/**
 * AI Study & Task Planner - Design Tokens & Variables
 * Clean modern aesthetic + high contrast + responsive typography.
 */

:root {
  /* Typography */
  --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Spacing Scale (High density developer workbench) */
  --space-2xs: 4px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;

  /* Border Radius */
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 250ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Elevation 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), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
  --shadow-glow-emerald: 0 0 15px rgba(16, 185, 129, 0.25);
  --shadow-glow-cyan: 0 0 15px rgba(6, 182, 212, 0.25);

  /* Layout */
  --sidebar-width: 250px;
  --sidebar-collapsed-width: 68px;
  --header-height: 64px;
  --mobile-bottom-nav-height: 64px;
}

/* Dark Theme (Default OLED Mode) */
body[data-theme='dark'], :root {
  --color-bg-base: #070B14;
  --color-bg-surface: #0E1526;
  --color-bg-surface-elevated: #151F36;
  --color-bg-surface-hover: #1C2844;
  --color-bg-subtle: #121A2F;

  --color-border: #1E2B45;
  --color-border-subtle: #172237;
  --color-border-active: #3B82F6;

  --color-text-main: #F8FAFC;
  --color-text-secondary: #94A3B8;
  --color-text-muted: #64748B;
  --color-text-dim: #475569;

  --color-primary: #3B82F6;
  --color-primary-hover: #2563EB;
  --color-primary-subtle: rgba(59, 130, 246, 0.12);

  --color-accent-emerald: #10B981;
  --color-accent-emerald-subtle: rgba(16, 185, 129, 0.12);
  --color-accent-cyan: #06B6D4;
  --color-accent-cyan-subtle: rgba(6, 182, 212, 0.12);
  --color-accent-purple: #8B5CF6;
  --color-accent-purple-subtle: rgba(139, 92, 246, 0.12);
  --color-accent-amber: #F59E0B;
  --color-accent-amber-subtle: rgba(245, 158, 11, 0.12);
  --color-accent-rose: #EF4444;
  --color-accent-rose-subtle: rgba(239, 68, 68, 0.12);

  --scrollbar-thumb: #23314F;
  --scrollbar-track: #0A101D;
}

/* Light Theme */
body[data-theme='light'] {
  --color-bg-base: #F8FAFC;
  --color-bg-surface: #FFFFFF;
  --color-bg-surface-elevated: #F1F5F9;
  --color-bg-surface-hover: #E2E8F0;
  --color-bg-subtle: #F1F5F9;

  --color-border: #CBD5E1;
  --color-border-subtle: #E2E8F0;
  --color-border-active: #2563EB;

  --color-text-main: #0F172A;
  --color-text-secondary: #334155;
  --color-text-muted: #64748B;
  --color-text-dim: #94A3B8;

  --color-primary: #2563EB;
  --color-primary-hover: #1D4ED8;
  --color-primary-subtle: rgba(37, 99, 235, 0.1);

  --color-accent-emerald: #059669;
  --color-accent-emerald-subtle: rgba(5, 150, 105, 0.1);
  --color-accent-cyan: #0891B2;
  --color-accent-cyan-subtle: rgba(8, 145, 178, 0.1);
  --color-accent-purple: #7C3AED;
  --color-accent-purple-subtle: rgba(124, 58, 237, 0.1);
  --color-accent-amber: #D97706;
  --color-accent-amber-subtle: rgba(217, 119, 6, 0.1);
  --color-accent-rose: #DC2626;
  --color-accent-rose-subtle: rgba(220, 38, 38, 0.1);

  --scrollbar-thumb: #CBD5E1;
  --scrollbar-track: #F1F5F9;
}