:root {
    --ink-950: #0c0a09;
    --ink-900: #1c1917;
    --ink-800: #292524;
    --ink-700: #44403c;
    --ink-600: #57534e;
    --ink-500: #78716c;
    --ink-400: #a8a29e;
    --ink-300: #d6d3d1;
    --ink-200: #e7e5e4;
    --ink-100: #f5f5f4;
    --ink-50: #fafaf9;

    --brand-500: #f59e0b;
    --brand-600: #d97706;
    --brand-700: #b45309;
    --brand-100: #fef3c7;
    --brand-50: #fffbeb;

    --emerald-600: #059669;
    --emerald-100: #d1fae5;
    --rose-600: #e11d48;
    --rose-100: #ffe4e6;
    --sky-600: #0284c7;
    --sky-100: #e0f2fe;

    --bg: var(--ink-50);
    --surface: #ffffff;
    --surface-2: var(--ink-100);
    --text: var(--ink-900);
    --text-muted: var(--ink-600);
    --text-faint: var(--ink-400);
    --border: var(--ink-200);
    --accent: var(--brand-500);
    --accent-ink: var(--ink-950);
    --accent-hover: var(--brand-600);
    --shadow-card: 0 1px 2px rgba(28,25,23,.04), 0 8px 24px -8px rgba(28,25,23,.10);

    --font-display: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
    --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Roboto Mono", Menlo, Consolas, monospace;
  }

  @media (prefers-color-scheme: dark) {
    :root {
      --bg: var(--ink-950);
      --surface: #17140f;
      --surface-2: #201c17;
      --text: #f5f1ea;
      --text-muted: #b6afa4;
      --text-faint: #7c766c;
      --border: #332c22;
      --accent: var(--brand-500);
      --accent-ink: #0c0a09;
      --accent-hover: #fbbf24;
      --shadow-card: 0 1px 2px rgba(0,0,0,.3), 0 8px 28px -8px rgba(0,0,0,.55);
      --emerald-100: #06301f;
      --rose-100: #3a0f18;
      --sky-100: #0b2436;
      --brand-100: #3a2a0c;
    }
  }
  :root[data-theme="dark"] {
    --bg: var(--ink-950);
    --surface: #17140f;
    --surface-2: #201c17;
    --text: #f5f1ea;
    --text-muted: #b6afa4;
    --text-faint: #7c766c;
    --border: #332c22;
    --accent: var(--brand-500);
    --accent-ink: #0c0a09;
    --accent-hover: #fbbf24;
    --shadow-card: 0 1px 2px rgba(0,0,0,.3), 0 8px 28px -8px rgba(0,0,0,.55);
    --emerald-100: #06301f;
    --rose-100: #3a0f18;
    --sky-100: #0b2436;
    --brand-100: #3a2a0c;
  }
  :root[data-theme="light"] {
    --bg: var(--ink-50);
    --surface: #ffffff;
    --surface-2: var(--ink-100);
    --text: var(--ink-900);
    --text-muted: var(--ink-600);
    --text-faint: var(--ink-400);
    --border: var(--ink-200);
    --accent: var(--brand-500);
    --accent-ink: var(--ink-950);
    --accent-hover: var(--brand-600);
    --shadow-card: 0 1px 2px rgba(28,25,23,.04), 0 8px 24px -8px rgba(28,25,23,.10);
    --emerald-100: #d1fae5;
    --rose-100: #ffe4e6;
    --sky-100: #e0f2fe;
    --brand-100: #fef3c7;
  }

  * { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  @media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
  }

  body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
  }

  a { color: var(--accent-hover); }
  :focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

  .layout {
    display: grid;
    grid-template-columns: 260px minmax(0, 1fr);
    max-width: 1180px;
    margin: 0 auto;
  }
  @media (max-width: 900px) {
    .layout { grid-template-columns: 1fr; }
  }

  /* ---------- Sidebar ---------- */
  .sidebar {
    position: sticky;
    top: 0;
    align-self: start;
    height: 100vh;
    overflow-y: auto;
    padding: 28px 20px 40px;
    border-inline-end: 1px solid var(--border);
  }
  @media (max-width: 900px) {
    .sidebar { position: static; height: auto; border-inline-end: none; border-bottom: 1px solid var(--border); padding: 20px; }
  }
  .brand {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 24px;
  }
  .brand-mark {
    width: 34px; height: 34px;
    border-radius: 9px;
    background: var(--ink-900);
    color: var(--brand-500);
    display: flex; align-items: center; justify-content: center;
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 17px;
    flex-shrink: 0;
  }
  :root[data-theme="dark"] .brand-mark, @media (prefers-color-scheme: dark) { }
  .brand-name { font-family: var(--font-display); font-weight: 700; font-size: 18px; letter-spacing: -0.01em; }
  .brand-sub { display: block; font-family: var(--font-body); font-size: 11px; color: var(--text-faint); text-transform: uppercase; letter-spacing: .08em; margin-top: 1px; }

  .nav-group { margin-bottom: 22px; }
  .nav-label {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: .08em;
    color: var(--text-faint);
    margin: 0 0 8px 10px;
  }
  .nav-link {
    display: flex;
    align-items: baseline;
    gap: 8px;
    padding: 7px 10px;
    border-radius: 8px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 14px;
    transition: background .12s ease, color .12s ease;
  }
  .nav-link:hover { background: var(--surface-2); color: var(--text); }
  .nav-link.is-active { background: var(--brand-100); color: var(--brand-700); font-weight: 600; }
  :root[data-theme="dark"] .nav-link.is-active, @media (prefers-color-scheme: dark){ .nav-link.is-active{ color: var(--brand-500);} }
  .nav-num { font-family: var(--font-mono); font-size: 11px; color: var(--text-faint); width: 16px; flex-shrink: 0; }

  /* ---------- Main ---------- */
  main { padding: 48px clamp(20px, 4vw, 64px) 120px; min-width: 0; }

  .eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: var(--brand-700);
    background: var(--brand-100);
    padding: 5px 11px;
    border-radius: 999px;
    margin-bottom: 18px;
  }
  :root[data-theme="dark"] .eyebrow, @media (prefers-color-scheme: dark){ .eyebrow{ color: var(--brand-500);} }

  h1.doc-title {
    font-family: var(--font-display);
    font-size: clamp(32px, 4vw, 44px);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.01em;
    margin: 0 0 14px;
    text-wrap: balance;
    max-width: 16ch;
  }
  .doc-intro {
    max-width: 62ch;
    font-size: 17px;
    color: var(--text-muted);
    margin: 0 0 8px;
  }
  .doc-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 18px;
    margin: 24px 0 56px;
    font-size: 13px;
    color: var(--text-faint);
  }
  .doc-meta strong { color: var(--text-muted); font-weight: 600; }

  .callout {
    max-width: 62ch;
    background: var(--surface);
    border: 1px solid var(--border);
    border-inline-start: 3px solid var(--accent);
    border-radius: 10px;
    padding: 16px 18px;
    margin: 0 0 56px;
    font-size: 14.5px;
    color: var(--text-muted);
  }
  .callout strong { color: var(--text); }

  section.scenario {
    padding-top: 64px;
    margin-top: -20px;
    scroll-margin-top: 20px;
    border-top: 1px solid var(--border);
    max-width: 860px;
  }
  section.scenario:first-of-type { border-top: none; }

  .scenario-head { display: flex; align-items: flex-start; gap: 16px; margin-bottom: 6px; }
  .scenario-index {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-faint);
    padding-top: 10px;
    width: 28px;
    flex-shrink: 0;
  }
  h2.scenario-title {
    font-family: var(--font-display);
    font-size: 28px;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin: 0;
    text-wrap: balance;
  }
  .scenario-role {
    display: inline-block;
    font-size: 11.5px;
    font-weight: 600;
    color: var(--sky-600);
    background: var(--sky-100);
    padding: 3px 9px;
    border-radius: 999px;
    margin-top: 6px;
  }
  .scenario-lede { max-width: 58ch; color: var(--text-muted); margin-block: 14px 28px; margin-inline-start: 44px; }
  @media (max-width: 560px) { .scenario-lede, .steps, .mockup { margin-inline-start: 0 !important; } }

  .steps { list-style: none; margin-block-end: 26px; margin-inline-start: 44px; padding: 0; counter-reset: step; }
  .steps > li {
    counter-increment: step;
    position: relative;
    padding-block-end: 22px;
    padding-inline-start: 34px;
    border-inline-start: 1px solid var(--border);
    margin-inline-start: 12px;
  }
  .steps > li:last-child { border-color: transparent; padding-bottom: 2px; }
  .steps > li::before {
    content: counter(step);
    position: absolute;
    inset-inline-start: -13px;
    top: 0;
    width: 24px; height: 24px;
    border-radius: 50%;
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 12px;
    display: flex; align-items: center; justify-content: center;
  }
  .steps h3 { margin: 0 0 4px; font-size: 15.5px; font-weight: 600; }
  .steps p { margin: 0; color: var(--text-muted); font-size: 14.5px; max-width: 56ch; }
  .steps .field { font-family: var(--font-mono); font-size: 12.5px; background: var(--surface-2); border: 1px solid var(--border); padding: 1px 6px; border-radius: 5px; color: var(--text); }

  /* ---------- UI mockup panel ---------- */
  .mockup {
    margin-block-end: 30px;
    margin-inline-start: 44px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    box-shadow: var(--shadow-card);
    overflow: hidden;
  }
  .mockup-bar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 10px 16px;
    background: var(--surface-2);
    border-bottom: 1px solid var(--border);
    font-size: 12px;
    color: var(--text-faint);
  }
  .mockup-bar .path { font-family: var(--font-mono); }
  .mockup-body { padding: 18px; }
  .m-h { font-weight: 700; font-size: 15px; margin: 0 0 3px; }
  .m-sub { font-size: 12.5px; color: var(--text-faint); margin: 0 0 14px; }
  .m-row {
    display: flex; align-items: center; justify-content: space-between; gap: 10px;
    padding: 10px 12px;
    background: var(--surface-2);
    border-radius: 9px;
    margin-bottom: 8px;
    font-size: 13.5px;
  }
  .m-row:last-child { margin-bottom: 0; }
  .m-row .label { color: var(--text); font-weight: 500; }
  .m-row .sub { color: var(--text-faint); font-size: 12px; display: block; }
  .m-btn {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: 12.5px; font-weight: 600;
    padding: 6px 12px;
    border-radius: 8px;
    border: none;
    cursor: default;
    white-space: nowrap;
  }
  .m-btn.primary { background: var(--ink-900); color: #fff; }
  :root[data-theme="dark"] .m-btn.primary, @media (prefers-color-scheme: dark){ .m-btn.primary{ background:#f5f1ea; color:#17140f; } }
  .m-btn.gold { background: var(--brand-500); color: var(--ink-950); }
  .m-btn.outline { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
  .m-btn.danger { background: var(--rose-100); color: var(--rose-600); }
  .m-btn.ghost { background: none; color: var(--text-faint); font-weight: 600; }
  .m-field { margin-bottom: 12px; }
  .m-field:last-child { margin-bottom: 0; }
  .m-field label { display: block; font-size: 11.5px; color: var(--text-faint); margin-bottom: 4px; }
  .m-input { border: 1px solid var(--border); border-radius: 8px; padding: 8px 10px; font-size: 13px; color: var(--text); background: var(--surface); }
  .m-badge { display: inline-flex; align-items: center; font-size: 11px; font-weight: 600; padding: 2px 9px; border-radius: 999px; }
  .m-badge.emerald { background: var(--emerald-100); color: var(--emerald-600); }
  .m-badge.rose { background: var(--rose-100); color: var(--rose-600); }
  .m-badge.amber { background: var(--brand-100); color: var(--brand-700); }
  :root[data-theme="dark"] .m-badge.amber, @media (prefers-color-scheme: dark){ .m-badge.amber{ color: var(--brand-500);} }
  .m-badge.stone { background: var(--surface-2); color: var(--text-faint); border: 1px solid var(--border); }
  .m-divider { height: 1px; background: var(--border); margin: 14px 0; }
  .m-grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
  .m-num { font-variant-numeric: tabular-nums; font-family: var(--font-mono); }

  .path-diagram {
    margin-block-end: 30px;
    margin-inline-start: 44px;
    display: flex; flex-wrap: wrap; align-items: center; gap: 0;
    font-size: 13px;
  }
  .path-step {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 9px;
    padding: 9px 13px;
    font-weight: 600;
    color: var(--text);
  }
  .path-step.accent { border-color: var(--accent); color: var(--brand-700); background: var(--brand-50); }
  :root[data-theme="dark"] .path-step.accent, @media (prefers-color-scheme: dark){ .path-step.accent{ color: var(--brand-500); background: var(--brand-100);} }
  .path-arrow { color: var(--text-faint); padding: 0 10px; font-family: var(--font-mono); }

  .note-box {
    margin-block-end: 30px;
    margin-inline-start: 44px;
    max-width: 58ch;
    background: var(--surface-2);
    border-radius: 10px;
    padding: 14px 16px;
    font-size: 13.5px;
    color: var(--text-muted);
    display: flex;
    gap: 10px;
  }
  .note-box .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); margin-top: 7px; flex-shrink: 0; }
  .note-box.warn .dot { background: var(--rose-600); }

  /* end to end */
  .journey {
    max-width: 860px;
    margin-top: 64px;
    padding-top: 64px;
    border-top: 1px solid var(--border);
  }
  .journey-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 14px;
    margin-top: 30px;
  }
  .day-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px;
    box-shadow: var(--shadow-card);
  }
  .day-card .day { font-family: var(--font-mono); font-size: 11px; color: var(--brand-700); font-weight: 700; letter-spacing: .04em; text-transform: uppercase; }
  :root[data-theme="dark"] .day-card .day, @media (prefers-color-scheme: dark){ .day-card .day{ color: var(--brand-500);} }
  .day-card h4 { margin: 6px 0 6px; font-size: 15px; }
  .day-card p { margin: 0; font-size: 13px; color: var(--text-muted); }

  /* faq */
  .faq { max-width: 860px; margin-top: 64px; padding-top: 64px; border-top: 1px solid var(--border); }
  details.q {
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
  }
  details.q summary {
    cursor: pointer;
    font-weight: 600;
    font-size: 15px;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
  }
  details.q summary::-webkit-details-marker { display: none; }
  details.q summary::after {
    content: "+";
    font-family: var(--font-mono);
    color: var(--text-faint);
    font-size: 18px;
    flex-shrink: 0;
    transition: transform .15s ease;
  }
  details.q[open] summary::after { content: "–"; }
  details.q .a { margin-top: 10px; color: var(--text-muted); font-size: 14.5px; max-width: 60ch; }

  footer.doc-footer {
    max-width: 860px;
    margin-top: 72px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    color: var(--text-faint);
    font-size: 13px;
  }

  .theme-toggle-hint { display: none; }

  table.ref-table { border-collapse: collapse; width: 100%; margin-block-end: 30px; margin-inline-start: 44px; max-width: 700px; font-size: 13.5px; }
  .ref-table-wrap { overflow-x: auto; margin-block-end: 30px; margin-inline-start: 44px; }
  .ref-table-wrap table { margin: 0; max-width: none; }
  table.ref-table th { text-align: start; font-size: 11px; text-transform: uppercase; letter-spacing: .05em; color: var(--text-faint); padding: 8px 12px; border-bottom: 1px solid var(--border); }
  table.ref-table td { padding: 10px 12px; border-bottom: 1px solid var(--border); color: var(--text-muted); vertical-align: top; }
  table.ref-table td:first-child { color: var(--text); font-weight: 600; white-space: nowrap; }

  /* ---------- Cross-guide nav ---------- */
  .back-link {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12.5px;
    color: var(--text-faint);
    text-decoration: none;
    margin-bottom: 18px;
  }
  .back-link:hover { color: var(--text); }

  /* ---------- Language switcher ---------- */
  .lang-switch {
    display: flex;
    align-items: center;
    gap: 2px;
    width: fit-content;
    padding: 3px;
    border-radius: 999px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    margin-block-end: 18px;
  }
  .lang-switch a {
    font-family: var(--font-mono);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: .03em;
    padding: 4px 10px;
    border-radius: 999px;
    color: var(--text-faint);
    text-decoration: none;
  }
  .lang-switch a:hover { color: var(--text); }
  .lang-switch a.is-active { background: var(--ink-900); color: #fff; }
  @media (prefers-color-scheme: dark) {
    .lang-switch a.is-active { background: #f5f1ea; color: #17140f; }
  }
  :root[data-theme="dark"] .lang-switch a.is-active { background: #f5f1ea; color: #17140f; }
  :root[data-theme="light"] .lang-switch a.is-active { background: var(--ink-900); color: #fff; }

  /* ---------- Hub page ---------- */
  .hub-hero { max-width: 68ch; }
  .role-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 16px;
    margin: 40px 0 64px;
    max-width: 900px;
  }
  .role-card {
    display: block;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 20px;
    box-shadow: var(--shadow-card);
    text-decoration: none;
    color: inherit;
    transition: transform .12s ease, border-color .12s ease;
  }
  .role-card:hover { transform: translateY(-2px); border-color: var(--accent); }
  .role-card .role-icon {
    width: 38px; height: 38px;
    border-radius: 10px;
    background: var(--ink-900);
    color: var(--brand-500);
    display: flex; align-items: center; justify-content: center;
    font-family: var(--font-display);
    font-weight: 700;
    margin-bottom: 14px;
  }
  .role-card h3 { font-family: var(--font-display); font-size: 17px; margin: 0 0 6px; }
  .role-card p { margin: 0; font-size: 13.5px; color: var(--text-muted); }
  .role-card .role-tag { display: inline-block; margin-top: 12px; font-size: 11.5px; font-weight: 600; color: var(--brand-700); }
  :root[data-theme="dark"] .role-card .role-tag, @media (prefers-color-scheme: dark){ .role-card .role-tag{ color: var(--brand-500);} }

  .checklist { list-style: none; margin: 30px 0 60px; padding: 0; max-width: 640px; counter-reset: cl; }
  .checklist > li {
    counter-increment: cl;
    display: flex;
    gap: 14px;
    padding: 14px 0;
    border-bottom: 1px solid var(--border);
  }
  .checklist > li:last-child { border-bottom: none; }
  .checklist > li::before {
    content: counter(cl);
    flex-shrink: 0;
    width: 26px; height: 26px;
    border-radius: 50%;
    background: var(--surface-2);
    border: 1px solid var(--border);
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 12px;
    display: flex; align-items: center; justify-content: center;
  }
  .checklist h4 { margin: 0 0 3px; font-size: 14.5px; }
  .checklist p { margin: 0; font-size: 13.5px; color: var(--text-muted); }
  .checklist a { font-size: 12.5px; }