/*
  Quiz App Styles
  Modern, clean design with smooth animations
*/

:root {
  --primary-color: #4a90e2;
  --primary-dark: #2e5f8e;
  --success-color: #4caf50;
  --error-color: #f44336;
  --warning-color: #ff9800;
  --text-primary: #2c3e50;
  --text-secondary: #7f8c8d;
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --border-color: #e1e4e8;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  color: var(--text-primary);
}

.container {
  width: 100%;
  max-width: 800px;
  background: var(--bg-primary);
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

/* Screen Management */
.screen {
  display: none;
  padding: 40px;
  animation: fadeIn 0.3s ease;
}

.screen.active {
  display: block;
}

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

/* Start Screen */
#startScreen {
  text-align: center;
}

#startScreen h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
  color: var(--primary-color);
}

.subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

.quiz-info {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-bottom: 40px;
  padding: 30px;
  background: var(--bg-secondary);
  border-radius: 12px;
}

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

.info-label {
  display: block;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.info-value {
  display: block;
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
}

/* Buttons */
.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  outline: none;
}

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

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

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

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

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
}

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

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

.btn-large {
  padding: 16px 48px;
  font-size: 1.2rem;
}

/* Footer */
.footer {
  margin-top: 40px;
}

.home-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s ease;
}

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

/* Quiz Screen */
.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 2px solid var(--border-color);
}

.progress-container {
  flex: 1;
}

.progress-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-secondary);
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--primary-color);
  transition: width 0.3s ease;
  border-radius: 4px;
}

/* Timer */
.timer-container {
  position: relative;
  width: 60px;
  height: 60px;
  margin-left: 20px;
}

.timer-ring-bg {
  stroke: var(--bg-secondary);
}

.timer-ring-progress {
  stroke: var(--primary-color);
  stroke-linecap: round;
  transform: rotate(-90deg);
  transform-origin: center;
  transition: stroke-dashoffset 1s linear;
}

.timer-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 1.2rem;
  font-weight: bold;
  color: var(--primary-color);
}

.timer-warning {
  stroke: var(--error-color);
  color: var(--error-color);
}

/* Question */
.question-container {
  margin-bottom: 30px;
}

.question-text {
  font-size: 1.5rem;
  margin-bottom: 30px;
  line-height: 1.5;
  color: var(--text-primary);
}

.options-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.option {
  padding: 16px 20px;
  background: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 1rem;
  text-align: left;
}

.option:hover {
  background: var(--bg-primary);
  border-color: var(--primary-color);
  transform: translateX(4px);
}

.option.selected {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.option.correct {
  background: var(--success-color);
  color: white;
  border-color: var(--success-color);
}

.option.incorrect {
  background: var(--error-color);
  color: white;
  border-color: var(--error-color);
}

.option.disabled {
  cursor: not-allowed;
  opacity: 0.7;
}

/* Quiz Controls */
.quiz-controls {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 30px;
}

.quiz-controls .btn {
  flex: 1;
}

/* Results Screen */
.results-container {
  text-align: center;
}

.results-icon {
  font-size: 5rem;
  margin-bottom: 20px;
  animation: bounce 0.5s ease;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

.results-title {
  font-size: 2rem;
  margin-bottom: 30px;
  color: var(--primary-color);
}

/* Score Circle */
.score-circle {
  position: relative;
  width: 200px;
  height: 200px;
  margin: 0 auto 40px;
}

.score-circle-bg {
  stroke: var(--bg-secondary);
}

.score-circle-progress {
  stroke: var(--success-color);
  stroke-linecap: round;
  transform: rotate(-90deg);
  transform-origin: center;
  transition: stroke-dashoffset 1s ease;
}

.score-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.score-percentage {
  font-size: 2.5rem;
  font-weight: bold;
  color: var(--success-color);
}

.score-label {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Results Stats */
.results-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin-bottom: 30px;
  padding: 30px;
  background: var(--bg-secondary);
  border-radius: 12px;
}

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

.stat-value {
  font-size: 2rem;
  font-weight: bold;
  color: var(--primary-color);
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

.results-message {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 30px;
  padding: 20px;
  background: var(--bg-secondary);
  border-radius: 8px;
}

.results-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

/* Review Screen */
.review-container {
  max-height: 600px;
  overflow-y: auto;
}

.review-item {
  margin-bottom: 30px;
  padding: 20px;
  background: var(--bg-secondary);
  border-radius: 12px;
  border-left: 4px solid var(--border-color);
}

.review-item.correct {
  border-left-color: var(--success-color);
}

.review-item.incorrect {
  border-left-color: var(--error-color);
}

.review-item.skipped {
  border-left-color: var(--warning-color);
}

.review-question {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.review-number {
  display: inline-block;
  background: var(--primary-color);
  color: white;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.8rem;
  margin-right: 8px;
}

.review-answer {
  margin-top: 12px;
  font-size: 0.9rem;
}

.review-label {
  font-weight: 600;
  margin-right: 8px;
}

.review-your-answer {
  color: var(--error-color);
}

.review-correct-answer {
  color: var(--success-color);
}

.review-status {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.review-status.correct {
  background: var(--success-color);
  color: white;
}

.review-status.incorrect {
  background: var(--error-color);
  color: white;
}

.review-status.skipped {
  background: var(--warning-color);
  color: white;
}

.review-actions {
  text-align: center;
  margin-top: 30px;
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    max-width: 100%;
  }

  .screen {
    padding: 30px 20px;
  }

  #startScreen h1 {
    font-size: 2rem;
  }

  .quiz-info {
    flex-direction: column;
    gap: 20px;
  }

  .quiz-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .timer-container {
    margin-left: 0;
    margin-top: 12px;
  }

  .question-text {
    font-size: 1.2rem;
  }

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

  .results-stats {
    flex-direction: column;
    gap: 20px;
  }

  .results-actions {
    flex-direction: column;
  }

  .results-actions .btn {
    width: 100%;
  }
}

/* Animations */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-10px); }
  75% { transform: translateX(10px); }
}

.shake {
  animation: shake 0.3s ease;
}

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

.pulse {
  animation: pulse 0.3s ease;
}