/* ===== Layout ===== */
.layout-grid {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-md);
}

@media (min-width: 900px) {
  .layout-grid {
    flex-direction: row;
    align-items: flex-start;
  }
}

.controls-sidebar {
  flex: 0 0 300px;
}

.control-group {
  margin-bottom: var(--spacing-md);
}

.control-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 4px;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.control-group span {
  font-weight: bold;
  color: var(--text-primary);
}

.select-input, input[type="range"], input[type="text"].select-input {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-color);
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text-primary);
  outline: none;
}

.select-input:focus {
  border-color: var(--text-primary);
}

input[type="range"] {
  padding: 0;
  accent-color: var(--text-primary);
}

/* ===== Demo Sections ===== */
.demo-section {
  margin-bottom: 3rem;
}

.demo-section h2 {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: var(--spacing-sm);
}

.section-desc {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  max-width: 700px;
}

.border-container {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--spacing-lg);
}

/* ===== Section 1: Breakpoint Bar ===== */
.breakpoint-bar {
  display: flex;
  gap: 2px;
  margin-bottom: var(--spacing-md);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}

.bp-segment {
  flex: 1;
  padding: 10px 14px;
  background: var(--surface);
  text-align: center;
  transition: all 0.3s ease;
  position: relative;
}

.bp-segment.active {
  background: var(--text-primary);
  color: var(--surface);
}

.bp-label {
  display: block;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.02em;
}

.bp-range {
  display: block;
  font-size: 0.72rem;
  opacity: 0.7;
  margin-top: 2px;
  font-variant-numeric: tabular-nums;
}

/* ===== Resizable Frame ===== */
.playground-wrapper {
  position: relative;
  margin-bottom: var(--spacing-lg);
}

.width-counter {
  position: absolute;
  top: -28px;
  right: 0;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-secondary);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
  z-index: 2;
}

.resizable-frame {
  position: relative;
  width: 100%;
  max-width: 100%;
  min-width: 260px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
  transition: border-color 0.2s ease;
}

.resizable-frame:hover {
  border-color: var(--text-secondary);
}

.resize-handle {
  position: absolute;
  top: 0;
  right: 0;
  width: 14px;
  height: 100%;
  cursor: ew-resize;
  background: linear-gradient(to right, transparent, rgba(0,0,0,0.04));
  z-index: 10;
  transition: background 0.2s ease;
}

.resize-handle:hover,
.resize-handle.dragging {
  background: linear-gradient(to right, transparent, rgba(0,0,0,0.12));
}

.resize-handle::after {
  content: '';
  position: absolute;
  top: 50%;
  right: 4px;
  transform: translateY(-50%);
  width: 3px;
  height: 30px;
  border-radius: 2px;
  background: var(--text-secondary);
  opacity: 0.3;
  transition: opacity 0.2s ease;
}

.resize-handle:hover::after,
.resize-handle.dragging::after {
  opacity: 0.7;
}

/* ===== Playground Content (inside resizable frame) ===== */
.playground-content {
  padding: 16px;
}

.pg-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: var(--text-primary);
  color: var(--surface);
  border-radius: var(--radius);
  margin-bottom: 16px;
}

.pg-logo {
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: -0.03em;
}

.pg-nav-links {
  display: flex;
  gap: 16px;
}

.pg-nav-links a {
  color: inherit;
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  opacity: 0.85;
  transition: opacity 0.2s;
}

.pg-nav-links a:hover {
  opacity: 1;
}

.pg-hamburger {
  display: none;
  background: none;
  border: 1px solid rgba(255,255,255,0.3);
  color: var(--surface);
  font-size: 1.1rem;
  padding: 4px 8px;
  border-radius: 4px;
  cursor: pointer;
}

.pg-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  transition: all 0.3s ease;
}

.pg-card {
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  transition: all 0.3s ease;
}

.pg-card-icon {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.pg-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.pg-card p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* ===== Active CSS Rules panel ===== */
.active-rules-panel {
  background: var(--surface);
}

.active-rules-panel h3 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.active-rules-panel pre {
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  font-size: 0.82rem;
  line-height: 1.6;
  overflow-x: auto;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  white-space: pre;
  color: var(--text-primary);
}

/* ===== Section 2: Builder ===== */
.builder-preview-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.code-preview h3,
.builder-target-container h3 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.code-preview pre {
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  font-size: 0.82rem;
  line-height: 1.6;
  overflow-x: auto;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  white-space: pre;
  color: var(--text-primary);
}

.builder-target {
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--spacing-lg);
  min-height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.bt-box {
  padding: 1.5rem 2.5rem;
  background: var(--text-primary);
  color: var(--surface);
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 1rem;
  text-align: center;
  transition: all 0.4s ease;
}

/* ===== Section 3: Patterns ===== */
.patterns-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
}

.pattern-tab {
  padding: 8px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--text-secondary);
}

.pattern-tab:hover {
  border-color: var(--text-secondary);
  color: var(--text-primary);
}

.pattern-tab.active {
  background: var(--text-primary);
  color: var(--surface);
  border-color: var(--text-primary);
}

.pattern-display {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

@media (min-width: 900px) {
  .pattern-display {
    flex-direction: row;
    align-items: flex-start;
  }
}

.pattern-code {
  flex: 0 0 380px;
}

.pattern-code h3 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.pattern-code pre {
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  font-size: 0.78rem;
  line-height: 1.6;
  overflow-x: auto;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  white-space: pre;
  color: var(--text-primary);
}

.pattern-preview {
  flex: 1;
  position: relative;
}

.pattern-frame {
  min-height: 280px;
}

.pattern-render {
  padding: 16px;
}

/* ===== Pattern: Responsive Nav ===== */
.ptn-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: var(--text-primary);
  color: var(--surface);
  border-radius: var(--radius);
}

.ptn-nav-logo {
  font-weight: 800;
  font-size: 0.95rem;
}

.ptn-nav-links {
  display: flex;
  gap: 14px;
}

.ptn-nav-links a {
  color: var(--surface);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 500;
}

.ptn-hamburger {
  display: none;
  background: none;
  border: 1px solid rgba(255,255,255,0.3);
  color: var(--surface);
  font-size: 1rem;
  padding: 3px 7px;
  border-radius: 4px;
  cursor: pointer;
}

/* ===== Pattern: Cards ===== */
.ptn-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.ptn-card {
  padding: 14px;
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  font-weight: 600;
  text-align: center;
}

/* ===== Pattern: Dark Mode ===== */
.ptn-dark-demo {
  padding: 20px;
  border-radius: var(--radius);
  transition: all 0.4s ease;
  background: #ffffff;
  color: #111;
}

.ptn-dark-demo h3 {
  font-size: 1rem;
  margin-bottom: 6px;
}

.ptn-dark-demo p {
  font-size: 0.82rem;
  opacity: 0.8;
}

/* ===== Section 4: Cheatsheet ===== */
.cheatsheet-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--spacing-md);
}

.cheatsheet-card {
  position: relative;
  padding: 1.25rem;
}

.cheatsheet-card .cs-type {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  background: var(--border);
  color: var(--text-secondary);
  padding: 2px 8px;
  border-radius: 20px;
  display: inline-block;
  margin-bottom: 8px;
}

.cheatsheet-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.cheatsheet-card code {
  display: block;
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 8px 10px;
  font-size: 0.75rem;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  margin-bottom: 8px;
  color: var(--text-primary);
  overflow-x: auto;
  white-space: nowrap;
}

.cheatsheet-card p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.45;
}