/**
 * CSS CUSTOM PROPERTIES (VARIABLES)
 * 
 * This file defines all colors, fonts, spacing, and other design tokens
 * used throughout the site. Changing values here updates the entire site.
 * 
 * THEME: Dark mode with Wisconsin Red accents
 */

:root {
  /* ===== BACKGROUND COLORS ===== */
  --bg-primary: #0d1117;        /* Main page background */
  --bg-secondary: #161b22;      /* Cards, elevated surfaces */
  --bg-tertiary: #21262d;       /* Subtle elevation (hover states) */
  --bg-code: #1f2428;           /* Code block backgrounds */
  
  /* ===== TEXT COLORS ===== */
  --text-primary: #e6edf3;      /* Main body text */
  --text-secondary: #8b949e;    /* Less important text */
  --text-muted: #6e7681;        /* Disabled, meta text */
  --text-inverse: #0d1117;      /* Text on light backgrounds */
  
  /* ===== ACCENT COLORS - WISCONSIN RED ===== */
  --accent-primary: #c5050c;    /* Primary red (UW Madison) - buttons, CTAs */
  --accent-soft: #da4167;       /* Softer red - hovers, secondary elements */
  --accent-muted: #8b2635;      /* Dark red - subtle backgrounds */
  --accent-hover: #e61e28;      /* Bright red - active/hover states */
  
  /* ===== FUNCTIONAL COLORS ===== */
  --link-blue: #58a6ff;         /* External links, info */
  --success: #3fb950;           /* Success states */
  --warning: #d29922;           /* Warning states */
  --error: #f85149;             /* Error states */
  
  /* ===== BORDER COLORS ===== */
  --border-primary: #30363d;    /* Main borders */
  --border-secondary: #21262d;  /* Subtle borders */
  --border-accent: #da4167;     /* Accent borders */
  
  /* ===== TYPOGRAPHY ===== */
  /* Font families */
  --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 
                  'Helvetica Neue', Arial, sans-serif;
  --font-headings: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Consolas', 'Monaco', 'Courier New', monospace;
  
  /* Font sizes - Mobile first */
  --font-size-xs: 0.75rem;      /* 12px */
  --font-size-sm: 0.875rem;     /* 14px */
  --font-size-base: 1rem;       /* 16px */
  --font-size-lg: 1.125rem;     /* 18px */
  --font-size-xl: 1.25rem;      /* 20px */
  --font-size-2xl: 1.5rem;      /* 24px */
  --font-size-3xl: 1.875rem;    /* 30px */
  --font-size-4xl: 2.25rem;     /* 36px */
  --font-size-5xl: 3rem;        /* 48px */
  
  /* Line heights */
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Font weights */
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* ===== SPACING ===== */
  --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 */
  
  /* ===== BORDER RADIUS ===== */
  --radius-sm: 0.25rem;         /* 4px */
  --radius-md: 0.5rem;          /* 8px */
  --radius-lg: 0.75rem;         /* 12px */
  --radius-xl: 1rem;            /* 16px */
  --radius-full: 9999px;        /* Fully rounded */
  
  /* ===== SHADOWS ===== */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
  
  /* ===== TRANSITIONS ===== */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 200ms ease-in-out;
  --transition-slow: 300ms ease-in-out;
  
  /* ===== LAYOUT ===== */
  --max-width-content: 1200px;  /* Max width for main content */
  --max-width-text: 65ch;       /* Max width for readable text */
  --header-height: 70px;        /* Fixed header height */
  
  /* ===== Z-INDEX LAYERS ===== */
  --z-base: 1;
  --z-dropdown: 10;
  --z-sticky: 100;
  --z-modal: 1000;
  --z-overlay: 1001;
  --z-toast: 2000;
}

/* ===== RESPONSIVE FONT SIZES ===== */
/* Scale up typography on larger screens */
@media (min-width: 768px) {
  :root {
    --font-size-base: 1.0625rem;  /* 17px */
    --font-size-lg: 1.1875rem;    /* 19px */
    --font-size-xl: 1.375rem;     /* 22px */
    --font-size-2xl: 1.75rem;     /* 28px */
    --font-size-3xl: 2.25rem;     /* 36px */
    --font-size-4xl: 3rem;        /* 48px */
    --font-size-5xl: 3.75rem;     /* 60px */
  }
}

@media (min-width: 1024px) {
  :root {
    --font-size-base: 1.125rem;   /* 18px */
  }
}