/* =============================================
   Subnetsplit — Brand Design System
   Based on brand.md (p3: light, spacious, Barlow + Fira Code, 4px radius, 8px spacing)
   ============================================= */

/* --- Google Fonts load --- */
@import url('https://fonts.googleapis.com/css2?family=Barlow:wght@400;600;700&family=Fira+Code:wght@400;500&display=swap');

/* --- Brand tokens as CSS custom properties --- */
:root {
  /* Typography */
  --font-display: 'Barlow', sans-serif;
  --font-body: 'Barlow', sans-serif;
  --font-mono: 'Fira Code', monospace;

  /* Colours — brand palette */
  --color-bg: #f9fafb;
  --color-surface: #ffffff;
  --color-primary: #0f4c81;
  --color-primary-hover: #0a3560;
  --color-accent: #d97706;
  --color-success: #059669;
  --color-danger: #dc2626;
  --color-text: #1f2937;
  --color-text-muted: #6b7280;
  --color-text-dim: #9ca3af;
  --color-border: #e5e7eb;
  --color-code-bg: #f3f4f6;

  /* Spacing & radius */
  --radius: 4px;
  --space: 8px;

  /* Shadows for surface elevation */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 2px 4px rgba(0,0,0,0.04);

  /* Motion */
  --transition-fast: 150ms ease;
  --transition-slow: 200ms ease;
}

/* --- Dark theme override --- */
[data-theme="dark"] {
  --color-bg: #111827;
  --color-surface: #1f2937;
  --color-primary: #3b82f6;
  --color-primary-hover: #2563eb;
  --color-accent: #f59e0b;
  --color-success: #10b981;
  --color-danger: #ef4444;
  --color-text: #f3f4f6;
  --color-text-muted: #9ca3af;
  --color-text-dim: #6b7280;
  --color-border: #374151;
  --color-code-bg: #374151;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.15);
  --shadow-md: 0 2px 4px rgba(0,0,0,0.2);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* --- Shared navigation --- */
.site-nav {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 calc(var(--space) * 2);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: calc(var(--space) * 1.5);
  text-decoration: none;
  color: var(--color-text);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
}

.nav-logo span { letter-spacing: -0.01em; }

.nav-links {
  display: flex;
  align-items: center;
  gap: calc(var(--space) * 3);
  list-style: none;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.nav-links a:hover { color: var(--color-primary); }

.nav-links a.active {
  color: var(--color-primary);
}

.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  color: var(--color-text-muted);
  transition: background var(--transition-fast), color var(--transition-fast);
  line-height: 1;
}

.theme-toggle:hover {
  background: var(--color-code-bg);
  color: var(--color-text);
}

/* --- Page container --- */
.page {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 calc(var(--space) * 2);
}

.page-wide {
  max-width: 960px;
}

.page-content {
  padding: calc(var(--space) * 8) 0 calc(var(--space) * 6);
}

.page-content-tool {
  padding: calc(var(--space) * 6) 0 calc(var(--space) * 6);
}

/* --- Section --- */
.section {
  margin-bottom: calc(var(--space) * 8);
}

.section:last-child { margin-bottom: 0; }

/* --- Eyebrow (section number + label above h2) --- */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: calc(var(--space) * 1.5);
  display: flex;
  align-items: center;
  gap: calc(var(--space) * 1.5);
}

.eyebrow::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
  max-width: 48px;
}

/* --- Headings --- */
h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 2.25rem;
  line-height: 1.15;
  color: var(--color-text);
  margin-bottom: calc(var(--space) * 2);
  letter-spacing: -0.01em;
}

h2 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.5rem;
  line-height: 1.3;
  color: var(--color-text);
  margin-bottom: calc(var(--space) * 2);
}

h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.125rem;
  line-height: 1.4;
  color: var(--color-text);
  margin-bottom: calc(var(--space) * 1.5);
}

/* --- Body text --- */
p { margin-bottom: calc(var(--space) * 2); }

p:last-child { margin-bottom: 0; }

.text-large {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-text-muted);
}

.text-small {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* --- Inline code --- */
code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-code-bg);
  padding: 0.15em 0.4em;
  border-radius: 2px;
  font-weight: 500;
}

/* --- Links --- */
a {
  color: var(--color-primary);
  text-decoration: none;
  text-underline-offset: 2px;
  transition: color var(--transition-fast), text-decoration var(--transition-fast);
}

a:hover { 
  color: var(--color-primary-hover);
  text-decoration: underline;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: calc(var(--space));
  padding: 0.625rem 1.25rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
  line-height: 1.3;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-border);
}

.btn-secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-sm {
  padding: 0.375rem 0.75rem;
  font-size: 0.8rem;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-group {
  display: flex;
  gap: calc(var(--space));
  flex-wrap: wrap;
}

/* --- Hero section --- */
.hero {
  margin-bottom: calc(var(--space) * 10);
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--space) * 6);
  align-items: center;
}

.hero-text h1 { margin-bottom: calc(var(--space) * 2); }

.hero-text .text-large { margin-bottom: calc(var(--space) * 3); }

.hero-actions {
  display: flex;
  gap: calc(var(--space) * 2);
  flex-wrap: wrap;
}

/* --- Hero figure (screenshot) --- */
.hero-figure {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.hero-figure img {
  display: block;
  width: 100%;
  height: auto;
}

/* --- Feature cards (two-column) --- */
.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--space) * 3);
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: calc(var(--space) * 3);
  box-shadow: var(--shadow-sm);
}

.feature-card h3 {
  font-size: 1rem;
  margin-bottom: calc(var(--space));
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

.feature-card .card-icon {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-primary);
  margin-bottom: calc(var(--space));
  display: inline-block;
}

/* --- Proof strip (big numbers) --- */
.proof-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: calc(var(--space) * 4);
  padding: calc(var(--space) * 4) 0;
  margin-bottom: calc(var(--space) * 4);
}

.proof-cell {
  text-align: center;
}

.proof-cell .proof-number {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 600;
  color: var(--color-primary);
  line-height: 1.1;
  margin-bottom: calc(var(--space));
}

.proof-cell .proof-label {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.proof-cell:not(:last-child)::after {
  display: none;
}

/* --- Steps list --- */
.steps {
  list-style: none;
  counter-reset: step;
}

.steps li {
  counter-increment: step;
  display: flex;
  gap: calc(var(--space) * 3);
  padding: calc(var(--space) * 3) 0;
  border-bottom: 1px solid var(--color-border);
}

.steps li:last-child { border-bottom: none; }

.steps li::before {
  content: counter(step);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-primary);
  min-width: 24px;
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 1rem;
  margin-bottom: calc(var(--space));
}

.step-content p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

/* --- What it cannot do section --- */
.limits-list {
  list-style: none;
}

.limits-list li {
  padding: calc(var(--space) * 2) 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.9rem;
  display: flex;
  gap: calc(var(--space) * 2);
  align-items: flex-start;
}

.limits-list li:last-child { border-bottom: none; }

.limits-list li .limit-mark {
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-weight: 500;
  flex-shrink: 0;
}

/* --- Objection section --- */
.objections {
  list-style: none;
}

.objections li {
  padding: calc(var(--space) * 2.5) 0;
  border-bottom: 1px solid var(--color-border);
}

.objections li:last-child { border-bottom: none; }

.objections li .obj-q {
  font-weight: 600;
  font-family: var(--font-display);
  color: var(--color-text);
  margin-bottom: calc(var(--space));
  display: block;
}

.objections li .obj-a {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* --- Result sample --- */
.result-sample {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.result-sample pre {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.6;
  color: var(--color-text);
  padding: calc(var(--space) * 3);
  overflow-x: auto;
  margin: 0;
  background: var(--color-surface);
}

/* --- Sample table in home page --- */
.sample-table-wrap {
  overflow-x: auto;
}

.sample-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.sample-table th {
  background: var(--color-code-bg);
  padding: 0.5rem 0.75rem;
  text-align: left;
  font-weight: 600;
  color: var(--color-text-muted);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

.sample-table td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

.sample-table tbody tr:last-child td {
  border-bottom: none;
}

.sample-table tbody tr:hover {
  background: var(--color-code-bg);
}

/* --- CTA section --- */
.cta-section {
  text-align: center;
  padding: calc(var(--space) * 8) 0;
}

.cta-section h2 { margin-bottom: calc(var(--space) * 2); }

.cta-section p {
  color: var(--color-text-muted);
  margin-bottom: calc(var(--space) * 3);
}

/* --- Card (generic container) --- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: calc(var(--space) * 3);
  box-shadow: var(--shadow-sm);
  margin-bottom: calc(var(--space) * 3);
}

.card:last-child { margin-bottom: 0; }

.card h2 {
  font-size: 1.125rem;
  margin-bottom: calc(var(--space) * 2);
}

/* --- Tool page specific --- */
.form-group {
  margin-bottom: calc(var(--space) * 2);
}

.form-group:last-child { margin-bottom: 0; }

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: calc(var(--space));
}

.form-group .hint {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: calc(var(--space));
}

input[type="text"],
textarea {
  width: 100%;
  padding: 0.6rem 0.75rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  transition: border-color var(--transition-fast);
  outline: none;
}

input[type="text"]:focus,
textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(15, 76, 129, 0.15);
}

textarea {
  min-height: 120px;
  resize: vertical;
  line-height: 1.5;
}

/* --- Results area (tool) --- */
.results-section {
  display: none;
}

.results-section.visible {
  display: block;
  animation: fadeSlideIn var(--transition-slow) ease both;
}

@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.results-summary {
  display: flex;
  gap: calc(var(--space) * 3);
  flex-wrap: wrap;
  margin-bottom: calc(var(--space) * 3);
}

.summary-stat {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: calc(var(--space) * 1.5) calc(var(--space) * 2);
  text-align: center;
  min-width: 120px;
  box-shadow: var(--shadow-sm);
}

.summary-stat .value {
  font-size: 1.5rem;
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--color-primary);
}

.summary-stat .label {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  margin-top: calc(var(--space) * 0.5);
}

/* --- Table (tool results) --- */
.table-wrapper {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

thead th {
  background: var(--color-code-bg);
  padding: 0.5rem 0.75rem;
  text-align: left;
  font-weight: 600;
  font-family: var(--font-body);
  color: var(--color-text-muted);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
  position: sticky;
  top: 0;
}

tbody td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
  font-family: var(--font-mono);
}

tbody tr:hover {
  background: var(--color-code-bg);
}

tbody tr:nth-child(even) {
  background: var(--color-bg);
}

tbody tr:nth-child(even):hover {
  background: var(--color-code-bg);
}

/* --- Gaps section --- */
.gaps-section {
  margin-top: calc(var(--space) * 3);
}

.gaps-section h3 {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: calc(var(--space) * 1.5);
}

/* --- Warning / overflow / error --- */
.overflow-section,
.error-section {
  margin-top: calc(var(--space) * 2);
}

.overflow-section h3,
.error-section h3 {
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: calc(var(--space));
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.overflow-section h3 { color: var(--color-accent); }
.error-section h3 { color: var(--color-danger); }

.overflow-item,
.error-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: var(--radius);
  padding: 0.5rem 0.75rem;
  margin-bottom: calc(var(--space));
  font-size: 0.85rem;
  color: var(--color-text);
}

.error-item {
  border-left-color: var(--color-danger);
}

/* --- No-JS fallback --- */
.no-js {
  display: block;
  padding: calc(var(--space) * 1.5);
  background: rgba(217, 119, 6, 0.08);
  border: 1px solid rgba(217, 119, 6, 0.25);
  border-radius: var(--radius);
  color: var(--color-accent);
  font-size: 0.9rem;
  margin-bottom: calc(var(--space) * 2);
}

[data-js-loaded] .no-js { display: none; }

/* --- Toast notification --- */
.toast {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-success);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  font-size: 0.85rem;
  color: var(--color-success);
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(1rem);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
  pointer-events: none;
  z-index: 200;
  font-family: var(--font-mono);
}

.toast.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Pricing page --- */
.pricing-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--space) * 4);
  margin-bottom: calc(var(--space) * 6);
}

.pricing-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: calc(var(--space) * 4);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.pricing-card.featured {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary), var(--shadow-md);
  position: relative;
}

.pricing-card.featured::before {
  content: 'RECOMMENDED';
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  padding: 2px 10px;
  border-radius: var(--radius);
}

.pricing-card h3 {
  font-size: 1.25rem;
  margin-bottom: calc(var(--space));
}

.pricing-card .price {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: calc(var(--space) * 1.5);
}

.pricing-card .price-unit {
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--color-text-muted);
}

.pricing-card p { color: var(--color-text-muted); font-size: 0.9rem; }

.pricing-features {
  list-style: none;
  margin: calc(var(--space) * 2.5) 0;
  flex: 1;
}

.pricing-features li {
  padding: calc(var(--space)) 0;
  font-size: 0.875rem;
  display: flex;
  gap: calc(var(--space));
  align-items: center;
  color: var(--color-text);
}

.pricing-features li .check {
  color: var(--color-success);
  font-family: var(--font-mono);
  font-weight: 500;
}

.pricing-features li .na {
  color: var(--color-text-dim);
  font-family: var(--font-mono);
}

.pricing-card .btn { margin-top: auto; }

/* --- Mock checkout (pricing page) --- */
.mock-checkout {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: calc(var(--space) * 4);
  max-width: 480px;
  margin: 0 auto;
  box-shadow: var(--shadow-sm);
}

.mock-checkout .demo-badge {
  display: inline-block;
  background: var(--color-accent);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  padding: 2px 8px;
  border-radius: var(--radius);
  margin-bottom: calc(var(--space) * 2);
  text-transform: uppercase;
}

.mock-checkout h3 { margin-bottom: calc(var(--space) * 2); }

.checkout-field {
  margin-bottom: calc(var(--space) * 2);
}

.checkout-field label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-bottom: calc(var(--space) * 0.5);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-family: var(--font-mono);
}

.checkout-field input {
  width: 100%;
  padding: 0.6rem 0.75rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 0.9rem;
  transition: border-color var(--transition-fast);
  outline: none;
}

.checkout-field input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(15, 76, 129, 0.15);
}

.checkout-total {
  display: flex;
  justify-content: space-between;
  padding: calc(var(--space) * 1.5) 0;
  border-top: 1px solid var(--color-border);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: calc(var(--space) * 2);
}

.checkout-total .total-amount {
  font-family: var(--font-mono);
  color: var(--color-primary);
}

.checkout-success {
  display: none;
  text-align: center;
  padding: calc(var(--space) * 4);
}

.checkout-success.show { display: block; }

.checkout-success .success-icon {
  font-size: 2.5rem;
  margin-bottom: calc(var(--space) * 2);
  color: var(--color-success);
}

.checkout-success h3 {
  color: var(--color-success);
  margin-bottom: calc(var(--space));
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: calc(var(--space) * 6) 0 calc(var(--space) * 4);
  margin-top: calc(var(--space) * 6);
}

.footer-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 calc(var(--space) * 2);
}

.footer-links {
  display: flex;
  gap: calc(var(--space) * 3);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: calc(var(--space) * 3);
}

.footer-links a {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  text-decoration: none;
}

.footer-links a:hover { color: var(--color-primary); }

.footer-main {
  text-align: center;
  color: var(--color-text-dim);
  font-size: 0.8rem;
  line-height: 1.6;
}

.footer-main p { margin-bottom: calc(var(--space) * 0.5); }

/* --- Responsive --- */
@media (max-width: 720px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: calc(var(--space) * 4);
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
  }

  .proof-strip {
    grid-template-columns: 1fr;
    gap: calc(var(--space) * 3);
  }

  h1 { font-size: 1.75rem; }

  h2 { font-size: 1.25rem; }

  .nav-links {
    gap: calc(var(--space) * 2);
  }

  .page,
  .page-wide,
  .nav-inner,
  .footer-inner {
    padding-left: calc(var(--space) * 1.5);
    padding-right: calc(var(--space) * 1.5);
  }
}

/* --- Responsive table → card layout --- */
/* At viewport widths too narrow for the wide allocation and sample tables,
   transform each row into a stacked card with data-label headers. */
@media (max-width: 640px) {
  .sample-table-wrap,
  .table-wrapper {
    overflow: visible;
  }

  .sample-table,
  .sample-table thead,
  .sample-table tbody,
  .sample-table tr,
  .sample-table th,
  .sample-table td,
  table,
  table thead,
  table tbody,
  table tr,
  table th,
  table td {
    display: block;
  }

  .sample-table thead,
  table thead {
    display: none;
  }

  .sample-table tr,
  table tr {
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: calc(var(--space) * 1.5);
    margin-bottom: calc(var(--space) * 2);
    background: var(--color-surface);
  }

  .sample-table tr:hover,
  table tr:hover {
    background: var(--color-surface);
  }

  .sample-table td,
  table td {
    padding: 0.35rem 0;
    border-bottom: none;
    white-space: normal;
    display: flex;
    gap: calc(var(--space));
    align-items: baseline;
  }

  .sample-table td::before,
  table td::before {
    content: attr(data-label);
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 0.7rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    min-width: 80px;
    flex-shrink: 0;
  }

  .sample-table tbody tr:last-child td,
  table tbody tr:last-child td {
    border-bottom: none;
  }
}

@media (max-width: 480px) {
  .nav-links a.nav-link-label { display: none; }

  .hero-actions { flex-direction: column; }

  .hero-actions .btn { width: 100%; justify-content: center; }
}

/* --- Compound control (split button) --- */
.compound-control {
  display: inline-flex;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.compound-control .btn {
  border-radius: 0;
  border: none;
}

.compound-control .btn:first-child {
  border-right: 1px solid var(--color-border);
}

/* --- Pause motion (accessibility) --- */
.pause-motion {
  font-size: 0.7rem;
  color: var(--color-text-dim);
  cursor: pointer;
  background: none;
  border: none;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.pause-motion:hover { color: var(--color-text-muted); }

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}