/**
 * TSG SYSTEM v2.0 - Global Admin Base CSS
 * 
 * Core layout, typography, and base styles for the Global Admin interface.
 * Professional dark theme with muted colors.
 */

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  overflow-x: hidden;
}

/* CSS Variables - Dark Professional Theme */
:root {
  /* Primary Colors - Muted Blues */
  --primary: #1e3a5f;
  --primary-light: #2c5282;
  --primary-dark: #1a2332;
  
  /* Secondary Colors */
  --secondary: #4a5568;
  --secondary-light: #718096;
  
  /* Accent Colors - Muted */
  --accent-success: #48bb78;
  --accent-warning: #ed8936;
  --accent-danger: #e53e3e;
  --accent-info: #4299e1;
  
  /* Background Colors */
  --bg-primary: #1a1a1a;
  --bg-secondary: #2d2d2d;
  --bg-tertiary: #3a3a3a;
  --bg-overlay: rgba(0, 0, 0, 0.8);
  
  /* Text Colors */
  --text-primary: #e2e8f0;
  --text-secondary: #a0aec0;
  --text-muted: #718096;
  --text-inverse: #1a1a1a;
  
  /* Border Colors */
  --border-light: #4a5568;
  --border-medium: #2d3748;
  --border-dark: #1a202c;
  
  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.35s ease;
}

/* Layout Structure */
body {
  display: grid;
  grid-template-rows: auto auto 1fr;
  grid-template-areas:
    "top-nav"
    "main-nav"
    "content";
  min-height: 100vh;
}

/* Top Navigation */
.top-nav {
  grid-area: top-nav;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-medium);
  padding: var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.nav-brand h1 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

.nav-brand .version {
  background: var(--primary);
  color: var(--text-primary);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 500;
}

.nav-user {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  color: var(--text-secondary);
}

/* Main Navigation */
.main-nav {
  grid-area: main-nav;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-medium);
  padding: var(--spacing-sm) var(--spacing-md);
  display: flex;
  gap: var(--spacing-xs);
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.main-nav::-webkit-scrollbar {
  display: none;
}

.nav-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  cursor: pointer;
  transition: all var(--transition-normal);
  white-space: nowrap;
  font-size: 0.875rem;
  font-weight: 500;
}

.nav-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-color: var(--border-light);
}

.nav-btn.active {
  background: var(--primary);
  color: var(--text-primary);
  border-color: var(--primary-light);
}

.nav-btn .icon {
  font-size: 1rem;
}

/* Main Content */
.main-content {
  grid-area: content;
  padding: var(--spacing-xl);
  overflow-y: auto;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

/* Content Sections */
.content-section {
  display: none;
}

.content-section.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.section-header {
  margin-bottom: var(--spacing-xl);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.section-header h2 {
  font-size: 1.875rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-xs);
}

.section-header p {
  color: var(--text-secondary);
  font-size: 1rem;
  margin: 0;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.4;
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

small {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Links */
a {
  color: var(--accent-info);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-info);
  text-decoration: underline;
}

/* Placeholders */
.placeholder {
  background: var(--bg-secondary);
  border: 2px dashed var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--spacing-2xl);
  text-align: center;
  color: var(--text-muted);
  font-size: 1.125rem;
  margin: var(--spacing-xl) 0;
}

/* Loading States */
.loading {
  text-align: center;
  color: var(--text-muted);
  font-style: italic;
  padding: var(--spacing-xl);
}

/* Responsive Design */
@media (max-width: 1024px) {
  .main-content {
    padding: var(--spacing-lg);
  }
  
  .section-header {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (max-width: 768px) {
  .top-nav {
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  .nav-brand h1 {
    font-size: 1.25rem;
  }
  
  .main-nav {
    padding: var(--spacing-xs) var(--spacing-md);
  }
  
  .nav-btn {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.8125rem;
  }
  
  .nav-btn .icon {
    font-size: 0.875rem;
  }
  
  .main-content {
    padding: var(--spacing-md);
  }
  
  .section-header h2 {
    font-size: 1.5rem;
  }
}

@media (max-width: 480px) {
  .nav-user {
    gap: var(--spacing-sm);
  }
  
  #currentUser {
    display: none;
  }
  
  .main-nav {
    gap: 0;
  }
  
  .nav-btn {
    flex-direction: column;
    gap: var(--spacing-xs);
    font-size: 0.75rem;
    min-width: 60px;
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus States */
*:focus {
  outline: 2px solid var(--accent-info);
  outline-offset: 2px;
}

/* Print Styles */
@media print {
  .top-nav, .main-nav {
    display: none;
  }
  
  .main-content {
    padding: 0;
  }
  
  * {
    color: black !important;
    background: white !important;
  }
}