/**
 * CSS Variables - Design System
 * Modern, accessible color scheme with WCAG AA contrast
 */

:root {
  /* Colors - Classic Academic (Burgundy & Gold) */
  --color-primary: #8b1a1a; /* Deep burgundy - main brand */
  --color-primary-light: #a52a2a;
  --color-primary-dark: #6b0f0f;
  --color-secondary: #b8860b; /* Dark goldenrod */
  --color-accent: #daa520; /* Goldenrod for highlights */

  /* Neutral colors */
  --color-background: #fefefe;
  --color-surface: #faf8f5; /* Warm cream */
  --color-surface-dark: #f5f1e8; /* Warmer beige */
  --color-border: #d4c5b0;
  --color-border-light: #e8dcc8;

  /* Text colors - WCAG AA compliant */
  --color-text-primary: #2d1810;
  --color-text-secondary: #5d4a3a;
  --color-text-muted: #8d7a6a;
  --color-text-inverse: #fefefe;
  --color-link: #b8860b;
  --color-link-hover: #daa520;
  --color-link-visited: #9a7510;

  /* Semantic colors */
  --color-success: #198754;
  --color-warning: #ffc107;
  --color-error: #dc3545;
  --color-info: #0dcaf0;

  /* Typography */
  --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
                      "Helvetica Neue", Arial, sans-serif;
  --font-family-heading: Georgia, "Times New Roman", serif;
  --font-family-mono: "SF Mono", Monaco, "Cascadia Code", monospace;

  /* Font sizes - Fluid typography */
  --font-size-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --font-size-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --font-size-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --font-size-md: clamp(1.125rem, 1.05rem + 0.35vw, 1.25rem);
  --font-size-lg: clamp(1.25rem, 1.15rem + 0.5vw, 1.5rem);
  --font-size-xl: clamp(1.5rem, 1.35rem + 0.75vw, 2rem);
  --font-size-2xl: clamp(2rem, 1.75rem + 1.25vw, 2.5rem);
  --font-size-3xl: clamp(2.5rem, 2rem + 2vw, 3.5rem);

  /* Font weights */
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Line heights */
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing scale */
  --space-xs: 0.25rem; /* 4px */
  --space-sm: 0.5rem; /* 8px */
  --space-md: 1rem; /* 16px */
  --space-lg: 1.5rem; /* 24px */
  --space-xl: 2rem; /* 32px */
  --space-2xl: 3rem; /* 48px */
  --space-3xl: 4rem; /* 64px */
  --space-4xl: 6rem; /* 96px */

  /* Layout */
  --max-width-sm: 640px;
  --max-width-md: 768px;
  --max-width-lg: 1024px;
  --max-width-xl: 1280px;
  --max-width-2xl: 1536px;
  --max-width-content: 1200px;

  /* Border radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  /* 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);

  /* Z-index scale */
  --z-base: 0;
  --z-dropdown: 1000;
  --z-sticky: 1100;
  --z-fixed: 1200;
  --z-modal-backdrop: 1300;
  --z-modal: 1400;
  --z-tooltip: 1500;

  /* Breakpoints (for JS) */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;
}

/* Focus visible styles - Accessibility */
:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* Remove default focus for mouse users */
:focus:not(:focus-visible) {
  outline: none;
}