/* Humor Memory Game - Main Styles */
/* A fun, responsive design for the DevOps learning game */

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

:root {
  /* Color Palette */
  --primary-color: #6366f1;
  --primary-light: #818cf8;
  --primary-dark: #4f46e5;
  --secondary-color: #f59e0b;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --info-color: #3b82f6;

  /* Neutral Colors */
  --white: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  /* Game Colors */
  --card-bg: var(--white);
  --card-back: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --card-hover: #f0f9ff;
  --card-matched: #dcfce7;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1);

  /* Typography */
  --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, 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;

  /* Spacing */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;

  /* Border Radius */
  --radius-sm: 0.125rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;
  --radius-full: 9999px;

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

  /* Z-Index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal: 1040;
  --z-popover: 1050;
  --z-tooltip: 1060;
}

/* ========================================
     RESET AND BASE STYLES
     ======================================== */

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

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

html {
  font-family: var(--font-family);
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--gray-800);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ========================================
     LOADING SCREEN
     ======================================== */

.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
}

.loading-content {
  text-align: center;
  color: var(--white);
  max-width: 400px;
  padding: var(--spacing-6);
}

.loading-spinner {
  font-size: var(--font-size-4xl);
  animation: bounce 1s infinite;
  margin-bottom: var(--spacing-4);
}

@keyframes bounce {
  0%,
  20%,
  53%,
  80%,
  100% {
    transform: translate3d(0, 0, 0);
  }
  40%,
  43% {
    transform: translate3d(0, -30px, 0);
  }
  70% {
    transform: translate3d(0, -15px, 0);
  }
  90% {
    transform: translate3d(0, -4px, 0);
  }
}

.loading-bar {
  width: 100%;
  height: 4px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: var(--spacing-4);
}

.loading-progress {
  height: 100%;
  background: var(--white);
  border-radius: var(--radius-full);
  animation: loadingProgress 2s ease-in-out infinite;
}

@keyframes loadingProgress {
  0% {
    width: 0%;
  }
  50% {
    width: 70%;
  }
  100% {
    width: 100%;
  }
}

/* ========================================
     MAIN GAME CONTAINER
     ======================================== */

.game-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-4);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ========================================
     HEADER AND NAVIGATION
     ======================================== */

.game-header {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: var(--spacing-6);
  margin-bottom: var(--spacing-6);
  box-shadow: var(--card-shadow);
  text-align: center;
}

.game-title {
  font-size: var(--font-size-3xl);
  font-weight: bold;
  color: var(--primary-color);
  margin-bottom: var(--spacing-2);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-3);
}

.title-emoji {
  font-size: var(--font-size-4xl);
  animation: wiggle 2s ease-in-out infinite;
}

@keyframes wiggle {
  0%,
  7% {
    transform: rotateZ(0);
  }
  15% {
    transform: rotateZ(-15deg);
  }
  20% {
    transform: rotateZ(10deg);
  }
  25% {
    transform: rotateZ(-10deg);
  }
  30% {
    transform: rotateZ(6deg);
  }
  35% {
    transform: rotateZ(-4deg);
  }
  40%,
  100% {
    transform: rotateZ(0);
  }
}

.game-subtitle {
  font-size: var(--font-size-lg);
  color: var(--gray-600);
  margin-bottom: var(--spacing-6);
}

.game-nav {
  display: flex;
  gap: var(--spacing-2);
  justify-content: center;
  flex-wrap: wrap;
}

.nav-btn {
  background: var(--gray-100);
  border: none;
  padding: var(--spacing-3) var(--spacing-5);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  color: var(--gray-700);
}

.nav-btn:hover {
  background: var(--gray-200);
  transform: translateY(-1px);
}

.nav-btn.active {
  background: var(--primary-color);
  color: var(--white);
  box-shadow: var(--card-shadow);
}

/* ========================================
     TAB CONTENT
     ======================================== */

.tab-content {
  display: none;
  flex: 1;
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: var(--spacing-6);
  box-shadow: var(--card-shadow);
  margin-bottom: var(--spacing-6);
}

.tab-content.active {
  display: block;
}

/* ========================================
     USER SETUP
     ======================================== */

.user-setup {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 400px;
}

.setup-card {
  background: var(--gray-50);
  border-radius: var(--radius-xl);
  padding: var(--spacing-8);
  max-width: 500px;
  width: 100%;
  text-align: center;
  box-shadow: var(--card-shadow);
}

.setup-card h2 {
  font-size: var(--font-size-2xl);
  color: var(--primary-color);
  margin-bottom: var(--spacing-4);
}

.setup-card p {
  color: var(--gray-600);
  margin-bottom: var(--spacing-6);
}

.input-group {
  margin-bottom: var(--spacing-5);
  text-align: left;
}

.input-group label {
  display: block;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: var(--spacing-2);
}

.input-group input,
.input-group select {
  width: 100%;
  padding: var(--spacing-3);
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-base);
  transition: border-color var(--transition-fast);
}

.input-group input:focus,
.input-group select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.category-selector {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: var(--spacing-2);
  margin-top: var(--spacing-2);
}

.category-option {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  cursor: pointer;
  padding: var(--spacing-2);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.category-option:hover {
  background: var(--gray-100);
}

.category-option input[type='checkbox'] {
  width: auto;
  margin: 0;
}

/* ========================================
     BUTTONS
     ======================================== */

.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-size: var(--font-size-base);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  min-height: 44px; /* Touch target size */
}

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

.btn-primary {
  background: var(--primary-color);
  color: var(--white);
  box-shadow: var(--card-shadow);
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--card-shadow-hover);
}

.btn-secondary {
  background: var(--gray-200);
  color: var(--gray-700);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--gray-300);
  transform: translateY(-1px);
}

.btn-danger {
  background: var(--error-color);
  color: var(--white);
}

.btn-danger:hover:not(:disabled) {
  background: #dc2626;
  transform: translateY(-1px);
}

/* ========================================
     GAME BOARD
     ======================================== */

.game-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-6);
  padding: var(--spacing-4);
  background: var(--gray-50);
  border-radius: var(--radius-lg);
}

.info-item {
  text-align: center;
}

.info-label {
  display: block;
  font-size: var(--font-size-sm);
  color: var(--gray-600);
  margin-bottom: var(--spacing-1);
}

.info-value {
  font-size: var(--font-size-lg);
  font-weight: bold;
  color: var(--primary-color);
}

.info-separator {
  color: var(--gray-400);
  margin: 0 var(--spacing-1);
}

/* ========================================
     CARDS GRID
     ======================================== */

.cards-grid {
  display: grid;
  gap: var(--spacing-3);
  margin-bottom: var(--spacing-6);
  justify-content: center;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

/* Dynamic grid layouts based on difficulty */
.cards-grid.easy {
  grid-template-columns: repeat(4, 1fr);
}

.cards-grid.medium {
  grid-template-columns: repeat(5, 1fr);
}

.cards-grid.hard {
  grid-template-columns: repeat(6, 1fr);
}

.cards-grid.expert {
  grid-template-columns: repeat(6, 1fr);
}

/* ========================================
     MEMORY CARDS
     ======================================== */

.memory-card {
  aspect-ratio: 1;
  min-height: 80px;
  max-height: 120px;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  transform-style: preserve-3d;
  position: relative;
  box-shadow: var(--card-shadow);
}

.memory-card:hover:not(.flipped):not(.matched) {
  transform: translateY(-2px) scale(1.02);
  box-shadow: var(--card-shadow-hover);
}

.memory-card.flipped {
  transform: rotateY(180deg);
}

.memory-card.flipping {
  pointer-events: none;
  cursor: wait;
}

.memory-card.matched {
  transform: scale(0.95);
  opacity: 0.8;
  cursor: default;
}

.memory-card.shake {
  animation: shake 0.5s ease-in-out;
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-5px);
  }
  75% {
    transform: translateX(5px);
  }
}

.card-face {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(1.5rem, 4vw, 3rem);
  border: 2px solid var(--gray-200);
}

.card-back {
  background: var(--card-back);
  color: var(--white);
  font-weight: bold;
}

.card-front {
  background: var(--card-bg);
  color: var(--gray-800);
  transform: rotateY(180deg);
  border-color: var(--primary-color);
}

.card-front.matched {
  background: var(--card-matched);
  border-color: var(--success-color);
}

/* ========================================
     GAME CONTROLS
     ======================================== */

.game-controls {
  display: flex;
  gap: var(--spacing-3);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: var(--spacing-6);
}

/* ========================================
     GAME MESSAGE
     ======================================== */

.game-message {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: var(--z-popover);
  pointer-events: none;
}

.message-content {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: var(--spacing-6);
  box-shadow: var(--card-shadow-hover);
  text-align: center;
  max-width: 300px;
  animation: messagePopup var(--transition-normal) ease-out;
}

@keyframes messagePopup {
  0% {
    transform: scale(0.8);
    opacity: 0;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

.message-emoji {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-2);
}

.message-text {
  font-size: var(--font-size-lg);
  font-weight: 500;
  color: var(--gray-800);
}

/* ========================================
     MODALS
     ======================================== */

.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  padding: var(--spacing-4);
}

.modal-content {
  background: var(--white);
  border-radius: var(--radius-xl);
  max-width: 600px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--card-shadow-hover);
  animation: modalSlideIn var(--transition-normal) ease-out;
}

@keyframes modalSlideIn {
  0% {
    transform: translateY(-20px);
    opacity: 0;
  }
  100% {
    transform: translateY(0);
    opacity: 1;
  }
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-6);
  border-bottom: 1px solid var(--gray-200);
}

.modal-header h2 {
  font-size: var(--font-size-2xl);
  color: var(--primary-color);
  margin: 0;
}

.modal-close {
  background: none;
  border: none;
  font-size: var(--font-size-2xl);
  cursor: pointer;
  color: var(--gray-400);
  padding: var(--spacing-2);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast);
}

.modal-close:hover {
  color: var(--gray-600);
}

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

.modal-footer {
  display: flex;
  gap: var(--spacing-3);
  justify-content: flex-end;
  padding: var(--spacing-6);
  border-top: 1px solid var(--gray-200);
  flex-wrap: wrap;
}

/* ========================================
     COMPLETION STATS
     ======================================== */

.completion-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-6);
}

.stat-item {
  text-align: center;
  padding: var(--spacing-4);
  background: var(--gray-50);
  border-radius: var(--radius-lg);
}

.stat-emoji {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--spacing-2);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
  margin-bottom: var(--spacing-1);
}

.stat-value {
  font-size: var(--font-size-xl);
  font-weight: bold;
  color: var(--primary-color);
}

.performance-rating {
  text-align: center;
  padding: var(--spacing-4);
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: var(--white);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-6);
}

.rating-emoji {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-2);
}

.rating-text {
  font-size: var(--font-size-xl);
  font-weight: bold;
}

/* ========================================
     ACHIEVEMENTS
     ======================================== */

.achievements-list {
  margin-top: var(--spacing-6);
}

.achievements-list h3 {
  text-align: center;
  color: var(--primary-color);
  margin-bottom: var(--spacing-4);
}

.achievements-container {
  display: grid;
  gap: var(--spacing-3);
}

.achievement-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-3);
  background: var(--gray-50);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--success-color);
  animation: achievementSlideIn 0.5s ease-out;
}

@keyframes achievementSlideIn {
  0% {
    transform: translateX(-20px);
    opacity: 0;
  }
  100% {
    transform: translateX(0);
    opacity: 1;
  }
}

.achievement-emoji {
  font-size: var(--font-size-2xl);
}

.achievement-details h4 {
  font-size: var(--font-size-base);
  color: var(--gray-800);
  margin-bottom: var(--spacing-1);
}

.achievement-details p {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
  margin: 0;
}

/* ========================================
     LEADERBOARD
     ======================================== */

.leaderboard-container h2 {
  text-align: center;
  color: var(--primary-color);
  margin-bottom: var(--spacing-6);
}

.leaderboard-controls {
  display: flex;
  gap: var(--spacing-3);
  justify-content: center;
  margin-bottom: var(--spacing-6);
  flex-wrap: wrap;
}

.leaderboard-controls select {
  padding: var(--spacing-2) var(--spacing-4);
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-lg);
  background: var(--white);
}

.leaderboard-table {
  width: 100%;
  border-collapse: collapse;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--card-shadow);
}

.leaderboard-table th,
.leaderboard-table td {
  padding: var(--spacing-3);
  text-align: left;
  border-bottom: 1px solid var(--gray-200);
}

.leaderboard-table th {
  background: var(--primary-color);
  color: var(--white);
  font-weight: 600;
}

.leaderboard-table tr:hover {
  background: var(--gray-50);
}

.rank-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-1);
  padding: var(--spacing-1) var(--spacing-2);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 500;
}

.rank-1 {
  background: #fef3c7;
  color: #92400e;
}
.rank-2 {
  background: #e5e7eb;
  color: #374151;
}
.rank-3 {
  background: #fed7aa;
  color: #9a3412;
}

/* ========================================
     RESPONSIVE DESIGN
     ======================================== */

@media (max-width: 768px) {
  .game-container {
    padding: var(--spacing-2);
  }

  .game-header {
    padding: var(--spacing-4);
  }

  .game-title {
    font-size: var(--font-size-2xl);
    flex-direction: column;
    gap: var(--spacing-2);
  }

  .game-nav {
    flex-direction: column;
  }

  .nav-btn {
    width: 100%;
  }

  .tab-content {
    padding: var(--spacing-4);
  }

  .setup-card {
    padding: var(--spacing-4);
  }

  .cards-grid {
    gap: var(--spacing-2);
  }

  .cards-grid.medium,
  .cards-grid.hard,
  .cards-grid.expert {
    grid-template-columns: repeat(4, 1fr);
  }

  .memory-card {
    min-height: 60px;
    max-height: 80px;
  }

  .game-controls {
    flex-direction: column;
  }

  .modal-footer {
    flex-direction: column;
  }

  .modal-footer .btn {
    width: 100%;
  }

  .completion-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .leaderboard-table {
    font-size: var(--font-size-sm);
  }

  .leaderboard-table th,
  .leaderboard-table td {
    padding: var(--spacing-2);
  }
}

@media (max-width: 480px) {
  .title-emoji {
    font-size: var(--font-size-2xl);
  }

  .cards-grid.easy,
  .cards-grid.medium,
  .cards-grid.hard,
  .cards-grid.expert {
    grid-template-columns: repeat(3, 1fr);
  }

  .memory-card {
    min-height: 50px;
    max-height: 70px;
  }

  .card-face {
    font-size: clamp(1rem, 6vw, 2rem);
  }

  .completion-stats {
    grid-template-columns: 1fr;
  }

  .game-info {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ========================================
     NOTIFICATIONS
     ======================================== */

.notification {
  position: fixed;
  top: var(--spacing-4);
  right: var(--spacing-4);
  z-index: var(--z-tooltip);
  max-width: 400px;
  animation: notificationSlideIn var(--transition-normal) ease-out;
}

@keyframes notificationSlideIn {
  0% {
    transform: translateX(100%);
    opacity: 0;
  }
  100% {
    transform: translateX(0);
    opacity: 1;
  }
}

.notification-content {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  background: var(--white);
  padding: var(--spacing-4);
  border-radius: var(--radius-lg);
  box-shadow: var(--card-shadow-hover);
  border-left: 4px solid var(--info-color);
}

.notification-emoji {
  font-size: var(--font-size-xl);
}

.notification-message {
  font-weight: 500;
  color: var(--gray-800);
}

/* ========================================
     STATS AND ANALYTICS
     ======================================== */

.stats-container h2 {
  text-align: center;
  color: var(--primary-color);
  margin-bottom: var(--spacing-6);
}

.stats-placeholder {
  text-align: center;
  padding: var(--spacing-8);
  color: var(--gray-600);
}

.placeholder-emoji {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-4);
}

.user-stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-6);
}

.stats-card {
  background: var(--gray-50);
  padding: var(--spacing-4);
  border-radius: var(--radius-lg);
  text-align: center;
  border: 2px solid transparent;
  transition: all var(--transition-fast);
}

.stats-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.stats-card-emoji {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--spacing-2);
}

.stats-card-value {
  font-size: var(--font-size-2xl);
  font-weight: bold;
  color: var(--primary-color);
  margin-bottom: var(--spacing-1);
}

.stats-card-label {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
}

/* ========================================
     ABOUT SECTION
     ======================================== */

.about-container h2 {
  text-align: center;
  color: var(--primary-color);
  margin-bottom: var(--spacing-6);
}

.about-content {
  max-width: 800px;
  margin: 0 auto;
}

.about-section {
  margin-bottom: var(--spacing-6);
}

.about-section h3 {
  color: var(--gray-800);
  margin-bottom: var(--spacing-3);
  font-size: var(--font-size-xl);
}

.about-section p,
.about-section li {
  color: var(--gray-600);
  line-height: 1.7;
  margin-bottom: var(--spacing-2);
}

.about-section ol,
.about-section ul {
  padding-left: var(--spacing-6);
}

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-2);
  margin-top: var(--spacing-3);
}

.tech-badge {
  background: var(--primary-color);
  color: var(--white);
  padding: var(--spacing-1) var(--spacing-3);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 500;
}

/* ========================================
     ERROR STATES
     ======================================== */

.error-modal .modal-content {
  border-top: 4px solid var(--error-color);
}

.error-content {
  text-align: center;
}

.error-emoji {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-4);
}

.error-message {
  font-size: var(--font-size-lg);
  color: var(--gray-800);
  margin-bottom: var(--spacing-3);
}

.error-suggestion {
  font-size: var(--font-size-base);
  color: var(--gray-600);
}

/* ========================================
     LOADING STATES
     ======================================== */

.loading-spinner {
  display: inline-block;
  animation: spin 1s linear infinite;
}

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

.skeleton {
  background: linear-gradient(
    90deg,
    var(--gray-200) 25%,
    var(--gray-100) 50%,
    var(--gray-200) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
}

@keyframes skeleton-loading {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

/* ========================================
     FOOTER
     ======================================== */

.game-footer {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: var(--spacing-4);
  text-align: center;
  box-shadow: var(--card-shadow);
  margin-top: auto;
}

.footer-content p {
  margin: 0;
  color: var(--gray-600);
  font-size: var(--font-size-sm);
}

.footer-subtitle {
  margin-top: var(--spacing-2) !important;
  font-style: italic;
}

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

.footer-content a:hover {
  text-decoration: underline;
}

/* ========================================
     ACCESSIBILITY
     ======================================== */

/* Focus styles for keyboard navigation */
.btn:focus,
.nav-btn:focus,
input:focus,
select:focus,
.memory-card:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* Reduced 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;
    scroll-behavior: auto !important;
  }

  .title-emoji {
    animation: none;
  }

  .loading-spinner {
    animation: none;
  }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --gray-100: #e0e0e0;
    --gray-200: #c0c0c0;
    --gray-800: #000000;
    --card-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
  }
}

/* Print styles */
@media print {
  .game-nav,
  .game-controls,
  .modal,
  .notification {
    display: none !important;
  }

  .game-container {
    background: var(--white);
  }

  .tab-content {
    display: block !important;
    box-shadow: none;
  }
}

/* ========================================
     UTILITY CLASSES
     ======================================== */

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

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

.font-bold {
  font-weight: bold;
}
.font-medium {
  font-weight: 500;
}

.text-primary {
  color: var(--primary-color);
}
.text-success {
  color: var(--success-color);
}
.text-warning {
  color: var(--warning-color);
}
.text-error {
  color: var(--error-color);
}

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

.hidden {
  display: none;
}
.block {
  display: block;
}
.flex {
  display: flex;
}
.grid {
  display: grid;
}

.w-full {
  width: 100%;
}
.h-full {
  height: 100%;
}

/* ========================================
     CUSTOM SCROLLBAR
     ======================================== */

::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--gray-100);
  border-radius: var(--radius-md);
}

::-webkit-scrollbar-thumb {
  background: var(--gray-400);
  border-radius: var(--radius-md);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--gray-500);
}