/* ============================================
   CSS VARIABLES - Centralized Color System
   ============================================
   This file contains all design tokens used across the application.
   Use CSS variables instead of hardcoded colors for easy theming.
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  /* === BRAND COLORS === */
  /* Primary brand color - used for main actions, buttons, links */
  --color-primary: #667eea;
  --color-primary-hover: #5a67d8;
  --color-primary-image: #856fc9;
  --color-primary-image-hover: #7461b8;
  
  /* === BACKGROUNDS === */
  /* Main application background */
  --color-bg-main: #ffffff;
  /* Sidebar background */
  --color-bg-sidebar: #f9fafb;
  /* Input field background */
  --color-bg-input: #f9fafb;
  /* User message bubble background */
  --color-bg-user-message: #e5e7eb;
  /* AI message bubble background */
  --color-bg-ai-message: #ffffff;
  /* Hover state background for interactive elements */
  --color-bg-hover: #e5e7eb;
  /* Selected/active state background */
  --color-bg-selected: #d1d5db;
  
  /* === TEXT === */
  /* Primary text color - main content */
  --color-text-primary: #374151;
  /* Secondary text color - less important content */
  --color-text-secondary: #6b7280;
  /* Muted text color - hints, placeholders, metadata */
  --color-text-muted: #9ca3af;
  /* Heading text color - titles, headers */
  --color-text-heading: #111827;
  /* User message text color */
  --color-text-user: #1f2937;
  /* Placeholder text color */
  --color-text-placeholder: #9ca3af;
  
  /* === BORDERS === */
  /* Main border color - most common borders */
  --color-border-main: #e5e7eb;
  /* Secondary border color - dividers, subtle borders */
  --color-border-secondary: #d1d5db;
  /* Thin border color - minimal separators */
  --color-border-thin: #e0e0e0;
  /* Focus border color - active input fields, focused elements */
  --color-border-focus: #667eea;
  
  /* === STATUS COLORS === */
  /* Success state - positive actions, confirmations */
  --color-success: #10b981;
  /* Error state - errors, failures */
  --color-error: #ef4444;
  /* Warning state - warnings, cautions */
  --color-warning: #f59e0b;
  /* Info state - informational messages */
  --color-info: #3b82f6;
  /* Danger state - destructive actions */
  --color-danger: #dc3545;
  
  /* === UI ELEMENTS === */
  /* Icon color - default icon color */
  --color-icon: #6b7280;
  /* Icon hover color - icon color on hover */
  --color-icon-hover: #374151;
  
  /* === TYPOGRAPHY === */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;

  --text-xs: 12px;
  --text-sm: 14px;
  --text-base: 15px;
  --text-md: 16px;
  --text-lg: 18px;
  --text-xl: 20px;
  --text-2xl: 24px;
  --text-3xl: 32px;

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* === SPACING === */
  /* Spacing scale for consistent margins and padding */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  
  /* === BORDERS & RADIUS === */
  /* Border radius for rounded corners */
  --border-radius: 6px;
  --border-radius-sm: 4px;
  --border-radius-lg: 8px;
  
  /* === SHADOWS === */
  /* Box shadows for depth and elevation */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.1);
  
  /* === TRANSITIONS === */
  /* Transition timings for smooth animations */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
}