/**
 * OmniBazaar Design System - Shared Theme CSS
 * 
 * This file provides a unified theme system for HTML mockups that mirrors
 * the TypeScript theme system. It includes:
 * - CSS custom properties for easy theme switching
 * - Light and dark theme support
 * - Component styles consistent with the React implementation
 * - Responsive design utilities
 * - Accessibility features
 */

/* ==================================================
   CSS CUSTOM PROPERTIES (CSS Variables)
   ================================================== */

:root {
  /* Brand Colors - Primary Purple Palette */
  --color-primary-50: #F8F7FF;
  --color-primary-100: #F3F3F9;
  --color-primary-200: #E7E7F3;
  --color-primary-300: #D2D3D7;
  --color-primary-400: #B8B8D9;
  --color-primary-500: #373373;
  --color-primary-600: #4B4881;
  --color-primary-700: #23234F;
  --color-primary-800: #1A1A3A;
  --color-primary-900: #0F0F23;
  
  /* Secondary Colors - Light Blue Accent */
  --color-secondary-50: #F0F9FF;
  --color-secondary-100: #E0F2FE;
  --color-secondary-200: #BAE6FD;
  --color-secondary-300: #7DD3FC;
  --color-secondary-400: #38BDF8;
  --color-secondary-500: #0EA5E9;
  --color-secondary-600: #0284C7;
  --color-secondary-700: #0369A1;
  --color-secondary-800: #075985;
  --color-secondary-900: #0C4A6E;
  
  /* Neutral Grays */
  --color-neutral-50: #FAFAFA;
  --color-neutral-100: #F5F5F5;
  --color-neutral-200: #E5E5E5;
  --color-neutral-300: #D4D4D4;
  --color-neutral-400: #A3A3A3;
  --color-neutral-500: #737373;
  --color-neutral-600: #525252;
  --color-neutral-700: #404040;
  --color-neutral-800: #262626;
  --color-neutral-900: #171717;
  
  /* Text Colors */
  --color-text-primary: #1F2937;
  --color-text-secondary: #6B7280;
  --color-text-muted: #9CA3AF;
  --color-text-disabled: #D1D5DB;
  --color-text-inverse: #FFFFFF;
  --color-text-accent: #374151;
  
  /* Background Colors */
  --color-bg-primary: #F9FAFB;
  --color-bg-secondary: #FFFFFF;
  --color-bg-tertiary: #F3F4F6;
  --color-bg-hover: #F3F3F9;
  --color-bg-active: #EDE9FE;
  --color-bg-input: #FFFFFF;
  --color-bg-disabled: #F9FAFB;
  --color-bg-overlay: rgba(0, 0, 0, 0.5);
  
  /* Border Colors */
  --color-border-light: #F3F4F6;
  --color-border-main: #E5E7EB;
  --color-border-medium: #D1D5DB;
  --color-border-dark: #6B7280;
  --color-border-focus: #8B5CF6;
  
  /* Semantic Colors */
  --color-success-50: #F0FDF4;
  --color-success-100: #DCFCE7;
  --color-success-500: #22C55E;
  --color-success-600: #16A34A;
  --color-success-700: #15803D;
  
  --color-warning-50: #FFFBEB;
  --color-warning-100: #FEF3C7;
  --color-warning-500: #F59E0B;
  --color-warning-600: #D97706;
  --color-warning-700: #B45309;
  
  --color-error-50: #FEF2F2;
  --color-error-100: #FEE2E2;
  --color-error-500: #EF4444;
  --color-error-600: #DC2626;
  --color-error-700: #B91C1C;
  
  --color-info-50: #EFF6FF;
  --color-info-100: #DBEAFE;
  --color-info-500: #3B82F6;
  --color-info-600: #2563EB;
  --color-info-700: #1D4ED8;
  
  /* Feature Colors */
  --color-marketplace-featured: #F59E0B;
  --color-marketplace-premium: #8B5CF6;
  --color-marketplace-sale: #EF4444;
  --color-marketplace-new: #10B981;
  
  --color-crypto-bitcoin: #F7931A;
  --color-crypto-ethereum: #627EEA;
  --color-crypto-omnicoin: #373373;
  --color-crypto-stable: #26A69A;
  
  /* Spacing Scale (8px base grid) */
  --spacing-0: 0;
  --spacing-0-5: 0.2rem;
  --spacing-1: 0.4rem;
  --spacing-1-5: 0.6rem;
  --spacing-2: 0.8rem;
  --spacing-2-5: 1rem;
  --spacing-3: 1.2rem;
  --spacing-3-5: 1.4rem;
  --spacing-4: 1.6rem;
  --spacing-5: 2rem;
  --spacing-6: 2.4rem;
  --spacing-7: 2.8rem;
  --spacing-8: 3.2rem;
  --spacing-9: 3.6rem;
  --spacing-10: 4rem;
  --spacing-11: 4.4rem;
  --spacing-12: 4.8rem;
  --spacing-14: 5.6rem;
  --spacing-16: 6.4rem;
  --spacing-18: 7.2rem;
  --spacing-20: 8rem;
  --spacing-24: 9.6rem;
  --spacing-32: 12.8rem;
  
  /* Typography Scale */
  --font-size-xs: 1.2rem;
  --font-size-sm: 1.4rem;
  --font-size-base: 1.6rem;
  --font-size-md: 1.8rem;
  --font-size-lg: 2rem;
  --font-size-xl: 2.4rem;
  --font-size-2xl: 3rem;
  --font-size-3xl: 3.6rem;
  --font-size-4xl: 4.8rem;
  --font-size-5xl: 6rem;
  --font-size-6xl: 7.2rem;
  
  --font-weight-thin: 100;
  --font-weight-extralight: 200;
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --font-weight-black: 900;
  
  --line-height-none: 1;
  --line-height-tight: 1.25;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  --line-height-loose: 2;
  
  /* Font Families */
  --font-family-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', 'Consolas', 'Liberation Mono', 'Menlo', monospace;
  
  /* Border Radius */
  --radius-none: 0;
  --radius-xs: 0.2rem;
  --radius-sm: 0.4rem;
  --radius-base: 0.6rem;
  --radius-md: 0.8rem;
  --radius-lg: 1.2rem;
  --radius-xl: 1.6rem;
  --radius-2xl: 2.4rem;
  --radius-3xl: 3.2rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-none: none;
  --shadow-xs: 0 0.1rem 0.2rem 0 rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 0.1rem 0.3rem 0 rgba(0, 0, 0, 0.1), 0 0.1rem 0.2rem -0.1rem rgba(0, 0, 0, 0.1);
  --shadow-base: 0 0.4rem 0.6rem -0.1rem rgba(0, 0, 0, 0.1), 0 0.2rem 0.4rem -0.2rem rgba(0, 0, 0, 0.1);
  --shadow-md: 0 0.8rem 1.6rem -0.3rem rgba(0, 0, 0, 0.1), 0 0.4rem 0.6rem -0.4rem rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 1rem 1.5rem -0.3rem rgba(0, 0, 0, 0.1), 0 0.4rem 0.6rem -0.4rem rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 2rem 2.5rem -0.5rem rgba(0, 0, 0, 0.1), 0 0.8rem 1rem -0.6rem rgba(0, 0, 0, 0.1);
  --shadow-2xl: 0 2.5rem 5rem -1.2rem rgba(0, 0, 0, 0.25);
  --shadow-inner: inset 0 0.2rem 0.4rem 0 rgba(0, 0, 0, 0.05);
  --shadow-focus: 0 0 0 0.3rem rgba(139, 92, 246, 0.3);
  --shadow-error: 0 0 0 0.3rem rgba(239, 68, 68, 0.3);
  
  /* Transitions */
  --transition-none: none;
  --transition-all: all 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-default: all 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: all 100ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-colors: color 150ms cubic-bezier(0.4, 0, 0.2, 1), background-color 150ms cubic-bezier(0.4, 0, 0.2, 1), border-color 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-opacity: opacity 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-shadow: box-shadow 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-transform: transform 150ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Breakpoints */
  --breakpoint-xs: 475px;
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
  --breakpoint-2xl: 1536px;
  
  /* Container Max-Widths */
  --container-xs: 47.5rem;
  --container-sm: 64rem;
  --container-md: 76.8rem;
  --container-lg: 102.4rem;
  --container-xl: 128rem;
  --container-2xl: 144rem;
}

/* ==================================================
   DARK THEME OVERRIDES
   ================================================== */

:root.theme-dark,
.theme-dark {
  /* Override colors for dark theme */
  --color-primary-500: #8B5CF6;
  --color-primary-600: #7C3AED;
  --color-primary-700: #6D28D9;
  
  /* Dark theme text colors */
  --color-text-primary: #F9FAFB;
  --color-text-secondary: #D1D5DB;
  --color-text-muted: #9CA3AF;
  --color-text-disabled: #6B7280;
  --color-text-inverse: #111827;
  --color-text-accent: #E5E7EB;
  
  /* Dark theme backgrounds */
  --color-bg-primary: #111827;
  --color-bg-secondary: #1F2937;
  --color-bg-tertiary: #374151;
  --color-bg-hover: rgba(139, 92, 246, 0.1);
  --color-bg-active: rgba(139, 92, 246, 0.2);
  --color-bg-input: #374151;
  --color-bg-disabled: #1F2937;
  --color-bg-overlay: rgba(0, 0, 0, 0.75);
  
  /* Dark theme borders */
  --color-border-light: #374151;
  --color-border-main: #4B5563;
  --color-border-medium: #6B7280;
  --color-border-dark: #9CA3AF;
  
  /* Adjust neutral colors for dark theme */
  --color-neutral-50: #111827;
  --color-neutral-100: #1F2937;
  --color-neutral-200: #374151;
  --color-neutral-300: #4B5563;
  --color-neutral-400: #6B7280;
  --color-neutral-500: #9CA3AF;
  --color-neutral-600: #D1D5DB;
  --color-neutral-700: #E5E7EB;
  --color-neutral-800: #F3F4F6;
  --color-neutral-900: #F9FAFB;
}

/* ==================================================
   BASE STYLES & RESET
   ================================================== */

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

html {
  font-size: 10px; /* 1rem = 10px for easier calculations */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
  transition: var(--transition-colors);
}

/* ==================================================
   TYPOGRAPHY STYLES
   ================================================== */

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
}

h1 { font-size: var(--font-size-4xl); font-weight: var(--font-weight-extrabold); }
h2 { font-size: var(--font-size-3xl); font-weight: var(--font-weight-bold); }
h3 { font-size: var(--font-size-2xl); font-weight: var(--font-weight-bold); }
h4 { font-size: var(--font-size-xl); font-weight: var(--font-weight-semibold); }
h5 { font-size: var(--font-size-lg); font-weight: var(--font-weight-semibold); }
h6 { font-size: var(--font-size-base); font-weight: var(--font-weight-semibold); }

p {
  margin-bottom: var(--spacing-4);
  line-height: var(--line-height-relaxed);
}

a {
  color: var(--color-primary-500);
  text-decoration: none;
  transition: var(--transition-colors);
}

a:hover {
  color: var(--color-primary-600);
  text-decoration: underline;
}

a:focus {
  outline: none;
  box-shadow: var(--shadow-focus);
  border-radius: var(--radius-xs);
}

/* ==================================================
   COMPONENT STYLES
   ================================================== */

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font-family-sans);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition-colors);
  user-select: none;
  white-space: nowrap;
}

.btn:focus {
  outline: none;
  box-shadow: var(--shadow-focus);
}

.btn:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

/* Button sizes */
.btn-xs {
  height: 2.4rem;
  padding: 0 var(--spacing-2);
  font-size: var(--font-size-xs);
}

.btn-sm {
  height: 3.2rem;
  padding: 0 var(--spacing-3);
  font-size: var(--font-size-sm);
}

.btn-md {
  height: 4rem;
  padding: 0 var(--spacing-4);
  font-size: var(--font-size-base);
}

.btn-lg {
  height: 4.8rem;
  padding: 0 var(--spacing-5);
  font-size: var(--font-size-lg);
}

/* Button variants */
.btn-primary {
  background-color: var(--color-primary-500);
  color: var(--color-text-inverse);
}

.btn-primary:hover {
  background-color: var(--color-primary-600);
}

.btn-primary:active {
  background-color: var(--color-primary-700);
}

.btn-secondary {
  background-color: var(--color-bg-secondary);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border-main);
}

.btn-secondary:hover {
  background-color: var(--color-bg-hover);
  border-color: var(--color-primary-500);
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-text-primary);
}

.btn-ghost:hover {
  background-color: var(--color-bg-hover);
}

/* Form Elements */
.input {
  width: 100%;
  border: 1px solid var(--color-border-main);
  border-radius: var(--radius-sm);
  background-color: var(--color-bg-input);
  color: var(--color-text-primary);
  font-family: var(--font-family-sans);
  transition: var(--transition-colors);
}

.input:focus {
  outline: none;
  border-color: var(--color-border-focus);
  box-shadow: var(--shadow-focus);
}

.input:disabled {
  background-color: var(--color-bg-disabled);
  color: var(--color-text-disabled);
  cursor: not-allowed;
}

.input-xs {
  height: 2.4rem;
  padding: 0 var(--spacing-2);
  font-size: var(--font-size-xs);
}

.input-sm {
  height: 3.2rem;
  padding: 0 var(--spacing-3);
  font-size: var(--font-size-sm);
}

.input-md {
  height: 4rem;
  padding: 0 var(--spacing-3);
  font-size: var(--font-size-base);
}

.input-lg {
  height: 4.8rem;
  padding: 0 var(--spacing-4);
  font-size: var(--font-size-lg);
}

/* Cards */
.card {
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border-main);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: var(--transition-all);
}

.card:hover {
  transform: translateY(-0.2rem);
  box-shadow: var(--shadow-md);
}

.card-body {
  padding: var(--spacing-6);
}

.card-header {
  padding: var(--spacing-4) var(--spacing-6);
  border-bottom: 1px solid var(--color-border-light);
}

.card-footer {
  padding: var(--spacing-4) var(--spacing-6);
  border-top: 1px solid var(--color-border-light);
  background-color: var(--color-bg-tertiary);
}

/* Header and Navigation */
.header {
  background-color: var(--color-bg-secondary);
  border-top: 0.5rem solid var(--color-primary-500);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: var(--transition-colors);
}

.header-container {
  max-width: var(--container-2xl);
  margin: 0 auto;
  padding: 0 var(--spacing-5);
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: var(--spacing-16);
}

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-extrabold);
  color: var(--color-primary-500);
  text-decoration: none;
  transition: var(--transition-colors);
}

.header-brand:hover {
  color: var(--color-primary-600);
  text-decoration: none;
}

.header-logo {
  height: 3.2rem;
  width: auto;
}

.header-nav {
  display: flex;
  gap: var(--spacing-8);
  align-items: center;
}

.header-nav-link {
  color: var(--color-text-primary);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
  transition: var(--transition-colors);
  padding: var(--spacing-2) 0;
  border-radius: var(--radius-xs);
}

.header-nav-link:hover {
  color: var(--color-primary-500);
  text-decoration: underline;
}

.header-nav-link.active {
  color: var(--color-primary-500);
  font-weight: var(--font-weight-semibold);
}

.header-nav-link:focus {
  outline: none;
  box-shadow: var(--shadow-focus);
}

.header-actions {
  display: flex;
  gap: var(--spacing-4);
  align-items: center;
}

.header-search {
  position: relative;
  display: flex;
  align-items: center;
}

.header-search-input {
  width: 28rem;
  padding: var(--spacing-2) var(--spacing-3);
  padding-right: var(--spacing-10);
  border: 1px solid var(--color-border-main);
  border-radius: var(--radius-md);
  background: var(--color-bg-input);
  font-size: var(--font-size-sm);
  transition: var(--transition-colors);
}

.header-search-input:focus {
  outline: none;
  border-color: var(--color-border-focus);
  box-shadow: var(--shadow-focus);
}

.header-search-btn {
  position: absolute;
  right: var(--spacing-2);
  padding: var(--spacing-1);
  background: none;
  border: none;
  color: var(--color-text-secondary);
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: var(--transition-colors);
}

.header-search-btn:hover {
  color: var(--color-primary-500);
  background: var(--color-bg-hover);
}

.header-user-menu {
  position: relative;
}

.header-user-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-3);
  background: none;
  border: 1px solid var(--color-border-main);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  cursor: pointer;
  transition: var(--transition-colors);
}

.header-user-btn:hover {
  background: var(--color-bg-hover);
  border-color: var(--color-primary-500);
}

.header-notification {
  position: relative;
}

.header-notification-badge {
  position: absolute;
  top: -var(--spacing-1);
  right: -var(--spacing-1);
  background: var(--color-error-500);
  color: var(--color-text-inverse);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-bold);
  padding: var(--spacing-0-5) var(--spacing-1);
  border-radius: var(--radius-full);
  min-width: 1.6rem;
  text-align: center;
  line-height: 1;
}

/* Theme Switch Integration in Header */
.header-theme-switch {
  width: 3.6rem;
  height: 3.6rem;
  background: var(--color-bg-input);
  border: 1px solid var(--color-border-main);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: var(--font-size-lg);
  transition: var(--transition-all);
}

.header-theme-switch:hover {
  background: var(--color-bg-hover);
  border-color: var(--color-primary-500);
  transform: scale(1.05);
}

/* Footer */
.footer {
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border-light);
  padding: var(--spacing-12) var(--spacing-5) var(--spacing-8);
  margin-top: var(--spacing-16);
  transition: var(--transition-colors);
}

.footer-container {
  max-width: var(--container-2xl);
  margin: 0 auto;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(25rem, 1fr));
  gap: var(--spacing-8);
  margin-bottom: var(--spacing-8);
}

.footer-section h3 {
  color: var(--color-text-primary);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-4);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.footer-link {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--font-size-sm);
  transition: var(--transition-colors);
}

.footer-link:hover {
  color: var(--color-primary-500);
  text-decoration: underline;
}

.footer-newsletter {
  display: flex;
  gap: var(--spacing-2);
  margin-top: var(--spacing-4);
}

.footer-newsletter-input {
  flex: 1;
  padding: var(--spacing-2) var(--spacing-3);
  border: 1px solid var(--color-border-main);
  border-radius: var(--radius-sm);
  background: var(--color-bg-input);
  font-size: var(--font-size-sm);
}

.footer-newsletter-btn {
  padding: var(--spacing-2) var(--spacing-4);
  background: var(--color-primary-500);
  color: var(--color-text-inverse);
  border: none;
  border-radius: var(--radius-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: var(--transition-colors);
}

.footer-newsletter-btn:hover {
  background: var(--color-primary-600);
}

.footer-social {
  display: flex;
  gap: var(--spacing-3);
  margin-top: var(--spacing-4);
}

.footer-social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 3.6rem;
  height: 3.6rem;
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--font-size-lg);
  transition: var(--transition-all);
}

.footer-social-link:hover {
  background: var(--color-primary-500);
  color: var(--color-text-inverse);
  transform: translateY(-0.2rem);
}

.footer-bottom {
  border-top: 1px solid var(--color-border-light);
  padding-top: var(--spacing-6);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-4);
}

.footer-copyright {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.footer-bottom-links {
  display: flex;
  gap: var(--spacing-6);
}

.footer-bottom-link {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--font-size-sm);
  transition: var(--transition-colors);
}

.footer-bottom-link:hover {
  color: var(--color-primary-500);
  text-decoration: underline;
}

/* Mobile responsive header */
@media (max-width: 768px) {
  .header-container {
    padding: 0 var(--spacing-4);
    min-height: var(--spacing-14);
  }
  
  .header-brand {
    font-size: var(--font-size-lg);
  }
  
  .header-logo {
    height: 2.8rem;
  }
  
  .header-nav {
    display: none;
  }
  
  .header-search-input {
    width: 20rem;
  }
  
  .header-actions {
    gap: var(--spacing-2);
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-6);
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-bottom-links {
    flex-wrap: wrap;
    justify-content: center;
  }
}

/* Layout Utilities */
.container {
  max-width: var(--container-2xl);
  margin: 0 auto;
  padding: 0 var(--spacing-5);
}

.container-sm { max-width: var(--container-sm); }
.container-md { max-width: var(--container-md); }
.container-lg { max-width: var(--container-lg); }
.container-xl { max-width: var(--container-xl); }

/* Grid System */
.grid {
  display: grid;
  gap: var(--spacing-6);
}

.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.grid-auto-fit { grid-template-columns: repeat(auto-fit, minmax(28rem, 1fr)); }
.grid-auto-fill { grid-template-columns: repeat(auto-fill, minmax(28rem, 1fr)); }

/* Flex Utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }
.gap-2 { gap: var(--spacing-2); }
.gap-4 { gap: var(--spacing-4); }
.gap-6 { gap: var(--spacing-6); }

/* Spacing Utilities */
.p-0 { padding: var(--spacing-0); }
.p-2 { padding: var(--spacing-2); }
.p-4 { padding: var(--spacing-4); }
.p-6 { padding: var(--spacing-6); }
.p-8 { padding: var(--spacing-8); }

.m-0 { margin: var(--spacing-0); }
.m-2 { margin: var(--spacing-2); }
.m-4 { margin: var(--spacing-4); }
.m-6 { margin: var(--spacing-6); }
.m-8 { margin: var(--spacing-8); }

.mb-4 { margin-bottom: var(--spacing-4); }
.mb-6 { margin-bottom: var(--spacing-6); }
.mb-8 { margin-bottom: var(--spacing-8); }

/* Text Utilities */
.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-base { font-size: var(--font-size-base); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-2xl { font-size: var(--font-size-2xl); }
.text-3xl { font-size: var(--font-size-3xl); }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--color-text-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-muted { color: var(--color-text-muted); }
.text-accent { color: var(--color-primary-500); }

.font-normal { font-weight: var(--font-weight-normal); }
.font-medium { font-weight: var(--font-weight-medium); }
.font-semibold { font-weight: var(--font-weight-semibold); }
.font-bold { font-weight: var(--font-weight-bold); }
.font-extrabold { font-weight: var(--font-weight-extrabold); }

/* Border Utilities */
.border { border: 1px solid var(--color-border-main); }
.border-light { border: 1px solid var(--color-border-light); }
.border-medium { border: 1px solid var(--color-border-medium); }

.rounded { border-radius: var(--radius-base); }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-full { border-radius: var(--radius-full); }

/* Shadow Utilities */
.shadow-none { box-shadow: var(--shadow-none); }
.shadow-xs { box-shadow: var(--shadow-xs); }
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-base { box-shadow: var(--shadow-base); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }

/* Background Utilities */
.bg-primary { background-color: var(--color-bg-primary); }
.bg-secondary { background-color: var(--color-bg-secondary); }
.bg-tertiary { background-color: var(--color-bg-tertiary); }

/* Theme Switch Component */
.theme-switch {
  position: fixed;
  top: var(--spacing-4);
  right: var(--spacing-4);
  width: 4rem;
  height: 4rem;
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border-main);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: var(--font-size-xl);
  transition: var(--transition-all);
  z-index: 1000;
}

.theme-switch:hover {
  background-color: var(--color-bg-hover);
  transform: scale(1.05);
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .grid-auto-fit {
    grid-template-columns: 1fr;
  }
  
  .container {
    padding: 0 var(--spacing-4);
  }
  
  h1 { font-size: var(--font-size-2xl); }
  h2 { font-size: var(--font-size-xl); }
  h3 { font-size: var(--font-size-lg); }
}

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

/* Focus styles for better accessibility */
*:focus-visible {
  outline: 2px solid var(--color-border-focus);
  outline-offset: 2px;
}

/* Print styles */
@media print {
  .theme-switch,
  .nav-header {
    display: none;
  }
  
  body {
    background: white;
    color: black;
  }
  
  a {
    color: black;
    text-decoration: underline;
  }
}