/* ==========================================================================
   Sudoku University — Support & Instructional Site
   ========================================================================== */

body {
  overflow-x: hidden;
}

/* ==========================================================================
   Chalk texture utilities
   ========================================================================== */

.chalk-panel {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}
[data-theme='dark'] .chalk-panel {
  background:
    radial-gradient(oklch(1 0 0 / 0.02) 1px, transparent 1px) 0 0 / 14px 14px,
    var(--color-surface);
  border: 1px solid var(--color-border);
  box-shadow: inset 0 0 0 1px oklch(1 0 0 / 0.02), var(--shadow-sm);
}

.wood-frame {
  border-radius: var(--radius-xl);
  padding: var(--space-2);
  background: linear-gradient(160deg, var(--color-walnut-light), var(--color-walnut) 55%, var(--color-walnut-dark));
  box-shadow: var(--shadow-lg);
}
.wood-frame > * {
  border-radius: calc(var(--radius-xl) - 0.35rem);
}

/* ==========================================================================
   Header
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(180deg, var(--color-walnut-light), var(--color-walnut));
  border-bottom: 3px solid var(--color-walnut-dark);
  box-shadow: var(--shadow-md);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  padding-block: var(--space-3);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: #f2d38c;
}
.brand svg {
  width: 2.1rem;
  height: 2.1rem;
  flex-shrink: 0;
}
.brand-name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  color: #f8f1de;
  white-space: nowrap;
}
.brand-name span {
  display: block;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #f2d38c;
  opacity: 0.85;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}
.nav-links a {
  font-size: var(--text-sm);
  font-weight: 500;
  text-decoration: none;
  color: #e9dcc0;
  opacity: 0.85;
  white-space: nowrap;
}
.nav-links a:hover,
.nav-links a[aria-current='page'] {
  opacity: 1;
  color: #f2d38c;
}
.nav-links a[aria-current='page'] {
  border-bottom: 2px solid #f2d38c;
  padding-bottom: 0.2rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.theme-toggle,
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-full);
  color: #f2d38c;
  border: 1px solid oklch(0.9 0.1 90 / 0.35);
}
.theme-toggle:hover,
.nav-toggle:hover {
  background: oklch(0.9 0.1 90 / 0.12);
}
.nav-toggle {
  display: none;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  white-space: nowrap;
}
.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-md);
}
.btn-ghost {
  border-color: var(--color-border);
  color: var(--color-text);
}
.btn-ghost:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: color-mix(in oklab, var(--color-primary) 8%, transparent);
}
.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
}

/* ==========================================================================
   Section headings (generic — light-surface sections)
   ========================================================================== */

.section-head {
  max-width: 56ch;
  margin-bottom: var(--space-10);
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
}
.eyebrow::before {
  content: '';
  width: 0.4rem;
  height: 0.4rem;
  border-radius: var(--radius-full);
  background: currentColor;
}
.section-head h2 {
  font-size: var(--text-2xl);
  margin-top: var(--space-3);
}
.section-head p {
  margin-top: var(--space-3);
  font-size: var(--text-base);
  color: var(--color-text-muted);
}
.btn-ghost.on-light {
  border-color: var(--color-border);
  color: var(--color-text);
}
.btn-ghost.on-light:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ==========================================================================
   Page hero (interior pages)
   ========================================================================== */

.page-hero {
  background: var(--color-walnut);
  background: radial-gradient(120% 140% at 15% 0%, var(--color-walnut-light), var(--color-walnut) 55%, var(--color-walnut-dark));
  padding-block: var(--space-16) var(--space-12);
  border-bottom: 1px solid var(--color-walnut-dark);
}
.page-hero .wrap {
  max-width: var(--content-default);
}
.page-hero .eyebrow {
  color: #f2d38c;
}
.page-hero .eyebrow::before {
  background: #f2d38c;
}
.page-hero h1 {
  color: #f8f1de;
  font-size: var(--text-2xl);
  margin-top: var(--space-3);
}
.page-hero p {
  color: oklch(0.92 0.03 90 / 0.85);
  font-size: var(--text-lg);
  margin-top: var(--space-4);
  max-width: 60ch;
}
.crumb {
  font-size: var(--text-xs);
  color: oklch(0.92 0.03 90 / 0.6);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-2);
}
.crumb a {
  color: inherit;
  text-decoration: none;
}
.crumb a:hover {
  color: #f2d38c;
}

/* ==========================================================================
   Home hero
   ========================================================================== */

.home-hero {
  position: relative;
  padding-block: clamp(var(--space-16), 9vw, var(--space-32)) clamp(var(--space-16), 8vw, var(--space-24));
  background: radial-gradient(120% 100% at 20% -10%, var(--color-walnut-light) 0%, var(--color-walnut) 45%, var(--color-walnut-dark) 100%);
  overflow: hidden;
  isolation: isolate;
}
.home-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    repeating-linear-gradient(90deg, oklch(1 0 0 / 0.025) 0 1px, transparent 1px 84px),
    repeating-linear-gradient(0deg, oklch(1 0 0 / 0.025) 0 1px, transparent 1px 84px);
  z-index: -1;
}
.home-hero .wrap {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: var(--space-16);
  align-items: center;
}
.home-hero-copy .eyebrow {
  color: #f2d38c;
}
.home-hero-copy .eyebrow::before {
  background: #f2d38c;
}
.home-hero-copy h1 {
  color: #f8f1de;
  font-size: var(--text-3xl);
  margin-top: var(--space-4);
}
.home-hero-copy p {
  color: oklch(0.92 0.03 90 / 0.85);
  font-size: var(--text-lg);
  margin-top: var(--space-5);
  max-width: 46ch;
}
.home-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  margin-top: var(--space-8);
}
.home-hero-art {
  position: relative;
}
.home-hero-art img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  width: 100%;
}
.home-hero-badge {
  position: absolute;
  left: var(--space-4);
  bottom: var(--space-4);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: color-mix(in oklab, var(--color-walnut-dark) 80%, transparent);
  border: 1px solid oklch(0.9 0.1 90 / 0.3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  color: #f2d38c;
  backdrop-filter: blur(6px);
}
.home-hero-badge::before {
  content: '';
  width: 0.4rem;
  height: 0.4rem;
  border-radius: var(--radius-full);
  background: currentColor;
}

/* ==========================================================================
   Feature grid / cards
   ========================================================================== */

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}
.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
}
.feature-card svg {
  width: 1.75rem;
  height: 1.75rem;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}
.feature-card h3 {
  font-size: var(--text-base);
  font-family: var(--font-body);
  font-weight: 700;
}
.feature-card p {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* ==========================================================================
   Colour legend (shared component — reused across pages)
   ========================================================================== */

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6);
  padding: var(--space-5);
  border-radius: var(--radius-md);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
}
.legend-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text);
}
.legend-dot {
  width: 0.9rem;
  height: 0.9rem;
  border-radius: var(--radius-full);
  border: 1px solid color-mix(in oklab, var(--color-text) 15%, transparent);
  flex-shrink: 0;
}
.legend-dot.given {
  background: var(--color-text);
}
.legend-dot.solved {
  background: var(--color-blue);
}
.legend-dot.hint {
  background: var(--color-blue);
  box-shadow: 0 0 0 3px var(--color-blue-highlight);
}
.legend-dot.error {
  background: var(--color-notification);
}

/* ==========================================================================
   Content layout — sidebar + article (docs pages)
   ========================================================================== */

.docs-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: var(--space-12);
  align-items: start;
}
.docs-toc {
  position: sticky;
  top: calc(var(--space-20));
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}
.docs-toc-label {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-faint);
  padding: var(--space-2) var(--space-3);
}
.docs-toc a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
}
.docs-toc a:hover {
  color: var(--color-text);
  background: var(--color-surface-offset);
}
.docs-toc a.active {
  color: var(--color-primary);
  background: var(--color-primary-highlight);
  font-weight: 600;
}

.docs-content > * + * {
  margin-top: var(--space-6);
}
.docs-content h2 {
  font-size: var(--text-xl);
  margin-top: var(--space-16);
  scroll-margin-top: var(--space-24);
}
.docs-content h2:first-of-type {
  margin-top: 0;
}
.docs-content h3 {
  font-size: var(--text-lg);
  font-family: var(--font-body);
  font-weight: 700;
  margin-top: var(--space-8);
}
.docs-content p {
  color: var(--color-text-muted);
}
.docs-content ul,
.docs-content ol {
  color: var(--color-text-muted);
  padding-left: var(--space-6);
}
.docs-content li {
  margin-top: var(--space-2);
}
.docs-content li::marker {
  color: var(--color-primary);
}
.docs-content strong {
  color: var(--color-text);
  font-weight: 600;
}
.docs-content code {
  font-family: ui-monospace, 'SF Mono', Consolas, monospace;
  font-size: 0.9em;
  background: var(--color-surface-offset);
  padding: 0.1em 0.4em;
  border-radius: var(--radius-sm);
}

.callout {
  padding: var(--space-5);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface-offset);
}
.callout.callout-primary {
  border-color: color-mix(in oklab, var(--color-primary) 40%, var(--color-border));
  background: var(--color-primary-highlight);
}
.callout h4 {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
}
.callout p {
  font-size: var(--text-sm);
  margin-top: var(--space-2);
}
.callout p:first-child {
  margin-top: 0;
}

/* Keyboard key chip */
kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.6em;
  padding: 0.15em 0.5em;
  font-family: ui-monospace, 'SF Mono', Consolas, monospace;
  font-size: 0.85em;
  color: var(--color-text);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-bottom-width: 2px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

/* Step list (hint stages, notation steps) */
.step-list {
  display: grid;
  gap: var(--space-4);
}
.step {
  display: grid;
  grid-template-columns: 2.25rem 1fr;
  gap: var(--space-4);
}
.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-full);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--text-sm);
  flex-shrink: 0;
}
.step-body h4 {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
}
.step-body p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

/* ==========================================================================
   Technique glossary
   ========================================================================== */

.tier-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-10);
}
.tier-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text-muted);
  text-decoration: none;
}
.tier-chip:hover,
.tier-chip.active {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: var(--color-primary-highlight);
}

.tier-section {
  padding-block: 0;
  margin-top: var(--space-20);
  scroll-margin-top: var(--space-24);
}
.tier-section:first-of-type {
  margin-top: 0;
}
.tier-head {
  display: flex;
  align-items: baseline;
  gap: var(--space-4);
  margin-bottom: var(--space-2);
}
.tier-head h2 {
  font-size: var(--text-xl);
}
.tier-badge {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--color-primary-highlight);
  color: var(--color-primary-active, var(--color-primary));
}
[data-theme='dark'] .tier-badge {
  color: var(--color-primary);
}
.tier-intro {
  color: var(--color-text-muted);
  max-width: 64ch;
  margin-bottom: var(--space-8);
}

.technique-list {
  display: grid;
  gap: var(--space-4);
}
.technique {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  overflow: hidden;
}
.technique summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5) var(--space-6);
  cursor: pointer;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-text);
}
.technique summary::-webkit-details-marker {
  display: none;
}
.technique summary .alt-name {
  font-weight: 400;
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-left: var(--space-2);
}
.technique summary .chevron {
  width: 1.1rem;
  height: 1.1rem;
  color: var(--color-primary);
  flex-shrink: 0;
  transition: transform var(--transition-interactive);
}
.technique[open] summary .chevron {
  transform: rotate(180deg);
}
.technique-body {
  padding: 0 var(--space-6) var(--space-6);
  border-top: 1px solid var(--color-divider);
  padding-top: var(--space-5);
}
.technique-body p {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}
.technique-body p + p {
  margin-top: var(--space-3);
}
.technique-body .result-line {
  margin-top: var(--space-4);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  background: var(--color-blue-highlight);
  color: var(--color-text);
  font-size: var(--text-sm);
}
.technique-body .result-line strong {
  color: var(--color-blue);
}

.technique-media {
  margin-top: var(--space-5);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-divider);
  display: grid;
  gap: var(--space-5);
}
.technique-media-pair figcaption {
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  max-width: 72ch;
}
.technique-media-images {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}
.technique-media-images img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}
@media (max-width: 640px) {
  .technique-media-images {
    grid-template-columns: 1fr;
  }
}
.technique-video {
  max-width: 32rem;
}
.technique-video iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  display: block;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}
.technique-video-facade {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  cursor: pointer;
  background: var(--color-surface-2);
}
.technique-video-facade img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform var(--transition-interactive);
}
.technique-video-facade:hover img {
  transform: scale(1.03);
}
.technique-video-play {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 3.25rem;
  height: 3.25rem;
  color: var(--color-primary);
  filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.35));
  transition: transform var(--transition-interactive);
}
.technique-video-facade:hover .technique-video-play {
  transform: translate(-50%, -50%) scale(1.08);
}
.technique-video-label {
  position: absolute;
  left: var(--space-3);
  bottom: var(--space-3);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: rgba(20, 20, 20, 0.65);
  color: #fff;
  font-size: var(--text-xs);
  font-weight: 600;
}

/* ==========================================================================
   FAQ accordion
   ========================================================================== */

.faq-list {
  display: grid;
  gap: var(--space-3);
}
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
}
.faq-item summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5);
  cursor: pointer;
  font-weight: 600;
  color: var(--color-text);
}
.faq-item summary::-webkit-details-marker {
  display: none;
}
.faq-item summary .chevron {
  width: 1.1rem;
  height: 1.1rem;
  color: var(--color-primary);
  flex-shrink: 0;
  transition: transform var(--transition-interactive);
}
.faq-item[open] summary .chevron {
  transform: rotate(180deg);
}
.faq-item-body {
  padding: 0 var(--space-5) var(--space-5);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}
.faq-item-body p + p {
  margin-top: var(--space-3);
}
.faq-item-body a {
  color: var(--color-blue);
}

/* ==========================================================================
   Requirements table
   ========================================================================== */

.req-table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}
.req-table th,
.req-table td {
  text-align: left;
  padding: var(--space-4) var(--space-5);
  font-size: var(--text-sm);
  border-bottom: 1px solid var(--color-divider);
}
.req-table th {
  width: 30%;
  background: var(--color-surface-offset);
  font-weight: 700;
  color: var(--color-text);
}
.req-table td {
  background: var(--color-surface);
  color: var(--color-text-muted);
}
.req-table tr:last-child th,
.req-table tr:last-child td {
  border-bottom: none;
}

/* ==========================================================================
   CTA band
   ========================================================================== */

.cta-band {
  background: var(--color-surface-offset);
  border-top: 1px solid var(--color-divider);
  border-bottom: 1px solid var(--color-divider);
}
.cta-band + .cta-band {
  border-top: none;
}
.cta-band .section-head {
  margin-inline: auto;
  text-align: center;
}
.cta-band .eyebrow {
  justify-content: center;
}
.cta-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  background: var(--color-walnut-dark);
  padding-block: var(--space-12) var(--space-8);
  color: #d9c9a5;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: var(--space-10);
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: #f8f1de;
  margin-bottom: var(--space-3);
}
.footer-brand svg {
  width: 1.75rem;
  height: 1.75rem;
  color: #f2d38c;
}
.footer-brand span {
  font-family: var(--font-display);
  font-size: var(--text-base);
}
.footer-col p {
  font-size: var(--text-sm);
  color: #b7a880;
  max-width: 32ch;
}
.footer-col h4 {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #f2d38c;
  margin-bottom: var(--space-3);
}
.footer-col ul {
  display: grid;
  gap: var(--space-2);
}
.footer-col a {
  font-size: var(--text-sm);
  color: #d9c9a5;
  text-decoration: none;
}
.footer-col a:hover {
  color: #f2d38c;
}
.footer-bottom {
  margin-top: var(--space-10);
  padding-top: var(--space-6);
  border-top: 1px solid oklch(0.9 0.1 90 / 0.12);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
  font-size: var(--text-xs);
  color: #a3937510;
  color: #9c8a67;
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 960px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .docs-layout {
    grid-template-columns: 1fr;
  }
  .docs-toc {
    position: static;
    flex-direction: row;
    overflow-x: auto;
    top: auto;
  }
}

@media (max-width: 860px) {
  .home-hero .wrap {
    grid-template-columns: 1fr;
  }
  .home-hero-art {
    max-width: 22rem;
    margin-inline: auto;
    width: 100%;
  }
  .feature-grid {
    grid-template-columns: 1fr;
  }
  .nav-links {
    position: fixed;
    top: 4.25rem;
    left: var(--space-4);
    right: var(--space-4);
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-1);
    background: var(--color-walnut);
    border: 1px solid var(--color-walnut-light);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    box-shadow: var(--shadow-lg);
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    z-index: 90;
    transition:
      opacity var(--transition-interactive),
      transform var(--transition-interactive);
  }
  .nav-links a {
    width: 100%;
    padding: var(--space-3) var(--space-2);
    opacity: 1;
  }
  .nav-links.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav-toggle {
    display: inline-flex;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 600px) {
  .step {
    grid-template-columns: 1fr;
  }
  .step-num {
    width: 1.8rem;
    height: 1.8rem;
  }
}

@media (max-width: 480px) {
  .brand-name {
    font-size: var(--text-sm);
    white-space: normal;
  }
  .brand-name span {
    display: none;
  }
  .brand svg {
    width: 1.7rem;
    height: 1.7rem;
  }
  .site-header .wrap {
    gap: var(--space-3);
  }
}