:root {
  /* Brand colors */
  --color-brand-primary: #10b981;      /* emerald-500 - Citizen tier */
  --color-brand-secondary: #f59e0b;    /* amber-500 - Visa tier */
  --color-brand-accent: #8b5cf6;       /* violet-500 - Cyborg tier */

  /* Semantic colors */
  --color-success: #22c55e;            /* high likelihood */
  --color-warning: #f59e0b;            /* moderate likelihood */
  --color-danger: #ef4444;             /* low likelihood */
  --color-info: #3b82f6;

  /* Neutral scale - dark theme */
  --color-bg-primary: #0a0a0a;         /* neutral-950 */
  --color-bg-secondary: #171717;       /* neutral-900 */
  --color-bg-tertiary: #262626;        /* neutral-800 */
  --color-bg-dark: #0a0a0a;           /* neutral-950 */
  --color-text-primary: #f5f5f5;       /* neutral-100 */
  --color-text-secondary: #a3a3a3;     /* neutral-400 */
  --color-text-tertiary: #737373;      /* neutral-500 */
  --color-border: #262626;             /* neutral-800 */

  /* Typography scale - major third 1.25 */
  --font-family-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-family-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.25rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 1.875rem;
  --font-size-3xl: 2.25rem;
  --font-size-4xl: 3rem;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing - 8px base grid */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radii */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Shadows - subtle, professional */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 400ms ease-in-out;
}