/* ==========================================================================
   Base Styles and CSS Variables
   ========================================================================== */

:root {
  /* Colors - Light Mode */
  --color-primary: #3b82f6;
  --color-primary-hover: #2563eb;
  --color-primary-subtle: rgba(59, 130, 246, 0.1);
  
  --color-bg: #f9fafb;
  --color-surface: #ffffff;
  --color-surface-alt: #f3f4f6;
  --color-border: #e5e7eb;
  --color-border-hover: #9ca3af;
  
  --color-text: #1f2937;
  --color-text-secondary: #4b5563;
  --color-text-muted: #6b7280;
  --color-text-inverse: #ffffff;

  /* Semantic Colors */
  --color-success: #10b981;
  --color-success-bg: rgba(16, 185, 129, 0.1);
  --color-success-border: rgba(16, 185, 129, 0.3);

  --color-danger: #ef4444;
  --color-danger-bg: rgba(239, 68, 68, 0.1);
  --color-danger-border: rgba(239, 68, 68, 0.3);

  --color-info: #3b82f6;
  --color-info-bg: rgba(59, 130, 246, 0.1);
  --color-info-border: rgba(59, 130, 246, 0.3);
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  
  /* Typography */
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.5;
  font-weight: 400;
  
  color-scheme: light dark;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #60a5fa;
    --color-primary-hover: #93c5fd;
    --color-primary-subtle: rgba(96, 165, 250, 0.1);
    
    --color-bg: #111827;
    --color-surface: #1f2937;
    --color-surface-alt: #374151;
    --color-border: #374151;
    --color-border-hover: #6b7280;
    
    --color-text: #f3f4f6;
    --color-text-secondary: #d1d5db;
    --color-text-muted: #9ca3af;
    --color-text-inverse: #111827;

    /* Semantic Colors - Dark Mode */
    --color-success: #10b981;
    --color-success-bg: rgba(16, 185, 129, 0.15);
    --color-success-border: rgba(16, 185, 129, 0.4);

    --color-danger: #f87171;
    --color-danger-bg: rgba(239, 68, 68, 0.15);
    --color-danger-border: rgba(239, 68, 68, 0.4);

    --color-info: #60a5fa;
    --color-info-bg: rgba(59, 130, 246, 0.15);
    --color-info-border: rgba(59, 130, 246, 0.4);
  }
}

/* Reset */
*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  width: 100%;
  overflow-x: hidden;
  background-color: var(--color-bg);
  color: var(--color-text);
}

a {
  font-weight: 500;
  color: var(--color-primary);
  text-decoration: none;
}

a:hover {
  color: var(--color-primary-hover);
  text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  line-height: 1.2;
}

h1 {
  font-size: 1.75rem;
}

@media (min-width: 768px) {
  h1 {
    font-size: 2.25rem;
  }
}

button {
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  padding: var(--space-sm) var(--space-md);
  font-size: 0.9rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

button:focus,
button:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}