/* ========================================
   Design System - Global Styles
   ======================================== */

/* CSS Custom Properties for Design Tokens */
:root {
  /* Color Palette - Light Mode */
  --color-primary: #7c3aed;
  --color-primary-light: #a78bfa;
  --color-primary-dark: #5b21b6;
  --color-accent: #d946ef;
  --color-accent-light: #f0abfc;
  --color-accent-dark: #a21caf;

  /* Neutral Colors */
  --color-background: #ffffff;
  --color-surface: #f9fafb;
  --color-border: #e5e7eb;
  --color-text-primary: #111827;
  --color-text-secondary: #6b7280;
  --color-text-tertiary: #9ca3af;

  /* Semantic Colors */
  --color-success: #10b981;
  --color-error: #ef4444;
  --color-warning: #f59e0b;
  --color-info: #3b82f6;

  /* Spacing Scale (0.25rem = 4px increments) */
  --spacing-xs: 0.25rem;    /* 4px */
  --spacing-sm: 0.5rem;     /* 8px */
  --spacing-md: 1rem;       /* 16px */
  --spacing-lg: 1.5rem;     /* 24px */
  --spacing-xl: 2rem;       /* 32px */
  --spacing-2xl: 3rem;      /* 48px */
  --spacing-3xl: 4rem;      /* 64px */

  /* Border Radius */
  --radius-sm: 0.25rem;     /* 4px */
  --radius-md: 0.5rem;      /* 8px */
  --radius-lg: 1rem;        /* 16px */
  --radius-full: 9999px;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --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 */

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

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;

  /* Z-Index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1100;
  --z-fixed: 1200;
  --z-modal: 1300;
  --z-popover: 1400;
  --z-tooltip: 1500;
}

/* Dark Mode */
.dark {
  --color-background: #111827;
  --color-surface: #1f2937;
  --color-border: #374151;
  --color-text-primary: #f9fafb;
  --color-text-secondary: #d1d5db;
  --color-text-tertiary: #9ca3af;
}

/* ========================================
   Base Styles
   ======================================== */

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--color-text-primary);
  background-color: var(--color-background);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ========================================
   Typography
   ======================================== */

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-text-primary);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

a:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ========================================
   Utility Classes
   ======================================== */

.container {
  width: 100%;
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--spacing-md);
  padding-right: var(--spacing-md);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--spacing-xl);
    padding-right: var(--spacing-xl);
  }
}

/* ========================================
   Responsive Design Breakpoints
   ======================================== */

/*
  Mobile: 320px - 767px (default)
  Tablet: 768px - 1023px
  Desktop: 1024px+
*/

@media (max-width: 767px) {
  h1 { font-size: var(--font-size-4xl); }
  h2 { font-size: var(--font-size-3xl); }
  h3 { font-size: var(--font-size-2xl); }
}

/* ========================================
   Accessibility
   ======================================== */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus visible for keyboard navigation */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Remove focus outline from headings and static content */
h1:focus, h2:focus, h3:focus, h4:focus, h5:focus, h6:focus {
  outline: none;
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}