:root {
  /* Text */
  --color-text-primary:     #1a1a1a;
  --color-text-secondary:   #6b7280;
  --color-text-tertiary:    #9ca3af;

  /* Backgrounds */
  --color-background-primary:   #ffffff;
  --color-background-secondary: #f3f4f6;
  --color-background-tertiary:  #e9eaeb;

  /* Borders */
  --color-border-tertiary:  rgba(0, 0, 0, 0.10);
  --color-border-secondary: rgba(0, 0, 0, 0.20);
  --color-border-primary:   rgba(0, 0, 0, 0.35);

  /* Semantic */
  --color-background-info:    #E6F1FB;
  --color-text-info:          #185FA5;
  --color-background-success: #E1F5EE;
  --color-text-success:       #0F6E56;
  --color-background-warning: #FEF3C7;
  --color-text-warning:       #92400E;
  --color-background-danger:  #FEE2E2;
  --color-text-danger:        #991B1B;

  /* Layout */
  --border-radius-md: 8px;
  --border-radius-lg: 12px;
  --border-radius-xl: 16px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI',
               Helvetica, Arial, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono',
               'Consolas', 'Courier New', monospace;
  --font-serif: Georgia, 'Times New Roman', serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font-sans); background: var(--color-background-tertiary); color: var(--color-text-primary); }