/* CSS Variables for Theme Management */
:root {
  --primary-color: #00d4ff;
  --secondary-color: #0099cc;
  --accent-color: #0066ff;
  --success-color: #00ff88;
  --error-color: #ff4757;
  --warning-color: #ffa502;
  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --bg-primary: linear-gradient(135deg, #0c0c0c 0%, #1a1a2e 50%, #16213e 100%);
  --bg-secondary: rgba(255, 255, 255, 0.05);
  --bg-tertiary: rgba(255, 255, 255, 0.1);
  --border-color: rgba(255, 255, 255, 0.1);
  --shadow-color: rgba(0, 0, 0, 0.3);
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
}

.light-theme {
  --text-primary: #2c3e50;
  --text-secondary: #7f8c8d;
  --bg-primary: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 50%, #dee2e6 100%);
  --bg-secondary: rgba(0, 0, 0, 0.05);
  --bg-tertiary: rgba(0, 0, 0, 0.1);
  --border-color: rgba(0, 0, 0, 0.1);
  --shadow-color: rgba(0, 0, 0, 0.1);
  --glass-bg: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(0, 0, 0, 0.1);
}

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

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  transition: all 0.3s ease;
}

/* Floating Animation Elements */
.floating-elements {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: hidden;
}

.floating-icon {
  position: absolute;
  font-size: 2rem;
  color: var(--primary-color);
  opacity: 0.1;
  animation: float 6s ease-in-out infinite;
}

.floating-icon:nth-child(1) {
  top: 10%;
  left: 10%;
  animation-delay: 0s;
}

.floating-icon:nth-child(2) {
  top: 20%;
  right: 15%;
  animation-delay: 1.5s;
}

.floating-icon:nth-child(3) {
  bottom: 30%;
  left: 20%;
  animation-delay: 3s;
}

.floating-icon:nth-child(4) {
  bottom: 20%;
  right: 10%;
  animation-delay: 4.5s;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg);
  }
  33% {
    transform: translateY(-20px) rotate(120deg);
  }
  66% {
    transform: translateY(10px) rotate(240deg);
  }
}

/* Enhanced Navigation Styles */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  z-index: 1000;
  transition: all 0.3s ease;
}

.navbar.scrolled {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  box-shadow: 0 2px 20px var(--shadow-color);
  border-bottom: 1px solid var(--glass-border);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  text-decoration: none;
}

.nav-logo i {
  font-size: 1.8rem;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
}

.nav-menu {
  display: flex;
  gap: 30px;
  align-items: center;
}

.nav-link {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
  padding: 8px 16px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link i {
  font-size: 1rem;
}

.nav-link span {
  font-size: 0.95rem;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-color);
  background: var(--bg-secondary);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 80%;
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 15px;
}

.theme-toggle,
.sound-toggle {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.3s ease;
}

.theme-toggle:hover,
.sound-toggle:hover {
  background: var(--primary-color);
  color: white;
  transform: scale(1.1);
}

.sound-toggle.muted {
  color: var(--error-color);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  padding: 5px;
  border-radius: 4px;
  transition: all 0.3s ease;
}

.nav-toggle:hover {
  background: var(--bg-secondary);
}

.bar {
  width: 25px;
  height: 3px;
  background: var(--text-primary);
  margin: 3px 0;
  transition: 0.3s;
  border-radius: 2px;
}

.nav-toggle.active .bar:nth-child(1) {
  transform: rotate(-45deg) translate(-5px, 6px);
}

.nav-toggle.active .bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active .bar:nth-child(3) {
  transform: rotate(45deg) translate(-5px, -6px);
}

/* Enhanced Mobile Navigation */
@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    left: -100%;
    top: 70px;
    flex-direction: column;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    width: 100%;
    text-align: center;
    transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    padding: 30px 0;
    border-bottom: 1px solid var(--glass-border);
    gap: 20px;
    box-shadow: 0 8px 32px var(--shadow-color);
    z-index: 999;
  }

  .nav-menu.active {
    left: 0;
    animation: slideInLeft 0.3s ease-out;
  }

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

  .nav-link {
    padding: 15px 30px;
    margin: 0 20px;
    border-radius: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    justify-content: center;
    font-size: 1.1rem;
    transform: translateY(20px);
    opacity: 0;
    animation: slideInUp 0.3s ease-out forwards;
    color: var(--text-primary);
  }

  .nav-link:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary-color);
    color: var(--primary-color);
  }

  .nav-menu.active .nav-link:nth-child(1) {
    animation-delay: 0.1s;
  }
  .nav-menu.active .nav-link:nth-child(2) {
    animation-delay: 0.2s;
  }
  .nav-menu.active .nav-link:nth-child(3) {
    animation-delay: 0.3s;
  }
  .nav-menu.active .nav-link:nth-child(4) {
    animation-delay: 0.4s;
  }

  @keyframes slideInUp {
    to {
      transform: translateY(0);
      opacity: 1;
    }
  }

  .nav-link::after {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-controls {
    gap: 10px;
  }

  .theme-toggle,
  .sound-toggle {
    width: 35px;
    height: 35px;
  }
}

/* Main Content */
.main-content {
  margin-top: 70px;
  min-height: calc(100vh - 70px);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

/* Enhanced Welcome Section */
.welcome-section {
  text-align: center;
  padding: 80px 0;
  position: relative;
  animation: fadeInUp 1s ease-out;
}

.welcome-content {
  position: relative;
  z-index: 2;
}

.main-title {
  font-size: 4rem;
  font-weight: bold;
  background: linear-gradient(45deg, var(--primary-color), var(--secondary-color), var(--accent-color));
  background-size: 200% 200%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 3s ease-in-out infinite;
  margin-bottom: 20px;
  text-shadow: 0 0 30px rgba(0, 212, 255, 0.3);
}

@keyframes gradientShift {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.main-subtitle {
  font-size: 1.3rem;
  color: var(--text-secondary);
  margin-bottom: 50px;
  animation: fadeInUp 1s ease-out 0.3s both;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
  margin-bottom: 50px;
  animation: fadeInUp 1s ease-out 0.6s both;
}

.stat-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 30px;
  text-align: center;
  border: 1px solid var(--glass-border);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.1), transparent);
  transition: left 0.5s ease;
}

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

.stat-card:hover {
  transform: translateY(-10px) scale(1.02);
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
  box-shadow: 0 20px 40px var(--shadow-color);
}

.stat-card i {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 15px;
  display: block;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%,
  20%,
  50%,
  80%,
  100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-10px);
  }
  60% {
    transform: translateY(-5px);
  }
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: bold;
  color: var(--text-primary);
  margin-bottom: 5px;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 1rem;
}

.welcome-actions {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 1s ease-out 0.9s both;
}

.start-quiz-btn,
.quick-start-btn {
  border: none;
  border-radius: 50px;
  padding: 20px 40px;
  font-size: 1.2rem;
  font-weight: bold;
  color: white;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  position: relative;
  overflow: hidden;
}

.start-quiz-btn {
  background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
}

.quick-start-btn {
  background: linear-gradient(45deg, var(--warning-color), #ff7675);
}

.start-quiz-btn:hover,
.quick-start-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 15px 35px rgba(0, 212, 255, 0.4);
}

.start-quiz-btn::before,
.quick-start-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;
}

.start-quiz-btn:hover::before,
.quick-start-btn:hover::before {
  left: 100%;
}

/* Enhanced Category Section */
.category-section {
  animation: slideIn 0.8s ease-out;
}

.section-header {
  text-align: center;
  margin-bottom: 50px;
}

.section-title {
  font-size: 2.5rem;
  font-weight: bold;
  color: var(--primary-color);
  margin-bottom: 15px;
  text-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
}

.section-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
}

.difficulty-selector {
  margin-bottom: 40px;
  text-align: center;
}

.difficulty-selector h3 {
  margin-bottom: 20px;
  color: var(--text-primary);
  font-size: 1.3rem;
}

.difficulty-buttons {
  display: flex;
  gap: 5px;
  justify-content: center;
  flex-wrap: wrap;
}

.difficulty-btn {
  background: var(--glass-bg);
  border: 2px solid var(--border-color);
  border-radius: 15px;
  padding: 20px 30px;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  min-width: 120px;
  color: var(--text-primary);
}

.difficulty-btn:hover,
.difficulty-btn.active {
  border-color: var(--primary-color);
  background: var(--bg-tertiary);
  transform: translateY(-5px);
  box-shadow: 0 10px 25px var(--shadow-color);
}

.difficulty-btn i {
  font-size: 1.5rem;
  color: var(--primary-color);
}

.difficulty-btn span {
  font-weight: bold;
  font-size: 1rem;
}

.difficulty-btn small {
  color: var(--text-secondary);
  font-size: 0.8rem;
}

/* Question count buttons (styled to match previous difficulty buttons) */
.question-count-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 140px;
  height: 140px;
  margin: 18px auto;
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01));
  border: 3px solid rgba(255,255,255,0.06);
  color: var(--primary-color);
  box-shadow: 0 6px 18px rgba(0,0,0,0.18);
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
  -webkit-tap-highlight-color: transparent;
  padding: 12px;
}

.question-count-btn:hover,
.question-count-btn.active {
  transform: translateY(-6px);
  box-shadow: 0 12px 28px rgba(0,0,0,0.22);
  border-color: var(--primary-color);
}

.question-count-btn i {
  font-size: 1.6rem;
  margin-bottom: 6px;
  color: var(--primary-color);
}

.question-count-btn span {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
}

.question-count-btn small {
  display: block;
  margin-top: 6px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 25px;
  margin-bottom: 40px;
}

.category-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 30px;
  border: 1px solid var(--glass-border);
  cursor: pointer;
  transition: all 0.3s ease;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.1), transparent);
  transition: left 0.5s ease;
}

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

.category-card:hover {
  transform: translateY(-10px) scale(1.02);
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
  box-shadow: 0 20px 40px var(--shadow-color);
}

.category-icon {
  font-size: 3rem;
  color: var(--primary-color);
  margin-bottom: 20px;
  display: block;
  animation: pulse 2s infinite;
}

.category-title {
  font-size: 1.5rem;
  font-weight: bold;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.category-description {
  color: var(--text-secondary);
  margin-bottom: 15px;
  line-height: 1.5;
}

.category-stats {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  color: var(--primary-color);
}

/* Enhanced Quiz Section */
.quiz-section {
  animation: slideIn 0.8s ease-out;
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  padding: 20px;
  background: var(--glass-bg);
  border-radius: 15px;
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
}

.quiz-info {
  display: flex;
  align-items: center;
  gap: 15px;
  flex-wrap: wrap;
}

.category-badge,
.difficulty-badge {
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: bold;
}

.category-badge {
  background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
  color: white;
}

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

.quiz-controls-header {
  display: flex;
  align-items: center;
  gap: 15px;
}

.total-timer {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--warning-color);
  font-weight: bold;
  font-size: 1.1rem;
}

.progress-container {
  margin-bottom: 30px;
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-secondary);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 15px;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  border-radius: 4px;
  transition: width 0.3s ease;
  box-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
}

.progress-indicators {
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}

.progress-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg-secondary);
  border: 2px solid var(--border-color);
  transition: all 0.3s ease;
  cursor: pointer;
}

.progress-dot.current {
  background: var(--primary-color);
  border-color: var(--primary-color);
  transform: scale(1.2);
}

.progress-dot.completed {
  background: var(--success-color);
  border-color: var(--success-color);
}

.progress-dot.skipped {
  background: var(--warning-color);
  border-color: var(--warning-color);
}

.quiz-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 40px;
  box-shadow: 0 8px 32px var(--shadow-color);
  border: 1px solid var(--glass-border);
}

.timer-section {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 40px;
  padding: 20px;
  background: var(--bg-secondary);
  border-radius: 15px;
  border: 1px solid var(--border-color);
}

.timer-display,
.score-display {
  font-size: 1.3rem;
  font-weight: bold;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: 8px;
}

.timer-bar-container {
  flex: 1;
  height: 10px;
  background: var(--bg-secondary);
  border-radius: 5px;
  margin: 0 30px;
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.timer-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  border-radius: 5px;
  transition: width 0.1s linear;
  box-shadow: 0 0 15px rgba(0, 212, 255, 0.5);
}

.question-section {
  margin-bottom: 40px;
  text-align: center;
}

.question-text {
  font-size: 1.6rem;
  line-height: 1.6;
  padding: 25px;
  background: var(--bg-secondary);
  border-radius: 15px;
  border-left: 4px solid var(--primary-color);
  margin-bottom: 15px;
  color: var(--text-primary);
}

.question-type {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-style: italic;
}

.answers-grid {
  display: grid;
  gap: 20px;
  margin-bottom: 40px;
}

.answer-option {
  background: var(--glass-bg);
  border: 2px solid var(--border-color);
  border-radius: 15px;
  padding: 25px;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.answer-option::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.1), transparent);
  transition: left 0.5s ease;
}

.answer-option:hover::before {
  left: 100%;
}

.answer-option:hover {
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
  transform: translateY(-3px);
  box-shadow: 0 8px 25px var(--shadow-color);
}

.answer-option.selected {
  border-color: var(--primary-color);
  background: rgba(0, 212, 255, 0.1);
}

.answer-option.correct {
  background: rgba(0, 255, 136, 0.2);
  border-color: var(--success-color);
  animation: correctPulse 0.6s ease-out;
}

.answer-option.incorrect {
  background: rgba(255, 71, 87, 0.2);
  border-color: var(--error-color);
  animation: incorrectShake 0.6s ease-out;
}

.answer-option.multiple-selected {
  border-color: var(--primary-color);
  background: rgba(0, 212, 255, 0.15);
}

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

@keyframes incorrectShake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-10px);
  }
  75% {
    transform: translateX(10px);
  }
}

.answer-icon {
  font-size: 1.5rem;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.answer-option.correct .answer-icon {
  opacity: 1;
  color: var(--success-color);
}

.answer-option.incorrect .answer-icon {
  opacity: 1;
  color: var(--error-color);
}

.quiz-navigation {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 15px;
  flex-wrap: wrap;
}

.nav-btn {
  border: none;
  border-radius: 12px;
  padding: 15px 25px;
  font-size: 1rem;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  opacity: 0;
  transform: translateY(20px);
}

.nav-btn.show {
  opacity: 1;
  transform: translateY(0);
}

.nav-btn.primary {
  background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
  color: white;
}

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

.nav-btn.skip-btn {
  background: var(--bg-secondary);
  color: var(--warning-color);
  border: 1px solid var(--warning-color);
}

.nav-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px var(--shadow-color);
}

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

.quit-btn {
  background: var(--error-color);
  border: none;
  border-radius: 8px;
  padding: 10px 15px;
  color: white;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 500;
}

.quit-btn:hover {
  background: #ff3742;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(255, 71, 87, 0.3);
}

.quit-btn i {
  font-size: 1rem;
}

/* Enhanced Results Section */
.results-section {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 60vh;
  animation: fadeInUp 1s ease-out;
}

.results-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border-radius: 25px;
  padding: 50px;
  text-align: center;
  border: 1px solid var(--glass-border);
  max-width: 700px;
  width: 100%;
  position: relative;
  overflow: hidden;
}

.results-animation {
  position: relative;
  margin-bottom: 30px;
}

.results-icon {
  font-size: 4rem;
  color: var(--primary-color);
  margin-bottom: 20px;
  animation: bounce 2s infinite;
}

.confetti {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.confetti::before,
.confetti::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
  background: var(--primary-color);
  animation: confetti 3s ease-in-out infinite;
}

.confetti::before {
  left: 20%;
  animation-delay: 0s;
}

.confetti::after {
  right: 20%;
  animation-delay: 1s;
}

@keyframes confetti {
  0% {
    transform: translateY(-100px) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(100px) rotate(720deg);
    opacity: 0;
  }
}

.final-score {
  font-size: 4rem;
  font-weight: bold;
  background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 30px;
  animation: scoreReveal 1s ease-out 0.5s both;
}

@keyframes scoreReveal {
  from {
    opacity: 0;
    transform: scale(0.5);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.score-breakdown {
  background: var(--bg-secondary);
  border-radius: 15px;
  padding: 25px;
  margin-bottom: 30px;
  border: 1px solid var(--border-color);
}

.breakdown-item {
  display: flex;
  justify-content: space-between;
  margin-bottom: 15px;
  font-size: 1.1rem;
}

.breakdown-item:last-child {
  margin-bottom: 0;
}

.breakdown-label {
  color: var(--text-secondary);
}

.breakdown-value {
  color: var(--primary-color);
  font-weight: bold;
}

.performance-message {
  font-size: 1.3rem;
  margin-bottom: 30px;
  padding: 20px;
  background: rgba(0, 212, 255, 0.1);
  border-radius: 10px;
  border-left: 4px solid var(--primary-color);
  color: var(--text-primary);
}

.achievement-badges {
  display: flex;
  justify-content: center;
  gap: 15px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.achievement-badge {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 25px;
  padding: 10px 20px;
  font-size: 0.9rem;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: 8px;
  animation: slideInUp 0.5s ease-out;
}

.results-actions {
  display: flex;
  gap: 15px;
  justify-content: center;
  flex-wrap: wrap;
}

.action-btn {
  padding: 15px 25px;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  border: none;
}

.action-btn.primary {
  background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
  color: white;
}

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

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

.action-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px var(--shadow-color);
}

/* Review Section */
.review-section {
  animation: fadeInUp 1s ease-out;
}

.review-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  padding: 20px;
  background: var(--glass-bg);
  border-radius: 15px;
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
}

.review-header h2 {
  color: var(--primary-color);
  font-size: 1.8rem;
}

.close-review-btn {
  background: var(--error-color);
  border: none;
  border-radius: 8px;
  padding: 10px 15px;
  color: white;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
}

.close-review-btn:hover {
  background: #ff3742;
  transform: translateY(-2px);
}

.review-content {
  display: grid;
  gap: 25px;
}

.review-question {
  background: var(--glass-bg);
  border-radius: 15px;
  padding: 25px;
  border: 1px solid var(--glass-border);
}

.review-question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
}

.review-question-number {
  color: var(--primary-color);
  font-weight: bold;
}

.review-result {
  padding: 5px 15px;
  border-radius: 15px;
  font-size: 0.9rem;
  font-weight: bold;
}

.review-result.correct {
  background: rgba(0, 255, 136, 0.2);
  color: var(--success-color);
}

.review-result.incorrect {
  background: rgba(255, 71, 87, 0.2);
  color: var(--error-color);
}

.review-result.skipped {
  background: rgba(255, 165, 2, 0.2);
  color: var(--warning-color);
}

.review-question-text {
  font-size: 1.2rem;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.review-answers {
  display: grid;
  gap: 10px;
}

.review-answer {
  padding: 15px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  background: var(--bg-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.review-answer.user-selected {
  border-color: var(--primary-color);
  background: rgba(0, 212, 255, 0.1);
}

.review-answer.correct-answer {
  border-color: var(--success-color);
  background: rgba(0, 255, 136, 0.1);
}

.review-answer.incorrect-selected {
  border-color: var(--error-color);
  background: rgba(255, 71, 87, 0.1);
}

/* Leaderboard Section */
.leaderboard-section {
  animation: fadeInUp 1s ease-out;
}

.leaderboard-filters {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.leaderboard-filters select {
  background: var(--glass-bg);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 12px 20px;
  color: var(--text-primary);
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6,9 12,15 18,9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 40px;
}

.leaderboard-filters select:hover,
.leaderboard-filters select:focus {
  border-color: var(--primary-color);
  outline: none;
  background: var(--bg-tertiary);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
}

.leaderboard-filters select option {
  background: var(--bg-primary);
  color: var(--text-primary);
  padding: 12px;
  border: none;
}

.light-theme .leaderboard-filters select option {
  background: #ffffff;
  color: #2c3e50;
}

.dark-theme .leaderboard-filters select option {
  background: #1a1a2e;
  color: #ffffff;
}

.leaderboard-content {
  background: var(--glass-bg);
  border-radius: 20px;
  padding: 30px;
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(10px);
}

.leaderboard-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
  margin-bottom: 15px;
  background: var(--bg-secondary);
  border-radius: 15px;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.leaderboard-item:hover {
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.leaderboard-rank {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  min-width: 50px;
}

.leaderboard-rank.top-3 {
  color: var(--warning-color);
}

.leaderboard-player {
  flex: 1;
  margin-left: 20px;
}

.leaderboard-name {
  font-weight: bold;
  font-size: 1.1rem;
  color: var(--text-primary);
}

.leaderboard-details {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.leaderboard-score {
  font-size: 1.3rem;
  font-weight: bold;
  color: var(--primary-color);
}

/* About Section */
.about-section {
  animation: fadeInUp 1s ease-out;
}

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

.about-content h2 {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 40px;
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  margin-bottom: 40px;
}

.about-card {
  background: var(--glass-bg);
  border-radius: 20px;
  padding: 30px;
  border: 1px solid var(--glass-border);
  transition: all 0.3s ease;
}

.about-card:hover {
  transform: translateY(-10px);
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
}

.about-card i {
  font-size: 3rem;
  color: var(--primary-color);
  margin-bottom: 20px;
}

.about-card h3 {
  font-size: 1.3rem;
  margin-bottom: 15px;
  color: var(--text-primary);
}

.about-card p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Share Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 2000;
  backdrop-filter: blur(5px);
}

.modal-content {
  background: var(--glass-bg);
  border-radius: 20px;
  padding: 30px;
  max-width: 500px;
  width: 90%;
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(20px);
  animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
  from {
    opacity: 0;
    transform: scale(0.8);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.modal-header h3 {
  color: var(--primary-color);
  font-size: 1.5rem;
}

.modal-close {
  background: var(--error-color);
  border: none;
  border-radius: 50%;
  width: 35px;
  height: 35px;
  color: white;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-close:hover {
  background: #ff3742;
  transform: scale(1.1);
}

.share-text {
  background: var(--bg-secondary);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 20px;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 1rem;
  line-height: 1.5;
}

.share-buttons {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 15px;
}

.share-btn {
  padding: 12px 20px;
  border: none;
  border-radius: 10px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: white;
}

.share-btn.twitter {
  background: #1da1f2;
}

.share-btn.facebook {
  background: #4267b2;
}

.share-btn.linkedin {
  background: #0077b5;
}

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

.share-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

/* Back Button */
.back-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 12px 25px;
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 auto;
  font-size: 1rem;
}

.back-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

/* Footer */
.footer {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-color);
  padding: 60px 0 20px;
  margin-top: 80px;
  transition: all 0.3s ease;
}

.light-theme .footer {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
}

.dark-theme .footer {
  background: rgba(0, 0, 0, 0.9);
  backdrop-filter: blur(20px);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h3 {
  color: var(--primary-color);
  margin-bottom: 20px;
  font-size: 1.2rem;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  margin-bottom: 15px;
}

.footer-description {
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

.social-links {
  display: flex;
  gap: 15px;
}

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--bg-secondary);
  border-radius: 50%;
  color: var(--text-primary);
  text-decoration: none;
  transition: all 0.3s ease;
  border: 1px solid var(--border-color);
}

.social-link:hover {
  background: var(--primary-color);
  color: white;
  transform: translateY(-3px);
  border-color: var(--primary-color);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-secondary);
}

.contact-item i {
  color: var(--primary-color);
  width: 20px;
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
}

.footer-bottom-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-secondary);
}

.footer-bottom-links {
  display: flex;
  gap: 20px;
}

.footer-bottom-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-bottom-links a:hover {
  color: var(--primary-color);
}

/* Utility Classes */
.hidden {
  display: none !important;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(50px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 20px 15px;
  }

  .main-title {
    font-size: 2.5rem;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .welcome-actions {
    flex-direction: column;
    align-items: center;
  }

  .start-quiz-btn,
  .quick-start-btn {
    width: 100%;
    max-width: 300px;
  }

  /* .difficulty-buttons {
    flex-direction: column;
    align-items: center;
  } */

  .difficulty-btn {
    width: 100%;
    max-width: 200px;
  }

  .categories-grid {
    grid-template-columns: 1fr;
  }

  .quiz-card {
    padding: 25px;
  }

  .timer-section {
    flex-direction: column;
    gap: 20px;
  }

  .timer-bar-container {
    margin: 0;
    width: 100%;
  }

  .quiz-header {
    flex-direction: column;
    gap: 15px;
    text-align: center;
  }

  .quiz-info {
    justify-content: center;
  }

  .quiz-navigation {
    flex-direction: column;
    gap: 10px;
  }

  .nav-btn {
    width: 100%;
    justify-content: center;
  }

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

  .action-btn {
    width: 100%;
    justify-content: center;
  }

  .results-card {
    padding: 30px 20px;
  }

  .final-score {
    font-size: 3rem;
  }

  .share-buttons {
    grid-template-columns: 1fr;
  }

  .footer-bottom-content {
    flex-direction: column;
    gap: 15px;
    text-align: center;
  }

  .footer-bottom-links {
    justify-content: center;
  }

  .leaderboard-filters {
    flex-direction: column;
    align-items: center;
  }

  .leaderboard-filters select {
    width: 100%;
    max-width: 250px;
  }

  .progress-indicators {
    gap: 6px;
  }

  .progress-dot {
    width: 10px;
    height: 10px;
  }
}

@media (max-width: 480px) {
  .main-title {
    font-size: 2rem;
  }

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

  .stat-card {
    padding: 20px;
  }

  .quiz-card {
    padding: 20px;
  }

  .question-text {
    font-size: 1.3rem;
    padding: 20px;
  }

  .answer-option {
    padding: 20px;
  }

  .results-card {
    padding: 25px 15px;
  }

  .final-score {
    font-size: 2.5rem;
  }

  .modal-content {
    padding: 20px;
    width: 95%;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .floating-icon {
    font-size: 1.5rem;
  }
}

/* Print Styles */
@media print {
  .navbar,
  .footer,
  .floating-elements,
  .nav-controls,
  .quiz-navigation,
  .results-actions {
    display: none !important;
  }

  body {
    background: white !important;
    color: black !important;
  }

  .quiz-card,
  .results-card {
    background: white !important;
    border: 1px solid #ccc !important;
    box-shadow: none !important;
  }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
  :root {
    --primary-color: #00ffff;
    --secondary-color: #ffffff;
    --text-primary: #ffffff;
    --text-secondary: #cccccc;
    --bg-secondary: #333333;
    --border-color: #666666;
  }
}

/* Reduced Motion */
@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 */
.keyboard-navigation *:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--primary-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--secondary-color);
}

.leaderboard-filters select {
  background: var(--glass-bg);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 12px 20px;
  color: var(--text-primary);
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6,9 12,15 18,9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 40px;
}

.leaderboard-filters select:hover,
.leaderboard-filters select:focus {
  border-color: var(--primary-color);
  outline: none;
  background: var(--bg-tertiary);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
}

.leaderboard-filters select option {
  background: var(--bg-primary);
  color: var(--text-primary);
  padding: 12px;
  border: none;
}

.light-theme .leaderboard-filters select option {
  background: #ffffff;
  color: #2c3e50;
}

.dark-theme .leaderboard-filters select option {
  background: #1a1a2e;
  color: #ffffff;
}