:root {
  /* Color */
  --color-canvas: #0d1117;
  --color-surface: #161b22;
  --color-surface-inset: #010409;
  --color-border-default: #30363d;
  --color-border-muted: #21262d;
  --color-text-primary: #e6edf3;
  --color-text-secondary: #8b949e;
  --color-text-tertiary: #7c8487;
  --color-accent: #00d4a0;
  --color-accent-emphasis: #22e6b5;
  --color-accent-muted: #0d3d31;
  --color-danger: #f85149;
  --color-warning: #d29922;
  --color-success: #3fb950;

  /* Typography */
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Consolas,
    "Liberation Mono", Menlo, monospace;

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

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.7;

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

  /* Spacing */
  --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;

  /* Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* Shadow */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.6);

  /* Transitions */
  --transition-fast: 100ms ease;
  --transition-base: 150ms ease;
  --transition-slow: 250ms ease;

  /* Layout */
  --sidebar-width: 280px;
  --content-max-width: 780px;
  --portfolio-max-width: 1200px;
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --transition-fast: 0ms;
    --transition-base: 0ms;
    --transition-slow: 0ms;
  }
}