/* ---------- Design tokens ---------- */
:root {
  --background: #0a0a0a;
  --surface: #121212;
  --surface-hover: #1a1a1a;
  --border: #27272a;
  --border-hover: #3f3f46;
  --text-primary: #ededed;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --accent-primary: #f59e0b;
  --accent-primary-hover: #d97706;
  --accent-secondary: #3b82f6;
  --grid-line: rgba(255, 255, 255, 0.03);

  --font-heading: "Chivo", ui-sans-serif, system-ui, sans-serif;
  --font-body: "IBM Plex Sans", ui-sans-serif, system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;

  --radius-sm: 2px;
  --radius-md: 4px;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
}

/* ---------- Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  padding: 0;
}
body {
  min-height: 100vh;
  background-color: var(--background);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a {
  color: inherit;
  text-decoration: none;
}
button {
  font-family: inherit;
}
img,
svg {
  display: block;
}
::selection {
  background: var(--accent-primary);
  color: #0a0a0a;
}

/* ---------- Skip link ---------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent-primary);
  color: #0a0a0a;
  padding: 0.5rem 1rem;
  z-index: 1000;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}
.skip-link:focus {
  left: 0;
}

/* ---------- Hero ---------- */
.hero {
  border-bottom: 1px solid var(--border);
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 40px 40px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(
      600px circle at 15% 0%,
      rgba(245, 158, 11, 0.08),
      transparent 60%
    );
  pointer-events: none;
}
.hero-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: var(--space-16) var(--space-8) var(--space-12);
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.hero-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}
.badge-mono {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text-secondary);
  text-transform: uppercase;
}
.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-primary);
  box-shadow: 0 0 8px var(--accent-primary);
  animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}
.hero-count-wrap {
  text-transform: uppercase;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1;
  margin: 0;
  color: var(--text-primary);
}
.hero-title .accent {
  color: var(--accent-primary);
}

.hero-subtitle {
  max-width: 640px;
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.55;
}

/* Search bar */
.search-wrap {
  position: relative;
  max-width: 640px;
  margin-top: var(--space-4);
}
.search-wrap input {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0.9rem 3.5rem 0.9rem 3rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}
.search-wrap input::placeholder {
  color: var(--text-muted);
}
.search-wrap input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 1px var(--accent-primary);
  background: #0f0f0f;
}
.search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}
.kbd {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  border: 1px solid var(--border);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  background: var(--background);
}

.hero-hints {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.hero-hints .mono {
  color: var(--accent-primary);
}

/* ---------- Layout ---------- */
.layout {
  max-width: 1440px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  border-bottom: 1px solid var(--border);
}
@media (min-width: 900px) {
  .layout {
    flex-direction: row;
    align-items: stretch;
  }
}

/* Sidebar */
.sidebar {
  border-bottom: 1px solid var(--border);
  padding: var(--space-6) 0;
  background: var(--background);
  flex-shrink: 0;
}
@media (min-width: 900px) {
  .sidebar {
    width: 280px;
    border-right: 1px solid var(--border);
    border-bottom: none;
    position: sticky;
    top: 0;
    align-self: flex-start;
    max-height: 100vh;
    overflow-y: auto;
  }
}
.sidebar-section {
  padding: var(--space-4) 0;
  border-bottom: 1px dashed var(--border);
}
.sidebar-section:last-of-type {
  border-bottom: none;
}
.sidebar-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0 var(--space-6);
  margin-bottom: var(--space-3);
}

.category-nav {
  display: flex;
  flex-direction: column;
}
.cat-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem var(--space-6);
  cursor: pointer;
  color: var(--text-secondary);
  transition: color 0.15s ease, background 0.15s ease, border-color 0.15s ease;
  border-left: 2px solid transparent;
  background: transparent;
  border-top: none;
  border-right: none;
  border-bottom: none;
  width: 100%;
  text-align: left;
  font-family: var(--font-body);
  font-size: 0.9rem;
}
.cat-item .cat-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}
.cat-item .cat-label svg {
  color: var(--text-muted);
  transition: color 0.15s ease;
}
.cat-item:hover {
  background: var(--surface);
  color: var(--text-primary);
}
.cat-item:hover svg {
  color: var(--accent-primary);
}
.cat-item.active {
  border-left-color: var(--accent-primary);
  color: var(--text-primary);
  background: var(--surface);
  font-weight: 600;
}
.cat-item.active svg {
  color: var(--accent-primary);
}
.cat-badge {
  background: var(--border);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  min-width: 24px;
  text-align: center;
}
.cat-item.active .cat-badge {
  background: var(--accent-primary);
  color: #0a0a0a;
}

/* Legend */
.legend {
  list-style: none;
  padding: 0 var(--space-6);
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.chip {
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: var(--space-2);
  border-radius: var(--radius-sm);
  vertical-align: middle;
}
.chip.amber { background: var(--accent-primary); }
.chip.blue { background: var(--accent-secondary); }
.chip.dashed { background: transparent; border: 1px dashed var(--text-muted); }

.sidebar-footer {
  padding: var(--space-4) var(--space-6) 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.6;
}
.sidebar-footer p {
  margin: 0;
}
.mono {
  font-family: var(--font-mono);
  color: var(--text-secondary);
}

/* Content area */
.content-area {
  flex: 1;
  padding: var(--space-8);
  min-width: 0;
}
.content-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-8);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--border);
}
.section-title {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--text-primary);
}
.content-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-secondary);
  white-space: nowrap;
}
.content-meta .dim {
  color: var(--text-muted);
  margin-left: 4px;
}

/* Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-5);
}

/* Card */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
  position: relative;
  min-height: 200px;
  animation: fadeUp 0.35s ease both;
}
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
.card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  background: var(--surface-hover);
}
.card::after {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 12px;
  height: 12px;
  border-top: 1px solid var(--text-muted);
  border-left: 1px solid var(--text-muted);
  opacity: 0;
  transition: opacity 0.2s ease;
}
.card:hover::after {
  opacity: 1;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-3);
}
.card-title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0;
  color: var(--text-primary);
  line-height: 1.3;
  letter-spacing: -0.01em;
}
.card-title a {
  transition: color 0.15s ease;
}
.card-title a:hover {
  color: var(--accent-primary);
}
.card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0;
  flex: 1;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--accent-secondary);
  background: rgba(59, 130, 246, 0.1);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  text-transform: lowercase;
  letter-spacing: 0.02em;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
  padding-top: var(--space-3);
  border-top: 1px dashed var(--border);
}
.card-link {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: color 0.15s ease;
  text-transform: lowercase;
  letter-spacing: 0.02em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 70%;
}
.card-link:hover {
  color: var(--accent-primary);
}
.card-link svg {
  transition: transform 0.2s ease;
  flex-shrink: 0;
}
.card-link:hover svg {
  transform: translate(2px, -2px);
}

.fav-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  transition: color 0.15s ease, transform 0.15s ease;
  padding: 4px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
}
.fav-btn:hover {
  color: var(--accent-primary);
  transform: scale(1.15);
}
.fav-btn.active {
  color: var(--accent-primary);
}
.fav-btn.active svg {
  fill: var(--accent-primary);
}
.fav-btn:focus-visible {
  outline: 1px solid var(--accent-primary);
  outline-offset: 2px;
}

/* Empty state */
.empty-state {
  padding: var(--space-16) var(--space-8);
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  color: var(--text-secondary);
  text-align: center;
  margin-top: var(--space-4);
}
.empty-state svg {
  color: var(--text-muted);
}
.empty-title {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  color: var(--text-primary);
  font-weight: 600;
}
.empty-text {
  font-size: 0.9rem;
  color: var(--text-muted);
  max-width: 320px;
}
.btn-ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 0.5rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: border-color 0.15s ease, background 0.15s ease, color 0.15s ease;
  margin-top: var(--space-2);
}
.btn-ghost:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  background: rgba(245, 158, 11, 0.06);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: var(--space-6) var(--space-8);
  background: var(--background);
}
.footer-inner {
  max-width: 1440px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  flex-wrap: wrap;
}
.footer-links {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.footer-links a {
  color: var(--text-secondary);
  transition: color 0.15s ease;
}
.footer-links a:hover {
  color: var(--accent-primary);
}

/* Responsive */
@media (max-width: 720px) {
  .hero-inner {
    padding: var(--space-12) var(--space-4) var(--space-8);
  }
  .content-area {
    padding: var(--space-6) var(--space-4);
  }
  .site-footer {
    padding: var(--space-5) var(--space-4);
  }
  .sidebar-label,
  .cat-item,
  .legend,
  .sidebar-footer {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
  }
  .content-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }
  .kbd { display: none; }
}