:root {
  /* =========================================
     Color Tokens - Numpath Puzzle Official
     ========================================= */
  --bg-canvas: #090B10;
  --bg-surface: #10141D;
  --bg-surface-elevated: #181F2C;
  --bg-glass: rgba(16, 20, 29, 0.75);
  --bg-glass-elevated: rgba(24, 31, 44, 0.85);

  /* Borders & Dividers */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-light: rgba(255, 255, 255, 0.15);
  --border-neon: rgba(0, 230, 118, 0.35);
  --border-glow: 0 0 20px rgba(0, 230, 118, 0.25);

  /* Brand Accents */
  --accent-mint: #00E676;
  --accent-mint-glow: rgba(0, 230, 118, 0.5);
  --accent-mint-dark: #00B359;
  --accent-amber: #F59E0B;
  --accent-amber-glow: rgba(245, 158, 11, 0.4);
  --accent-cyan: #00E5FF;
  --accent-cyan-glow: rgba(0, 229, 255, 0.4);
  --accent-purple: #A855F7;
  --accent-purple-glow: rgba(168, 85, 247, 0.4);
  --accent-rose: #FF3366;

  /* Typography Colors */
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --text-inverse: #090B10;

  /* Board Grid Tokens */
  --cell-bg: #141A24;
  --cell-border: rgba(255, 255, 255, 0.06);
  --cell-active: #00E676;
  --checkpoint-bg: #F59E0B;
  --checkpoint-color: #090B10;

  /* Elevation & Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.65);
  --shadow-neon: 0 0 25px rgba(0, 230, 118, 0.4);
  --shadow-amber: 0 0 25px rgba(245, 158, 11, 0.35);

  /* Layout & Spacing */
  --max-width: 1200px;
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  /* Text Gradients */
  --gradient-text-start: #FFFFFF;
  --gradient-text-mint: #00E676;
  --gradient-text-amber: #F59E0B;
  --gradient-text-cyan: #00E5FF;

  /* Header & Footer */
  --bg-header: rgba(9, 11, 16, 0.82);
  --bg-footer: #06080C;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light Mode Overrides (Polished High-Contrast Palette) */
[data-theme="light"] {
  --bg-canvas: #F8FAFC;
  --bg-surface: #FFFFFF;
  --bg-surface-elevated: #F1F5F9;
  --bg-glass: rgba(255, 255, 255, 0.85);
  --bg-glass-elevated: rgba(241, 245, 249, 0.9);

  --border-subtle: rgba(15, 23, 42, 0.08);
  --border-light: rgba(15, 23, 42, 0.14);
  --border-neon: rgba(5, 150, 105, 0.3);
  --border-glow: 0 0 20px rgba(5, 150, 105, 0.15);

  /* Deep High-Contrast Brand Accents for Light Background */
  --accent-mint: #059669;
  --accent-mint-glow: rgba(5, 150, 105, 0.35);
  --accent-mint-dark: #047857;
  --accent-amber: #D97706;
  --accent-amber-glow: rgba(217, 119, 6, 0.3);
  --accent-cyan: #0284C7;
  --accent-cyan-glow: rgba(2, 132, 199, 0.3);
  --accent-purple: #7C3AED;
  --accent-rose: #E11D48;

  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #64748B;
  --text-inverse: #FFFFFF;

  --cell-bg: #E2E8F0;
  --cell-border: rgba(15, 23, 42, 0.06);
  --cell-active: #059669;
  --checkpoint-bg: #D97706;
  --checkpoint-color: #FFFFFF;

  /* Gradients tailored for light mode readability */
  --gradient-text-start: #0F172A;
  --gradient-text-mint: #059669;
  --gradient-text-amber: #D97706;
  --gradient-text-cyan: #0284C7;

  /* Header & Footer */
  --bg-header: rgba(255, 255, 255, 0.88);
  --bg-footer: #F1F5F9;

  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.07);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.1);
  --shadow-neon: 0 0 25px rgba(5, 150, 105, 0.2);
}