:root {
      --rf-navy: #0c2f4d;
      --rf-blue: #087fa7;
      --rf-cyan: #12a9c7;
      --rf-pale: #eef8fb;
      --rf-line: #d4e8ee;
      --rf-text: #22343e;
      --rf-muted: #617782;
      --rf-white: #ffffff;
      --rf-warm: #fff8ed;
      --rf-warm-line: #f0d29b;
      --rf-shadow: 0 18px 50px rgba(12, 47, 77, .10);
    }

    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; }
    body {
      margin: 0;
      background: #f7fbfc;
      color: var(--rf-text);
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
      font-size: 17px;
      line-height: 1.75;
    }

    a { color: #08799d; text-decoration-thickness: 1px; text-underline-offset: 3px; }
    a:hover { color: var(--rf-navy); }
    img { max-width: 100%; height: auto; }
    .rf-page { overflow: hidden; }
    .rf-container { width: min(1160px, calc(100% - 34px)); margin: 0 auto; }

    .rf-hero {
      position: relative;
      padding: 34px 0 76px;
      background:
        radial-gradient(circle at 88% 8%, rgba(18, 169, 199, .18), transparent 27%),
        linear-gradient(145deg, #f8fdff 0%, #e9f7fb 55%, #f8fcfd 100%);
      border-bottom: 1px solid var(--rf-line);
    }
    .rf-hero::after {
      content: "";
      position: absolute;
      right: -180px;
      bottom: -260px;
      width: 520px;
      height: 520px;
      border: 1px solid rgba(18, 169, 199, .24);
      border-radius: 50%;
    }
    .rf-breadcrumbs {
      margin-bottom: 44px;
      color: var(--rf-muted);
      font-size: 14px;
    }
    .rf-breadcrumbs a { color: var(--rf-muted); text-decoration: none; }
    .rf-breadcrumbs span { margin: 0 8px; color: #8da4ae; }
    .rf-hero-grid {
      position: relative;
      z-index: 1;
      display: grid;
      grid-template-columns: minmax(0, 1.15fr) minmax(320px, .85fr);
      align-items: center;
      gap: 58px;
    }
    .rf-kicker {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      margin: 0 0 18px;
      color: var(--rf-blue);
      font-size: 13px;
      font-weight: 800;
      letter-spacing: .12em;
      text-transform: uppercase;
    }
    .rf-kicker::before {
      content: "";
      width: 28px;
      height: 3px;
      border-radius: 3px;
      background: var(--rf-cyan);
    }
    h1, h2, h3 { color: var(--rf-navy); line-height: 1.2; letter-spacing: -.025em; }
    h1 { margin: 0 0 24px; font-size: clamp(39px, 5.3vw, 67px); }
    h2 { margin: 0 0 18px; font-size: clamp(28px, 3.4vw, 41px); }
    h3 { margin: 0 0 12px; font-size: 23px; }
    .rf-lead { max-width: 760px; margin: 0; color: #3b5663; font-size: 20px; }
    .rf-meta { display: flex; flex-wrap: wrap; gap: 10px 22px; margin-top: 28px; color: var(--rf-muted); font-size: 14px; }

    .rf-needle-visual {
      min-height: 430px;
      padding: 28px;
      border: 1px solid rgba(8, 127, 167, .18);
      border-radius: 28px;
      background: rgba(255, 255, 255, .74);
      box-shadow: var(--rf-shadow);
      backdrop-filter: blur(7px);
    }
    .rf-visual-title { margin: 0 0 22px; color: var(--rf-navy); font-size: 18px; font-weight: 800; text-align: center; }
    .rf-visual-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
    .rf-needle-card { padding: 20px 14px 18px; border-radius: 20px; background: #fff; text-align: center; }
    .rf-needle-card strong { display: block; margin-top: 15px; color: var(--rf-navy); }
    .rf-needle-card small { display: block; margin-top: 4px; color: var(--rf-muted); line-height: 1.45; }
    .rf-skin {
      position: relative;
      height: 200px;
      margin-top: 8px;
      overflow: hidden;
      border-radius: 16px;
      background: linear-gradient(#f4cfc3 0 20%, #eebdaf 20% 38%, #dca494 38% 100%);
    }
    .rf-skin::before {
      content: "EPIDERMIS\A DERMIS";
      white-space: pre;
      position: absolute;
      left: 9px;
      top: 11px;
      color: rgba(75, 45, 40, .62);
      font-size: 8px;
      font-weight: 800;
      letter-spacing: .08em;
      line-height: 3.8;
    }
    .rf-needle {
      position: absolute;
      top: -8px;
      left: 50%;
      width: 9px;
      height: 159px;
      transform: translateX(-50%);
      border-radius: 8px 8px 3px 3px;
      background: #a8b7be;
      box-shadow: inset -2px 0 0 rgba(25, 49, 59, .2);
    }
    .rf-needle.insulated { background: linear-gradient(#eaf1f3 0 68%, #a8b7be 68% 100%); }
    .rf-energy {
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      border: 2px solid rgba(0, 151, 183, .78);
      background: radial-gradient(circle, rgba(18, 169, 199, .38), rgba(18, 169, 199, .04) 70%);
      border-radius: 50%;
    }
    .rf-energy.tip { bottom: 22px; width: 66px; height: 48px; }
    .rf-energy.column { top: 34px; width: 58px; height: 138px; border-radius: 48%; }

    .rf-main { padding: 70px 0 86px; }
    .rf-layout { display: grid; grid-template-columns: minmax(0, 1fr) 292px; gap: 54px; align-items: start; }
    .rf-article { min-width: 0; }
    .rf-article p { margin: 0 0 20px; }
    .rf-article section { scroll-margin-top: 24px; margin: 0 0 72px; }
    .rf-article ul, .rf-article ol { margin: 0 0 22px; padding-left: 24px; }
    .rf-article li { margin-bottom: 9px; }

    .rf-answer {
      margin-bottom: 58px;
      padding: 26px 28px;
      border-left: 5px solid var(--rf-cyan);
      border-radius: 0 18px 18px 0;
      background: var(--rf-pale);
      box-shadow: 0 9px 26px rgba(12, 47, 77, .06);
    }
    .rf-answer strong { color: var(--rf-navy); }
    .rf-answer p:last-child { margin-bottom: 0; }

    .rf-toc {
      position: sticky;
      top: 22px;
      padding: 24px;
      border: 1px solid var(--rf-line);
      border-radius: 18px;
      background: #fff;
      box-shadow: 0 12px 34px rgba(12, 47, 77, .07);
    }
    .rf-toc-title { margin: 0 0 13px; color: var(--rf-navy); font-size: 16px; font-weight: 800; }
    .rf-toc ol { margin: 0; padding-left: 20px; }
    .rf-toc li { margin: 8px 0; color: #7b9099; font-size: 14px; }
    .rf-toc a { color: #425e6a; text-decoration: none; }
    .rf-toc a:hover { color: var(--rf-blue); }
    .rf-toc-cta {
      display: block;
      margin-top: 18px;
      padding: 11px 14px;
      border-radius: 11px;
      background: var(--rf-navy);
      color: #fff;
      font-size: 14px;
      font-weight: 750;
      text-align: center;
      text-decoration: none;
    }
    .rf-toc-cta:hover { background: var(--rf-blue); color: #fff; }

    .rf-card-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; margin: 30px 0; }
    .rf-info-card { padding: 26px; border: 1px solid var(--rf-line); border-radius: 18px; background: #fff; }
    .rf-card-label { display: inline-block; margin-bottom: 13px; color: var(--rf-blue); font-size: 12px; font-weight: 850; letter-spacing: .1em; text-transform: uppercase; }
    .rf-info-card p:last-child { margin-bottom: 0; }

    .rf-table-wrap { margin: 30px 0; overflow-x: auto; border: 1px solid var(--rf-line); border-radius: 18px; background: #fff; }
    .rf-table { width: 100%; min-width: 720px; border-collapse: collapse; }
    .rf-table th, .rf-table td { padding: 17px 18px; border-bottom: 1px solid #e4eef1; text-align: left; vertical-align: top; }
    .rf-table th { background: var(--rf-navy); color: #fff; font-size: 14px; letter-spacing: .02em; }
    .rf-table td:first-child { color: var(--rf-navy); font-weight: 750; }
    .rf-table tr:last-child td { border-bottom: 0; }
    .rf-table tbody tr:nth-child(even) { background: #f8fbfc; }

    .rf-note, .rf-safety {
      margin: 28px 0;
      padding: 24px 26px;
      border-radius: 17px;
    }
    .rf-note { border: 1px solid var(--rf-line); background: #f5fbfd; }
    .rf-safety { border: 1px solid var(--rf-warm-line); background: var(--rf-warm); }
    .rf-note strong, .rf-safety strong { color: var(--rf-navy); }
    .rf-note p:last-child, .rf-safety p:last-child { margin-bottom: 0; }

    .rf-checklist { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 18px; margin: 26px 0; padding: 0; list-style: none; }
    .rf-checklist li { position: relative; margin: 0; padding: 15px 16px 15px 43px; border: 1px solid var(--rf-line); border-radius: 13px; background: #fff; }
    .rf-checklist li::before {
      content: "✓";
      position: absolute;
      left: 15px;
      top: 15px;
      color: var(--rf-cyan);
      font-weight: 900;
    }

    .rf-product-box {
      display: grid;
      grid-template-columns: .8fr 1.2fr;
      gap: 28px;
      margin: 34px 0;
      padding: 30px;
      border-radius: 22px;
      background: linear-gradient(140deg, #0b2d49, #105875);
      color: #eaf8fc;
      box-shadow: var(--rf-shadow);
    }
    .rf-product-box h3 { color: #fff; font-size: 28px; }
    .rf-product-box p { color: #d9eef4; }
    .rf-specs { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
    .rf-spec { padding: 13px 15px; border: 1px solid rgba(255, 255, 255, .17); border-radius: 12px; background: rgba(255, 255, 255, .07); }
    .rf-spec strong { display: block; color: #fff; font-size: 15px; }
    .rf-spec span { color: #c6e6ef; font-size: 13px; }
    .rf-button {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      margin-top: 10px;
      padding: 13px 19px;
      border-radius: 12px;
      background: #fff;
      color: var(--rf-navy);
      font-weight: 800;
      text-decoration: none;
    }
    .rf-button:hover { background: #dff6fb; color: var(--rf-navy); }

    .rf-faq details { margin-bottom: 12px; border: 1px solid var(--rf-line); border-radius: 14px; background: #fff; }
    .rf-faq summary { padding: 18px 20px; color: var(--rf-navy); font-weight: 780; cursor: pointer; }
    .rf-faq details p { padding: 0 20px 20px; margin: 0; }

    .rf-references { padding-top: 28px; border-top: 1px solid var(--rf-line); color: var(--rf-muted); font-size: 14px; }
    .rf-references h2 { font-size: 26px; }
    .rf-references li { margin-bottom: 10px; }
    .rf-disclaimer { margin-top: 30px; padding: 18px 20px; border-radius: 13px; background: #edf3f5; color: #59707b; font-size: 13px; }

    .rf-final-cta {
      padding: 62px 0;
      background: var(--rf-navy);
      color: #dceef4;
      text-align: center;
    }
    .rf-final-cta h2 { color: #fff; }
    .rf-final-cta p { max-width: 710px; margin: 0 auto 20px; }
    .rf-final-cta .rf-button { margin: 0; }

    @media (max-width: 900px) {
      .rf-hero-grid, .rf-layout { grid-template-columns: 1fr; }
      .rf-hero-grid { gap: 36px; }
      .rf-layout { gap: 0; }
      .rf-toc { position: static; order: -1; margin-bottom: 44px; }
      .rf-product-box { grid-template-columns: 1fr; }
    }
    @media (max-width: 620px) {
      body { font-size: 16px; }
      .rf-container { width: min(100% - 22px, 1160px); }
      .rf-hero { padding-bottom: 48px; }
      .rf-breadcrumbs { margin-bottom: 28px; }
      .rf-lead { font-size: 18px; }
      .rf-needle-visual { min-height: auto; padding: 18px; }
      .rf-visual-grid, .rf-card-grid, .rf-checklist, .rf-specs { grid-template-columns: 1fr; }
      .rf-skin { height: 180px; }
      .rf-answer, .rf-note, .rf-safety, .rf-info-card, .rf-product-box { padding: 21px; }
      .rf-main { padding: 48px 0 60px; }
      .rf-article section { margin-bottom: 54px; }
    }