:root {
    --bg: #ECEFF3;
    --surface: #FFFFFF;
    --surface-alt: #E1E6EB;
    --text: #12161D;
    --text-muted: #576270;
    --rule: #C9D1D9;
    --accent: #3552D6;
    --accent-contrast: #FFFFFF;
    --highlight: #AD6F0C;
    --highlight-soft: rgba(173, 111, 12, 0.12);
    --grid-line: rgba(18, 22, 29, 0.06);
    --shadow: 0 1px 2px rgba(18, 22, 29, 0.04);

    --mock-bg: #1a1a1e;
    --mock-elevated: #232327;
    --mock-inset: #17171a;
    --mock-border: #303036;
    --mock-text: #e7e7ea;
    --mock-muted: #94949c;
    --mock-accent: #5b85ff;
    --mock-success: #3fc07a;
    --mock-warning: #e0ac2f;

    --font-mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
    --font-serif: "Source Serif 4", Georgia, "Iowan Old Style", serif;
  }

  @media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
      --bg: #12151B;
      --surface: #1A1E26;
      --surface-alt: #212631;
      --text: #E8ECF1;
      --text-muted: #929CAA;
      --rule: #2A3140;
      --accent: #7C97FF;
      --accent-contrast: #0B0F1A;
      --highlight: #E3A63F;
      --highlight-soft: rgba(227, 166, 63, 0.14);
      --grid-line: rgba(232, 236, 241, 0.07);
      --shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    }
  }

  :root[data-theme="dark"] {
    --bg: #12151B;
    --surface: #1A1E26;
    --surface-alt: #212631;
    --text: #E8ECF1;
    --text-muted: #929CAA;
    --rule: #2A3140;
    --accent: #7C97FF;
    --accent-contrast: #0B0F1A;
    --highlight: #E3A63F;
    --highlight-soft: rgba(227, 166, 63, 0.14);
    --grid-line: rgba(232, 236, 241, 0.07);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
  }

  * { box-sizing: border-box; }

  html { -webkit-text-size-adjust: 100%; }

  body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-serif);
    font-size: 17px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
  }

  ::selection { background: var(--highlight-soft); color: var(--text); }

  a { color: inherit; }

  :focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
    border-radius: 2px;
  }

  img, svg { max-width: 100%; display: block; }

  h1, h2, h3 { font-family: var(--font-mono); text-wrap: balance; margin: 0; }

  p { text-wrap: pretty; }

  .wrap {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 32px;
  }

  .prose { max-width: 640px; }

  /* ---------- nav ---------- */

  nav.top {
    border-bottom: 1px solid var(--rule);
  }
  nav.top .wrap {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
  }
  .wordmark {
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 15px;
    letter-spacing: -0.01em;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
  }
  .wordmark .dot {
    width: 8px;
    height: 8px;
    background: var(--accent);
    display: inline-block;
    flex-shrink: 0;
  }
  .nav-links {
    display: flex;
    gap: 28px;
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-muted);
  }
  .nav-links a { text-decoration: none; }
  .nav-links a:hover { color: var(--text); }
  .nav-links a.sponsor { color: var(--highlight); }
  .nav-links a.sponsor:hover { color: var(--highlight); opacity: 0.8; }

  /* ---------- hero ---------- */

  header.hero {
    position: relative;
    padding: 88px 0 96px;
    background-color: var(--bg);
    background-image: repeating-linear-gradient(
        to right, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 96px
      ),
      repeating-linear-gradient(
        to bottom, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 96px
      );
    background-position: center top;
    -webkit-mask-image: linear-gradient(to bottom, black 0%, black 55%, transparent 96%);
    mask-image: linear-gradient(to bottom, black 0%, black 55%, transparent 96%);
  }
  header.hero .wrap { position: relative; }

  .hero-grid {
    display: grid;
    grid-template-columns: 1.05fr 1fr;
    gap: 56px;
    align-items: center;
  }

  .eyebrow {
    font-family: var(--font-mono);
    font-size: 12.5px;
    font-weight: 500;
    letter-spacing: 0.09em;
    text-transform: uppercase;
    color: var(--accent);
    margin: 0 0 18px;
  }
  .eyebrow::before { content: "-- "; color: var(--text-muted); }

  h1.headline {
    font-size: clamp(2.15rem, 3.6vw, 3.15rem);
    font-weight: 700;
    line-height: 1.14;
    letter-spacing: -0.015em;
    margin-bottom: 22px;
  }
  h1.headline .kw { color: var(--accent); }
  h1.headline .punct { color: var(--text-muted); }

  .cursor {
    display: inline-block;
    width: 0.5ch;
    height: 0.85em;
    background: var(--accent);
    margin-left: 2px;
    transform: translateY(0.12em);
  }
  @media (prefers-reduced-motion: no-preference) {
    .cursor { animation: blink 1.1s steps(1) infinite; }
  }
  @keyframes blink { 50% { opacity: 0; } }

  .dek {
    font-size: 18px;
    line-height: 1.65;
    color: var(--text-muted);
    max-width: 46ch;
    margin-bottom: 32px;
  }
  .dek strong { color: var(--text); font-weight: 600; }

  .cta-row { display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
  .cta-note {
    margin: 14px 0 0;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
  }

  .btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-mono);
    font-size: 13.5px;
    font-weight: 500;
    text-decoration: none;
    padding: 12px 20px;
    border: 1px solid var(--accent);
    border-radius: 3px;
    transition: transform 0.12s ease, background 0.12s ease;
  }
  .btn-primary { background: var(--accent); color: var(--accent-contrast); }
  .btn-primary:hover { transform: translateY(-1px); }
  .btn-ghost {
    color: var(--text-muted);
    border-color: transparent;
    padding-left: 4px;
    padding-right: 4px;
  }
  .btn-ghost:hover { color: var(--text); }

  /* ---------- app mockup ---------- */

  .mockup {
    background: var(--mock-bg);
    border: 1px solid var(--mock-border);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 24px 48px -20px rgba(0,0,0,0.45);
    font-family: var(--font-mono);
    font-size: 10.5px;
    color: var(--mock-text);
  }
  .mockup-titlebar {
    height: 30px;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 0 12px;
    background: var(--mock-elevated);
    border-bottom: 1px solid var(--mock-border);
  }
  .mockup-titlebar .traffic { width: 9px; height: 9px; border-radius: 50%; background: var(--mock-border); }
  .mockup-titlebar .label { margin-left: 8px; color: var(--mock-muted); font-size: 10px; }

  .mockup-body { display: flex; height: 340px; }

  .mockup-sidebar {
    width: 112px;
    flex-shrink: 0;
    background: var(--mock-elevated);
    border-right: 1px solid var(--mock-border);
    padding: 10px 0;
  }
  .mockup-sidebar .sidebar-label {
    color: var(--mock-muted);
    font-size: 9px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    padding: 0 10px 6px;
  }
  .mockup-sidebar .tbl {
    padding: 4px 10px;
    display: flex;
    align-items: center;
    gap: 6px;
  }
  .mockup-sidebar .tbl.active { background: var(--mock-inset); }
  .mockup-sidebar .tbl .sq { width: 6px; height: 6px; background: var(--mock-accent); flex-shrink: 0; }
  .mockup-sidebar .tbl span { font-size: 10px; }

  .mockup-main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

  .mockup-tabs {
    display: flex;
    border-bottom: 1px solid var(--mock-border);
    background: var(--mock-bg);
  }
  .mockup-tabs .tab {
    padding: 7px 14px;
    font-size: 10px;
    border-right: 1px solid var(--mock-border);
    color: var(--mock-muted);
  }
  .mockup-tabs .tab.active { color: var(--mock-text); background: var(--mock-elevated); }

  .mockup-editor {
    padding: 12px 14px;
    border-bottom: 1px solid var(--mock-border);
    line-height: 1.7;
  }
  .mockup-editor .kw { color: var(--mock-accent); }
  .mockup-editor .str { color: var(--mock-success); }
  .mockup-editor .num { color: var(--mock-warning); }
  .mockup-editor .mut { color: var(--mock-muted); }

  .mockup-grid { flex: 1; overflow: hidden; }
  .mockup-row {
    display: grid;
    grid-template-columns: 34px 1.3fr 1fr;
    border-bottom: 1px solid var(--mock-border);
  }
  .mockup-row > div { padding: 6px 10px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .mockup-row.head { color: var(--mock-muted); background: var(--mock-elevated); font-size: 9.5px; }
  .mockup-row.edited { background: rgba(224, 172, 47, 0.12); }
  .mockup-row.new { background: rgba(63, 192, 122, 0.12); }

  .mockup-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 7px 12px;
    background: var(--mock-elevated);
    border-top: 1px solid var(--mock-border);
    font-size: 9.5px;
  }
  .mockup-footer .pending { color: var(--mock-warning); }
  .mockup-footer .actions { display: flex; gap: 10px; color: var(--mock-muted); }
  .mockup-footer .actions .commit { color: var(--mock-accent); font-weight: 600; }

  /* ---------- sections ---------- */

  section { padding: 88px 0; }
  section.tight { padding: 64px 0; }
  section + section { border-top: 1px solid var(--rule); }

  .section-head { margin-bottom: 40px; }
  .section-head h2 {
    font-size: 1.55rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    margin-bottom: 10px;
  }
  .section-head p { color: var(--text-muted); max-width: 56ch; }

  /* pull quote */

  blockquote.stage {
    margin: 0;
    padding-left: 28px;
    border-left: 3px solid var(--accent);
    font-family: var(--font-serif);
    font-size: 22px;
    font-style: italic;
    line-height: 1.55;
    color: var(--text);
    max-width: 640px;
  }
  blockquote.stage cite {
    display: block;
    margin-top: 18px;
    font-family: var(--font-mono);
    font-style: normal;
    font-size: 12.5px;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--text-muted);
  }

  /* feature table */

  .feature-table {
    border: 1px solid var(--rule);
    border-radius: 4px;
    overflow: hidden;
    background: var(--surface);
    box-shadow: var(--shadow);
  }
  .ft-row {
    display: grid;
    grid-template-columns: 200px 1fr 168px;
    gap: 20px;
    padding: 18px 22px;
    align-items: start;
  }
  .ft-row + .ft-row { border-top: 1px solid var(--rule); }
  .ft-row.head {
    background: var(--surface-alt);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.07em;
    text-transform: uppercase;
    color: var(--text-muted);
    padding-top: 12px;
    padding-bottom: 12px;
  }
  .ft-row:not(.head):nth-child(even) { background: var(--surface-alt); }
  .ft-name {
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 14px;
    letter-spacing: -0.005em;
  }
  .ft-desc { color: var(--text-muted); font-size: 15px; line-height: 1.55; }
  .ft-badges { display: flex; gap: 6px; flex-wrap: wrap; }
  .badge {
    font-family: var(--font-mono);
    font-size: 10.5px;
    letter-spacing: 0.03em;
    padding: 3px 8px;
    border: 1px solid var(--rule);
    border-radius: 2px;
    color: var(--text-muted);
    white-space: nowrap;
  }
  .badge.accent { border-color: var(--accent); color: var(--accent); }

  /* dialect cards */

  .dialect-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }
  .dialect-card {
    border: 1px solid var(--rule);
    border-radius: 4px;
    background: var(--surface);
    overflow: hidden;
    box-shadow: var(--shadow);
  }
  .dialect-card .dc-head {
    padding: 14px 18px;
    border-bottom: 1px solid var(--rule);
    display: flex;
    align-items: center;
    justify-content: space-between;
  }
  .dialect-card .dc-head h3 { font-size: 15px; font-weight: 600; }
  .dialect-card .kv {
    font-family: var(--font-mono);
    font-size: 12.5px;
    padding: 16px 18px;
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 7px 12px;
    background: var(--surface-alt);
  }
  .dialect-card .kv dt { color: var(--text-muted); }
  .dialect-card .kv dd { margin: 0; color: var(--text); }
  .dialect-card .dc-note {
    padding: 14px 18px;
    font-size: 13.5px;
    color: var(--text-muted);
    border-top: 1px solid var(--rule);
  }

  /* footer */

  footer {
    border-top: 1px solid var(--rule);
    padding: 40px 0;
  }
  footer .wrap {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
  }
  footer .fine {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
  }
  footer a.dl { text-decoration: none; }
  footer a.dl:hover { color: var(--accent); }

  @media (max-width: 860px) {
    .hero-grid { grid-template-columns: 1fr; }
    .ft-row { grid-template-columns: 1fr; gap: 8px; }
    .ft-row.head { display: none; }
    .dialect-grid { grid-template-columns: 1fr; }
    .mockup-body { height: auto; }
  }

  @media (max-width: 560px) {
    .wrap { padding: 0 20px; }
    section { padding: 56px 0; }
  }

  /* ---------- subpage hero ---------- */

  header.page-hero {
    padding: 64px 0 56px;
    border-bottom: 1px solid var(--rule);
    background-color: var(--bg);
    background-image: repeating-linear-gradient(
        to right, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 96px
      ),
      repeating-linear-gradient(
        to bottom, var(--grid-line) 0, var(--grid-line) 1px, transparent 1px, transparent 96px
      );
    background-position: center top;
  }
  header.page-hero h1 {
    font-size: clamp(1.9rem, 3.4vw, 2.6rem);
    font-weight: 700;
    letter-spacing: -0.015em;
    line-height: 1.16;
    margin-bottom: 16px;
  }
  header.page-hero .dek { margin-bottom: 0; }

  /* ---------- breadcrumb ---------- */

  .crumb {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 18px;
  }
  .crumb a { text-decoration: none; }
  .crumb a:hover { color: var(--accent); }

  /* ---------- FAQ accordion ---------- */

  .faq-list { max-width: 720px; }
  .faq-item { border-bottom: 1px solid var(--rule); }
  .faq-item summary {
    cursor: pointer;
    list-style: none;
    padding: 20px 0;
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 15px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
  }
  .faq-item summary::-webkit-details-marker { display: none; }
  .faq-item summary::after {
    content: "+";
    color: var(--accent);
    font-size: 19px;
    flex-shrink: 0;
  }
  .faq-item[open] summary::after { content: "\2212"; }
  .faq-item .faq-answer {
    padding: 0 0 22px;
    color: var(--text-muted);
    font-size: 15.5px;
    line-height: 1.65;
    max-width: 62ch;
  }
  .faq-item .faq-answer a { color: var(--accent); }
  .faq-item .faq-answer code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--surface-alt);
    padding: 1px 5px;
    border-radius: 3px;
  }

  /* ---------- comparison table ---------- */

  .table-scroll {
    overflow-x: auto;
    border: 1px solid var(--rule);
    border-radius: 4px;
    background: var(--surface);
    box-shadow: var(--shadow);
  }
  table.compare { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 760px; }
  table.compare th, table.compare td {
    padding: 14px 18px;
    text-align: left;
    border-bottom: 1px solid var(--rule);
    vertical-align: top;
  }
  table.compare thead th {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-muted);
    background: var(--surface-alt);
    white-space: nowrap;
  }
  table.compare tbody th {
    font-family: var(--font-mono);
    font-weight: 600;
    white-space: nowrap;
  }
  table.compare tbody tr:last-child td, table.compare tbody tr:last-child th { border-bottom: none; }
  table.compare tr.highlight td, table.compare tr.highlight th { background: var(--highlight-soft); }
  table.compare td.muted { color: var(--text-muted); }

  .caveat {
    margin-top: 18px;
    font-size: 13.5px;
    color: var(--text-muted);
    max-width: 68ch;
  }

  /* ---------- inline link list (used in About/FAQ prose) ---------- */

  .prose h2 {
    font-size: 1.2rem;
    font-weight: 600;
    letter-spacing: -0.005em;
    margin: 0 0 12px;
  }
  .prose p, .prose li { color: var(--text-muted); font-size: 15.5px; line-height: 1.65; }
  .prose p { margin: 0 0 16px; }
  .prose strong { color: var(--text); font-weight: 600; }
  .prose code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--surface-alt);
    padding: 1px 5px;
    border-radius: 3px;
  }
  .prose section + section { border-top: none; padding-top: 0; }