/* ==========================================================================
   AI-Assisted Development - "Hello World" Stylesheet
   Modern High-Contrast Technical Aesthetic (Linear / Vercel Inspired)
   Solid Surfaces, Crisp Borders, Tech Grid, Precision Typography
   ========================================================================== */

:root {
  /* Color Palette - Crisp Obsidian & Precision Accents */
  --bg-base: #090a0f;
  --bg-surface: #11131a;
  --bg-surface-elevated: #161922;
  --bg-surface-hover: #1c202c;
  --bg-subtle: #0d0f14;

  --border-subtle: #1e2230;
  --border-medium: #2a3044;
  --border-focus: #3b82f6;

  --accent-cyan: #06b6d4;
  --accent-blue: #3b82f6;
  --accent-indigo: #6366f1;
  --accent-purple: #8b5cf6;
  --accent-emerald: #10b981;
  --accent-rose: #f43f5e;
  --accent-amber: #f59e0b;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #090a0f;

  --font-main: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-code: 'Fira Code', 'JetBrains Mono', Consolas, monospace;

  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --shadow-subtle: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-card: 0 4px 20px -2px rgba(0, 0, 0, 0.5), inset 0 1px 0 0 rgba(255, 255, 255, 0.06);
  --shadow-elevated: 0 12px 32px -4px rgba(0, 0, 0, 0.6), inset 0 1px 0 0 rgba(255, 255, 255, 0.08);

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.6;
}

body {
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--bg-base);
  /* Tech Grid Background Pattern */
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 36px 36px;
}

/* Layout */
.section-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 5rem 1.5rem;
  position: relative;
  z-index: 1;
}

/* Solid Modern Cards (Replaces Glassmorphism) */
.glass-panel {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal), transform var(--transition-normal);
}

.glass-panel:hover {
  border-color: var(--border-medium);
}

/* Typography & Badges */
.gradient-text {
  background: linear-gradient(135deg, #38bdf8 0%, #818cf8 50%, #c084fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent-cyan);
  margin-bottom: 1.25rem;
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 6px var(--accent-cyan);
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 0.75rem;
  color: #fff;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 650px;
  margin: 0 auto;
}

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

/* Buttons */
.cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.8rem 1.6rem;
  font-size: 0.92rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  border: none;
  transition: all var(--transition-fast);
  font-family: var(--font-main);
}

.cta-btn-primary {
  background: #f8fafc;
  color: #090a0f;
  font-weight: 700;
  box-shadow: 0 2px 8px rgba(255, 255, 255, 0.15);
}

.cta-btn-primary:hover {
  background: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(255, 255, 255, 0.25);
}

.cta-btn-secondary {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-medium);
  color: var(--text-primary);
}

.cta-btn-secondary:hover {
  background: var(--bg-surface-hover);
  border-color: #475569;
  transform: translateY(-1px);
}

.cta-btn-sm {
  padding: 0.45rem 1rem;
  font-size: 0.82rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-medium);
  color: #e2e8f0;
}

.cta-btn-sm:hover {
  background: #f8fafc;
  color: #090a0f;
  border-color: #f8fafc;
}

.full-width {
  width: 100%;
}

/* Site Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9, 10, 15, 0.92);
  border-bottom: 1px solid var(--border-subtle);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-logo {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: #181c28;
  border: 1px solid var(--border-medium);
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-sparkle {
  color: var(--accent-cyan);
  font-size: 1rem;
}

.brand-text {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand-title {
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  color: #fff;
}

.brand-badge {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.15rem 0.45rem;
  background: rgba(6, 182, 212, 0.1);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.25);
  border-radius: var(--radius-xs);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: #fff;
}

/* Hero Section */
.hero-section {
  position: relative;
  z-index: 1;
  padding: 5rem 1.5rem 3.5rem;
  text-align: center;
}

.hero-container {
  max-width: 900px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3.4rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.035em;
  margin-bottom: 1.35rem;
}

.hero-subtitle {
  font-size: 1.18rem;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 2.2rem;
  line-height: 1.65;
}

.hero-subtitle strong {
  color: var(--text-primary);
  font-weight: 600;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3.5rem;
}

/* Terminal Component */
.hero-terminal {
  max-width: 820px;
  margin: 0 auto;
  overflow: hidden;
  text-align: left;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-elevated);
}

.terminal-bar {
  background: var(--bg-subtle);
  padding: 0.7rem 1.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-subtle);
}

.terminal-dots {
  display: flex;
  gap: 0.45rem;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.dot-red { background: #ef4444; }
.dot-yellow { background: #eab308; }
.dot-green { background: #22c55e; }

.terminal-title {
  font-family: var(--font-code);
  font-size: 0.78rem;
  color: var(--text-muted);
}

.terminal-badge {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-xs);
  background: rgba(59, 130, 246, 0.12);
  color: var(--accent-blue);
  border: 1px solid rgba(59, 130, 246, 0.25);
}

.terminal-body {
  padding: 1.4rem;
  font-family: var(--font-code);
  font-size: 0.88rem;
  background: var(--bg-base);
}

.code-line {
  margin-bottom: 0.5rem;
  line-height: 1.55;
}

.code-comment {
  color: #475569;
  font-style: italic;
}

.code-prompt-tag {
  color: var(--accent-cyan);
  font-weight: 600;
  margin-right: 0.4rem;
}

.code-ai-tag {
  color: var(--accent-purple);
  font-weight: 600;
  margin-right: 0.4rem;
}

.code-text-prompt {
  color: #f1f5f9;
}

.cursor {
  display: inline-block;
  color: var(--accent-cyan);
  font-weight: 700;
  animation: blinkCursor 0.9s infinite;
}

@keyframes blinkCursor {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.code-separator {
  height: 1px;
  background: var(--border-subtle);
  margin: 0.85rem 0;
}

.code-text-highlight {
  color: #10b981;
}

.terminal-code-block {
  margin-top: 0.75rem;
  padding: 1rem;
  background: var(--bg-surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  overflow-x: auto;
  color: #e2e8f0;
  line-height: 1.55;
}

/* 4 Pillars Section */
.principles-section {
  position: relative;
  z-index: 1;
}

.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-top: 3.5rem;
}

.principle-card {
  padding: 2rem 1.75rem;
  position: relative;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}

.principle-card:hover {
  border-color: var(--border-medium);
  transform: translateY(-3px);
}

.card-icon-box {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-medium);
}

.icon-cyan { color: var(--accent-cyan); }
.icon-purple { color: var(--accent-purple); }
.icon-pink { color: var(--accent-rose); }
.icon-emerald { color: var(--accent-emerald); }

.pillar-number {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  font-family: var(--font-code);
  font-size: 1.3rem;
  font-weight: 700;
  color: #334155;
}

.card-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: #fff;
}

.card-text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.35rem;
}

.card-text strong {
  color: #e2e8f0;
}

.card-footer-tip {
  padding-top: 0.85rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.tip-label {
  font-weight: 600;
  color: var(--text-secondary);
  margin-right: 0.3rem;
}

/* Prompt Simulator Section */
.simulator-section {
  position: relative;
  z-index: 1;
}

.scenario-tabs-wrapper {
  display: flex;
  justify-content: center;
  margin-top: 2.2rem;
  margin-bottom: 1.8rem;
}

.scenario-tabs {
  display: inline-flex;
  padding: 0.35rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  gap: 0.4rem;
  overflow-x: auto;
  max-width: 100%;
}

.scenario-tab {
  background: transparent;
  border: 1px solid transparent;
  padding: 0.55rem 1.15rem;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-family: var(--font-main);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.tab-badge {
  font-family: var(--font-code);
  font-size: 0.72rem;
  color: var(--text-muted);
}

.scenario-tab:hover {
  color: #fff;
  background: var(--bg-surface-elevated);
}

.scenario-tab.active {
  background: var(--bg-surface-hover);
  color: #fff;
  border-color: var(--border-medium);
  box-shadow: var(--shadow-subtle);
}

.lab-workspace {
  padding: 1.75rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

/* Prompts Split View */
.prompts-split-view {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 1.75rem;
}

.prompt-box {
  padding: 1.35rem;
  border-radius: var(--radius-md);
  background: var(--bg-base);
  border: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.prompt-naive {
  border-left: 3px solid var(--accent-rose);
}

.prompt-engineered {
  border-left: 3px solid var(--accent-emerald);
}

.prompt-box-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.85rem;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.status-indicator {
  width: 7px;
  height: 7px;
  border-radius: 50%;
}

.status-bad { background: var(--accent-rose); }
.status-good { background: var(--accent-emerald); }

.box-title {
  font-weight: 700;
  font-size: 0.92rem;
  color: #fff;
}

.tag-critique {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.15rem 0.55rem;
  border-radius: var(--radius-xs);
  background: rgba(244, 63, 94, 0.1);
  color: var(--accent-rose);
  border: 1px solid rgba(244, 63, 94, 0.25);
}

.tag-critique-good {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.15rem 0.55rem;
  border-radius: var(--radius-xs);
  background: rgba(16, 185, 129, 0.1);
  color: var(--accent-emerald);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.prompt-content {
  font-family: var(--font-code);
  font-size: 0.88rem;
  line-height: 1.6;
  color: #e2e8f0;
  margin-bottom: 1.1rem;
  padding: 0.85rem;
  background: var(--bg-surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.prompt-analysis {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.82rem;
}

.analysis-item.negative {
  color: #fb7185;
}

.analysis-item.positive {
  color: #34d399;
}

/* Sandbox Split View */
.sandbox-split-view {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.code-preview-pane,
.interactive-preview-pane {
  background: var(--bg-base);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 480px;
}

.pane-header {
  padding: 0.75rem 1.2rem;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.pane-tab-group {
  display: flex;
  gap: 0.4rem;
}

.pane-tab {
  background: transparent;
  border: 1px solid transparent;
  font-family: var(--font-main);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pane-tab:hover {
  color: #fff;
}

.pane-tab.active {
  background: var(--bg-surface-elevated);
  border-color: var(--border-medium);
  color: #fff;
}

.copy-code-btn,
.reset-preview-btn {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-medium);
  color: var(--text-secondary);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.copy-code-btn:hover,
.reset-preview-btn:hover {
  background: var(--bg-surface-hover);
  color: #fff;
  border-color: #475569;
}

.code-display-body {
  flex: 1;
  padding: 1.25rem;
  overflow: auto;
  max-height: 420px;
  background: var(--bg-base);
}

.code-display-body.hidden {
  display: none;
}

.code-view {
  margin: 0;
  font-family: var(--font-code);
  font-size: 0.84rem;
  color: #cbd5e1;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
}

.rationale-box {
  padding: 0.5rem;
}

.rationale-heading {
  font-size: 0.95rem;
  color: var(--accent-cyan);
  margin-bottom: 0.9rem;
}

.rationale-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.rationale-list li {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.55;
  padding-left: 1.2rem;
  position: relative;
}

.rationale-list li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--accent-blue);
  font-size: 0.85rem;
}

.preview-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
}

.live-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
}

.sandbox-output-viewport {
  flex: 1;
  padding: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #090b10;
  position: relative;
  overflow: auto;
}

/* Embedded components inside sandbox */
.sandbox-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  text-align: center;
  box-shadow: var(--shadow-card);
  width: 100%;
  max-width: 320px;
  transition: transform var(--transition-fast);
}

.counter-display {
  font-family: var(--font-code);
  font-size: 3.2rem;
  font-weight: 800;
  color: #fff;
  margin: 0.5rem 0 1.25rem;
  transition: transform 0.15s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.counter-display.bump {
  transform: scale(1.15);
  color: var(--accent-cyan);
}

.counter-controls {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
}

.btn-counter {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-medium);
  color: #fff;
  font-size: 1.2rem;
  font-weight: bold;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-counter:hover:not(:disabled) {
  background: #fff;
  color: #090a0f;
  border-color: #fff;
  transform: translateY(-1px);
}

.btn-counter:disabled {
  opacity: 0.25;
  cursor: not-allowed;
}

.status-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  margin-top: 1rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
}

.status-badge.limit {
  background: rgba(244, 63, 94, 0.12);
  color: var(--accent-rose);
  border-color: rgba(244, 63, 94, 0.3);
}

/* Prompt Studio Section */
.builder-section {
  position: relative;
  z-index: 1;
}

.builder-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2rem;
  padding: 2.25rem;
  margin-top: 3rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  background: var(--bg-base);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.9rem;
  color: #fff;
  font-family: var(--font-main);
  font-size: 0.9rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
}

.builder-output-box {
  background: var(--bg-base);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
}

.output-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.85rem;
}

.output-preview {
  flex: 1;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 1.1rem;
  overflow: auto;
  max-height: 380px;
}

.output-preview pre {
  margin: 0;
  font-family: var(--font-code);
  font-size: 0.82rem;
  color: #7dd3fc;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
}

.builder-tip {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  margin-top: 1.1rem;
  padding: 0.75rem 0.9rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  color: #cbd5e1;
}

/* Playbook Section */
.playbook-section {
  position: relative;
  z-index: 1;
}

.playbook-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-top: 3.5rem;
}

.playbook-card {
  padding: 1.85rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  position: relative;
}

.playbook-step {
  font-family: var(--font-code);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-cyan);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-medium);
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-xs);
  margin-bottom: 1.1rem;
}

.playbook-card h4 {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.65rem;
}

.playbook-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.playbook-card code {
  font-family: var(--font-code);
  font-size: 0.82rem;
  color: #7dd3fc;
  background: var(--bg-subtle);
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-subtle);
}

/* Checklist Section */
.checklist-section {
  position: relative;
  z-index: 1;
  padding-bottom: 6rem;
}

.checklist-panel {
  padding: 2.25rem;
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.checklist-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-subtle);
}

.checklist-header h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
}

.progress-container {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.progress-bar-track {
  width: 120px;
  height: 6px;
  background: var(--bg-surface-elevated);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar-fill {
  width: 0%;
  height: 100%;
  background: var(--accent-emerald);
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

.checklist-items {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.check-item {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  cursor: pointer;
  padding: 0.8rem 1.15rem;
  background: var(--bg-base);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.check-item:hover {
  background: var(--bg-surface-elevated);
  border-color: var(--border-medium);
}

.checklist-toggle {
  position: absolute;
  opacity: 0;
  cursor: pointer;
}

.custom-checkbox {
  width: 18px;
  height: 18px;
  border-radius: 4px;
  border: 1px solid #475569;
  background: var(--bg-surface);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.check-item input:checked ~ .custom-checkbox {
  background: var(--accent-emerald);
  border-color: var(--accent-emerald);
}

.check-item input:checked ~ .custom-checkbox::after {
  content: "✓";
  color: #090a0f;
  font-size: 0.8rem;
  font-weight: 800;
}

.check-item input:checked ~ .item-text {
  text-decoration: line-through;
  color: var(--text-muted);
}

.item-text {
  font-size: 0.92rem;
  color: var(--text-primary);
  transition: color var(--transition-fast);
}

.checklist-celebration {
  margin-top: 1.5rem;
  padding: 1.15rem;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius-md);
  text-align: center;
  font-size: 0.92rem;
  color: #34d399;
  animation: fadeIn 0.3s ease;
}

.checklist-celebration.hidden {
  display: none;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Site Footer */
.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 2.2rem 1.5rem;
  background: var(--bg-base);
  position: relative;
  z-index: 1;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-brand {
  font-size: 0.88rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-notes {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Responsive adjustments */
@media (max-width: 992px) {
  .hero-title {
    font-size: 2.7rem;
  }
  .prompts-split-view,
  .sandbox-split-view,
  .builder-grid {
    grid-template-columns: 1fr;
  }
  .nav-links {
    display: none;
  }
}

@media (max-width: 640px) {
  .hero-title {
    font-size: 2.1rem;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .cta-btn {
    width: 100%;
  }
  .scenario-tabs {
    border-radius: var(--radius-sm);
  }
}