/* ============================================================
   modular_app_template — docs site design system
   Palette mirrors the README's architecture diagram:
   indigo (app) · purple (features) · violet (base) · teal (core)
   ============================================================ */

:root {
  --indigo: #4f46e5;
  --indigo-ink: #1e1b4b;
  --indigo-bg: #eef2ff;
  --purple: #a21caf;
  --purple-ink: #701a75;
  --purple-bg: #fdf4ff;
  --violet: #8b5cf6;
  --violet-ink: #4c1d95;
  --violet-bg: #f5f3ff;
  --teal: #0f766e;
  --teal-ink: #134e4a;
  --teal-bg: #f0fdfa;

  --bg: #ffffff;
  --bg-raised: #ffffff;
  --bg-sunken: #f8fafc;
  --bg-code: #0f172a;
  --text: #0f172a;
  --text-secondary: #475569;
  --text-tertiary: #94a3b8;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --link: var(--indigo);
  --focus: var(--indigo);
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.04), 0 8px 24px -12px rgba(15, 23, 42, 0.12);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --maxw: 1120px;

  color-scheme: light;
}

:root:not([data-theme="light"]) {
  @media (prefers-color-scheme: dark) {
    --indigo: #818cf8;
    --indigo-ink: #e0e7ff;
    --indigo-bg: #1e1b4b;
    --purple: #e879f9;
    --purple-ink: #fae8ff;
    --purple-bg: #3b0764;
    --violet: #a78bfa;
    --violet-ink: #ede9fe;
    --violet-bg: #2e1065;
    --teal: #2dd4bf;
    --teal-ink: #ccfbf1;
    --teal-bg: #042f2e;

    --bg: #0b1120;
    --bg-raised: #131b2e;
    --bg-sunken: #0f172a;
    --bg-code: #060b17;
    --text: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;
    --border: #1e293b;
    --border-strong: #334155;
    --link: var(--indigo);
    --focus: var(--indigo);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px -12px rgba(0, 0, 0, 0.5);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --indigo: #818cf8;
  --indigo-ink: #e0e7ff;
  --indigo-bg: #1e1b4b;
  --purple: #e879f9;
  --purple-ink: #fae8ff;
  --purple-bg: #3b0764;
  --violet: #a78bfa;
  --violet-ink: #ede9fe;
  --violet-bg: #2e1065;
  --teal: #2dd4bf;
  --teal-ink: #ccfbf1;
  --teal-bg: #042f2e;

  --bg: #0b1120;
  --bg-raised: #131b2e;
  --bg-sunken: #0f172a;
  --bg-code: #060b17;
  --text: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-tertiary: #64748b;
  --border: #1e293b;
  --border-strong: #334155;
  --link: var(--indigo);
  --focus: var(--indigo);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px -12px rgba(0, 0, 0, 0.5);
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

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

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

a {
  color: var(--link);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
  border-radius: 4px;
}

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 700;
  font-size: 15px;
  color: var(--text);
  white-space: nowrap;
}
.brand:hover {
  text-decoration: none;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  border-radius: 7px;
  background: linear-gradient(135deg, var(--indigo), var(--purple));
  color: white;
  font-size: 14px;
  flex-shrink: 0;
}
.brand code {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 13.5px;
  color: var(--text-secondary);
}

.main-nav {
  display: flex;
  gap: 4px;
  flex: 1;
}
.main-nav a {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 600;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
}
.main-nav a:hover {
  color: var(--text);
  background: var(--bg-sunken);
  text-decoration: none;
}
.main-nav a.active {
  color: var(--indigo);
  background: var(--indigo-bg);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-btn {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-raised);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 15px;
}
.icon-btn:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

.nav-toggle {
  display: none;
}

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

.hero {
  padding: 72px 0 56px;
  border-bottom: 1px solid var(--border);
  background:
    radial-gradient(circle at 15% 0%, var(--indigo-bg), transparent 45%),
    radial-gradient(circle at 85% 20%, var(--purple-bg), transparent 45%);
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--indigo);
  background: var(--indigo-bg);
  border: 1px solid color-mix(in srgb, var(--indigo) 30%, transparent);
  padding: 5px 11px;
  border-radius: 999px;
  margin-bottom: 20px;
}
h1 {
  font-size: clamp(32px, 5vw, 46px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  font-weight: 800;
  max-width: 18ch;
}
.lede {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 60ch;
  margin: 0 0 30px;
}
.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 44px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 14.5px;
  padding: 11px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
}
.btn:hover {
  text-decoration: none;
}
.btn-primary {
  background: var(--text);
  color: var(--bg);
}
.btn-primary:hover {
  opacity: 0.88;
}
:root[data-theme="dark"] .btn-primary,
:root:not([data-theme="light"]) .btn-primary {
  @media (prefers-color-scheme: dark) {
    background: var(--indigo);
    color: white;
  }
}
:root[data-theme="dark"] .btn-primary {
  background: var(--indigo);
  color: white;
}
.btn-ghost {
  background: var(--bg-raised);
  color: var(--text);
  border-color: var(--border-strong);
}
.btn-ghost:hover {
  background: var(--bg-sunken);
}

/* ---------- stat strip ---------- */

.stat-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.stat {
  background: var(--bg-raised);
  padding: 18px 20px;
}
.stat-num {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.stat-label {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 2px;
}

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

section {
  padding: 64px 0;
}
section + section {
  border-top: 1px solid var(--border);
}
.section-head {
  max-width: 62ch;
  margin-bottom: 36px;
}
.kicker {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin: 0 0 8px;
}
h2 {
  font-size: clamp(24px, 3.4vw, 32px);
  letter-spacing: -0.015em;
  margin: 0 0 10px;
  font-weight: 800;
}
h3 {
  font-size: 19px;
  letter-spacing: -0.01em;
  font-weight: 700;
  margin: 0 0 8px;
}
.section-head p {
  color: var(--text-secondary);
  font-size: 15.5px;
  margin: 0;
}

/* ---------- cards / grid ---------- */

.grid {
  display: grid;
  gap: 16px;
}
.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}
.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}
.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.card {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 20px;
}
.card-tight {
  padding: 16px 18px;
}
.card h3 {
  margin-bottom: 6px;
}
.card p {
  color: var(--text-secondary);
  font-size: 14.5px;
  margin: 0;
}
.card p + p {
  margin-top: 8px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 6px;
  border: 1px solid transparent;
}
.chip-indigo {
  background: var(--indigo-bg);
  color: var(--indigo-ink);
  border-color: color-mix(in srgb, var(--indigo) 25%, transparent);
}
.chip-purple {
  background: var(--purple-bg);
  color: var(--purple-ink);
  border-color: color-mix(in srgb, var(--purple) 25%, transparent);
}
.chip-violet {
  background: var(--violet-bg);
  color: var(--violet-ink);
  border-color: color-mix(in srgb, var(--violet) 25%, transparent);
}
.chip-teal {
  background: var(--teal-bg);
  color: var(--teal-ink);
  border-color: color-mix(in srgb, var(--teal) 25%, transparent);
}
.chip-neutral {
  background: var(--bg-sunken);
  color: var(--text-secondary);
  border-color: var(--border);
}

/* ---------- code ---------- */

pre {
  background: var(--bg-code);
  color: #e2e8f0;
  border-radius: var(--radius-md);
  padding: 16px 18px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13.2px;
  line-height: 1.65;
  margin: 0;
  border: 1px solid color-mix(in srgb, var(--bg-code) 60%, black);
}
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
}
:not(pre) > code {
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: 5px;
  color: var(--text);
}
.code-block {
  position: relative;
}
.code-block .copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  font-family: var(--font-sans);
  font-size: 11.5px;
  font-weight: 700;
  color: #cbd5e1;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 6px;
  padding: 4px 8px;
  cursor: pointer;
}
.code-block .copy-btn:hover {
  background: rgba(255, 255, 255, 0.12);
}
.code-block .copy-btn.copied {
  color: #6ee7b7;
}
.code-label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  margin: 0 0 8px;
}
/* very small syntax coloring, class-based, applied via data-hl spans server-side (none) —
   kept intentionally plain/monochrome for reliability without a JS highlighter */
.tok-com { color: #94a3b8; }
.tok-str { color: #86efac; }
.tok-kw { color: #93c5fd; }
.tok-type { color: #fca5a5; }
.tok-fn { color: #fcd34d; }
.tok-punc { color: #cbd5e1; }

/* ---------- tables ---------- */

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 14.5px;
}
th,
td {
  text-align: left;
  padding: 11px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
thead th {
  background: var(--bg-sunken);
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-secondary);
  font-weight: 700;
}
tbody tr:last-child td {
  border-bottom: none;
}
tbody tr:hover {
  background: var(--bg-sunken);
}
td code {
  white-space: nowrap;
}

/* ---------- diagram (architecture) ---------- */

.diagram {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-raised);
  padding: 28px;
}
.layer {
  border: 1.5px dashed var(--border-strong);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-bottom: 16px;
  position: relative;
}
.layer:last-child {
  margin-bottom: 0;
}
.layer-label {
  position: absolute;
  top: -11px;
  left: 14px;
  background: var(--bg-raised);
  padding: 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-tertiary);
}
.layer-boxes {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.box {
  border-radius: 9px;
  padding: 10px 14px;
  font-size: 13.5px;
  font-weight: 700;
  border: 1.5px solid;
  cursor: default;
  transition: transform 0.12s ease;
}
.box:hover {
  transform: translateY(-1px);
}
.box small {
  display: block;
  font-weight: 500;
  font-size: 11.5px;
  opacity: 0.8;
  margin-top: 2px;
}
.box-app {
  background: var(--indigo-bg);
  border-color: var(--indigo);
  color: var(--indigo-ink);
}
.box-feature {
  background: var(--purple-bg);
  border-color: var(--purple);
  color: var(--purple-ink);
}
.box-base {
  background: var(--violet-bg);
  border-color: var(--violet);
  color: var(--violet-ink);
}
.box-core {
  background: var(--teal-bg);
  border-color: var(--teal);
  color: var(--teal-ink);
}
.arrow-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-tertiary);
  padding: 4px 0;
}
.arrow-row .line {
  flex: 1;
  max-width: 220px;
  height: 1px;
  background: var(--border-strong);
}

/* ---------- api/impl split visual ---------- */

.split {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 18px;
  align-items: stretch;
}
.split-arrow {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
  font-size: 12px;
  min-width: 90px;
  text-align: center;
}
.split-arrow .glyph {
  font-size: 22px;
}
.split-arrow .forbidden {
  color: #ef4444;
  font-size: 11px;
  font-weight: 700;
}
.pane {
  border-radius: var(--radius-md);
  padding: 20px;
  border: 1.5px solid;
}
.pane-api {
  background: var(--teal-bg);
  border-color: var(--teal);
}
.pane-impl {
  background: var(--indigo-bg);
  border-color: var(--indigo);
}
.pane h4 {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 14px;
}
.pane p {
  font-size: 13.5px;
  color: var(--text-secondary);
  margin: 0 0 12px;
}

/* ---------- state/event/effect loop ---------- */

.loop {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex-wrap: wrap;
}
.loop-node {
  border: 1.5px solid var(--border-strong);
  background: var(--bg-sunken);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  min-width: 140px;
  text-align: center;
}
.loop-node strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 14px;
}
.loop-node span {
  font-size: 12px;
  color: var(--text-secondary);
}
.loop-conn {
  font-size: 20px;
  color: var(--text-tertiary);
  padding: 0 4px;
}

/* ---------- accordion (modules reference) ---------- */

.accordion-group {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
details.mod {
  border-bottom: 1px solid var(--border);
  background: var(--bg-raised);
}
details.mod:last-child {
  border-bottom: none;
}
details.mod > summary {
  list-style: none;
  cursor: pointer;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 15px;
  user-select: none;
}
details.mod > summary::-webkit-details-marker {
  display: none;
}
details.mod > summary .caret {
  margin-left: auto;
  color: var(--text-tertiary);
  transition: transform 0.15s ease;
  font-size: 12px;
}
details.mod[open] > summary .caret {
  transform: rotate(90deg);
}
details.mod > summary code {
  font-size: 13.5px;
}
.mod-body {
  padding: 0 20px 22px 20px;
}
.mod-body p {
  color: var(--text-secondary);
  font-size: 14.5px;
  margin: 0 0 12px;
}
.mod-body .filelist {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-secondary);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  margin: 0 0 12px;
  white-space: pre;
  overflow-x: auto;
}
.mod-tags {
  display: flex;
  gap: 6px;
  margin-left: 4px;
}

/* ---------- rule list ---------- */

.rule-list {
  display: grid;
  gap: 12px;
}
.rule {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 14px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--bg-raised);
}
.rule-num {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  color: var(--text-secondary);
}
.rule h4 {
  margin: 0 0 4px;
  font-size: 14.5px;
}
.rule p {
  margin: 0;
  font-size: 13.5px;
  color: var(--text-secondary);
}
.rule code {
  font-size: 12.5px;
}

/* ---------- terminal simulator ---------- */

.terminal {
  background: var(--bg-code);
  border-radius: var(--radius-md);
  border: 1px solid color-mix(in srgb, var(--bg-code) 60%, black);
  overflow: hidden;
}
.terminal-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.terminal-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.terminal-dot.r { background: #ef4444; }
.terminal-dot.y { background: #f59e0b; }
.terminal-dot.g { background: #22c55e; }
.terminal-title {
  margin-left: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: #94a3b8;
}
.terminal-run {
  margin-left: auto;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 700;
  color: #cbd5e1;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 6px;
  padding: 4px 10px;
  cursor: pointer;
}
.terminal-run:hover {
  background: rgba(255, 255, 255, 0.12);
}
.terminal-body {
  padding: 16px 18px 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.75;
  color: #e2e8f0;
  min-height: 260px;
  max-height: 420px;
  overflow-y: auto;
  white-space: pre-wrap;
  word-break: break-word;
}
.terminal-body .prompt {
  color: #38bdf8;
}
.terminal-body .cmd {
  color: #f8fafc;
  font-weight: 600;
}
.terminal-body .ok {
  color: #4ade80;
}
.terminal-body .path {
  color: #fbbf24;
}
.terminal-body .dim {
  color: #64748b;
}
.terminal-cursor {
  display: inline-block;
  width: 7px;
  height: 14px;
  background: #e2e8f0;
  margin-left: 2px;
  vertical-align: text-bottom;
  animation: blink 1s steps(1) infinite;
}
@keyframes blink {
  50% { opacity: 0; }
}

.tabs {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.tab-btn {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 600;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-raised);
  color: var(--text-secondary);
  cursor: pointer;
}
.tab-btn:hover {
  border-color: var(--border-strong);
  color: var(--text);
}
.tab-btn.active {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}

/* ---------- callout ---------- */

.callout {
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  border-left: 4px solid var(--indigo);
  background: var(--indigo-bg);
  padding: 14px 18px;
  font-size: 14.5px;
  color: var(--indigo-ink);
}
.callout strong {
  display: block;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 4px;
}
.callout.teal {
  border-left-color: var(--teal);
  background: var(--teal-bg);
  color: var(--teal-ink);
}
.callout.purple {
  border-left-color: var(--purple);
  background: var(--purple-bg);
  color: var(--purple-ink);
}

/* ---------- page hero (non-landing pages) ---------- */

.page-hero {
  padding: 48px 0 40px;
  border-bottom: 1px solid var(--border);
}
.page-hero p {
  color: var(--text-secondary);
  font-size: 16.5px;
  max-width: 68ch;
  margin: 0;
}
.breadcrumb {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--text-tertiary);
  margin-bottom: 12px;
}
.breadcrumb a {
  color: var(--text-tertiary);
}

/* ---------- footer ---------- */

footer {
  border-top: 1px solid var(--border);
  padding: 36px 0 48px;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-inner p {
  margin: 0;
  font-size: 13.5px;
  color: var(--text-tertiary);
}
.footer-links {
  display: flex;
  gap: 18px;
  font-size: 13.5px;
}
.footer-links a {
  color: var(--text-secondary);
}

/* ---------- misc ---------- */

.mono {
  font-family: var(--font-mono);
}
.center {
  text-align: center;
}
ul.plain {
  margin: 0;
  padding: 0;
  list-style: none;
}
.small {
  font-size: 13.5px;
  color: var(--text-secondary);
}

/* ---------- responsive ---------- */

@media (max-width: 880px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .stat-strip { grid-template-columns: repeat(2, 1fr); }
  .split { grid-template-columns: 1fr; }
  .split-arrow { flex-direction: row; min-width: 0; padding: 6px 0; }
}

@media (max-width: 720px) {
  .main-nav {
    position: fixed;
    inset: 60px 12px auto 12px;
    background: var(--bg-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow);
    flex-direction: column;
    padding: 8px;
    display: none;
    z-index: 50;
  }
  .main-nav.open {
    display: flex;
  }
  .nav-toggle {
    display: grid;
  }
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
}