/* ==========================================================================
   Modern Blog Base CSS - Complete Redesign
   ========================================================================== */

/* CSS Custom Properties (Variables) */
:root {
  /* Typography - Inter Font System */
  --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-weight-light: 300;
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --line-height-tight: 1.2;
  --line-height-base: 1.6;
  --line-height-relaxed: 1.8;
  
  /* Modern Color Palette - Light Theme */
  --color-primary: #0066FF;
  --color-primary-light: #3385FF;
  --color-primary-dark: #0052CC;
  --color-secondary: #00D4FF;
  --color-accent: #FF6B6B;
  
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #FFFFFF;
  --color-bg-tertiary: #F1F5F9;
  --color-bg-elevated: #FFFFFF;
  
  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-tertiary: #64748B;
  --color-text-muted: #94A3B8;
  
  --color-border-light: #E2E8F0;
  --color-border-medium: #CBD5E1;
  --color-border-strong: #94A3B8;
  
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  --color-info: #3B82F6;
  
  /* Spacing Scale */
  --spacing-0: 0;
  --spacing-1: 0.25rem;   /* 4px */
  --spacing-2: 0.5rem;    /* 8px */
  --spacing-3: 0.75rem;   /* 12px */
  --spacing-4: 1rem;      /* 16px */
  --spacing-5: 1.25rem;   /* 20px */
  --spacing-6: 1.5rem;    /* 24px */
  --spacing-8: 2rem;      /* 32px */
  --spacing-10: 2.5rem;   /* 40px */
  --spacing-12: 3rem;     /* 48px */
  --spacing-16: 4rem;     /* 64px */
  --spacing-20: 5rem;     /* 80px */
  --spacing-24: 6rem;     /* 96px */
  
  /* Layout */
  --container-max-width: 1280px;
  --content-max-width: 768px;
  --sidebar-width: 320px;
  --header-height: 80px;
  
  /* Border Radius */
  --radius-none: 0;
  --radius-sm: 0.375rem;   /* 6px */
  --radius-md: 0.5rem;     /* 8px */
  --radius-lg: 0.75rem;    /* 12px */
  --radius-xl: 1rem;       /* 16px */
  --radius-2xl: 1.5rem;    /* 24px */
  --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);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-medium: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Z-Index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
  --z-toast: 1080;
}

/* Dark Theme */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg-primary: #FFFFFF;
    --color-bg-secondary: #F8FAFC;
    --color-bg-tertiary: #F1F5F9;
    --color-bg-elevated: #FFFFFF;
    
    --color-text-primary: #111827;
    --color-text-secondary: #374151;
    --color-text-tertiary: #6B7280;
    --color-text-muted: #9CA3AF;
    
    --color-border-light: #E5E7EB;
    --color-border-medium: #D1D5DB;
    --color-border-strong: #9CA3AF;
  }
}

/* Manual Dark Theme Override */
[data-theme="dark"] {
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F8FAFC;
  --color-bg-tertiary: #F1F5F9;
  --color-bg-elevated: #FFFFFF;
  
  --color-text-primary: #111827;
  --color-text-secondary: #374151;
  --color-text-tertiary: #6B7280;
  --color-text-muted: #9CA3AF;
  
  --color-border-light: #E5E7EB;
  --color-border-medium: #D1D5DB;
  --color-border-strong: #9CA3AF;
}

/* Manual Light Theme Override */
[data-theme="light"] {
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F8FAFC;
  --color-bg-tertiary: #F1F5F9;
  --color-bg-elevated: #FFFFFF;
  
  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-tertiary: #64748B;
  --color-text-muted: #94A3B8;
  
  --color-border-light: #E2E8F0;
  --color-border-medium: #CBD5E1;
  --color-border-strong: #94A3B8;
}

/* Reset and Base Styles */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family-primary);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-base);
  color: var(--color-text-primary);
  background-color: var(--color-bg-secondary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-medium), color var(--transition-medium);
  overflow-x: hidden;
  
  /* Hide scrollbar for all browsers */
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none; /* Internet Explorer 10+ */
}

/* Hide scrollbar for WebKit browsers (Chrome, Safari, Edge) */
body::-webkit-scrollbar {
  display: none;
}

/* Global Scrollbar Hiding */
html {
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none; /* Internet Explorer 10+ */
}

html::-webkit-scrollbar {
  display: none; /* WebKit browsers */
}

/* Universal scrollbar hiding for all elements */
* {
  scrollbar-width: none; /* Firefox */
  -ms-overflow-style: none; /* Internet Explorer 10+ */
}

*::-webkit-scrollbar {
  display: none; /* WebKit browsers */
}

/* Typography System */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-4);
  letter-spacing: -0.025em;
}

h1 { 
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: var(--font-weight-extrabold);
  letter-spacing: -0.05em;
}

h2 { 
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: var(--font-weight-bold);
}

h3 { 
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: var(--font-weight-semibold);
}

h4 { 
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
  font-weight: var(--font-weight-semibold);
}

h5 { 
  font-size: clamp(1.125rem, 2vw, 1.25rem);
  font-weight: var(--font-weight-medium);
}

h6 { 
  font-size: 1rem;
  font-weight: var(--font-weight-medium);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

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

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

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

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

/* Layout Components */
.content-container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

@media (max-width: 768px) {
  .content-container {
    padding: 0 var(--spacing-4);
  }
}

/* Modern Card Component */
.modern-card {
  background: var(--color-bg-elevated);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border-light);
  overflow: hidden;
  transition: all var(--transition-medium);
  position: relative;
}

.modern-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-border-medium);
}

.modern-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.modern-card:hover::before {
  opacity: 1;
}

/* Button System */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-6);
  border: none;
  border-radius: var(--radius-lg);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  background: linear-gradient(135deg, var(--color-primary-dark), var(--color-primary));
}

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

.btn-secondary:hover {
  background: var(--color-bg-tertiary);
  border-color: var(--color-border-strong);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border: 1px solid transparent;
}

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

/* Form Elements */
input, textarea, select {
  font-family: inherit;
  font-size: 1rem;
  padding: var(--spacing-3) var(--spacing-4);
  border: 1px solid var(--color-border-medium);
  border-radius: var(--radius-lg);
  background: var(--color-bg-elevated);
  color: var(--color-text-primary);
  transition: all var(--transition-fast);
  width: 100%;
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
  background: var(--color-bg-primary);
}

input::placeholder, textarea::placeholder {
  color: var(--color-text-muted);
}

/* Skip Link for Accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: var(--spacing-4);
  background: var(--color-primary);
  color: white;
  padding: var(--spacing-2) var(--spacing-4);
  text-decoration: none;
  border-radius: var(--radius-md);
  z-index: var(--z-tooltip);
  transition: top var(--transition-medium);
  font-weight: var(--font-weight-medium);
}

.skip-link:focus {
  top: var(--spacing-4);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

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

.bg-primary { background-color: var(--color-bg-primary); }
.bg-secondary { background-color: var(--color-bg-secondary); }
.bg-tertiary { background-color: var(--color-bg-tertiary); }

/* Spacing Utilities */
.m-0 { margin: 0; }
.m-1 { margin: var(--spacing-1); }
.m-2 { margin: var(--spacing-2); }
.m-3 { margin: var(--spacing-3); }
.m-4 { margin: var(--spacing-4); }
.m-5 { margin: var(--spacing-5); }
.m-6 { margin: var(--spacing-6); }
.m-8 { margin: var(--spacing-8); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-1); }
.mb-2 { margin-bottom: var(--spacing-2); }
.mb-3 { margin-bottom: var(--spacing-3); }
.mb-4 { margin-bottom: var(--spacing-4); }
.mb-5 { margin-bottom: var(--spacing-5); }
.mb-6 { margin-bottom: var(--spacing-6); }
.mb-8 { margin-bottom: var(--spacing-8); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-1); }
.mt-2 { margin-top: var(--spacing-2); }
.mt-3 { margin-top: var(--spacing-3); }
.mt-4 { margin-top: var(--spacing-4); }
.mt-5 { margin-top: var(--spacing-5); }
.mt-6 { margin-top: var(--spacing-6); }
.mt-8 { margin-top: var(--spacing-8); }

/* Responsive Utilities */
@media (max-width: 640px) {
  .sm\:hidden { display: none; }
  .sm\:block { display: block; }
  .sm\:flex { display: flex; }
}

@media (max-width: 768px) {
  .md\:hidden { display: none; }
  .md\:block { display: block; }
  .md\:flex { display: flex; }
}

@media (max-width: 1024px) {
  .lg\:hidden { display: none; }
  .lg\:block { display: block; }
  .lg\:flex { display: flex; }
}

/* 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 keyboard navigation */
.keyboard-navigation *:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Print Styles */
@media print {
  * {
    background: transparent !important;
    color: black !important;
    box-shadow: none !important;
    text-shadow: none !important;
  }
  
  .skip-link,
  .theme-toggle,
  .mobile-menu-toggle,
  .scroll-to-top {
    display: none !important;
  }
  
  .modern-card {
    border: 1px solid #ccc !important;
    box-shadow: none !important;
  }
}

/* ==========================================================================
   Base CSS - Apple Style Design System
   ========================================================================== */

/* CSS Custom Properties (Variables) */
:root {
  /* Typography */
  --font-family-primary: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --line-height-base: 1.6;
  --line-height-heading: 1.2;
  
  /* Light Theme Colors */
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F9FAFB;
  --color-text-primary: #111827;
  --color-text-secondary: #6B7280;
  --color-accent: #0A84FF;
  --color-border: rgba(0, 0, 0, 0.06);
  --color-shadow: rgba(0, 0, 0, 0.06);
  
  /* Spacing */
  --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 */
  
  /* Layout */
  --container-max-width: 1240px;
  --content-max-width: 740px;
  --grid-gap: 24px;
  
  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  
  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.08);
  
  /* Transitions */
  --transition-fast: 180ms ease;
  --transition-medium: 300ms ease;
}

/* Dark Theme */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg-primary: #FFFFFF;
    --color-bg-secondary: #F9FAFB;
    --color-text-primary: #111827;
    --color-text-secondary: #6B7280;
    --color-accent: #64D2FF;
    --color-border: rgba(0, 0, 0, 0.06);
    --color-shadow: rgba(0, 0, 0, 0.3);
  }
}

/* Manual Dark Theme Override */
[data-theme="dark"] {
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F9FAFB;
  --color-text-primary: #111827;
  --color-text-secondary: #6B7280;
  --color-accent: #64D2FF;
  --color-border: rgba(0, 0, 0, 0.06);
  --color-shadow: rgba(0, 0, 0, 0.3);
}

/* Manual Light Theme Override */
[data-theme="light"] {
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F9FAFB;
  --color-text-primary: #111827;
  --color-text-secondary: #6B7280;
  --color-accent: #0A84FF;
  --color-border: rgba(0, 0, 0, 0.06);
  --color-shadow: rgba(0, 0, 0, 0.06);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family-primary);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-base);
  color: var(--color-text-primary);
  background-color: var(--color-bg-secondary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-medium), color var(--transition-medium);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--spacing-md) 0;
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-heading);
  color: var(--color-text-primary);
}

h1 { font-size: 2.5rem; font-weight: var(--font-weight-bold); }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin: 0 0 var(--spacing-md) 0;
  color: var(--color-text-primary);
}

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

a:hover {
  opacity: 0.8;
}

/* Layout Components */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }
}

/* Card Component */
.card {
  background: var(--color-bg-primary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--color-accent);
  color: white;
}

.btn:hover {
  transform: translateY(-1px);
  opacity: 0.9;
}

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

/* Theme Toggle Button */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  background: var(--color-bg-primary);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-right: var(--spacing-lg);
}

.theme-toggle:hover {
  background: var(--color-bg-secondary);
  color: var(--color-text-primary);
  transform: scale(1.05);
}

.theme-toggle:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Form Elements */
input, textarea, select {
  font-family: inherit;
  font-size: 1rem;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast);
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--color-accent);
}

/* Skip Link for Accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--color-accent);
  color: white;
  padding: var(--spacing-sm);
  text-decoration: none;
  border-radius: var(--radius-sm);
  z-index: 1000;
  transition: top var(--transition-medium);
}

.skip-link:focus {
  top: 6px;
}

/* Keyboard Navigation Styles */
.keyboard-navigation *:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

/* 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 accessibility */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Print Styles */
@media print {
  * {
    background: transparent !important;
    color: black !important;
    box-shadow: none !important;
    text-shadow: none !important;
  }
  
  .theme-toggle,
  .skip-link {
    display: none !important;
  }
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family-primary);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-base);
  color: var(--color-text-primary);
  background-color: var(--color-bg-secondary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--spacing-md) 0;
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-heading);
  color: var(--color-text-primary);
}

h1 { font-size: 2.5rem; font-weight: var(--font-weight-bold); }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin: 0 0 var(--spacing-md) 0;
  color: var(--color-text-primary);
}

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

a:hover {
  opacity: 0.8;
}

/* Layout Components */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }
}

/* Card Component */
.card {
  background: var(--color-bg-primary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--color-accent);
  color: white;
}

.btn:hover {
  transform: translateY(-1px);
  opacity: 0.9;
}

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

/* Form Elements */
input, textarea, select {
  font-family: inherit;
  font-size: 1rem;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast);
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--color-accent);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

/* 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 accessibility */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}