:root {
  --bg-primary: #0b0f19;
  --bg-secondary: #111827;
  --bg-card: #1f2937;
  --bg-card-hover: #283548;
  --border-color: #374151;
  --text-primary: #f9fafb;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;
  --accent-green: #10b981;
  --accent-amber: #f59e0b;
  --accent-red: #ef4444;

  --code-bg: #0f172a;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.15);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  padding: 2rem 1rem;
}

.app-container {
  max-width: 1100px;
  margin: 0 auto;
}

/* Header */
.header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.badge {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border-radius: 9999px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-purple { background: rgba(139, 92, 246, 0.2); color: #c4b5fd; border: 1px solid rgba(139, 92, 246, 0.4); }
.badge-blue   { background: rgba(59, 130, 246, 0.2); color: #93c5fd; border: 1px solid rgba(59, 130, 246, 0.4); }
.badge-green  { background: rgba(16, 185, 129, 0.2); color: #6ee7b7; border: 1px solid rgba(16, 185, 129, 0.4); }
.badge-amber  { background: rgba(245, 158, 11, 0.2); color: #fde68a; border: 1px solid rgba(245, 158, 11, 0.4); }

.header h1 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  background: linear-gradient(135deg, #ffffff 0%, #93c5fd 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Tabs */
.nav-tabs {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--border-color);
}

.tab-btn {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid transparent;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.tab-btn:hover {
  background: var(--bg-card);
  color: var(--text-primary);
}

.tab-btn.active {
  background: var(--accent-blue);
  color: #ffffff;
  border-color: var(--accent-blue);
  box-shadow: 0 0 15px rgba(59, 130, 246, 0.4);
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
  animation: fadeIn 0.25s ease-in-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-md);
}

.card h2 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  font-weight: 700;
  color: #ffffff;
}

.stat-card {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.stat-icon {
  font-size: 1.8rem;
  line-height: 1;
}

.stat-details h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.stat-details p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* Architecture Comparison */
.arch-comparison {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
}

.arch-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.arch-box.target {
  border-color: rgba(59, 130, 246, 0.5);
  background: rgba(30, 41, 59, 0.7);
}

.arch-header {
  margin-bottom: 1rem;
}

.arch-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.active-tag {
  color: var(--accent-green);
}

.arch-list {
  list-style: none;
  font-size: 0.9rem;
}

.arch-list li {
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.arch-list li strong {
  color: var(--text-primary);
}

.arch-arrow {
  font-size: 1.5rem;
  color: var(--text-muted);
  text-align: center;
}

/* Tables */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin-top: 0.75rem;
}

.data-table th, .data-table td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.data-table th {
  background: var(--bg-card);
  color: var(--text-secondary);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

.data-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

/* Pros and Cons Split Grid */
.pros-cons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.pro-card {
  border-left: 4px solid var(--accent-green);
}

.con-card {
  border-left: 4px solid var(--accent-amber);
}

.pro-title { color: var(--accent-green); margin-bottom: 0.75rem; }
.con-title { color: var(--accent-amber); margin-bottom: 0.75rem; }

.bullet-list {
  padding-left: 1.25rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.bullet-list li {
  margin-bottom: 0.65rem;
}

.bullet-list li strong {
  color: var(--text-primary);
}

/* Code Boxes */
.card-header-flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.file-path {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--accent-blue);
  background: rgba(59, 130, 246, 0.1);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
}

.code-container {
  background: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-top: 1rem;
  overflow: hidden;
}

.code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 1rem;
  background: #090d16;
  border-bottom: 1px solid var(--border-color);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.copy-btn {
  background: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.copy-btn:hover {
  background: var(--accent-blue);
  color: white;
  border-color: var(--accent-blue);
}

pre {
  padding: 1rem;
  overflow-x: auto;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  line-height: 1.5;
  color: #e2e8f0;
}

code {
  font-family: 'JetBrains Mono', monospace;
}

.code-block {
  background: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  margin-top: 0.75rem;
}

.code-block pre {
  padding: 0.85rem;
}

/* Timeline */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-top: 1rem;
}

.timeline-item {
  display: flex;
  gap: 1.25rem;
}

.timeline-marker {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--accent-blue);
  color: #ffffff;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 0 10px rgba(59, 130, 246, 0.4);
}

.timeline-content {
  flex-grow: 1;
}

.timeline-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.timeline-content p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Checklist */
.checklist {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1rem;
}

.check-item {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  background: var(--bg-card);
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.check-item input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent-green);
}

.check-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.check-text strong {
  color: var(--text-primary);
  margin-right: 0.5rem;
}

.check-text code {
  color: #93c5fd;
  background: rgba(59, 130, 246, 0.1);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}

.rollback-card {
  border-left: 4px solid var(--accent-red);
}

.rollback-title {
  color: var(--accent-red);
}

/* Footer */
.footer {
  text-align: center;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 768px) {
  .arch-comparison {
    grid-template-columns: 1fr;
  }
  .arch-arrow {
    transform: rotate(90deg);
    margin: 0.5rem 0;
  }
  .header h1 {
    font-size: 1.75rem;
  }
}