:root {
  /* Dark theme (default) */
  --color-bg: #0a0a0f;
  --color-bg-light: #12121a;
  --color-surface: #1a1a2e;
  --color-surface-hover: #222240;
  --color-border: #2a2a4a;
  --color-border-hover: #4f8cff40;
  --color-text: #e0e0e8;
  --color-text-muted: #8888a0;
  --color-text-heading: #ffffff;
  --color-primary: #4f8cff;
  --color-primary-hover: #6ba0ff;
  --color-secondary: #6c63ff;
  --color-accent-gradient: linear-gradient(135deg, #4f8cff, #6c63ff);
  --color-glow: #4f8cff30;
  --color-success: #2ecc71;
  --color-error: #e74c3c;
  --header-bg-scrolled: rgba(10, 10, 15, 0.95);
  --header-shadow-scrolled: 0 2px 20px rgba(0, 0, 0, 0.5);
  color-scheme: dark;

  /* Typography */
  --font-family: 'Roboto', sans-serif;
  --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: 1.75rem;
  --font-size-3xl: 2.15rem;
  --font-size-4xl: 3rem;
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 700;
  --line-height-tight: 1.2;
  --line-height-normal: 1.6;

  /* Spacing (8px grid) */
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2rem;
  --space-5: 2.5rem;
  --space-6: 3rem;
  --space-8: 4rem;
  --space-10: 5rem;
  --space-12: 6rem;
  --space-16: 8rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 6px 16px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.55);
  --shadow-glow: 0 0 20px var(--color-glow);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Layout */
  --container-max: 1200px;
  --header-height: 72px;
}

/* Light theme */
[data-theme="light"] {
  --color-bg: #f5f5f7;
  --color-bg-light: #ffffff;
  --color-surface: #eaeaef;
  --color-surface-hover: #dddde5;
  --color-border: #ccccd6;
  --color-border-hover: #2563eb40;
  --color-text: #1e1e2e;
  --color-text-muted: #5a5a72;
  --color-text-heading: #0a0a14;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-secondary: #4f46e5;
  --color-accent-gradient: linear-gradient(135deg, #2563eb, #4f46e5);
  --color-glow: #2563eb20;
  --color-success: #16a34a;
  --color-error: #dc2626;
  --header-bg-scrolled: rgba(245, 245, 247, 0.95);
  --header-shadow-scrolled: 0 2px 20px rgba(0, 0, 0, 0.08);
  color-scheme: light;
}