/* ========================================
   DESIGN SYSTEM - CSS VARIABLES
   ======================================== */
:root {
  /* Colors - Dark Theme */
  --color-bg-primary: #0a0e27;
  --color-bg-secondary: #151932;
  --color-bg-tertiary: #1e2139;
  --color-bg-elevated: #252a45;
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-success: linear-gradient(135deg, #10b981 0%, #059669 100%);
  --gradient-warning: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  --gradient-danger: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
  
  /* Text Colors */
  --color-text-primary: #f8fafc;
  --color-text-secondary: #cbd5e1;
  --color-text-tertiary: #94a3b8;
  --color-text-muted: #64748b;
  
  /* Accent Colors */
  --color-primary: #667eea;
  --color-primary-hover: #5568d3;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --color-info: #3b82f6;
  
  /* Border & Divider */
  --color-border: #2d3250;
  --color-divider: #1e2139;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 20px rgba(102, 126, 234, 0.3);
  
  /* Glassmorphism */
  --glass-bg: rgba(37, 42, 69, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-blur: blur(10px);
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'Fira Code', 'Courier New', monospace;
  
  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  
  /* Layout */
  --sidebar-width: 280px;
  --header-height: 70px;
  --content-max-width: 1400px;
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   RESET & BASE STYLES
   ======================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

/* Background Pattern */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(118, 75, 162, 0.1) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

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

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border-right: 1px solid var(--glass-border);
  position: fixed;
  left: 0;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  z-index: 100;
  transition: transform var(--transition-base);
}

.sidebar.collapsed {
  transform: translateX(-100%);
}

.sidebar-header {
  padding: var(--space-xl);
  border-bottom: 1px solid var(--color-divider);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  font-size: var(--text-xl);
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--gradient-primary);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.sidebar-nav {
  flex: 1;
  padding: var(--space-lg);
  overflow-y: auto;
}

.nav-section {
  margin-bottom: var(--space-xl);
}

.nav-section-title {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-md);
  padding: 0 var(--space-md);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  margin-bottom: var(--space-xs);
  position: relative;
}

.nav-item:hover {
  background: rgba(102, 126, 234, 0.1);
  color: var(--color-text-primary);
  transform: translateX(4px);
}

.nav-item.active {
  background: var(--gradient-primary);
  color: white;
  box-shadow: var(--shadow-glow);
}

.nav-item.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 60%;
  background: white;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.nav-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.nav-badge {
  margin-left: auto;
  background: var(--color-danger);
  color: white;
  font-size: var(--text-xs);
  font-weight: 600;
  padding: 0.125rem 0.5rem;
  border-radius: var(--radius-full);
}

.sidebar-footer {
  padding: var(--space-lg);
  border-top: 1px solid var(--color-divider);
}

.user-profile {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  background: var(--color-bg-tertiary);
  transition: all var(--transition-fast);
}

.user-profile:hover {
  background: var(--color-bg-elevated);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  color: white;
  flex-shrink: 0;
}

.user-info {
  flex: 1;
  min-width: 0;
}

.user-name {
  font-weight: 600;
  font-size: var(--text-sm);
  color: var(--color-text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-role {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  text-transform: capitalize;
}

/* Main Content Area */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  transition: margin-left var(--transition-base);
}

.main-content.expanded {
  margin-left: 0;
}

/* Header */
.header {
  height: var(--header-height);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  padding: 0 var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.menu-toggle {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.menu-toggle:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.page-title {
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.header-action {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  position: relative;
}

.header-action:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.header-action .badge {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 8px;
  height: 8px;
  background: var(--color-danger);
  border-radius: var(--radius-full);
  border: 2px solid var(--color-bg-secondary);
}

/* Content Container */
.content {
  padding: var(--space-xl);
  max-width: var(--content-max-width);
  margin: 0 auto;
}

/* ========================================
   COMPONENTS
   ======================================== */

/* Cards */
.card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.card-header {
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-divider);
}

.card-title {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.card-subtitle {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
}

/* Buttons */
.btn {
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: var(--text-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  outline: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

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

.btn-secondary:hover:not(:disabled) {
  background: var(--color-bg-elevated);
  border-color: var(--color-primary);
}

.btn-success {
  background: var(--gradient-success);
  color: white;
}

.btn-danger {
  background: var(--gradient-danger);
  color: white;
}

.btn-sm {
  padding: 0.375rem 0.875rem;
  font-size: var(--text-xs);
}

.btn-lg {
  padding: 0.875rem 1.75rem;
  font-size: var(--text-base);
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

.badge-primary {
  background: rgba(102, 126, 234, 0.2);
  color: var(--color-primary);
}

.badge-success {
  background: rgba(16, 185, 129, 0.2);
  color: var(--color-success);
}

.badge-warning {
  background: rgba(245, 158, 11, 0.2);
  color: var(--color-warning);
}

.badge-danger {
  background: rgba(239, 68, 68, 0.2);
  color: var(--color-danger);
}

.badge-info {
  background: rgba(59, 130, 246, 0.2);
  color: var(--color-info);
}

/* Forms */
.form-group {
  margin-bottom: var(--space-lg);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-sm);
}

.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  font-size: var(--text-base);
  transition: all var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-input::placeholder {
  color: var(--color-text-muted);
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.stat-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-base);
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-primary);
}

.stat-card.success::before {
  background: var(--gradient-success);
}

.stat-card.warning::before {
  background: var(--gradient-warning);
}

.stat-card.danger::before {
  background: var(--gradient-danger);
}

.stat-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--space-md);
}

.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  background: rgba(102, 126, 234, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
}

.stat-value {
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
}

.stat-change {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: var(--text-xs);
  font-weight: 600;
  margin-top: var(--space-sm);
}

.stat-change.positive {
  color: var(--color-success);
}

.stat-change.negative {
  color: var(--color-danger);
}

/* Tables */
.table-container {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.table {
  width: 100%;
  border-collapse: collapse;
}

.table thead {
  background: var(--color-bg-tertiary);
  border-bottom: 1px solid var(--color-divider);
}

.table th {
  padding: var(--space-md) var(--space-lg);
  text-align: left;
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-tertiary);
}

.table td {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-divider);
  color: var(--color-text-secondary);
}

.table tbody tr {
  transition: background var(--transition-fast);
}

.table tbody tr:hover {
  background: rgba(102, 126, 234, 0.05);
}

.table tbody tr:last-child td {
  border-bottom: none;
}

/* Utilities */
.mt-1 { margin-top: var(--space-sm); }
.mt-2 { margin-top: var(--space-md); }
.mt-3 { margin-top: var(--space-lg); }
.mt-4 { margin-top: var(--space-xl); }

.mb-1 { margin-bottom: var(--space-sm); }
.mb-2 { margin-bottom: var(--space-md); }
.mb-3 { margin-bottom: var(--space-lg); }
.mb-4 { margin-bottom: var(--space-xl); }

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

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-md); }

/* Responsive */
@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(-100%);
    z-index: 1000;
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
  }
  
  /* Mobile overlay backdrop */
  .sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(10, 14, 39, 0.8);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
    z-index: 999;
  }
  
  .sidebar-overlay.active {
    opacity: 1;
    pointer-events: auto;
  }
}

@media (max-width: 768px) {
  :root {
    --sidebar-width: 100%;
    --header-height: 60px;
  }
  
  .content {
    padding: var(--space-md);
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .page-title {
    font-size: var(--text-xl);
  }
}

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

.fade-in {
  animation: fadeIn var(--transition-base) ease-out;
}

@keyframes slideIn {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(0);
  }
}

.slide-in {
  animation: slideIn var(--transition-base) ease-out;
}

/* Loading Spinner */
.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--color-bg-tertiary);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(10, 14, 39, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}