:root[data-theme="simple"] {
  --color-bg:              #111827;
  --color-surface:         #1f2937;
  --color-surface-alt:     #374151;
  --color-border:          #4b5563;
  --color-primary:         #6366f1;
  --color-primary-hover:   #4f46e5;
  --color-primary-glow:    rgba(99, 102, 241, 0.2);
  --color-text:            #ffffff;
  --color-text-muted:      #e5e7eb;
  --color-text-on-primary: #ffffff;
  --color-accent:          #818cf8;
  --font-heading:          'Inter', system-ui, sans-serif;
  --font-body:             'Inter', system-ui, sans-serif;
  --radius-sm:             4px;
  --radius-md:             8px;
  --radius-lg:             12px;
  --radius-full:           9999px;
  --transition:            all 0.3s ease;
  --shadow-sm:             0 2px 8px rgba(0,0,0,0.3);
  --shadow-md:             0 4px 20px rgba(0,0,0,0.4);
  --shadow-lg:             0 8px 40px rgba(0,0,0,0.5);
  --shadow-neu-out:        none;
  --shadow-neu-in:         none;
}