:root {
  /* ===========================================
     Trusted Blue Palette
     =========================================== */
  --color-primary: #2563EB;
  --color-primary-hover: #1D4ED8;
  --color-primary-active: #1E40AF;
  --color-secondary: #60A5FA;          /* lighter blue for accents */
  --color-accent: #DBEAFE;             /* used in tool‑card gradients */
  --color-accent-light: #EFF6FF;       /* very light blue for highlights */

  /* Surfaces */
  --color-bg: #F8FAFC;                /* soft light gray‑blue background */
  --color-bg-elevated: #FFFFFF;       /* pure white for elevated cards */
  --color-bg-dark: #0F172A;           /* dark mode background */
  --color-bg-dark-elevated: #1E293B;  /* dark mode elevated surface */
  --color-card: #FFFFFF;
  --color-card-hover: #F1F5F9;

  /* Text */
  --color-text: #0F172A;
  --color-text-secondary: #475569;
  --color-text-tertiary: #94A3B8;
  --color-text-inverse: #FFFFFF;

  /* Borders */
  --color-border: #E2E8F0;
  --color-border-hover: #CBD5E1;
  --color-border-focus: var(--color-primary);

  /* Status */
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  --color-info: var(--color-primary);   /* info uses primary blue */

  /* ===========================================
     Typography (unchanged)
     =========================================== */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;

  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  --weight-regular: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;

  /* ===========================================
     Spacing – 4pt grid (unchanged)
     =========================================== */
  --space-0: 0;
  --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;

  /* ===========================================
     Radius (unchanged)
     =========================================== */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-2xl: 2rem;
  --radius-full: 9999px;

  /* ===========================================
     Shadows – Soft (unchanged)
     =========================================== */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-glass: 0 8px 32px rgba(37, 99, 235, 0.12);   /* subtle blue glass */

  /* ===========================================
     Transitions (unchanged)
     =========================================== */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: 400ms cubic-bezier(0.16, 1, 0.3, 1);

  /* ===========================================
     Layout (unchanged)
     =========================================== */
  --header-height: 4rem;
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
  --container-2xl: 1440px;

  /* ===========================================
     Z‑index (unchanged)
     =========================================== */
  --z-base: 0;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-overlay: 300;
  --z-modal: 400;
  --z-toast: 500;
}

/* ===========================================
   Dark Mode – Trusted Blue
   =========================================== */
[data-theme="dark"] {
  --color-bg: var(--color-bg-dark);
  --color-bg-elevated: var(--color-bg-dark-elevated);
  --color-card: #1E293B;
  --color-card-hover: #334155;
  --color-text: #F1F5F9;
  --color-text-secondary: #CBD5E1;
  --color-text-tertiary: #94A3B8;
  --color-border: #334155;
  --color-border-hover: #475569;

  /* Shadows become darker in dark mode */
  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4), 0 1px 2px -1px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
  --shadow-glass: 0 8px 32px rgba(0, 0, 0, 0.5);
}