/* CSS Variables for Theming */
:root {
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --secondary-color: #8b5cf6;
  --success-color: #10b981;
  --error-color: #ef4444;
  --warning-color: #f59e0b;
  --info-color: #3b82f6;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --text-light: #9ca3af;
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-tertiary: #f3f4f6;
  --border-color: #e5e7eb;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  
  /* Difficulty Colors */
  --easy-color: #10b981;
  --medium-color: #f59e0b;
  --hard-color: #ef4444;
  --expert-color: #8b5cf6;
}

/* Dark Theme Variables */
[data-theme="dark"] {
  --text-primary: #f9fafb;
  --text-secondary: #d1d5db;
  --text-light: #9ca3af;
  --bg-primary: #111827;
  --bg-secondary: #1f2937;
  --bg-tertiary: #374151;
  --border-color: #374151;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  min-height: 100vh;
  color: var(--text-primary);
  transition: all 0.3s ease;
  position: relative;
  overflow-x: hidden;
}

/* Background Pattern */
.background-pattern {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    radial-gradient(circle at 25% 25%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* Main App Container */
.app {
  max-width: 900px;
  margin: 2rem auto;
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  position: relative;
    -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

/* Header Styles */
.header {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
  padding: 1.5rem 2rem;
  position: relative;
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.1'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  pointer-events: none;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 1;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo i {
  font-size: 2rem;
  background: linear-gradient(45deg, #fff, #e0e7ff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin: 0;
  letter-spacing: -0.025em;
}

.controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.language-selector {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255, 255, 255, 0.1);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-lg);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.language-selector i {
  opacity: 0.8;
}

.language-selector select {
  background: transparent;
  border: none;
  color: white;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  outline: none;
}

.language-selector select option {
  background: var(--bg-primary);
  color: var(--text-primary);
}

#theme-toggle {
  background: rgba(255, 255, 255, 0.1);
  border: none;
  color: white;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
    -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

#theme-toggle:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.05);
}

/* Difficulty Selection */
.difficulty-selection {
  padding: 3rem 2rem;
  text-align: center;
}

.difficulty-content h2 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.difficulty-content p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 3rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.difficulty-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  max-width: 1000px;
  margin: 0 auto;
}

.difficulty-card {
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2rem;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  text-align: center;
}

.difficulty-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  transition: left 0.5s ease;
}

.difficulty-card:hover::before {
  left: 100%;
}

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

.difficulty-card.easy:hover {
  border-color: var(--easy-color);
  box-shadow: 0 20px 40px rgba(16, 185, 129, 0.3);
}

.difficulty-card.medium:hover {
  border-color: var(--medium-color);
  box-shadow: 0 20px 40px rgba(245, 158, 11, 0.3);
}

.difficulty-card.hard:hover {
  border-color: var(--hard-color);
  box-shadow: 0 20px 40px rgba(239, 68, 68, 0.3);
}

.difficulty-card.expert:hover {
  border-color: var(--expert-color);
  box-shadow: 0 20px 40px rgba(139, 92, 246, 0.3);
}

.difficulty-icon {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 2rem;
  color: white;
  position: relative;
}

.difficulty-icon.easy {
  background: linear-gradient(135deg, var(--easy-color), #059669);
}

.difficulty-icon.medium {
  background: linear-gradient(135deg, var(--medium-color), #d97706);
}

.difficulty-icon.hard {
  background: linear-gradient(135deg, var(--hard-color), #dc2626);
}

.difficulty-icon.expert {
  background: linear-gradient(135deg, var(--expert-color), #7c3aed);
}

.difficulty-card h3 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.difficulty-card p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  font-size: 0.875rem;
  line-height: 1.6;
}

.difficulty-stats {
  display: flex;
  justify-content: space-around;
  gap: 1rem;
}

.difficulty-stats span {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-light);
  font-weight: 500;
}

.difficulty-stats i {
  color: var(--primary-color);
}

/* Progress Section */
.progress-section {
  padding: 1.5rem 2rem 1rem;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}

.progress-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.progress-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.current-difficulty {
  background: var(--primary-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-lg);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.current-difficulty.easy {
  background: var(--easy-color);
}

.current-difficulty.medium {
  background: var(--medium-color);
}

.current-difficulty.hard {
  background: var(--hard-color);
}

.current-difficulty.expert {
  background: var(--expert-color);
}

.progress-bar {
  width: 100%;
  height: 0.5rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  border-radius: var(--radius-sm);
  transition: width 0.5s ease;
  position: relative;
}

.progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* Quiz Container */
.quiz-container {
  padding: 2rem;
}

.quiz {
  max-width: 100%;
}

/* Question Section */
.question-section {
  margin-bottom: 2rem;
}

.question-section h2 {
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.question-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.difficulty-badge {
  background: var(--success-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-lg);
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.difficulty-badge.easy {
  background: var(--easy-color);
}

.difficulty-badge.medium {
  background: var(--medium-color);
}

.difficulty-badge.hard {
  background: var(--hard-color);
}

.difficulty-badge.expert {
  background: var(--expert-color);
}

.timer {
  background: var(--warning-color);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: 0.875rem;
  min-width: 4rem;
  text-align: center;
  animation: pulse 1s infinite alternate;
}

@keyframes pulse {
  from { opacity: 1; }
  to { opacity: 0.7; }
}

/* Answers Section */
.answers-section {
  margin-bottom: 2rem;
}

#answer-buttons {
  display: grid;
  gap: 0.75rem;
}

.btn {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 2px solid var(--border-color);
  padding: 1rem 1.25rem;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 500;
  text-align: left;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  transition: left 0.5s ease;
}

.btn:hover:not([disabled])::before {
  left: 100%;
}

.btn:hover:not([disabled]) {
  border-color: var(--primary-color);
  background: var(--bg-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

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

.btn.correct {
  background: linear-gradient(135deg, var(--success-color), #059669);
  color: white;
  border-color: var(--success-color);
  animation: correctAnswer 0.6s ease;
}

.btn.incorrect {
  background: linear-gradient(135deg, var(--error-color), #dc2626);
  color: white;
  border-color: var(--error-color);
  animation: incorrectAnswer 0.6s ease;
}

@keyframes correctAnswer {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

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

/* Quiz Actions */
.quiz-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

#hint-btn {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 2px solid var(--border-color);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#hint-btn:hover {
  background: var(--warning-color);
  color: white;
  border-color: var(--warning-color);
}

#hint-btn i {
  font-size: 1rem;
}

#next-btn {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
  border: none;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: none;
  align-items: center;
  gap: 0.5rem;
  position: relative;
  overflow: hidden;
}

#next-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 ease;
}

#next-btn:hover::before {
  left: 100%;
}

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

#next-btn:active {
  transform: translateY(0);
}

/* Results Section */
.results-section {
  text-align: center;
  padding: 2rem;
  animation: fadeInUp 0.6s ease;
}

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

.results-content {
  max-width: 500px;
  margin: 0 auto;
}

.results-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--warning-color), #f59e0b);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: bounce 1s ease infinite alternate;
}

@keyframes bounce {
  from { transform: translateY(0); }
  to { transform: translateY(-10px); }
}

.results-content h3 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.difficulty-completed {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  padding: 0.5rem 1.5rem;
  border-radius: var(--radius-lg);
  font-weight: 600;
  margin-bottom: 2rem;
  display: inline-block;
}

.score-breakdown {
  margin-bottom: 2rem;
}

.score-circle {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0 auto 2rem;
  color: white;
  position: relative;
  box-shadow: var(--shadow-xl);
}

.score-circle::before {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  z-index: -1;
  animation: rotate 3s linear infinite;
}

@keyframes rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.score-number {
  font-size: 2.5rem;
  font-weight: 700;
  line-height: 1;
}

.score-total {
  font-size: 1rem;
  opacity: 0.8;
}

.performance-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.stat {
  background: var(--bg-secondary);
  padding: 1rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.stat i {
  font-size: 1.25rem;
  color: var(--primary-color);
}

.stat span {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.results-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

#restart-btn,
#new-level-btn {
  background: linear-gradient(135deg, var(--success-color), #059669);
  color: white;
  border: none;
  padding: 1rem 2rem;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-width: 150px;
}

#new-level-btn {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
}

#restart-btn:hover,
#new-level-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Confetti Canvas */
#confetti-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1000;
}

/* Responsive Design */
@media (max-width: 768px) {
  .app {
    margin: 1rem;
    border-radius: var(--radius-lg);
  }
  
  .header {
    padding: 1rem 1.5rem;
  }
  
  .logo h1 {
    font-size: 1.5rem;
  }
  
  .difficulty-selection {
    padding: 2rem 1.5rem;
  }
  
  .difficulty-content h2 {
    font-size: 2rem;
  }
  
  .difficulty-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .quiz-container {
    padding: 1.5rem;
  }
  
  .question-section h2 {
    font-size: 1.25rem;
  }
  
  .quiz-actions {
    flex-direction: column;
    gap: 1rem;
  }
  
  #hint-btn,
  #next-btn {
    width: 100%;
    justify-content: center;
  }
  
  .performance-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .results-actions {
    flex-direction: column;
  }
  
  #restart-btn,
  #new-level-btn {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .header-content {
    flex-direction: column;
    gap: 1rem;
  }
  
  .controls {
    width: 100%;
    justify-content: space-between;
  }
  
  .progress-section {
    padding: 1rem 1.5rem;
  }
  
  .quiz-container {
    padding: 1rem;
  }
  
  .performance-stats {
    grid-template-columns: 1fr;
  }
}

/* RTL Support */
[dir="rtl"] {
  text-align: right;
}

[dir="rtl"] .logo {
  flex-direction: row-reverse;
}

[dir="rtl"] .controls {
  flex-direction: row-reverse;
}

[dir="rtl"] .btn {
  text-align: right;
}

[dir="rtl"] .quiz-actions {
  flex-direction: row-reverse;
}

/* Print Styles */
@media print {
  .background-pattern,
  .controls,
  #confetti-canvas {
    display: none;
  }
  
  .app {
    box-shadow: none;
    border: 1px solid #ccc;
  }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  :root {
    --border-color: #000;
    --text-secondary: #000;
  }
  
  .btn {
    border-width: 3px;
  }
}

/* Reduced Motion */
@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;
  }
}
/* Add these new styles to your existing CSS */

/* Enhanced Progress Section */
.progress-right {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* Quiz Navigation */
.quiz-nav {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 2rem;
}

.nav-content h4 {
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-size: 1rem;
  font-weight: 600;
}

.question-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(40px, 1fr));
  gap: 0.5rem;
  margin-bottom: 1rem;
  max-width: 500px;
}

.question-nav-btn {
  width: 40px;
  height: 40px;
  border: 2px solid var(--border-color);
  background: var(--bg-primary);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 600;
  font-size: 0.875rem;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.question-nav-btn:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

.question-nav-btn.answered {
  background: var(--success-color);
  color: white;
  border-color: var(--success-color);
}

.question-nav-btn.current {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
  animation: pulse-ring 2s infinite;
}

.question-nav-btn.unanswered {
  background: var(--bg-tertiary);
  border-color: var(--border-color);
}

@keyframes pulse-ring {
  0% {
    box-shadow: 0 0 0 0 rgba(99, 102, 241, 0.4);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(99, 102, 241, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(99, 102, 241, 0);
  }
}

.nav-legend {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.legend-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 2px solid var(--border-color);
}

.legend-dot.answered {
  background: var(--success-color);
  border-color: var(--success-color);
}

.legend-dot.current {
  background: var(--primary-color);
  border-color: var(--primary-color);
}

.legend-dot.unanswered {
  background: var(--bg-tertiary);
  border-color: var(--border-color);
}

/* Enhanced Quiz Actions */
.action-buttons {
  display: flex;
  gap: 1rem;
  align-items: center;
}

#skip-btn {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 2px solid var(--border-color);
  padding: 0.875rem 1.5rem;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#skip-btn:hover {
  background: var(--warning-color);
  color: white;
  border-color: var(--warning-color);
  transform: translateY(-2px);
}

#submit-btn {
  background: linear-gradient(135deg, var(--success-color), #059669);
  color: white;
  border: none;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  position: relative;
  overflow: hidden;
}

#submit-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 ease;
}

#submit-btn:hover::before {
  left: 100%;
}

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

/* Enhanced Performance Stats */
.performance-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

/* Responsive Updates */
@media (max-width: 768px) {
  .quiz-nav {
    padding: 1rem 1.5rem;
  }
  
  .question-grid {
    grid-template-columns: repeat(auto-fill, minmax(35px, 1fr));
  }
  
  .question-nav-btn {
    width: 35px;
    height: 35px;
    font-size: 0.75rem;
  }
  
  .nav-legend {
    gap: 1rem;
  }
  
  .action-buttons {
    flex-direction: column;
    width: 100%;
  }
  
  #skip-btn,
  #next-btn,
  #submit-btn {
    width: 100%;
    justify-content: center;
  }
  
  .quiz-actions {
    flex-direction: column;
    gap: 1rem;
  }
  
  #hint-btn {
    width: 100%;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .progress-right {
    flex-direction: column;
    gap: 0.5rem;
    align-items: flex-end;
  }
  
  .performance-stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Skip Animation */
.question-skipped {
  animation: skipAnimation 0.3s ease;
}

@keyframes skipAnimation {
  0% { transform: translateX(0); opacity: 1; }
  50% { transform: translateX(20px); opacity: 0.5; }
  100% { transform: translateX(0); opacity: 1; }
}

/* Submit Button Pulse */
.submit-ready {
  animation: submitPulse 2s infinite;
}

@keyframes submitPulse {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.4); }
  70% { box-shadow: 0 0 0 10px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}