:root {
  /* Core Colors */
  --color-primary: #0078d4;
  --color-primary-dark: #005a9e;
  --color-primary-light: #50a0e0;
  --color-secondary: #00b294;
  --color-accent: #8764b8;

  --color-success: #107c10;
  --color-warning: #ff8c00;
  --color-danger: #d13438;
  --color-info: #00b7c3;

  /* Backgrounds & Text */
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f5f5f5;
  --color-bg-tertiary: #fafafa;
  --color-surface: #ffffff;
  --color-surface-hover: #f3f2f1;

  --color-text-primary: #323130;
  --color-text-secondary: #605e5c;
  --color-text-tertiary: #8a8886;
  --color-text-inverse: #ffffff;

  --color-border: #e1dfdd;
  --color-border-light: #edebe9;

  /* Accent palette for icon and tint utilities */
  --accent-blue: #3b82f6;
  --accent-teal: #10b981;
  --accent-purple: #8b5cf6;
  --accent-pink: #ec4899;
  --accent-amber: #f59e0b;
  --accent-green: #22c55e;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.15);
  --shadow-xl: 0 12px 24px rgba(0, 0, 0, 0.2);

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* Typography */
  --font-family-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Helvetica Neue', sans-serif;
  --font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Courier New', monospace;

  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;

  --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;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --container-max-width: 1440px;
  --header-height: 64px;
  --sidebar-width: 280px;
}

/* Dark mode - manual toggle */
[data-theme="dark"] {
  --color-bg-primary: #1a1a1a;
  --color-bg-secondary: #252525;
  --color-bg-tertiary: #2f2f2f;
  --color-surface: #252525;
  --color-surface-hover: #3a3a3a;

  --color-text-primary: #f5f5f5;
  --color-text-secondary: #d1d1d1;
  --color-text-tertiary: #a0a0a0;

  --color-border: #3f3f3f;
  --color-border-light: #2f2f2f;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 12px 24px rgba(0, 0, 0, 0.6);
}

/* Auto dark mode based on system preference (when no manual preference set) */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg-primary: #1a1a1a;
    --color-bg-secondary: #252525;
    --color-bg-tertiary: #2f2f2f;
    --color-surface: #252525;
    --color-surface-hover: #3a3a3a;

    --color-text-primary: #f5f5f5;
    --color-text-secondary: #d1d1d1;
    --color-text-tertiary: #a0a0a0;

    --color-border: #3f3f3f;
    --color-border-light: #2f2f2f;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 12px 24px rgba(0, 0, 0, 0.6);
  }
}