/* Motion (DESIGN.md section 11): purposeful entrance transitions, driven
   by assets/js/motion-utils.js. Reduced motion is handled entirely by
   theme.css zeroing --transition-slow, not by a separate media query
   here, so this stays correct automatically. */

.fade-in-up {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.fade-in-up.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Sidebar (DESIGN.md section 4.1) */

.sidebar {
  width: var(--sidebar-width);
  background: var(--color-surface);
  border-right: 1px solid var(--color-border-default);
  height: 100vh;
  overflow-y: auto;
  min-height: 0;
  padding: var(--space-6) var(--space-4);
}

.sidebar-title {
  display: block;
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-6);
}

.sidebar-title:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.sidebar-group {
  margin-bottom: var(--space-2);
}

.sidebar-group-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  background: transparent;
  border: none;
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  padding: var(--space-2) var(--space-2);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.sidebar-group-toggle:hover {
  background: var(--color-surface-inset);
  color: var(--color-text-primary);
}

.sidebar-group-toggle svg {
  transition: transform var(--transition-base);
  flex-shrink: 0;
}

.sidebar-group.is-expanded .sidebar-group-toggle svg {
  transform: rotate(90deg);
}

.sidebar-group-list {
  list-style: none;
  margin: var(--space-1) 0 var(--space-3) 0;
  padding: 0;
  display: none;
}

.sidebar-group.is-expanded .sidebar-group-list {
  display: block;
}

.sidebar-link {
  display: block;
  padding: var(--space-2) var(--space-3);
  margin: 0 0 var(--space-1) 0;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.sidebar-link:hover {
  background: var(--color-surface-inset);
  color: var(--color-text-primary);
  text-decoration: none;
}

.sidebar-link.is-active {
  background: var(--color-accent-muted);
  color: var(--color-accent);
  font-weight: var(--font-weight-medium);
}

/* Sidebar toggle button, mobile and tablet only (DESIGN.md section 6.1) */

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  background: var(--color-surface);
  border: 1px solid var(--color-border-default);
  color: var(--color-text-primary);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  position: fixed;
  top: var(--space-4);
  left: var(--space-4);
  z-index: 50;
}

/* Content area (DESIGN.md section 4.2) */

/* min-width: 0 because .content is a flex item in the wiki layout, and a flex
   item's automatic minimum size is its content-based minimum, not zero. Without
   this it refuses to shrink below the widest thing inside it: a demo stage or a
   table then pushes the whole column past the viewport instead of scrolling
   inside its own box, which is what .demo-stage and .table-wrap already ask for.
   See DESIGN.md section 8 and the lesson in 02-layout-and-structure. */
.content {
  min-width: 0;
  max-width: var(--content-max-width);
  padding: var(--space-10) var(--space-6);
}

.content > *:last-child {
  margin-bottom: 0;
}

.eyebrow {
  display: block;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-2);
}

/* Code block (DESIGN.md section 4.3) */

pre {
  background: var(--color-surface-inset);
  border: 1px solid var(--color-border-muted);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  overflow-x: auto;
  margin: 0 0 var(--space-6) 0;
}

code {
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
}

p code,
li code {
  background: var(--color-surface-inset);
  border: 1px solid var(--color-border-muted);
  border-radius: var(--radius-sm);
  padding: 0.1em 0.4em;
}

/* Callout (DESIGN.md section 4.4) */

.callout {
  display: flex;
  gap: var(--space-2);
  background: var(--color-surface);
  border-left: 4px solid var(--color-accent);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  padding: var(--space-4);
  margin: 0 0 var(--space-6) 0;
}

.callout svg {
  flex-shrink: 0;
  margin-top: 0.15em;
}

.callout--warning {
  border-left-color: var(--color-warning);
}

.callout--caution {
  border-left-color: var(--color-danger);
}

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

/* Button (DESIGN.md section 4.8) */

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: 40px;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color var(--transition-base), color var(--transition-base);
}

.button--primary {
  background: var(--color-accent);
  color: #0d1117;
}

.button--primary:hover {
  background: var(--color-accent-emphasis);
  text-decoration: none;
}

.button--secondary {
  background: transparent;
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.button--secondary:hover {
  background: var(--color-accent-muted);
  text-decoration: none;
}

.button--ghost {
  background: transparent;
  color: var(--color-text-secondary);
}

.button--ghost:hover {
  color: var(--color-text-primary);
  text-decoration: none;
}

/* Demo container (DESIGN.md section 4.5) */

.demo-container {
  position: relative;
  background: var(--color-surface);
  border: 1px dashed var(--color-border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-8) var(--space-6) var(--space-6);
  margin: 0 0 var(--space-6) 0;
}

.demo-label {
  position: absolute;
  top: var(--space-3);
  left: var(--space-4);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.demo-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
}

.demo-stage {
  background: var(--color-surface-inset);
  border: 1px solid var(--color-border-muted);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  overflow-x: auto;
}

.demo-readout {
  margin-top: var(--space-4);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.demo-readout strong {
  color: var(--color-text-primary);
}

/* Interactive control (DESIGN.md section 4.6) */

.control-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

input[type="range"] {
  accent-color: var(--color-accent);
}

input[type="text"],
input[type="email"],
input[type="color"] {
  background: var(--color-surface-inset);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-3);
  color: var(--color-text-primary);
  font-family: inherit;
  font-size: var(--font-size-sm);
}

input[type="color"] {
  padding: var(--space-1);
  width: 48px;
  height: 36px;
}

.tab-row {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.tab-button {
  background: var(--color-surface-inset);
  border: 1px solid var(--color-border-default);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.tab-button.is-active {
  background: var(--color-accent-muted);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* Card (DESIGN.md section 4.7) */

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* Table (DESIGN.md section 4.9) */

.table-wrap {
  overflow-x: auto;
  margin: 0 0 var(--space-6) 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-sm);
}

th,
td {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  border-bottom: 1px solid var(--color-border-muted);
}

th {
  background: var(--color-surface);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

td {
  color: var(--color-text-secondary);
}

.difficulty {
  display: inline-block;
  padding: 0.15em 0.6em;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  background: var(--color-accent-muted);
  color: var(--color-accent);
}