/* CSS Variables for Consistent Theming */
:root {
  --primary-color: #007bff;
  --secondary-color: #6c757d;
  --success-color: #28a745;
  --warning-color: #ffc107;
  --danger-color: #dc3545;
  --light-color: #f8f9fa;
  --dark-color: #343a40;
  
  --text-primary: #333;
  --text-secondary: #6c757d;
  --bg-primary: #f8f9fa;
  --bg-secondary: #fff;
  
  --border-radius: 6px;
  --border-radius-lg: 8px;
  --box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  --transition: 0.3s ease;
  
  --container-max-width: 1200px;
  --spacing-sm: 10px;
  --spacing-md: 20px;
  --spacing-lg: 30px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition), color var(--transition);
}

.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: var(--spacing-md);
}

/* Page Management */
.page {
  display: none;
}

.page.active {
  display: block;
}

/* Typography */
h1, h2, h3 {
  margin-bottom: 1rem;
  color: #2c3e50;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }

/* Basic Layout Utilities */
.actions {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

.empty-state {
  text-align: center;
  padding: var(--spacing-lg);
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border-radius: var(--border-radius-lg);
  border: 2px dashed #dee2e6;
}

.empty-state h2 {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slideIn {
  from {
    transform: translateY(-20px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

/* Basic Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: var(--spacing-sm);
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
  
  .actions {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}