:root {
  --color-primary: #2563EB;
  --color-primary-dark: #1E40AF;
  --color-primary-light: #DBEAFE;
  --color-primary-lighter: #EFF6FF;
  --color-accent: #0D9488;
  --color-accent-light: #CCFBF1;
  --color-highlight: #F59E0B;
  --color-highlight-light: #FEF3C7;
  --color-success: #10B981;
  --color-success-light: #D1FAE5;
  --color-warning: #EF4444;
  --color-warning-light: #FEE2E2;

  --color-bg: #FFFFFF;
  --color-bg-alt: #F9FAFB;
  --color-bg-dark: #111827;
  --color-border: #E5E7EB;
  --color-border-dark: #D1D5DB;

  --color-text: #111827;
  --color-text-dim: #6B7280;
  --color-text-light: #9CA3AF;
  --color-text-inverse: #FFFFFF;

  --font-display: 'PingFang SC', 'Microsoft YaHei', -apple-system, sans-serif;
  --font-body: 'PingFang SC', 'Hiragino Sans GB', -apple-system, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', 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;

  --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-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
  --shadow-xl: 0 20px 25px rgba(0,0,0,0.15);

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;

  --nav-height: 64px;
  --max-width: 1200px;
  --max-width-narrow: 800px;
  --max-width-wide: 1400px;
}

@media (max-width: 768px) {
  :root {
    --text-4xl: 1.875rem;
    --text-5xl: 2.25rem;
    --nav-height: 56px;
    --space-16: 3rem;
    --space-20: 4rem;
    --space-24: 5rem;
  }
}