:root {
      --bg: #f7f8fa;
      --surface: #ffffff;
      --ink: #12141a;
      --muted: #5c6370;
      --line: #e4e7ec;
      --accent: #1a6b5c;
      --accent-soft: #e8f4f1;
      --radius: 16px;
      --shadow: 0 1px 2px rgba(18, 20, 26, 0.04), 0 12px 32px rgba(18, 20, 26, 0.06);
      --font: "Plus Jakarta Sans", ui-sans-serif, sans-serif;
      --max: 42rem;
    }

    * { box-sizing: border-box; }

    html { scroll-behavior: smooth; }

    body {
      margin: 0;
      font-family: var(--font);
      background:
        radial-gradient(1200px 600px at 10% -10%, #e8f4f1 0%, transparent 55%),
        radial-gradient(900px 500px at 100% 0%, #eef1f8 0%, transparent 50%),
        var(--bg);
      color: var(--ink);
      line-height: 1.65;
      -webkit-font-smoothing: antialiased;
    }

    a {
      color: var(--accent);
      text-decoration-thickness: 1px;
      text-underline-offset: 0.18em;
    }

    a:hover { color: #0f4f43; }

    .wrap {
      width: min(100% - 2rem, 52rem);
      margin: 0 auto;
      padding: 2.5rem 0 4rem;
    }

    header.top {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 1rem;
      margin-bottom: 2rem;
    }

    .brand {
      display: inline-flex;
      align-items: center;
      gap: 0.7rem;
      color: inherit;
      text-decoration: none;
    }

    .brand-mark {
      width: 2.25rem;
      height: 2.25rem;
      border-radius: 10px;
      background: linear-gradient(145deg, #1a6b5c, #2a9b84);
      box-shadow: 0 8px 20px rgba(26, 107, 92, 0.28);
      position: relative;
    }

    .brand-mark::after {
      content: "";
      position: absolute;
      inset: 28% 28%;
      border: 2px solid rgba(255, 255, 255, 0.92);
      border-radius: 50%;
      box-shadow: inset 0 0 0 3px transparent;
    }

    .brand-mark::before {
      content: "";
      position: absolute;
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background: #fff;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
    }

    .brand-text {
      display: flex;
      flex-direction: column;
      gap: 0.05rem;
    }

    .brand-name {
      font-weight: 700;
      font-size: 1.05rem;
      letter-spacing: -0.02em;
    }

    .brand-tag {
      font-size: 0.72rem;
      color: var(--muted);
      font-weight: 500;
    }

    .pill {
      font-size: 0.75rem;
      font-weight: 600;
      color: var(--accent);
      background: var(--accent-soft);
      padding: 0.4rem 0.75rem;
      border-radius: 999px;
    }

    .hero {
      background: var(--surface);
      border: 1px solid var(--line);
      border-radius: calc(var(--radius) + 4px);
      box-shadow: var(--shadow);
      padding: clamp(1.5rem, 4vw, 2.25rem);
      margin-bottom: 1.5rem;
    }

    .hero h1 {
      margin: 0 0 0.65rem;
      font-size: clamp(1.75rem, 4vw, 2.35rem);
      line-height: 1.15;
      letter-spacing: -0.03em;
      font-weight: 700;
    }

    .hero p {
      margin: 0;
      color: var(--muted);
      max-width: 38rem;
      font-size: 1.02rem;
    }

    .meta {
      display: flex;
      flex-wrap: wrap;
      gap: 0.5rem 1rem;
      margin-top: 1.25rem;
      font-size: 0.85rem;
      color: var(--muted);
    }

    .meta strong { color: var(--ink); font-weight: 600; }

    .toc {
      background: var(--surface);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      padding: 1.1rem 1.25rem;
      margin-bottom: 1.5rem;
    }

    .toc h2 {
      margin: 0 0 0.65rem;
      font-size: 0.78rem;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      color: var(--muted);
      font-weight: 600;
    }

    .toc ol {
      margin: 0;
      padding-left: 1.15rem;
      columns: 2;
      column-gap: 2rem;
    }

    .toc li {
      margin: 0.25rem 0;
      break-inside: avoid;
      font-size: 0.9rem;
    }

    .toc a {
      color: var(--ink);
      text-decoration: none;
    }

    .toc a:hover { color: var(--accent); }

    article {
      background: var(--surface);
      border: 1px solid var(--line);
      border-radius: calc(var(--radius) + 4px);
      box-shadow: var(--shadow);
      padding: clamp(1.4rem, 3.5vw, 2.25rem);
    }

    section {
      padding: 1.35rem 0;
      border-top: 1px solid var(--line);
    }

    section:first-of-type {
      border-top: 0;
      padding-top: 0;
    }

    section:last-of-type { padding-bottom: 0; }

    h2 {
      margin: 0 0 0.7rem;
      font-size: 1.15rem;
      letter-spacing: -0.02em;
      font-weight: 700;
    }

    p { margin: 0 0 0.85rem; color: #2a2f3a; }
    p:last-child { margin-bottom: 0; }

    ul {
      margin: 0 0 0.85rem;
      padding-left: 1.2rem;
      color: #2a2f3a;
    }

    li { margin: 0.35rem 0; }
    li:last-child { margin-bottom: 0; }

    .note {
      margin-top: 0.85rem;
      padding: 0.9rem 1rem;
      background: var(--accent-soft);
      border-radius: 12px;
      color: #1e3f38;
      font-size: 0.95rem;
    }

    footer.bottom {
      margin-top: 2rem;
      padding-top: 1.25rem;
      border-top: 1px solid var(--line);
      display: flex;
      flex-wrap: wrap;
      gap: 0.75rem 1.25rem;
      justify-content: space-between;
      color: var(--muted);
      font-size: 0.85rem;
    }

    footer.bottom a { color: var(--muted); }
    footer.bottom a:hover { color: var(--accent); }

    @media (max-width: 640px) {
      .toc ol { columns: 1; }
      .wrap { padding-top: 1.5rem; }
    }