*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

  :root {
    --white: #ffffff;
    --black: #0a0a0a;
    --gray: #888888;
    --gray-light: #e8e8e8;
    --accent: #004225;
    --bg: var(--white);
    --fg: var(--black);
    --muted: #555;
    --line: var(--gray-light);
    --soft: #fafafa;
    --pixel: 'Press Start 2P', monospace;
    --mono: 'Space Mono', monospace;
    --kr: 'Noto Sans KR', sans-serif;
    --sans: 'Inter', sans-serif;
  }

  [data-theme="dark"] {
    --bg: #050505;
    --fg: #f0f0f0;
    --muted: #aaa;
    --line: #1c1c1c;
    --accent: #00704a;
    --soft: #0d0d0d;
  }

  html { scroll-behavior: smooth; }

  body {
    background: var(--bg);
    color: var(--fg);
    font-family: var(--kr), var(--mono);
    font-size: 14px;
    line-height: 1.85;
    transition: background 0.3s, color 0.3s;
  }

  html[lang="en"] body { font-family: var(--sans), var(--mono); }

  ::selection { background: var(--accent); color: var(--white); }
  a { color: inherit; }

  nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 48px;
    background: var(--bg);
    z-index: 100;
    border-bottom: 1px solid var(--line);
  }
  .nav-logo {
    font-family: var(--pixel);
    font-size: 10px;
    letter-spacing: 0.05em;
    color: var(--fg);
    text-decoration: none;
  }
  .nav-logo span { color: var(--accent); }

  .nav-right { display: flex; gap: 12px; align-items: center; }
  .nav-btn {
    background: none;
    border: 1px solid var(--line);
    color: var(--muted);
    padding: 8px 14px;
    font-family: var(--pixel);
    font-size: 8px;
    letter-spacing: 0.08em;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.15s;
  }
  .nav-btn:hover { color: var(--fg); border-color: var(--fg); }

  .doc-header {
    padding: 140px 48px 60px;
    border-bottom: 1px solid var(--line);
    background: var(--soft);
  }
  .doc-eyebrow {
    font-family: var(--pixel);
    font-size: 9px;
    color: var(--accent);
    letter-spacing: 0.2em;
    margin-bottom: 22px;
  }
  .doc-title {
    font-size: clamp(32px, 5vw, 56px);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.15;
    margin-bottom: 18px;
  }
  .doc-title .green { color: var(--accent); }
  .doc-meta {
    display: flex;
    gap: 32px;
    flex-wrap: wrap;
    font-family: var(--mono);
    font-size: 11px;
    color: var(--muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-top: 24px;
  }
  .doc-meta strong { color: var(--fg); margin-right: 6px; font-weight: 700; }

  .corner-deco {
    margin-top: 26px;
    display: flex;
    gap: 8px;
    align-items: center;
    font-family: var(--pixel);
    font-size: 8px;
    color: var(--muted);
    letter-spacing: 0.15em;
  }
  .corner-deco::before {
    content: "";
    width: 28px; height: 1px;
    background: var(--accent);
  }

  .doc-layout {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 64px;
    padding: 60px 48px 100px;
    max-width: 1280px;
    margin: 0 auto;
  }

  /* TOC 없는 단일 컬럼 문서 (계정 삭제 안내 등) */
  .doc-layout--single {
    display: block;
    max-width: 900px;
  }

  .toc {
    position: sticky;
    top: 90px;
    align-self: start;
    border-left: 1px solid var(--line);
    padding-left: 18px;
    max-height: calc(100vh - 110px);
    overflow-y: auto;
  }
  .toc-title {
    font-family: var(--pixel);
    font-size: 9px;
    color: var(--accent);
    letter-spacing: 0.18em;
    margin-bottom: 16px;
  }
  .toc ol { list-style: none; counter-reset: toc; }
  .toc li { counter-increment: toc; margin-bottom: 8px; }
  .toc a {
    display: block;
    font-size: 12px;
    color: var(--muted);
    text-decoration: none;
    padding: 4px 0 4px 10px;
    border-left: 2px solid transparent;
    margin-left: -12px;
    transition: all 0.15s;
  }
  .toc a::before {
    content: counter(toc, decimal-leading-zero) ". ";
    font-family: var(--mono);
    color: var(--accent);
    margin-right: 6px;
    font-size: 10px;
  }
  .toc a:hover, .toc a.active {
    color: var(--fg);
    border-left-color: var(--accent);
  }

  .doc-body { min-width: 0; }
  .doc-body section.article {
    padding: 36px 0;
    border-bottom: 1px dashed var(--line);
  }
  .doc-body section.article:last-of-type { border-bottom: none; }
  .doc-body h2 {
    font-size: 22px;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin-bottom: 18px;
    display: flex;
    align-items: baseline;
    gap: 14px;
  }
  .doc-body h2 .marker {
    font-family: var(--pixel);
    font-size: 9px;
    color: var(--accent);
    letter-spacing: 0.1em;
    flex-shrink: 0;
  }
  .doc-body h3 {
    font-size: 15px;
    font-weight: 700;
    margin-top: 22px;
    margin-bottom: 10px;
  }
  .doc-body p { margin-bottom: 12px; color: var(--muted); }
  .doc-body p strong { color: var(--fg); font-weight: 700; }
  .doc-body ul, .doc-body ol {
    padding-left: 22px;
    margin-bottom: 14px;
    color: var(--muted);
  }
  .doc-body li { margin-bottom: 6px; }
  .doc-body ul li::marker { color: var(--accent); }
  .doc-body ol li::marker { color: var(--accent); font-family: var(--mono); font-weight: 700; }

  .callout {
    background: var(--soft);
    border-left: 3px solid var(--accent);
    padding: 18px 22px;
    margin: 18px 0;
    font-size: 13px;
  }
  .callout strong { color: var(--accent); }

  table.info {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
    margin: 14px 0;
  }
  table.info th, table.info td {
    border: 1px solid var(--line);
    padding: 10px 14px;
    text-align: left;
    vertical-align: top;
    color: var(--muted);
  }
  table.info td strong { color: var(--fg); }
  table.info th {
    background: var(--soft);
    font-family: var(--pixel);
    font-size: 9px;
    letter-spacing: 0.08em;
    color: var(--accent);
    font-weight: 400;
  }

  .data-card {
    border: 1px solid var(--line);
    border-radius: 2px;
    padding: 20px 22px;
    margin: 14px 0;
    background: var(--soft);
    position: relative;
  }
  .data-card::before {
    content: "";
    position: absolute;
    top: 0; left: 0;
    width: 26px; height: 26px;
    border-top: 2px solid var(--accent);
    border-left: 2px solid var(--accent);
  }
  .data-card::after {
    content: "";
    position: absolute;
    bottom: 0; right: 0;
    width: 26px; height: 26px;
    border-bottom: 2px solid var(--accent);
    border-right: 2px solid var(--accent);
  }
  .data-card h4 {
    font-family: var(--pixel);
    font-size: 9px;
    color: var(--accent);
    letter-spacing: 0.1em;
    margin-bottom: 10px;
  }
  .data-card p { margin-bottom: 6px; font-size: 13px; }

  footer {
    border-top: 1px solid var(--line);
    padding: 50px 48px;
    background: var(--soft);
    font-size: 12px;
    color: var(--muted);
  }
  .footer-grid {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 32px;
    flex-wrap: wrap;
  }
  .footer-logo {
    font-family: var(--pixel);
    font-size: 10px;
    color: var(--fg);
    margin-bottom: 12px;
    letter-spacing: 0.06em;
  }
  .footer-logo span { color: var(--accent); }
  .footer-info { line-height: 2; font-family: var(--mono); font-size: 11px; }
  .footer-links a {
    text-decoration: none;
    color: var(--muted);
    border-bottom: 1px solid var(--line);
    padding-bottom: 2px;
    transition: color 0.15s, border-color 0.15s;
  }
  .footer-links a:hover { color: var(--accent); border-color: var(--accent); }
  .footer-links { display: flex; gap: 24px; font-family: var(--pixel); font-size: 8px; letter-spacing: 0.1em; }

  @media (max-width: 900px) {
    nav { padding: 16px 22px; }
    .doc-header { padding: 110px 22px 40px; }
    .doc-layout {
      grid-template-columns: 1fr;
      padding: 40px 22px 60px;
      gap: 32px;
    }
    .toc {
      position: static;
      max-height: none;
      border-left: none;
      border-top: 1px solid var(--line);
      padding: 24px 0 0;
    }
    .doc-body h2 { flex-direction: column; gap: 4px; }
    footer { padding: 40px 22px; }
  }