:root {
  --primary: #9b59b6;
  --primary-light: #bb8fce;
  --primary-dark: #6c3483;
  --secondary: #00ff88;
  --accent: #00ffff;
  --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;
  overflow-x: hidden;
  color: #fff;
}

.bg-animation {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background:
    radial-gradient(
      ellipse at 20% 20%,
      rgba(155, 89, 182, 0.15) 0%,
      transparent 50%
    ),
    radial-gradient(
      ellipse at 80% 80%,
      rgba(142, 68, 173, 0.1) 0%,
      transparent 50%
    ),
    radial-gradient(
      ellipse at 50% 50%,
      rgba(0, 255, 136, 0.05) 0%,
      transparent 70%
    );
}

.particles {
  position: fixed;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
}

/* Navigation */
.top-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 30px;
  background: var(--card-bg);
  border-bottom: 1px solid rgba(155, 89, 182, 0.3);
  position: sticky;
  top: 0;
  z-index: 100;
}

.back-btn {
  color: var(--primary-light);
  text-decoration: none;
  font-family: 'Orbitron', sans-serif;
  font-size: 0.9rem;
  padding: 8px 16px;
  border: 1px solid var(--primary);
  border-radius: 20px;
  transition: all 0.3s;
}

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

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

.nav-stats {
  display: flex;
  gap: 20px;
  font-family: 'Orbitron', sans-serif;
}

.xp-counter {
  color: var(--secondary);
}

.level-indicator {
  color: var(--accent);
}

/* Level Selector */
.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(280px, 1fr));
  gap: 25px;
}

.world-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 30px;
  text-align: center;
  border: 2px solid rgba(155, 89, 182, 0.3);
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  position: relative;
  overflow: hidden;
}

.world-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(155, 89, 182, 0.2),
    transparent
  );
  transition: 0.5s;
}

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

.world-card:hover {
  transform: translateY(-10px);
  border-color: var(--primary);
  box-shadow: 0 20px 40px rgba(155, 89, 182, 0.3);
}

.world-card.locked {
  opacity: 0.5;
  cursor: not-allowed;
}

.world-card.locked:hover {
  transform: none;
  box-shadow: none;
}

.world-icon {
  font-size: 4rem;
  margin-bottom: 15px;
}

.world-card h3 {
  font-family: 'Orbitron', sans-serif;
  color: var(--primary-light);
  margin-bottom: 10px;
}

.world-card p {
  color: #aaa;
  margin-bottom: 15px;
}

.world-status {
  display: inline-block;
  padding: 5px 15px;
  border-radius: 15px;
  font-size: 0.8rem;
  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 */
.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;
  font-family: 'Rajdhani', sans-serif;
  transition: all 0.3s;
}

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

.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;
}

/* Challenge Container */
.challenge-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.challenge-panel {
  background: var(--card-bg);
  border-radius: 15px;
  padding: 25px;
  border: 1px solid rgba(155, 89, 182, 0.3);
}

.challenge-title {
  font-family: 'Orbitron', sans-serif;
  color: var(--primary);
  font-size: 1.3rem;
  margin-bottom: 10px;
}

.challenge-description {
  color: #bbb;
  line-height: 1.6;
  margin-bottom: 20px;
}

.input-section {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.input-section label {
  color: var(--accent);
  font-weight: 500;
}

.input-section input {
  width: 80px;
  padding: 10px;
  border: 2px solid var(--primary);
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.3);
  color: #fff;
  font-family: 'Fira Code', monospace;
  font-size: 1rem;
  text-align: center;
}

.run-btn,
.step-btn,
.reset-btn {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-family: 'Orbitron', sans-serif;
  font-size: 0.85rem;
  transition: all 0.3s;
}

.run-btn {
  background: linear-gradient(135deg, var(--success), #27ae60);
  color: #fff;
}

.run-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(46, 204, 113, 0.5);
}

.step-btn {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
}

.step-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(155, 89, 182, 0.5);
}

.reset-btn {
  background: linear-gradient(135deg, var(--warning), #e67e22);
  color: #fff;
}

.reset-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(243, 156, 18, 0.5);
}

/* Visualization Container */
.viz-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  gap: 15px;
}

.code-panel,
.stack-panel,
.output-panel {
  background: var(--card-bg);
  border-radius: 15px;
  padding: 20px;
  border: 1px solid rgba(155, 89, 182, 0.3);
}

.code-panel h4,
.stack-panel h4,
.output-panel h4,
.explanation-panel h4 {
  font-family: 'Orbitron', sans-serif;
  color: var(--accent);
  font-size: 0.9rem;
  margin-bottom: 15px;
}

.code-panel {
  grid-row: span 2;
  position: relative;
}

.code-display {
  font-family: 'Fira Code', monospace;
  font-size: 0.85rem;
  line-height: 1.8;
  color: #e0e0e0;
  background: rgba(0, 0, 0, 0.3);
  padding: 15px;
  border-radius: 10px;
  overflow-x: auto;
  position: relative;
}

.code-display .keyword {
  color: #c792ea;
}

.code-display .function {
  color: #82aaff;
}

.code-display .number {
  color: #f78c6c;
}

.code-display .string {
  color: #c3e88d;
}

.code-display .comment {
  color: #676e95;
}

.code-line {
  display: block;
  padding: 2px 5px;
  border-radius: 3px;
  transition: background 0.3s;
}

.code-line.active {
  background: rgba(155, 89, 182, 0.3);
  border-left: 3px solid var(--primary);
}

.code-line.executed {
  background: rgba(46, 204, 113, 0.2);
}

/* Stack Container */
.stack-container {
  display: flex;
  flex-direction: column-reverse;
  gap: 8px;
  max-height: 200px;
  overflow-y: auto;
}

.stack-frame {
  background: linear-gradient(
    135deg,
    rgba(155, 89, 182, 0.3),
    rgba(142, 68, 173, 0.2)
  );
  border: 1px solid var(--primary);
  border-radius: 8px;
  padding: 10px 15px;
  font-family: 'Fira Code', monospace;
  font-size: 0.85rem;
  animation: pushIn 0.3s ease-out;
}

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

.stack-frame.popping {
  animation: popOut 0.3s ease-in forwards;
}

@keyframes popOut {
  to {
    transform: translateX(50px);
    opacity: 0;
  }
}

.stack-frame .func-name {
  color: var(--primary-light);
  font-weight: 600;
}

.stack-frame .params {
  color: var(--secondary);
}

.stack-frame .return-val {
  color: var(--warning);
  margin-left: 10px;
}

/* Output Display */
.output-display {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 10px;
  padding: 15px;
  font-family: 'Fira Code', monospace;
  font-size: 0.9rem;
  min-height: 100px;
  max-height: 150px;
  overflow-y: auto;
}

.output-item {
  color: var(--secondary);
  margin-bottom: 5px;
  animation: fadeIn 0.3s;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Explanation Panel */
.explanation-panel {
  grid-column: span 2;
  background: var(--card-bg);
  border-radius: 15px;
  padding: 20px;
  border: 1px solid rgba(155, 89, 182, 0.3);
}

.explanation-content {
  color: #bbb;
  line-height: 1.8;
}

.explanation-content strong {
  color: var(--primary-light);
}

.explanation-content code {
  background: rgba(155, 89, 182, 0.2);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: 'Fira Code', monospace;
  color: var(--accent);
}

/* Tree Container */
.tree-container {
  grid-column: span 2;
  background: var(--card-bg);
  border-radius: 15px;
  padding: 20px;
  border: 1px solid rgba(155, 89, 182, 0.3);
  margin-top: 20px;
}

.tree-canvas {
  min-height: 300px;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: auto;
}

.tree-node {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  border-radius: 50%;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Fira Code', monospace;
  font-weight: 600;
  position: relative;
  transition: all 0.3s;
}

.tree-node.active {
  box-shadow: 0 0 20px var(--primary);
  transform: scale(1.1);
}

.tree-node.computed {
  background: linear-gradient(135deg, var(--success), #27ae60);
}

.tree-level {
  display: flex;
  gap: 20px;
  margin: 15px 0;
  position: relative;
}

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

.sub-btn {
  padding: 12px 24px;
  border: 2px solid rgba(155, 89, 182, 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: #fff;
  border-color: var(--primary);
}

.sub-btn.completed {
  border-color: var(--success);
  color: var(--success);
}

.sub-btn.completed::after {
  content: ' ✓';
}

/* Quiz Modal */
.quiz-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.quiz-content {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 40px;
  max-width: 500px;
  text-align: center;
  border: 2px solid var(--primary);
}

.quiz-content h3 {
  font-family: 'Orbitron', sans-serif;
  color: var(--primary-light);
  margin-bottom: 20px;
}

.quiz-content p {
  color: #ddd;
  margin-bottom: 25px;
  font-size: 1.1rem;
}

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

.quiz-option {
  padding: 15px 20px;
  background: rgba(0, 0, 0, 0.3);
  border: 2px solid rgba(255, 255, 255, 0.2);
  border-radius: 10px;
  color: #fff;
  cursor: pointer;
  transition: all 0.3s;
  font-size: 1rem;
}

.quiz-option:hover {
  border-color: var(--primary);
  background: rgba(155, 89, 182, 0.2);
}

.quiz-option.correct {
  border-color: var(--success);
  background: rgba(46, 204, 113, 0.3);
}

.quiz-option.wrong {
  border-color: var(--danger);
  background: rgba(231, 76, 60, 0.3);
}

.quiz-result {
  margin-top: 20px;
  font-size: 1.2rem;
  font-weight: 600;
}

/* Complete Modal */
.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: 3rem;
  color: var(--success);
  margin-bottom: 20px;
}

.complete-content p {
  font-size: 1.5rem;
  color: #ddd;
  margin-bottom: 30px;
}

.rewards {
  margin-bottom: 30px;
}

.xp-earned {
  font-family: 'Orbitron', sans-serif;
  font-size: 2rem;
  color: var(--warning);
  animation: pulse 1s infinite;
}

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

.next-level-btn {
  padding: 15px 40px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  border: none;
  border-radius: 30px;
  font-family: 'Orbitron', sans-serif;
  font-size: 1.2rem;
  cursor: pointer;
  transition: all 0.3s;
}

.next-level-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 30px rgba(155, 89, 182, 0.5);
}

/* Sandbox */
.sandbox-area {
  max-width: 1000px;
  margin: 40px auto;
  padding: 30px;
  background: var(--card-bg);
  border-radius: 20px;
  border: 1px solid rgba(155, 89, 182, 0.3);
}

.sandbox-area h2 {
  font-family: 'Orbitron', sans-serif;
  color: var(--primary-light);
  margin-bottom: 10px;
}

.sandbox-area > p {
  color: #aaa;
  margin-bottom: 20px;
}

.sandbox-editor textarea {
  width: 100%;
  height: 200px;
  background: rgba(0, 0, 0, 0.5);
  border: 2px solid var(--primary);
  border-radius: 10px;
  padding: 15px;
  font-family: 'Fira Code', monospace;
  font-size: 0.9rem;
  color: #e0e0e0;
  resize: vertical;
}

.sandbox-controls {
  display: flex;
  gap: 10px;
  margin-top: 15px;
  align-items: center;
}

.sandbox-controls input {
  width: 80px;
  padding: 10px;
  border: 2px solid var(--primary);
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.3);
  color: #fff;
  font-family: 'Fira Code', monospace;
}

#sandboxRun {
  padding: 12px 24px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-family: 'Orbitron', sans-serif;
  transition: all 0.3s;
}

#sandboxRun:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(155, 89, 182, 0.5);
}

.sandbox-output {
  margin-top: 20px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 10px;
  padding: 15px;
  min-height: 150px;
  font-family: 'Fira Code', monospace;
}

/* Responsive */
@media (max-width: 1024px) {
  .challenge-container {
    grid-template-columns: 1fr;
  }

  .viz-container {
    grid-template-columns: 1fr;
  }

  .code-panel {
    grid-row: span 1;
  }
}

@media (max-width: 768px) {
  .top-nav {
    flex-direction: column;
    gap: 15px;
  }

  .nav-title {
    font-size: 1.2rem;
  }

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

  .game-header {
    flex-direction: column;
    text-align: center;
  }
}