/* roulang page: index */
:root {
      --bg-primary: #0a0d14;
      --bg-secondary: #111622;
      --bg-tertiary: #171f30;
      --bg-card: rgba(23, 31, 48, 0.75);
      --accent-main: #3b82f6;
      --accent-grad: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 50%, #ec4899 100%);
      --accent-glow: rgba(59, 130, 246, 0.35);
      --text-main: #f8fafc;
      --text-muted: #94a3b8;
      --text-sub: #cbd5e1;
      --border-color: rgba(255, 255, 255, 0.08);
      --border-hover: rgba(59, 130, 246, 0.5);
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --radius-full: 9999px;
      --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.6);
      --container-max: 1200px;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-primary);
      color: var(--text-main);
      line-height: 1.6;
      overflow-x: hidden;
    }
    a { color: inherit; text-decoration: none; transition: all 0.25s ease; }
    img { max-width: 100%; height: auto; display: block; }
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* Header */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(10, 13, 20, 0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .site-brand {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 1.2rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: #fff;
    }
    .brand-mark {
      width: 36px;
      height: 36px;
      background: var(--accent-grad);
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 0 15px var(--accent-glow);
    }
    .site-nav { display: flex; align-items: center; gap: 24px; }
    .nav-link { font-size: 0.95rem; color: var(--text-sub); }
    .nav-link:hover, .nav-link.active { color: #fff; }
    .header-cta {
      display: inline-flex;
      align-items: center;
      padding: 8px 18px;
      border-radius: var(--radius-full);
      background: var(--accent-grad);
      color: #fff;
      font-size: 0.88rem;
      font-weight: 600;
      box-shadow: 0 0 20px var(--accent-glow);
    }

    /* Common Section */
    .section-wrap {
      padding: 80px 0;
      position: relative;
    }
    .section-alt {
      background-color: var(--bg-secondary);
      border-top: 1px solid var(--border-color);
      border-bottom: 1px solid var(--border-color);
    }
    .sec-head {
      margin-bottom: 48px;
      max-width: 800px;
    }
    .sec-head.center {
      text-align: center;
      margin-left: auto;
      margin-right: auto;
    }
    .badge {
      display: inline-block;
      padding: 4px 12px;
      font-size: 0.78rem;
      font-weight: 600;
      color: #60a5fa;
      background: rgba(59, 130, 246, 0.15);
      border: 1px solid rgba(59, 130, 246, 0.3);
      border-radius: var(--radius-full);
      margin-bottom: 12px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .sec-title {
      font-size: 2rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
      color: #fff;
    }
    .sec-desc {
      font-size: 1rem;
      color: var(--text-muted);
      line-height: 1.7;
    }

    /* Hero */
    .hero-section {
      position: relative;
      padding: 120px 0 100px;
      background: radial-gradient(circle at 50% 20%, rgba(59, 130, 246, 0.18), transparent 70%), var(--bg-primary);
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
      align-items: center;
    }
    .hero-h1 {
      font-size: 2.6rem;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 24px;
      background: linear-gradient(180deg, #fff 0%, #cbd5e1 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .hero-sub {
      font-size: 1.05rem;
      color: var(--text-sub);
      line-height: 1.8;
      margin-bottom: 36px;
    }
    .hero-action-group {
      display: flex;
      align-items: center;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-main {
      padding: 14px 28px;
      border-radius: var(--radius-md);
      background: var(--accent-grad);
      color: #fff;
      font-weight: 600;
      font-size: 1rem;
      box-shadow: 0 4px 20px var(--accent-glow);
    }
    .btn-main:hover {
      transform: translateY(-2px);
      box-shadow: 0 8px 25px rgba(59, 130, 246, 0.5);
    }
    .btn-ghost {
      padding: 14px 28px;
      border-radius: var(--radius-md);
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid var(--border-color);
      color: #fff;
      font-weight: 600;
      font-size: 1rem;
    }
    .btn-ghost:hover {
      background: rgba(255, 255, 255, 0.1);
      border-color: rgba(255, 255, 255, 0.2);
    }
    .hero-visual {
      position: relative;
      border-radius: var(--radius-lg);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-card);
    }
    .hero-visual img {
      width: 100%;
      height: 420px;
      object-fit: cover;
      transform: scale(1.02);
      transition: transform 0.5s ease;
    }
    .hero-visual:hover img {
      transform: scale(1.05);
    }
    .hero-badge-overlay {
      position: absolute;
      bottom: 20px;
      left: 20px;
      right: 20px;
      background: rgba(10, 13, 20, 0.85);
      backdrop-filter: blur(8px);
      padding: 16px 20px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .hero-stat-item b {
      display: block;
      font-size: 1.25rem;
      color: #60a5fa;
    }
    .hero-stat-item span {
      font-size: 0.75rem;
      color: var(--text-muted);
    }

    /* Cards & Grids */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }
    .card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-lg);
      padding: 30px;
      backdrop-filter: blur(10px);
      transition: all 0.3s ease;
      position: relative;
    }
    .card:hover {
      border-color: var(--border-hover);
      transform: translateY(-4px);
      box-shadow: var(--shadow-card);
    }
    .card-title {
      font-size: 1.2rem;
      font-weight: 700;
      color: #fff;
      margin-bottom: 12px;
    }
    .card-p {
      font-size: 0.92rem;
      color: var(--text-muted);
      line-height: 1.65;
    }

    /* Matrix / Comparison */
    .compare-table {
      width: 100%;
      border-collapse: collapse;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      background: var(--bg-card);
    }
    .compare-table th, .compare-table td {
      padding: 16px 20px;
      text-align: left;
      border-bottom: 1px solid var(--border-color);
      font-size: 0.92rem;
    }
    .compare-table th {
      background: rgba(255, 255, 255, 0.03);
      color: #fff;
      font-weight: 600;
    }
    .compare-table td { color: var(--text-sub); }
    .compare-table tr:last-child td { border-bottom: none; }
    .tag-blue { color: #60a5fa; font-weight: 600; }
    .tag-green { color: #34d399; font-weight: 600; }

    /* Step flow */
    .step-list {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }
    .step-card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 24px;
    }
    .step-idx {
      font-size: 1.8rem;
      font-weight: 800;
      color: rgba(59, 130, 246, 0.4);
      margin-bottom: 12px;
    }

    /* Wall / Quotes */
    .quote-box {
      border-left: 3px solid #3b82f6;
      padding-left: 20px;
      margin-top: 14px;
      font-size: 0.88rem;
      color: var(--text-muted);
      font-style: italic;
    }

    /* List with Icons */
    .tech-list {
      list-style: none;
      margin-top: 16px;
    }
    .tech-list li {
      font-size: 0.9rem;
      color: var(--text-sub);
      margin-bottom: 10px;
      position: relative;
      padding-left: 20px;
    }
    .tech-list li::before {
      content: "•";
      position: absolute;
      left: 0;
      color: #3b82f6;
      font-size: 1.2rem;
      line-height: 1;
    }

    /* Form */
    .lead-box {
      max-width: 600px;
      margin: 0 auto;
      background: var(--bg-card);
      padding: 40px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
    }
    .form-group {
      margin-bottom: 20px;
    }
    .form-group label {
      display: block;
      font-size: 0.88rem;
      color: var(--text-sub);
      margin-bottom: 8px;
    }
    .form-control {
      width: 100%;
      padding: 12px 16px;
      background: rgba(10, 13, 20, 0.6);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      color: #fff;
      font-size: 0.95rem;
    }
    .form-control:focus {
      outline: none;
      border-color: #3b82f6;
    }

    /* Footer */
    .site-footer {
      background: #06080d;
      border-top: 1px solid var(--border-color);
      padding: 60px 0 30px;
      font-size: 0.88rem;
      color: var(--text-muted);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-brand { font-size: 1.15rem; font-weight: 700; color: #fff; margin-bottom: 14px; }
    .footer-links { list-style: none; }
    .footer-links li { margin-bottom: 8px; }
    .footer-links a:hover { color: #fff; }
    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.05);
      padding-top: 24px;
      display: flex;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 16px;
    }

    /* Responsive */
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; gap: 40px; }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .step-list { grid-template-columns: repeat(2, 1fr); }
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .grid-3, .grid-2, .footer-grid { grid-template-columns: 1fr; }
      .site-nav { display: none; }
      .hero-h1 { font-size: 2rem; }
      .sec-title { font-size: 1.6rem; }
      .section-wrap { padding: 60px 0; }
    }