display: flex; flex-direction: column; gap: 18px; }
    .tech-item { background: var(--dark-card); border: 1px solid rgba(255, 255, 255, 0.1); border-radius: 12px; padding: 20px; }
    .tech-item h4 { font-size: 1.1rem; color: #5EEAD4; margin-bottom: 6px; font-weight: 700; }
    .tech-item p { font-size: 0.9rem; color: #CBD5E1; line-height: 1.65; }
    .tech-visual-box { position: relative; border-radius: 16px; overflow: hidden; border: 1px solid rgba(255, 255, 255, 0.15); box-shadow: 0 16px 36px rgba(0, 0, 0, 0.5); }
    .tech-visual-box img { width: 100%; height: 420px; object-fit: cover; }

    /* 10. School Cases */
    .cases-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
    .case-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); }
    .case-card img { width: 100%; height: 230px; object-fit: cover; }
    .case-card-body { padding: 26px; }
    .case-tag { font-size: 0.8rem; background: var(--primary-light); color: var(--primary); padding: 4px 10px; border-radius: 9999px; font-weight: 700; display: inline-block; margin-bottom: 10px; }
    .case-card-body h3 { font-size: 1.25rem; color: var(--text); margin-bottom: 10px; font-weight: 700; }
    .case-card-body p { font-size: 0.925rem; color: var(--text-light); line-height: 1.7; margin-bottom: 16px; }
    .case-stats { display: flex; gap: 20px; padding-top: 14px; border-top: 1px solid var(--border); }
    .case-stat-item strong { display: block; font-size: 1.35rem; color: var(--primary); font-weight: 800; }
    .case-stat-item span { font-size: 0.8rem; color: var(--text-light); }

    /* 11. Testimonials Wall */
    .testimonials-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
    .testimonial-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow-sm); display: flex; flex-direction: column; justify-content: space-between; }
    .testimonial-quote { font-size: 0.95rem; color: var(--text-muted); line-height: 1.75; margin-bottom: 20px; font-style: normal; }
    .testimonial-author { display: flex; align-items: center; gap: 12px; }
    .author-avatar { width: 44px; height: 44px; border-radius: 50%; background: var(--primary); color: #fff; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 1.1rem; }
    .author-info h4 { font-size: 0.95rem; color: var(--text); font-weight: 700; }
    .author-info span { font-size: 0.8rem; color: var(--text-light); }

    /* 12. Industry News */
    .news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
    .news-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); transition: var(--transition); }
    .news-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--primary); }
    .news-card-img { height: 180px; overflow: hidden; }
    .news-card-img img { width: 100%; height: 100%; object-fit: cover; }
    .news-body { padding: 22px; }
    .news-meta { font-size: 0.8rem; color: var(--text-light); margin-bottom: 8px; }
    .news-title { font-size: 1.1rem; color: var(--text); font-weight: 700; margin-bottom: 10px; line-height: 1.5; }
    .news-desc { font-size: 0.875rem; color: var(--text-light); line-height: 1.65; }

    /* 13. Consultation & Final Action Call (Single Terminal CTA) */
    .cta-section {
      background: linear-gradient(135deg, var(--primary-dark), #042F2E);
      color: #fff;
      padding: 90px 0;
      position: relative;
    }
    .cta-box { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
    .cta-content h2 { font-size: 2.3rem; font-weight: 800; line-height: 1.35; margin-bottom: 16px; }
    .cta-content p { font-size: 1.05rem; color: #CBD5E1; line-height: 1.8; margin-bottom: 24px; }
    .cta-guarantee-list { list-style: none; display: flex; flex-direction: column; gap: 10px; font-size: 0.925rem; color: #5EEAD4; }
    .cta-form-card { background: #fff; color: var(--text); border-radius: 16px; padding: 34px 28px; box-shadow: 0 20px 45px rgba(0, 0, 0, 0.25); }
    .cta-form-title { font-size: 1.35rem; font-weight: 800; color: var(--text); margin-bottom: 8px; text-align: center; }
    .cta-form-subtitle { font-size: 0.85rem; color: var(--text-light); margin-bottom: 22px; text-align: center; }
    .form-group { margin-bottom: 16px; }
    .form-group label { display: block; font-size: 0.875rem; font-weight: 600; color: var(--text); margin-bottom: 6px; }
    .form-control { width: 100%; padding: 12px 14px; border: 1px solid var(--border); border-radius: 8px; font-size: 0.95rem; color: var(--text); background: #F8FAFC; outline: none; transition: var(--transition); }
    .form-control:focus { border-color: var(--primary); background: #fff; box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.15); }
    .form-submit-btn { width: 100%; padding: 13px; font-size: 1rem; margin-top: 6px; }

    /* Footer */
    .footer { background: #0B1120; color: #94A3B8; font-size: 0.9rem; padding: 70px 0 24px; border-top: 1px solid #1E293B; }
    .footer-grid { display: grid; grid-template-columns: 1.3fr 0.9fr 0.9fr 1.2fr; gap: 36px; margin-bottom: 50px; }
    .footer-brand h4 { font-size: 1.25rem; color: #fff; font-weight: 800; margin-bottom: 14px; display: flex; align-items: center; gap: 10px; }
    .footer-brand p { font-size: 0.875rem; line-height: 1.8; color: #94A3B8; }
    .footer-col h5 { font-size: 1rem; color: #F1F5F9; font-weight: 700; margin-bottom: 18px; }
    .footer-links { list-style: none; display: flex; flex-direction: column; gap: 10px; }
    .footer-links a { color: #94A3B8; transition: var(--transition); font-size: 0.875rem; }
    .footer-links a:hover { color: #5EEAD4; }
    .footer-contact-info { display: flex; flex-direction: column; gap: 10px; font-size: 0.875rem; }
    .footer-bottom { border-top: 1px solid #1E293B; padding-top: 24px; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 14px; font-size: 0.825rem; color: #64748B; }

    /* Responsive */
    @media (max-width: 1024px) {
      .hero-title { font-size: 2.6rem; }
      .demo-showcase, .bottleneck-wrap, .tech-showcase, .cta-box { grid-template-columns: 1fr; }
      .roadmap-timeline { grid-template-columns: repeat(2, 1fr); }
      .products-grid, .testimonials-grid, .news-grid { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .topbar { display: none; }
      .nav-links { display: none; }
      .mobile-menu-btn { display: block; }
      .hero-title { font-size: 2rem; }
      .hero-section { padding: 90px 0 70px; }
      .section-title { font-size: 1.7rem; }
      .products-grid, .scenarios-grid, .cases-grid, .testimonials-grid, .news-grid, .roadmap-timeline { grid-template-columns: 1fr; }
      .scenario-box { flex-direction: column; }
      .scenario-thumb, .scenario-info { width: 100%; }
      .footer-grid { grid-template-columns: 1fr; }
      .footer-bottom { flex-direction: column; text-align: center; }
      .hero-preview-box img { height: 240px; }
    }