:root {
      --rfdg-ink: #091a36;
      --rfdg-muted: #53637b;
      --rfdg-line: #dce7f5;
      --rfdg-blue: #1768e5;
      --rfdg-cyan: #10b9d2;
      --rfdg-ice: #f2f8ff;
      --rfdg-navy: #071c3e;
      --rfdg-white: #ffffff;
      --rfdg-shadow: 0 22px 60px rgba(7, 28, 62, 0.12);
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      color: var(--rfdg-ink);
      background: #fff;
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
      line-height: 1.72;
      -webkit-font-smoothing: antialiased;
    }
    img { display: block; max-width: 100%; }
    a { color: var(--rfdg-blue); }
    a:hover { color: #0c4fb3; }

    .rfdg-page { overflow: hidden; }
    .rfdg-container { width: min(1160px, calc(100% - 40px)); margin-inline: auto; }

    .rfdg-hero {
      position: relative;
      isolation: isolate;
      padding: 72px 0 54px;
      color: #fff;
      background:
        radial-gradient(circle at 82% 18%, rgba(16, 185, 210, .28), transparent 30%),
        linear-gradient(135deg, #06152f 0%, #082955 58%, #0b5590 100%);
    }
    .rfdg-hero::before {
      content: "";
      position: absolute;
      z-index: -1;
      inset: 0;
      opacity: .22;
      background-image: linear-gradient(rgba(255,255,255,.08) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.08) 1px, transparent 1px);
      background-size: 42px 42px;
      mask-image: linear-gradient(to bottom, #000, transparent 94%);
    }
    .rfdg-hero-grid {
      display: grid;
      grid-template-columns: minmax(0, 1.22fr) minmax(320px, .78fr);
      gap: 54px;
      align-items: center;
    }
    .rfdg-eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      margin: 0 0 22px;
      color: #8feeff;
      font-size: .78rem;
      font-weight: 800;
      letter-spacing: .16em;
      text-transform: uppercase;
    }
    .rfdg-eyebrow::before { content: ""; width: 34px; height: 2px; background: currentColor; }
    .rfdg-hero h1 {
      max-width: 780px;
      margin: 0;
      font-size: clamp(2.35rem, 5.2vw, 4.85rem);
      line-height: 1.04;
      letter-spacing: -.045em;
    }
    .rfdg-lead {
      max-width: 700px;
      margin: 24px 0 0;
      color: #dbeaff;
      font-size: clamp(1rem, 1.8vw, 1.2rem);
    }
    .rfdg-meta {
      display: flex;
      flex-wrap: wrap;
      gap: 12px 24px;
      margin-top: 28px;
      color: #b9d2ee;
      font-size: .9rem;
    }
    .rfdg-hero-visual {
      position: relative;
      min-height: 430px;
      border: 1px solid rgba(255,255,255,.2);
      border-radius: 30px;
      background: linear-gradient(160deg, rgba(255,255,255,.98), rgba(222,244,255,.88));
      box-shadow: 0 32px 80px rgba(0,0,0,.28);
    }
    .rfdg-hero-visual img {
      width: 100%;
      height: 430px;
      object-fit: contain;
      padding: 22px;
    }
    .rfdg-depth-badge {
      position: absolute;
      left: -26px;
      bottom: 30px;
      padding: 18px 21px;
      border-radius: 18px;
      color: var(--rfdg-navy);
      background: #fff;
      box-shadow: var(--rfdg-shadow);
    }
    .rfdg-depth-badge strong { display: block; color: var(--rfdg-blue); font-size: 1.75rem; line-height: 1; }
    .rfdg-depth-badge span { font-size: .75rem; font-weight: 800; letter-spacing: .09em; text-transform: uppercase; }

    .rfdg-ruler-wrap {
      position: relative;
      z-index: 2;
      margin-top: -1px;
      padding: 28px 0;
      color: #fff;
      background: #071b3b;
    }
    .rfdg-ruler {
      display: grid;
      grid-template-columns: repeat(8, 1fr);
      gap: 0;
      align-items: end;
    }
    .rfdg-ruler span {
      position: relative;
      min-height: 55px;
      padding-top: 25px;
      border-left: 1px solid rgba(255,255,255,.22);
      color: #bad0eb;
      font-size: .8rem;
      text-align: center;
    }
    .rfdg-ruler span::before {
      content: "";
      position: absolute;
      top: 0;
      left: 50%;
      width: 2px;
      height: 14px;
      background: #7feaff;
    }
    .rfdg-ruler strong { display: block; color: #fff; font-size: 1rem; }

    .rfdg-main { padding: 72px 0 92px; }
    .rfdg-layout { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 58px; align-items: start; }
    .rfdg-toc {
      position: sticky;
      top: 24px;
      padding: 24px;
      border: 1px solid var(--rfdg-line);
      border-radius: 20px;
      background: #fff;
      box-shadow: 0 12px 34px rgba(7,28,62,.06);
    }
    .rfdg-toc strong { display: block; margin-bottom: 12px; font-size: .78rem; letter-spacing: .12em; text-transform: uppercase; }
    .rfdg-toc a { display: block; padding: 8px 0; color: #56667e; font-size: .88rem; text-decoration: none; border-bottom: 1px solid #edf2f8; }
    .rfdg-toc a:last-child { border: 0; }
    .rfdg-toc a:hover { color: var(--rfdg-blue); }

    .rfdg-content { min-width: 0; }
    .rfdg-content h2 {
      margin: 72px 0 18px;
      color: var(--rfdg-navy);
      font-size: clamp(1.75rem, 3.3vw, 2.75rem);
      line-height: 1.15;
      letter-spacing: -.035em;
    }
    .rfdg-content h2:first-child { margin-top: 0; }
    .rfdg-content h3 { margin: 34px 0 10px; color: var(--rfdg-navy); font-size: 1.22rem; line-height: 1.3; }
    .rfdg-content p { margin: 0 0 20px; color: #34445b; }
    .rfdg-content ul, .rfdg-content ol { margin: 0 0 24px; padding-left: 23px; color: #34445b; }
    .rfdg-content li { margin: 8px 0; }

    .rfdg-summary {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 16px;
      margin: 30px 0 10px;
    }
    .rfdg-summary article {
      padding: 24px;
      border: 1px solid var(--rfdg-line);
      border-radius: 18px;
      background: linear-gradient(145deg, #fff, var(--rfdg-ice));
    }
    .rfdg-summary b { display: block; margin-bottom: 7px; color: var(--rfdg-blue); font-size: 1.1rem; }
    .rfdg-summary p { margin: 0; font-size: .92rem; }

    .rfdg-note {
      margin: 28px 0;
      padding: 22px 24px;
      border-left: 4px solid var(--rfdg-cyan);
      border-radius: 0 16px 16px 0;
      background: #eefbfe;
    }
    .rfdg-note strong { color: #07566b; }
    .rfdg-note p { margin: 0; color: #275765; }

    .rfdg-depth-stack { display: grid; gap: 14px; margin: 30px 0; }
    .rfdg-depth-card {
      display: grid;
      grid-template-columns: 122px minmax(0, 1fr);
      gap: 24px;
      padding: 25px;
      border: 1px solid var(--rfdg-line);
      border-radius: 20px;
      background: #fff;
      transition: transform .2s ease, box-shadow .2s ease;
    }
    .rfdg-depth-card:hover { transform: translateY(-2px); box-shadow: 0 16px 38px rgba(7,28,62,.09); }
    .rfdg-depth-number {
      display: grid;
      place-items: center;
      min-height: 86px;
      padding: 12px;
      border-radius: 16px;
      color: #fff;
      background: linear-gradient(145deg, var(--rfdg-blue), var(--rfdg-cyan));
      font-size: 1.35rem;
      font-weight: 900;
      line-height: 1.05;
      text-align: center;
    }
    .rfdg-depth-card:nth-child(4) .rfdg-depth-number,
    .rfdg-depth-card:nth-child(5) .rfdg-depth-number { background: linear-gradient(145deg, #123c78, #071c3e); }
    .rfdg-depth-card h3 { margin: 0 0 8px; }
    .rfdg-depth-card p { margin: 0; }

    .rfdg-table-wrap { margin: 28px 0; overflow-x: auto; border: 1px solid var(--rfdg-line); border-radius: 20px; }
    .rfdg-table { width: 100%; min-width: 740px; border-collapse: collapse; background: #fff; }
    .rfdg-table th, .rfdg-table td { padding: 17px 18px; border-bottom: 1px solid var(--rfdg-line); text-align: left; vertical-align: top; }
    .rfdg-table th { color: #fff; background: var(--rfdg-navy); font-size: .79rem; letter-spacing: .07em; text-transform: uppercase; }
    .rfdg-table tr:last-child td { border-bottom: 0; }
    .rfdg-table tbody tr:nth-child(even) { background: #f8fbff; }
    .rfdg-table td:first-child { color: var(--rfdg-blue); font-weight: 850; white-space: nowrap; }

    .rfdg-equation {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 12px;
      margin: 30px 0;
    }
    .rfdg-equation div { padding: 20px 16px; border-radius: 16px; color: #fff; background: var(--rfdg-navy); text-align: center; }
    .rfdg-equation b { display: block; color: #80eaff; font-size: 1rem; }
    .rfdg-equation span { display: block; margin-top: 5px; color: #c8d9ed; font-size: .8rem; }

    .rfdg-checklist { counter-reset: steps; display: grid; gap: 13px; margin: 26px 0; padding: 0 !important; list-style: none; }
    .rfdg-checklist li {
      position: relative;
      margin: 0;
      padding: 20px 20px 20px 70px;
      border: 1px solid var(--rfdg-line);
      border-radius: 16px;
      background: #fff;
    }
    .rfdg-checklist li::before {
      counter-increment: steps;
      content: counter(steps);
      position: absolute;
      top: 17px;
      left: 18px;
      display: grid;
      width: 34px;
      height: 34px;
      place-items: center;
      border-radius: 50%;
      color: #fff;
      background: var(--rfdg-blue);
      font-weight: 850;
    }

    .rfdg-product {
      position: relative;
      overflow: hidden;
      display: grid;
      grid-template-columns: 1.1fr .9fr;
      gap: 28px;
      align-items: center;
      margin: 68px 0;
      padding: 40px;
      border-radius: 28px;
      color: #fff;
      background: linear-gradient(135deg, #071c3e, #0a5d99);
      box-shadow: var(--rfdg-shadow);
    }
    .rfdg-product::after { content: "7.0"; position: absolute; right: -20px; bottom: -70px; color: rgba(255,255,255,.06); font-size: 13rem; font-weight: 900; line-height: 1; }
    .rfdg-product h2 { margin: 0 0 14px; color: #fff; }
    .rfdg-product p { color: #d3e4f6; }
    .rfdg-specs { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; position: relative; z-index: 1; }
    .rfdg-specs span { padding: 12px 13px; border: 1px solid rgba(255,255,255,.18); border-radius: 12px; background: rgba(255,255,255,.08); font-size: .84rem; }
    .rfdg-button {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      margin-top: 9px;
      padding: 14px 20px;
      border-radius: 999px;
      color: var(--rfdg-navy);
      background: #fff;
      font-weight: 850;
      text-decoration: none;
      transition: transform .2s ease;
    }
    .rfdg-button:hover { color: var(--rfdg-navy); transform: translateY(-2px); }

    .rfdg-faq { display: grid; gap: 12px; margin-top: 28px; }
    .rfdg-faq details { border: 1px solid var(--rfdg-line); border-radius: 16px; background: #fff; }
    .rfdg-faq summary { padding: 19px 50px 19px 20px; color: var(--rfdg-navy); font-weight: 820; cursor: pointer; }
    .rfdg-faq details p { padding: 0 20px 20px; margin: 0; }

    .rfdg-references { margin-top: 58px; padding: 28px; border-radius: 20px; background: #f6f9fd; }
    .rfdg-references h2 { margin-top: 0; font-size: 1.45rem; }
    .rfdg-references ol { margin-bottom: 0; font-size: .9rem; }

    .rfdg-disclaimer { margin-top: 34px; padding-top: 24px; border-top: 1px solid var(--rfdg-line); color: #6b778a; font-size: .82rem; }

    @media (max-width: 900px) {
      .rfdg-hero-grid, .rfdg-product { grid-template-columns: 1fr; }
      .rfdg-layout { grid-template-columns: 1fr; }
      .rfdg-toc { position: static; }
      .rfdg-summary { grid-template-columns: 1fr; }
      .rfdg-equation { grid-template-columns: repeat(2, 1fr); }
      .rfdg-hero-visual { width: min(520px, 100%); margin-inline: auto; }
      .rfdg-depth-badge { left: 16px; }
    }
    @media (max-width: 580px) {
      .rfdg-container { width: min(100% - 28px, 1160px); }
      .rfdg-hero { padding-top: 48px; }
      .rfdg-hero-visual, .rfdg-hero-visual img { min-height: 340px; height: 340px; }
      .rfdg-ruler { grid-template-columns: repeat(4, 1fr); row-gap: 16px; }
      .rfdg-depth-card { grid-template-columns: 1fr; }
      .rfdg-depth-number { min-height: 64px; }
      .rfdg-equation, .rfdg-specs { grid-template-columns: 1fr; }
      .rfdg-product { padding: 28px 22px; }
    }