:root {
  /* Color Palette - Industrial / Precision Engineering */
  --bg-primary: #f8f9fa;
  --bg-secondary: #ffffff;
  --text-main: #1a1c1e;
  --text-muted: #64748b;
  --accent-color: #0052cc;
  --accent-hover: #0747a6;
  --border-color: #e2e8f0;
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  
  /* System Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.5rem;
  
  /* Typography */
  --font-display: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Roboto Mono', monospace;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-display);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.5;
  overflow-x: hidden;
}

/* Layout */
.app-container {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 260px;
  background-color: #0f172a;
  color: white;
  display: flex;
  flex-direction: column;
  position: fixed;
  height: 100vh;
  z-index: 100;
}

.main-content {
  flex: 1;
  margin-left: 260px;
  padding: var(--space-xl);
  max-width: calc(100% - 260px);
}

/* Sidebar Navigation */
.brand {
  padding: var(--space-lg);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.025em;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.nav-list {
  list-style: none;
  padding: var(--space-md);
  margin: 0;
}

.nav-item {
  margin-bottom: var(--space-xs);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  color: #94a3b8;
  text-decoration: none;
  border-radius: 6px;
  transition: all 0.2s;
}

.nav-link:hover, .nav-link.active {
  background-color: rgba(255,255,255,0.1);
  color: white;
}

/* Header */
.page-header {
  margin-bottom: var(--space-xl);
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
}

.page-title h1 {
  margin: 0;
  font-size: 1.875rem;
  font-weight: 700;
}

.page-title p {
  margin: var(--space-xs) 0 0 0;
  color: var(--text-muted);
}

/* Table Design */
.data-card {
  background: var(--bg-secondary);
  border-radius: 12px;
  border: 1px solid var(--border-color);
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
  overflow: hidden;
}

.table-container {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.875rem;
}

thead {
  background-color: #f1f5f9;
}

th {
  padding: var(--space-md);
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  border-bottom: 2px solid var(--border-color);
}

td {
  padding: var(--space-md);
  border-bottom: 1px solid var(--border-color);
}

tbody tr:hover {
  background-color: #f8fafc;
}

/* Comparison Styles */
.existing-col {
  background-color: rgba(241, 245, 249, 0.3);
}

.proposed-col {
  background-color: rgba(239, 246, 255, 0.5);
  font-weight: 600;
}

.diff-negative {
  color: var(--success);
  font-weight: 700;
}

.diff-positive {
  color: var(--danger);
  font-weight: 700;
}

/* Components */
.badge {
  padding: 2px 8px;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 500;
}

.badge-blue { background: #dbeafe; color: #1e40af; }

.status-indicator {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  margin-right: var(--space-sm);
}

.btn {
  padding: var(--space-sm) var(--space-lg);
  border-radius: 6px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
}

.btn-primary {
  background-color: var(--accent-color);
  color: white;
}

.btn-outline {
  background-color: transparent;
  border-color: var(--border-color);
  color: var(--text-main);
}

/* Info Grid */
.summary-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.summary-card {
  background: white;
  padding: var(--space-lg);
  border-radius: 12px;
  border: 1px solid var(--border-color);
}

.summary-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: var(--space-xs);
}

.summary-value {
  font-size: 1.5rem;
  font-weight: 700;
}

.mono {
  font-family: var(--font-mono);
}