:root {
  --primary: #2ecc71;
  --primary-light: #58d68d;
  --primary-dark: #27ae60;
  --secondary: #00ffff;
  --accent: #f39c12;
  --dark: #0a0a1a;
  --darker: #050510;
  --card-bg: rgba(20, 20, 40, 0.95);
  --success: #2ecc71;
  --warning: #f39c12;
  --danger: #e74c3c;
}

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

body {
  font-family: 'Rajdhani', sans-serif;
  background: var(--darker);
  min-height: 100vh;
  color: #fff;
}

.bg-animation {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background:
    radial-gradient(
      ellipse at 30% 30%,
      rgba(46, 204, 113, 0.1) 0%,
      transparent 50%
    ),
    radial-gradient(
      ellipse at 70% 70%,
      rgba(39, 174, 96, 0.08) 0%,
      transparent 50%
    );
}

.top-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 30px;
  background: var(--card-bg);
  border-bottom: 1px solid rgba(46, 204, 113, 0.3);
  position: sticky;
  top: 0;
  z-index: 100;
}

.back-btn {
  color: var(--primary-light);
  text-decoration: none;
  font-family: 'Orbitron', sans-serif;
  padding: 8px 16px;
  border: 1px solid var(--primary);
  border-radius: 20px;
  transition: all 0.3s;
}

.back-btn:hover {
  background: var(--primary);
  color: var(--dark);
}

.nav-title {
  font-family: 'Orbitron', sans-serif;
  font-size: 1.5rem;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-stats {
  display: flex;
  gap: 20px;
  font-family: 'Orbitron', sans-serif;
}
.xp-counter {
  color: var(--accent);
}
.level-indicator {
  color: var(--secondary);
}

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

.section-title {
  font-family: 'Orbitron', sans-serif;
  font-size: 2rem;
  text-align: center;
  color: var(--primary-light);
  margin-bottom: 40px;
}

.worlds-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.world-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 25px;
  text-align: center;
  border: 2px solid rgba(46, 204, 113, 0.3);
  cursor: pointer;
  transition: all 0.4s;
}

.world-card:hover {
  transform: translateY(-8px);
  border-color: var(--primary);
  box-shadow: 0 15px 30px rgba(46, 204, 113, 0.2);
}

.world-card.locked {
  opacity: 0.5;
  cursor: not-allowed;
}
.world-card.locked:hover {
  transform: none;
  box-shadow: none;
}

.world-icon {
  font-size: 2.5rem;
  margin-bottom: 10px;
}
.world-card h3 {
  font-family: 'Orbitron', sans-serif;
  color: var(--primary-light);
  margin-bottom: 5px;
  font-size: 0.9rem;
}
.world-card p {
  color: #aaa;
  font-size: 0.85rem;
  margin-bottom: 10px;
}

.world-status {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 12px;
  font-size: 0.7rem;
  font-weight: 600;
  background: rgba(231, 76, 60, 0.2);
  color: var(--danger);
}

.world-status.unlocked {
  background: rgba(46, 204, 113, 0.2);
  color: var(--success);
}

.game-area {
  padding: 20px;
  max-width: 1600px;
  margin: 0 auto;
}

.game-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.back-to-levels {
  background: transparent;
  border: 1px solid var(--primary);
  color: var(--primary-light);
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  transition: all 0.3s;
}

.back-to-levels:hover {
  background: var(--primary);
  color: var(--dark);
}

.level-title {
  font-family: 'Orbitron', sans-serif;
  color: var(--primary-light);
  flex: 1;
}

.level-progress {
  width: 200px;
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  width: 0%;
  transition: width 0.5s;
}

.game-container {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 20px;
}

.array-panel,
.control-panel,
.info-panel {
  background: var(--card-bg);
  border-radius: 15px;
  padding: 20px;
  border: 1px solid rgba(46, 204, 113, 0.3);
}

.array-panel h3,
.control-panel h3,
.info-panel h3,
.freq-panel h3,
.log-panel h3 {
  font-family: 'Orbitron', sans-serif;
  color: var(--secondary);
  font-size: 1rem;
  margin-bottom: 15px;
}

.array-controls {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
  flex-wrap: wrap;
}

.array-controls input {
  flex: 1;
  min-width: 120px;
  padding: 10px;
  border: 1px solid var(--primary);
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.3);
  color: #fff;
  font-family: 'Fira Code', monospace;
}

.array-controls button {
  padding: 10px 15px;
  background: var(--primary);
  border: none;
  border-radius: 8px;
  color: var(--dark);
  cursor: pointer;
  font-weight: 600;
  transition: all 0.3s;
}

.array-controls button:hover {
  background: var(--primary-light);
}

.window-display {
  position: relative;
  padding: 30px 10px;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 10px;
  margin-bottom: 15px;
}

.array-container {
  display: flex;
  gap: 5px;
  flex-wrap: wrap;
  justify-content: center;
}

.array-element {
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(46, 204, 113, 0.2);
  border: 2px solid rgba(46, 204, 113, 0.4);
  border-radius: 10px;
  font-family: 'Fira Code', monospace;
  font-weight: 600;
  font-size: 1.1rem;
  position: relative;
  transition: all 0.3s;
}

.array-element .index {
  position: absolute;
  bottom: -20px;
  font-size: 0.7rem;
  color: #888;
}

.array-element.in-window {
  background: linear-gradient(
    135deg,
    rgba(46, 204, 113, 0.6),
    rgba(39, 174, 96, 0.5)
  );
  border-color: var(--primary);
  box-shadow: 0 0 15px rgba(46, 204, 113, 0.4);
  transform: scale(1.05);
}

.array-element.start-pointer {
  border-left: 4px solid #e74c3c;
}

.array-element.end-pointer {
  border-right: 4px solid #3498db;
}

.pointer-labels {
  position: absolute;
  bottom: 5px;
  left: 0;
  right: 0;
  display: flex;
  justify-content: center;
  gap: 40px;
}

.pointer-i,
.pointer-j {
  padding: 3px 10px;
  border-radius: 10px;
  font-family: 'Orbitron', sans-serif;
  font-size: 0.8rem;
}

.pointer-i {
  background: #e74c3c;
  color: #fff;
}
.pointer-j {
  background: #3498db;
  color: #fff;
}

.window-info {
  display: flex;
  gap: 20px;
  font-size: 0.9rem;
  color: #aaa;
  justify-content: center;
}

.window-info span strong {
  color: var(--secondary);
}

.constraint-inputs {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 15px;
}

.constraint-inputs label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: #aaa;
}

.constraint-inputs input {
  width: 80px;
  padding: 8px;
  border: 1px solid var(--primary);
  border-radius: 5px;
  background: rgba(0, 0, 0, 0.3);
  color: #fff;
  font-family: 'Fira Code', monospace;
  text-align: center;
}

.window-buttons {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

.window-btn {
  flex: 1;
  padding: 15px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  font-family: 'Orbitron', sans-serif;
  font-size: 0.9rem;
  transition: all 0.3s;
}

.window-btn.expand {
  background: linear-gradient(135deg, #3498db, #2980b9);
  color: #fff;
}

.window-btn.shrink {
  background: linear-gradient(135deg, #e74c3c, #c0392b);
  color: #fff;
}

.window-btn:hover {
  transform: scale(1.05);
}

.action-buttons {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

.action-buttons button {
  flex: 1;
  padding: 12px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-family: 'Orbitron', sans-serif;
  font-size: 0.85rem;
  transition: all 0.3s;
}

.action-buttons button:first-child {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
}
.action-buttons button:last-child {
  background: linear-gradient(135deg, var(--accent), #e67e22);
  color: #fff;
}
.action-buttons button:hover {
  transform: scale(1.05);
}

.state-display {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 10px;
  padding: 15px;
}

.state-display h4 {
  color: var(--accent);
  font-size: 0.9rem;
  margin-bottom: 10px;
}

.state-item {
  display: flex;
  justify-content: space-between;
  padding: 5px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.state-item span {
  color: #888;
}
.state-item strong {
  color: var(--primary-light);
  font-family: 'Fira Code', monospace;
}

.challenge-info {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 10px;
  padding: 15px;
  margin-bottom: 15px;
}

.challenge-info h4 {
  color: var(--primary-light);
  font-family: 'Orbitron', sans-serif;
  font-size: 1rem;
  margin-bottom: 8px;
}
.challenge-info p {
  color: #aaa;
  font-size: 0.9rem;
  line-height: 1.5;
}

.explanation-content {
  background: rgba(0, 0, 0, 0.2);
  border-radius: 10px;
  padding: 15px;
  margin-bottom: 15px;
  color: #bbb;
  line-height: 1.6;
  font-size: 0.9rem;
  max-height: 150px;
  overflow-y: auto;
}

.explanation-content strong {
  color: var(--primary-light);
}
.explanation-content code {
  background: rgba(46, 204, 113, 0.2);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'Fira Code', monospace;
  color: var(--secondary);
}

.code-display h4 {
  color: var(--secondary);
  font-size: 0.9rem;
  margin-bottom: 10px;
}
.code-display pre {
  background: rgba(0, 0, 0, 0.5);
  border-radius: 8px;
  padding: 15px;
  font-family: 'Fira Code', monospace;
  font-size: 0.75rem;
  overflow-x: auto;
  color: #e0e0e0;
  line-height: 1.5;
  max-height: 150px;
}

.complexity-info {
  display: flex;
  gap: 20px;
  font-size: 0.85rem;
  color: #aaa;
  padding: 10px;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 8px;
  margin-top: 15px;
}

.complexity-info strong {
  color: var(--accent);
}

.freq-panel,
.log-panel {
  background: var(--card-bg);
  border-radius: 15px;
  padding: 20px;
  border: 1px solid rgba(46, 204, 113, 0.3);
  margin-top: 20px;
}

.freq-container {
  display: flex;
  gap: 15px;
  flex-wrap: wrap;
}

.freq-item {
  background: rgba(0, 0, 0, 0.3);
  padding: 10px 20px;
  border-radius: 10px;
  text-align: center;
}

.freq-item .key {
  color: var(--secondary);
  font-family: 'Fira Code', monospace;
  font-size: 1.2rem;
}
.freq-item .count {
  color: var(--accent);
  font-family: 'Orbitron', sans-serif;
  font-size: 0.9rem;
}

.log-display {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 10px;
  padding: 15px;
  max-height: 150px;
  overflow-y: auto;
  font-family: 'Fira Code', monospace;
  font-size: 0.85rem;
  color: var(--primary-light);
}

.log-entry {
  padding: 3px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}
.log-entry.expand {
  color: #3498db;
}
.log-entry.shrink {
  color: #e74c3c;
}
.log-entry.valid {
  color: var(--success);
}
.log-entry.invalid {
  color: var(--danger);
}

.sub-challenges {
  display: flex;
  gap: 10px;
  margin-top: 20px;
  flex-wrap: wrap;
  justify-content: center;
}

.sub-btn {
  padding: 12px 24px;
  border: 2px solid rgba(46, 204, 113, 0.5);
  background: transparent;
  color: #aaa;
  border-radius: 25px;
  cursor: pointer;
  font-family: 'Rajdhani', sans-serif;
  font-size: 1rem;
  transition: all 0.3s;
}

.sub-btn:hover {
  border-color: var(--primary);
  color: var(--primary-light);
}
.sub-btn.active {
  background: var(--primary);
  color: var(--dark);
  border-color: var(--primary);
}
.sub-btn.completed {
  border-color: var(--success);
  color: var(--success);
}
.sub-btn.completed::after {
  content: ' ✓';
}

.complete-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.complete-content {
  text-align: center;
  animation: scaleIn 0.5s ease-out;
}

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

.complete-content h2 {
  font-family: 'Orbitron', sans-serif;
  font-size: 2.5rem;
  color: var(--success);
  margin-bottom: 20px;
}
.complete-content p {
  font-size: 1.3rem;
  color: #ddd;
  margin-bottom: 20px;
}
.xp-earned {
  font-family: 'Orbitron', sans-serif;
  font-size: 1.8rem;
  color: var(--accent);
}

.next-level-btn {
  padding: 15px 40px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--dark);
  border: none;
  border-radius: 30px;
  font-family: 'Orbitron', sans-serif;
  font-size: 1.1rem;
  cursor: pointer;
  transition: all 0.3s;
  margin-top: 20px;
}

.next-level-btn:hover {
  transform: scale(1.05);
}

@media (max-width: 1200px) {
  .game-container {
    grid-template-columns: 1fr 1fr;
  }
  .info-panel {
    grid-column: span 2;
  }
}

@media (max-width: 768px) {
  .game-container {
    grid-template-columns: 1fr;
  }
  .info-panel {
    grid-column: span 1;
  }
  .top-nav {
    flex-direction: column;
    gap: 10px;
  }
}