:root {
      --bg: #090d16;
      --card-bg: #111827;
      --card-border: #1f2937;
      --accent: #2563eb;
      --accent-hover: #1d4ed8;
      --accent-glow: rgba(37, 99, 235, 0.25);
      --emerald: #059669;
      --emerald-glow: rgba(5, 150, 105, 0.2);
      --amber: #d97706;
      --text-main: #f9fafb;
      --text-muted: #9ca3af;
      --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      background-color: var(--bg);
      color: var(--text-main);
      font-family: var(--font);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    a { color: #60a5fa; text-decoration: none; }
    a:hover { text-decoration: underline; }
    .container { max-width: 1200px; margin: 0 auto; padding: 0 1.25rem; }
    
    /* Header & Navigation */
    header {
      background: rgba(17, 24, 39, 0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--card-border);
      position: sticky;
      top: 0;
      z-index: 100;
    }
    .nav-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.85rem 0;
      gap: 1rem;
    }
    .brand {
      display: flex;
      align-items: center;
      gap: 0.65rem;
      font-weight: 700;
      font-size: 1.15rem;
      color: #fff;
      text-decoration: none;
    }
    .brand svg { width: 28px; height: 28px; fill: #3b82f6; }
    .nav-links {
      display: flex;
      gap: 1.25rem;
      list-style: none;
      align-items: center;
    }
    .nav-links a {
      color: var(--text-muted);
      font-size: 0.9rem;
      font-weight: 500;
      transition: color 0.15s;
    }
    .nav-links a:hover { color: #fff; text-decoration: none; }
    .phone-pill {
      background: linear-gradient(135deg, #1e40af, #2563eb);
      color: #fff !important;
      padding: 0.5rem 1rem;
      border-radius: 9999px;
      font-weight: 600;
      font-size: 0.875rem;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      box-shadow: 0 2px 10px var(--accent-glow);
      text-decoration: none !important;
    }
    .phone-pill:hover { background: #1d4ed8; }

    /* Top Viewport Calculator Grid */
    .hero-section {
      padding: 2.25rem 0 1.5rem 0;
      border-bottom: 1px solid var(--card-border);
      background: radial-gradient(circle at 50% 0%, rgba(37,99,235,0.08) 0%, rgba(9,13,22,1) 75%);
    }
    .badge-pill {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      border-radius: 9999px;
      font-size: 0.75rem;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      background: rgba(37, 99, 235, 0.15);
      color: #60a5fa;
      border: 1px solid rgba(59, 130, 246, 0.3);
      margin-bottom: 0.75rem;
    }
    h1 {
      font-size: 2.15rem;
      line-height: 1.25;
      font-weight: 800;
      letter-spacing: -0.025em;
      margin-bottom: 0.65rem;
      color: #fff;
    }
    .hero-lead {
      color: var(--text-muted);
      font-size: 1.05rem;
      max-width: 820px;
      margin-bottom: 1.75rem;
    }
    
    /* Interactive Calculator Container */
    .calculator-card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: 14px;
      padding: 1.5rem;
      box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
      margin-bottom: 1.75rem;
    }
    .calc-grid {
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      gap: 1.5rem;
    }
    @media (max-width: 900px) {
      .calc-grid { grid-template-columns: 1fr; }
      .nav-links { display: none; }
      h1 { font-size: 1.75rem; }
    }
    .input-group { margin-bottom: 1rem; }
    .input-group label {
      display: flex;
      justify-content: space-between;
      font-size: 0.825rem;
      font-weight: 600;
      color: #d1d5db;
      margin-bottom: 0.35rem;
    }
    .input-val-tag {
      color: #60a5fa;
      font-weight: 700;
    }
    input[type="range"] {
      width: 100%;
      height: 6px;
      background: #374151;
      border-radius: 4px;
      outline: none;
      -webkit-appearance: none;
    }
    input[type="range"]::-webkit-slider-thumb {
      -webkit-appearance: none;
      width: 18px;
      height: 18px;
      border-radius: 50%;
      background: #2563eb;
      cursor: pointer;
      box-shadow: 0 0 8px rgba(37,99,235,0.6);
    }
    .grid-2 {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0.75rem;
    }
    select, input[type="text"], input[type="tel"] {
      width: 100%;
      background: #1f2937;
      border: 1px solid #374151;
      color: #fff;
      padding: 0.55rem 0.75rem;
      border-radius: 8px;
      font-size: 0.875rem;
      outline: none;
    }
    select:focus, input:focus { border-color: #3b82f6; }
    
    /* Engineering Math Output Panel (Rule 7.1 Zero-Click Gate) */
    .output-panel {
      background: #0d121f;
      border: 1px solid #1e293b;
      border-radius: 12px;
      padding: 1.25rem;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .output-badge {
      font-size: 0.75rem;
      font-weight: 700;
      color: #34d399;
      background: rgba(5, 150, 105, 0.15);
      border: 1px solid rgba(5, 150, 105, 0.3);
      padding: 0.2rem 0.6rem;
      border-radius: 6px;
      display: inline-block;
      margin-bottom: 0.75rem;
    }
    .stat-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.45rem 0;
      border-bottom: 1px solid #1e293b;
      font-size: 0.85rem;
    }
    .stat-row:last-child { border-bottom: none; }
    .stat-label { color: #9ca3af; }
    .stat-value { font-weight: 700; color: #fff; font-size: 0.95rem; }
    .stat-highlight { color: #60a5fa; font-size: 1.15rem; }
    
    .btn-group-navboost {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0.5rem;
      margin-top: 1rem;
    }
    .btn-secondary {
      background: #1f2937;
      border: 1px solid #374151;
      color: #e5e7eb;
      font-size: 0.8rem;
      padding: 0.5rem;
      border-radius: 8px;
      cursor: pointer;
      font-weight: 600;
      text-align: center;
      transition: background 0.15s;
    }
    .btn-secondary:hover { background: #374151; }

    /* Locked Price Drawer (Lead Capture Form) */
    .locked-drawer {
      margin-top: 1.25rem;
      background: linear-gradient(180deg, rgba(30, 41, 59, 0.7) 0%, rgba(15, 23, 42, 0.9) 100%);
      border: 1px solid rgba(59, 130, 246, 0.4);
      border-radius: 12px;
      padding: 1.25rem;
      position: relative;
    }
    .locked-header {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-size: 0.95rem;
      font-weight: 700;
      color: #93c5fd;
      margin-bottom: 0.5rem;
    }
    .locked-desc {
      font-size: 0.825rem;
      color: #9ca3af;
      margin-bottom: 0.85rem;
    }
    .lead-form-grid {
      display: grid;
      grid-template-columns: 1fr 1.2fr 1fr;
      gap: 0.65rem;
    }
    @media (max-width: 650px) {
      .lead-form-grid { grid-template-columns: 1fr; }
    }
    .btn-primary {
      background: linear-gradient(135deg, #2563eb, #1d4ed8);
      border: none;
      color: #fff;
      font-weight: 700;
      font-size: 0.875rem;
      border-radius: 8px;
      cursor: pointer;
      padding: 0.65rem 1rem;
      box-shadow: 0 4px 14px var(--accent-glow);
      transition: transform 0.1s, background 0.15s;
    }
    .btn-primary:hover { background: #1e40af; transform: translateY(-1px); }
    .form-guarantee {
      font-size: 0.725rem;
      color: #6b7280;
      margin-top: 0.5rem;
      text-align: center;
    }
    
    /* 135-Second Estimator Call Priming Card */
    .call-prep-card {
      background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(15, 23, 42, 0.6));
      border: 1px solid rgba(59, 130, 246, 0.3);
      border-radius: 12px;
      padding: 1rem 1.25rem;
      margin-top: 1.5rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 1.25rem;
      flex-wrap: wrap;
    }
    .call-prep-left { max-width: 680px; }
    .call-prep-title {
      font-weight: 700;
      font-size: 0.95rem;
      color: #93c5fd;
      margin-bottom: 0.25rem;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }
    .call-prep-text {
      font-size: 0.825rem;
      color: #cbd5e1;
      line-height: 1.5;
    }
    .call-prep-right {
      text-align: right;
      display: flex;
      flex-direction: column;
      align-items: flex-end;
      gap: 0.25rem;
    }
    .est-clock {
      font-size: 0.75rem;
      color: #34d399;
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 0.35rem;
    }
    .est-clock::before {
      content: "";
      width: 7px;
      height: 7px;
      background: #10b981;
      border-radius: 50%;
      display: inline-block;
      box-shadow: 0 0 6px #10b981;
    }

    /* Content & Article Styles */
    .article-wrap {
      padding: 3rem 0;
    }
    .article-inner {
      max-width: 880px;
      margin: 0 auto;
    }
    .article-inner h2 {
      font-size: 1.65rem;
      font-weight: 700;
      color: #fff;
      margin: 2.25rem 0 1rem 0;
      line-height: 1.3;
      border-bottom: 1px solid #1f2937;
      padding-bottom: 0.5rem;
    }
    .article-inner h3 {
      font-size: 1.25rem;
      font-weight: 600;
      color: #93c5fd;
      margin: 1.5rem 0 0.75rem 0;
    }
    .article-inner p {
      color: #d1d5db;
      font-size: 0.975rem;
      line-height: 1.75;
      margin-bottom: 1.25rem;
    }
    .article-inner ul, .article-inner ol {
      margin: 1rem 0 1.5rem 1.75rem;
      color: #d1d5db;
      font-size: 0.95rem;
    }
    .article-inner li { margin-bottom: 0.5rem; }
    
    /* Data Tables */
    .table-container {
      overflow-x: auto;
      margin: 1.75rem 0;
      border: 1px solid var(--card-border);
      border-radius: 10px;
    }
    table {
      width: 100%;
      border-collapse: collapse;
      font-size: 0.875rem;
      text-align: left;
    }
    th {
      background: #1e293b;
      color: #f1f5f9;
      font-weight: 600;
      padding: 0.75rem 1rem;
      border-bottom: 1px solid var(--card-border);
    }
    td {
      padding: 0.75rem 1rem;
      border-bottom: 1px solid #1f2937;
      color: #cbd5e1;
    }
    tr:nth-child(even) { background: rgba(30, 41, 59, 0.4); }
    tr:hover { background: rgba(59, 130, 246, 0.08); }

    /* Counter-Positioning Matrix */
    .compare-box {
      background: #111827;
      border: 1px solid #374151;
      border-radius: 12px;
      padding: 1.5rem;
      margin: 2.25rem 0;
    }
    .compare-title {
      font-size: 1.15rem;
      font-weight: 700;
      color: #f3f4f6;
      margin-bottom: 1rem;
      text-align: center;
    }

    /* FAQ Section */
    .faq-block {
      margin: 2.5rem 0;
    }
    .faq-item {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: 8px;
      padding: 1.15rem;
      margin-bottom: 0.85rem;
    }
    .faq-q {
      font-weight: 700;
      color: #fff;
      font-size: 1rem;
      margin-bottom: 0.5rem;
    }
    .faq-a {
      font-size: 0.925rem;
      color: #9ca3af;
      line-height: 1.6;
    }

    /* Internal Sibling Links */
    .hub-links {
      background: #0f172a;
      border: 1px solid #1e293b;
      border-radius: 12px;
      padding: 1.75rem;
      margin: 3rem 0;
    }
    .hub-links h3 {
      font-size: 1.15rem;
      color: #fff;
      margin-bottom: 1rem;
    }
    .hub-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
      gap: 0.75rem;
    }
    .hub-grid a {
      background: #1e293b;
      padding: 0.65rem 0.85rem;
      border-radius: 6px;
      font-size: 0.825rem;
      color: #93c5fd;
      display: block;
      transition: background 0.15s;
    }
    .hub-grid a:hover {
      background: #2563eb;
      color: #fff;
      text-decoration: none;
    }

    /* Footer & Marketcall Disclaimers */
    footer {
      background: #030712;
      border-top: 1px solid var(--card-border);
      padding: 3rem 0 2rem 0;
      font-size: 0.8rem;
      color: #6b7280;
    }
    .footer-disclaimer-card {
      background: #090d16;
      border: 1px solid #1f2937;
      border-radius: 8px;
      padding: 1.25rem;
      margin-bottom: 1.5rem;
      line-height: 1.6;
    }
    .footer-disclaimer-card p { margin-bottom: 0.75rem; }
    .footer-disclaimer-card p:last-child { margin-bottom: 0; }
    .footer-legal-line {
      text-align: center;
      padding-top: 1.5rem;
      border-top: 1px solid #111827;
      font-size: 0.75rem;
      color: #4b5563;
    }
input[type="email"] { width: 100%; background: #1f2937; border: 1px solid #374151; color: #fff; padding: 0.55rem 0.75rem; border-radius: 8px; font-size: 0.875rem; outline: none; }
input[type="email"]:focus { border-color: #3b82f6; }