/* ==========================================================================
   This Day in History - Modern CSS Styles
   ========================================================================== */

/* CSS Custom Properties for Theming */
:root {
  /* Light Theme Colors */
  --color-primary: #3B82F6;
  --color-primary-dark: #2563EB;
  --color-primary-light: #DBEAFE;
  --color-secondary: #6B7280;
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-danger: #EF4444;
  --color-info: #06B6D4;
  
  /* Category Colors */
  --color-events: #3B82F6;
  --color-births: #10B981;
  --color-deaths: #6B7280;
  --color-holidays: #F59E0B;
  
  /* Background Colors */
  --bg-primary: #FFFFFF;
  --bg-secondary: #F8FAFC;
  --bg-tertiary: #F1F5F9;
  --bg-card: #FFFFFF;
  --bg-overlay: rgba(255, 255, 255, 0.95);
  
  /* Text Colors */
  --text-primary: #1F2937;
  --text-secondary: #6B7280;
  --text-muted: #9CA3AF;
  --text-inverse: #FFFFFF;
  
  /* Border Colors */
  --border-primary: #E5E7EB;
  --border-secondary: #D1D5DB;
  --border-focus: #3B82F6;
  
  /* Shadow Definitions */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  
  /* Enhancement Colors */
  --enhancement-primary: #667eea;
  --enhancement-secondary: #764ba2;
  --enhancement-accent: #ffecd2;
  --radius-xl: 1rem;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  /* Transitions */
  --transition-fast: 0.15s ease-in-out;
  --transition-base: 0.2s ease-in-out;
  --transition-slow: 0.3s ease-in-out;
  
  /* Z-index Stack */
  --z-dropdown: 1000;
  --z-modal: 1050;
  --z-tooltip: 1070;
}

/* Dark Theme */
[data-theme="dark"] {
  --bg-primary: #111827;
  --bg-secondary: #1F2937;
  --bg-tertiary: #374151;
  --bg-card: #1F2937;
  --bg-overlay: rgba(31, 41, 55, 0.95);
  
  --text-primary: #F9FAFB;
  --text-secondary: #D1D5DB;
  --text-muted: #9CA3AF;
  
  --border-primary: #374151;
  --border-secondary: #4B5563;
  
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.3);
}

/* ==========================================================================
   Base Styles & Reset
   ========================================================================== */

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

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  transition: background-color var(--transition-base), color var(--transition-base);
  min-height: 100vh;
}

/* Accessibility Improvements */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Focus Styles */
*:focus {
  outline: 2px solid var(--border-focus);
  outline-offset: 2px;
}

*:focus:not(:focus-visible) {
  outline: none;
}

*:focus-visible {
  outline: 2px solid var(--border-focus);
  outline-offset: 2px;
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  html {
    scroll-behavior: auto;
  }
}

/* ==========================================================================
   Layout Components
   ========================================================================== */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

@media (min-width: 640px) {
  .container {
    padding: 0 var(--space-lg);
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--space-xl);
  }
}

/* ==========================================================================
   Header Styles
   ========================================================================== */

.header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-primary);
  position: sticky;
  top: 0;
  z-index: var(--z-dropdown);
  backdrop-filter: blur(10px);
  transition: all var(--transition-base);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg) 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.logo i {
  font-size: var(--font-size-2xl);
  color: var(--color-primary);
}

.logo h1 {
  font-size: clamp(var(--font-size-xl), 4vw, var(--font-size-3xl));
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* Theme Toggle */
.theme-toggle {
  position: relative;
  width: 60px;
  height: 32px;
  background: var(--bg-tertiary);
  border: 2px solid var(--border-primary);
  border-radius: 20px;
  cursor: pointer;
  transition: all var(--transition-base);
  overflow: hidden;
}

.theme-toggle:hover {
  transform: scale(1.05);
  border-color: var(--color-primary);
}

.theme-toggle i {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  font-size: var(--font-size-sm);
  transition: all var(--transition-base);
}

.theme-toggle .fa-sun {
  left: 8px;
  color: var(--color-warning);
  opacity: 1;
}

.theme-toggle .fa-moon {
  right: 8px;
  color: var(--color-info);
  opacity: 0;
}

[data-theme="dark"] .theme-toggle .fa-sun {
  opacity: 0;
}

[data-theme="dark"] .theme-toggle .fa-moon {
  opacity: 1;
}

.theme-toggle::before {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 24px;
  height: 24px;
  background: var(--bg-primary);
  border-radius: 50%;
  transition: transform var(--transition-base);
  box-shadow: var(--shadow-sm);
}

[data-theme="dark"] .theme-toggle::before {
  transform: translateX(28px);
}

/* ==========================================================================
   Main Content Styles
   ========================================================================== */

.main {
  min-height: calc(100vh - 200px);
  padding: var(--space-2xl) 0;
}

/* Date Input Section */
.date-input-section {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.date-input-container {
  max-width: 600px;
  margin: 0 auto;
}

.section-title {
  font-size: clamp(var(--font-size-2xl), 5vw, var(--font-size-4xl));
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
  line-height: 1.2;
}

.section-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  margin-bottom: var(--space-2xl);
  line-height: 1.6;
}

.date-input-wrapper {
  position: relative;
  margin-bottom: var(--space-xl);
}

.date-input {
  width: 100%;
  max-width: 300px;
  padding: var(--space-md) var(--space-lg);
  font-size: var(--font-size-lg);
  font-family: var(--font-family);
  background: var(--bg-card);
  border: 2px solid var(--border-primary);
  border-radius: var(--radius-lg);
  color: var(--text-primary);
  text-align: center;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.date-input:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.date-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
  transform: translateY(-2px);
}

.date-help {
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  margin-top: var(--space-sm);
}

/* Action Buttons */
.action-buttons {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* Button Styles */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-base);
  font-weight: 600;
  font-family: var(--font-family);
  text-decoration: none;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  min-height: 48px; /* Minimum touch target */
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.btn:hover::before {
  left: 100%;
}

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

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

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 2px solid var(--border-primary);
}

.btn-secondary:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ==========================================================================
   Filter Section Styles
   ========================================================================== */

.filter-section {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-lg);
  padding: var(--space-xl);
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  margin-bottom: var(--space-2xl);
  border: 1px solid var(--border-primary);
}

.filter-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--text-primary);
  width: 100%;
  margin-bottom: var(--space-md);
}

@media (min-width: 768px) {
  .filter-title {
    width: auto;
    margin-bottom: 0;
  }
}

.filter-buttons {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.filter-btn {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
}

.filter-btn:hover {
  background: var(--color-primary);
  color: var(--text-inverse);
  transform: translateY(-2px);
}

.filter-btn.active {
  background: var(--color-primary);
  color: var(--text-inverse);
  border-color: var(--color-primary);
}

.view-toggle {
  display: flex;
  gap: var(--space-xs);
}

.view-btn {
  padding: var(--space-sm);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-base);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.view-btn:hover {
  background: var(--color-primary);
  color: var(--text-inverse);
}

.view-btn.active {
  background: var(--color-primary);
  color: var(--text-inverse);
  border-color: var(--color-primary);
}

/* ==========================================================================
   Results Section Styles
   ========================================================================== */

.results-section {
  animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Loading State */
.loading-state {
  text-align: center;
  padding: var(--space-2xl);
}

.loading-spinner {
  margin-bottom: var(--space-lg);
}

.spinner {
  width: 60px;
  height: 60px;
  border: 4px solid var(--border-primary);
  border-top: 4px solid var(--color-primary);
  border-radius: 50%;
  margin: 0 auto;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.loading-text {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* Error State */
.error-state {
  text-align: center;
  padding: var(--space-2xl);
}

.error-icon {
  font-size: var(--font-size-4xl);
  color: var(--color-danger);
  margin-bottom: var(--space-lg);
}

.error-title {
  font-size: var(--font-size-2xl);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
}

.error-message {
  font-size: var(--font-size-base);
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: var(--space-2xl);
}

.empty-icon {
  font-size: var(--font-size-4xl);
  color: var(--text-muted);
  margin-bottom: var(--space-lg);
  opacity: 0.6;
}

.empty-title {
  font-size: var(--font-size-2xl);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
}

.empty-message {
  font-size: var(--font-size-base);
  color: var(--text-secondary);
}

/* Results Header */
.results-content {
  animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--space-lg);
  margin-bottom: var(--space-2xl);
}

.results-title {
  font-size: clamp(var(--font-size-xl), 4vw, var(--font-size-3xl));
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.results-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.results-count {
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
}

.share-buttons {
  display: flex;
  gap: var(--space-xs);
}

.share-btn,
.bookmark-btn {
  padding: var(--space-sm);
  background: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-base);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.share-btn:hover,
.bookmark-btn:hover {
  background: var(--color-primary);
  color: var(--text-inverse);
  transform: translateY(-2px);
}

/* ==========================================================================
   Event Cards Styles
   ========================================================================== */

.events-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-lg);
}

@media (max-width: 639px) {
  .events-grid {
    grid-template-columns: 1fr;
  }
}

.event-card {
  background: var(--bg-card);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-xl);
  padding: var(--space-lg);
  transition: all var(--transition-base);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  animation: cardSlideIn 0.5s ease-out backwards;
}

@keyframes cardSlideIn {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.event-card:nth-child(1) { animation-delay: 0.1s; }
.event-card:nth-child(2) { animation-delay: 0.2s; }
.event-card:nth-child(3) { animation-delay: 0.3s; }
.event-card:nth-child(4) { animation-delay: 0.4s; }
.event-card:nth-child(n+5) { animation-delay: 0.5s; }

.event-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: var(--shadow-xl);
}

.event-card:focus {
  transform: translateY(-4px) scale(1.01);
}

/* Category-specific styling */
.event-card[data-category="events"] {
  border-left: 4px solid var(--color-events);
}

.event-card[data-category="births"] {
  border-left: 4px solid var(--color-births);
}

.event-card[data-category="deaths"] {
  border-left: 4px solid var(--color-deaths);
}

.event-card[data-category="holidays"] {
  border-left: 4px solid var(--color-holidays);
}

.event-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, 
    var(--color-primary), 
    var(--color-success), 
    var(--color-warning), 
    var(--color-info)
  );
  opacity: 0;
  transition: opacity var(--transition-base);
}

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

.event-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-md);
}

.event-category-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-xl);
  transition: all var(--transition-base);
}

.event-card[data-category="events"] .event-category-icon {
  background: rgba(59, 130, 246, 0.1);
  color: var(--color-events);
}

.event-card[data-category="births"] .event-category-icon {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-births);
}

.event-card[data-category="deaths"] .event-category-icon {
  background: rgba(107, 114, 128, 0.1);
  color: var(--color-deaths);
}

.event-card[data-category="holidays"] .event-category-icon {
  background: rgba(245, 158, 11, 0.1);
  color: var(--color-holidays);
}

.event-year {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--text-primary);
  background: var(--bg-secondary);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
}

.event-content {
  margin-bottom: var(--space-lg);
}

.event-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  line-height: 1.3;
}

.event-description {
  font-size: var(--font-size-base);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.event-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.event-category {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--text-muted);
  text-transform: capitalize;
  background: var(--bg-tertiary);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
}

.event-source {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
}

.event-actions {
  display: flex;
  gap: var(--space-xs);
}

.action-btn {
  padding: var(--space-sm);
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-base);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.action-btn:hover {
  background: var(--color-primary);
  color: var(--text-inverse);
  border-color: var(--color-primary);
}

/* ==========================================================================
   Timeline View Styles
   ========================================================================== */

.timeline-view {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline-view::before {
  content: '';
  position: absolute;
  left: 30px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-primary), var(--color-success));
}

@media (max-width: 639px) {
  .timeline-view::before {
    left: 20px;
  }
}

.timeline-item {
  position: relative;
  margin-bottom: var(--space-2xl);
  padding-left: 80px;
  animation: timelineSlideIn 0.6s ease-out backwards;
}

@media (max-width: 639px) {
  .timeline-item {
    padding-left: 60px;
  }
}

@keyframes timelineSlideIn {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.timeline-item:nth-child(1) { animation-delay: 0.1s; }
.timeline-item:nth-child(2) { animation-delay: 0.2s; }
.timeline-item:nth-child(3) { animation-delay: 0.3s; }
.timeline-item:nth-child(4) { animation-delay: 0.4s; }
.timeline-item:nth-child(n+5) { animation-delay: 0.5s; }

.timeline-marker {
  position: absolute;
  left: -50px;
  top: 0;
}

@media (max-width: 639px) {
  .timeline-marker {
    left: -40px;
  }
}

.timeline-icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 3px solid var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-lg);
  color: var(--color-primary);
  box-shadow: var(--shadow-md);
}

@media (max-width: 639px) {
  .timeline-icon {
    width: 40px;
    height: 40px;
    font-size: var(--font-size-base);
  }
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
}

.timeline-content:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-sm);
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.timeline-year {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-primary);
}

.timeline-category {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  text-transform: capitalize;
}

.timeline-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  line-height: 1.3;
}

.timeline-description {
  font-size: var(--font-size-base);
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ==========================================================================
   Footer Styles
   ========================================================================== */

.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-primary);
  margin-top: var(--space-2xl);
  padding: var(--space-2xl) 0;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-lg);
  text-align: center;
}

@media (max-width: 639px) {
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
}

.footer-content p {
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

.footer-links {
  display: flex;
  gap: var(--space-lg);
}

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

.footer-link:hover {
  color: var(--color-primary);
}

/* ==========================================================================
   Responsive Design Enhancements
   ========================================================================== */

@media (max-width: 639px) {
  .action-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }
  
  .filter-section {
    flex-direction: column;
    align-items: stretch;
  }
  
  .filter-buttons {
    justify-content: center;
  }
  
  .results-header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .results-meta {
    width: 100%;
    justify-content: space-between;
  }
}

@media (min-width: 640px) and (max-width: 1023px) {
  .events-grid {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  }
}

@media (min-width: 1024px) {
  .events-grid {
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  }
  
  .event-card {
    padding: var(--space-xl);
  }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */

@media print {
  .header,
  .filter-section,
  .action-buttons,
  .share-buttons,
  .event-actions,
  .footer {
    display: none !important;
  }
  
  body {
    background: white !important;
    color: black !important;
  }
  
  .event-card {
    break-inside: avoid;
    box-shadow: none !important;
    border: 1px solid #ccc !important;
  }
}

/* ==========================================================================
   High Contrast Mode Support
   ========================================================================== */

@media (prefers-contrast: high) {
  :root {
    --shadow-sm: none;
    --shadow-md: none;
    --shadow-lg: none;
    --shadow-xl: none;
  }
  
  .event-card,
  .timeline-content,
  .filter-section {
    border-width: 2px;
  }
  
  .btn-primary {
    background: #000000;
    color: #ffffff;
  }
  
  .btn-secondary {
    background: #ffffff;
    color: #000000;
    border: 2px solid #000000;
  }
}

/* ==========================================================================
   Achievement Notification Styles
   ========================================================================== */

.achievement-notification {
  position: fixed;
  top: 20px;
  right: 20px;
  background: linear-gradient(135deg, var(--enhancement-primary) 0%, var(--enhancement-secondary) 100%);
  color: white;
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-xl);
  display: flex;
  align-items: center;
  gap: 16px;
  max-width: 400px;
  z-index: 9999;
  animation: slideInRight 0.5s ease-out;
}

.achievement-notification .achievement-icon {
  font-size: 2em;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.achievement-notification .achievement-content h4 {
  margin: 0 0 4px 0;
  font-size: 1.1em;
  opacity: 0.9;
}

.achievement-notification .achievement-content h5 {
  margin: 0 0 4px 0;
  font-size: 1.3em;
  font-weight: 700;
}

.achievement-notification .achievement-content p {
  margin: 0;
  opacity: 0.9;
  font-size: 0.9em;
}

.achievement-notification .achievement-close {
  background: none;
  border: none;
  color: white;
  font-size: 1.5em;
  cursor: pointer;
  opacity: 0.8;
  transition: opacity 0.2s;
  margin-left: auto;
}

.achievement-notification .achievement-close:hover {
  opacity: 1;
}

@keyframes slideInRight {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

@media (max-width: 768px) {
  .achievement-notification {
    top: 10px;
    right: 10px;
    left: 10px;
    max-width: none;
  }
}