/* ==========================================
   BIT MANIPULATION QUEST - STYLES
   Cyberpunk/Retro-Tech Aesthetic
   ========================================== */

:root {
  /* Core palette - Electric Neon on Deep Space */
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: #1a1a28;
  --bg-hover: #252538;

  /* Neon accents */
  --neon-cyan: #00f5ff;
  --neon-magenta: #ff00ff;
  --neon-green: #39ff14;
  --neon-yellow: #ffff00;
  --neon-orange: #ff6600;
  --neon-red: #ff3366;
  --neon-blue: #3366ff;
  --neon-purple: #9933ff;

  /* Text */
  --text-primary: #e0e0e8;
  --text-secondary: #8888aa;
  --text-dim: #555570;

  /* Gradients */
  --gradient-primary: linear-gradient(
    135deg,
    var(--neon-cyan) 0%,
    var(--neon-magenta) 100%
  );
  --gradient-success: linear-gradient(
    135deg,
    var(--neon-green) 0%,
    var(--neon-cyan) 100%
  );
  --gradient-warning: linear-gradient(
    135deg,
    var(--neon-yellow) 0%,
    var(--neon-orange) 100%
  );
  --gradient-danger: linear-gradient(
    135deg,
    var(--neon-red) 0%,
    var(--neon-magenta) 100%
  );

  /* Shadows */
  --glow-cyan: 0 0 20px rgba(0, 245, 255, 0.5);
  --glow-magenta: 0 0 20px rgba(255, 0, 255, 0.5);
  --glow-green: 0 0 20px rgba(57, 255, 20, 0.5);

  /* Sizing */
  --header-height: 80px;
  --border-radius: 8px;
  --border-radius-lg: 16px;
}

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

html,
body {
  height: 100%;
  overflow-x: hidden;
}

body {
  font-family: 'Rajdhani', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  background-image:
    radial-gradient(
      ellipse at 20% 20%,
      rgba(0, 245, 255, 0.08) 0%,
      transparent 50%
    ),
    radial-gradient(
      ellipse at 80% 80%,
      rgba(255, 0, 255, 0.08) 0%,
      transparent 50%
    );
}

/* Scanline effect overlay */
.scanlines {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1000;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0, 0, 0, 0.1) 2px,
    rgba(0, 0, 0, 0.1) 4px
  );
  opacity: 0.3;
}

/* Grid overlay */
.grid-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 999;
  background-image:
    linear-gradient(rgba(0, 245, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 245, 255, 0.03) 1px, transparent 1px);
  background-size: 50px 50px;
}

/* ==========================================
   SCREENS
   ========================================== */

.screen {
  display: none;
  min-height: 100vh;
  padding: 20px;
}

.screen.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

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

/* ==========================================
   HUB HEADER
   ========================================== */

.hub-header {
  text-align: center;
  padding: 40px 20px;
  margin-bottom: 30px;
}

.logo-container {
  display: inline-block;
}

.bit-icon {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 20px;
}

.bit-icon span {
  font-family: 'Share Tech Mono', monospace;
  font-size: 4rem;
  font-weight: bold;
  animation: bitPulse 2s ease infinite;
}

.bit-0 {
  color: var(--neon-magenta);
  text-shadow: var(--glow-magenta);
  animation-delay: 0s !important;
}

.bit-1 {
  color: var(--neon-cyan);
  text-shadow: var(--glow-cyan);
  animation-delay: 1s !important;
}

@keyframes bitPulse {
  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.7;
    transform: scale(0.95);
  }
}

.hub-header h1 {
  font-family: 'Orbitron', sans-serif;
  font-size: 3.5rem;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 4px;
  margin-bottom: 5px;
}

.hub-header h2 {
  font-family: 'Orbitron', sans-serif;
  font-size: 2rem;
  font-weight: 400;
  color: var(--text-secondary);
  letter-spacing: 20px;
  margin-left: 20px;
}

.tagline {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-top: 20px;
  letter-spacing: 2px;
}

/* ==========================================
   HUB STATS
   ========================================== */

.hub-stats {
  display: flex;
  justify-content: center;
  gap: 30px;
  margin-bottom: 40px;
}

.stat-box {
  background: var(--bg-card);
  border: 1px solid rgba(0, 245, 255, 0.2);
  border-radius: var(--border-radius);
  padding: 20px 40px;
  text-align: center;
  transition: all 0.3s ease;
}

.stat-box:hover {
  border-color: var(--neon-cyan);
  box-shadow: var(--glow-cyan);
  transform: translateY(-2px);
}

.stat-value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 2.5rem;
  color: var(--neon-cyan);
  display: block;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 2px;
}

/* ==========================================
   GROUP NAVIGATION
   ========================================== */

.group-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
  padding: 0 20px;
}

.group-btn {
  font-family: 'Rajdhani', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 10px 20px;
  border: 1px solid var(--text-dim);
  border-radius: 30px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.3s ease;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.group-btn:hover {
  border-color: var(--neon-cyan);
  color: var(--neon-cyan);
}

.group-btn.active {
  background: var(--gradient-primary);
  border-color: transparent;
  color: var(--bg-primary);
}

/* ==========================================
   GAMES GRID
   ========================================== */

.games-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
  max-width: 1600px;
  margin: 0 auto;
  padding-bottom: 60px;
}

.game-card {
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius-lg);
  padding: 25px;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.game-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--card-accent, var(--gradient-primary));
}

.game-card:hover {
  transform: translateY(-5px);
  border-color: rgba(0, 245, 255, 0.3);
  box-shadow:
    0 10px 40px rgba(0, 0, 0, 0.4),
    0 0 30px rgba(0, 245, 255, 0.1);
}

.game-card-header {
  display: flex;
  align-items: flex-start;
  gap: 15px;
  margin-bottom: 15px;
}

.game-number {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.5rem;
  color: var(--neon-cyan);
  opacity: 0.5;
  min-width: 40px;
}

.game-card-title {
  flex: 1;
}

.game-card-title h3 {
  font-family: 'Orbitron', sans-serif;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 5px;
  line-height: 1.3;
}

.game-card-title .subtitle {
  font-size: 0.85rem;
  color: var(--neon-magenta);
  font-style: italic;
}

.game-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 15px;
}

.game-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.game-group {
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 4px 10px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 20px;
}

.game-status {
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 5px;
}

.game-status.completed {
  color: var(--neon-green);
}

.game-status.locked {
  color: var(--text-dim);
}

/* Group accent colors */
.game-card[data-group='A'] {
  --card-accent: linear-gradient(90deg, #00f5ff, #00aaff);
}
.game-card[data-group='B'] {
  --card-accent: linear-gradient(90deg, #ff00ff, #ff66ff);
}
.game-card[data-group='C'] {
  --card-accent: linear-gradient(90deg, #39ff14, #00ff88);
}
.game-card[data-group='D'] {
  --card-accent: linear-gradient(90deg, #ffff00, #ffaa00);
}
.game-card[data-group='E'] {
  --card-accent: linear-gradient(90deg, #ff6600, #ff3300);
}
.game-card[data-group='F'] {
  --card-accent: linear-gradient(90deg, #3366ff, #0099ff);
}
.game-card[data-group='G'] {
  --card-accent: linear-gradient(90deg, #9933ff, #ff33ff);
}
.game-card[data-group='H'] {
  --card-accent: linear-gradient(90deg, #ff3366, #ff0066);
}
.game-card[data-group='I'] {
  --card-accent: linear-gradient(90deg, #00ff88, #00ffcc);
}
.game-card[data-group='J'] {
  --card-accent: linear-gradient(90deg, #ffcc00, #ff9900);
}
.game-card[data-group='K'] {
  --card-accent: linear-gradient(90deg, #ff0099, #9900ff);
}

/* ==========================================
   GAME SCREEN
   ========================================== */

.game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 15px 25px;
  background: var(--bg-secondary);
  border-bottom: 1px solid rgba(0, 245, 255, 0.1);
  margin: -20px -20px 20px -20px;
}

.back-btn {
  font-family: 'Rajdhani', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  padding: 10px 20px;
  border: 1px solid var(--neon-cyan);
  border-radius: var(--border-radius);
  background: transparent;
  color: var(--neon-cyan);
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
}

.back-btn:hover {
  background: var(--neon-cyan);
  color: var(--bg-primary);
}

.back-btn .arrow {
  font-size: 1.2rem;
}

.game-title-container {
  text-align: center;
}

.game-title-container h1 {
  font-family: 'Orbitron', sans-serif;
  font-size: 1.5rem;
  color: var(--text-primary);
}

.game-title-container p {
  font-size: 0.9rem;
  color: var(--neon-magenta);
}

.game-score-display {
  text-align: right;
}

.score-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  display: block;
}

.score-value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 2rem;
  color: var(--neon-green);
}

.game-content {
  max-width: 1200px;
  margin: 0 auto;
  min-height: calc(100vh - 200px);
}

.game-footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 15px 30px;
  background: var(--bg-secondary);
  border-top: 1px solid rgba(0, 245, 255, 0.1);
}

.concept-display {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.2rem;
  text-align: center;
  color: var(--neon-cyan);
}

/* ==========================================
   GAME COMPONENTS
   ========================================== */

/* Binary Display */
.binary-display {
  display: flex;
  justify-content: center;
  gap: 5px;
  margin: 20px 0;
}

.bit-cell {
  width: 50px;
  height: 60px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
  border: 2px solid var(--text-dim);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
}

.bit-cell.active {
  border-color: var(--neon-cyan);
  background: rgba(0, 245, 255, 0.1);
}

.bit-cell .bit-value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.8rem;
  color: var(--text-primary);
}

.bit-cell .bit-weight {
  font-size: 0.65rem;
  color: var(--text-dim);
  position: absolute;
  bottom: 4px;
}

.bit-cell:hover {
  transform: scale(1.05);
  border-color: var(--neon-magenta);
}

.bit-cell.is-1 {
  background: rgba(0, 245, 255, 0.2);
  border-color: var(--neon-cyan);
  box-shadow: var(--glow-cyan);
}

.bit-cell.is-1 .bit-value {
  color: var(--neon-cyan);
}

/* Number Input */
.number-input-container {
  text-align: center;
  margin: 30px 0;
}

.number-input {
  font-family: 'Share Tech Mono', monospace;
  font-size: 2rem;
  width: 200px;
  padding: 15px 20px;
  text-align: center;
  background: var(--bg-card);
  border: 2px solid var(--text-dim);
  border-radius: var(--border-radius);
  color: var(--text-primary);
  outline: none;
  transition: all 0.3s ease;
}

.number-input:focus {
  border-color: var(--neon-cyan);
  box-shadow: var(--glow-cyan);
}

/* Target Display */
.target-display {
  text-align: center;
  margin: 20px 0;
  padding: 20px;
  background: var(--bg-card);
  border-radius: var(--border-radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.target-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 10px;
}

.target-value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 3rem;
  color: var(--neon-yellow);
  text-shadow: 0 0 20px rgba(255, 255, 0, 0.5);
}

/* Buttons */
.btn-primary {
  font-family: 'Rajdhani', sans-serif;
  font-size: 1.1rem;
  font-weight: 600;
  padding: 15px 40px;
  border: none;
  border-radius: var(--border-radius);
  background: var(--gradient-primary);
  color: var(--bg-primary);
  cursor: pointer;
  transition: all 0.3s ease;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.btn-primary:hover {
  transform: scale(1.05);
  box-shadow: var(--glow-cyan);
}

.btn-secondary {
  font-family: 'Rajdhani', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  padding: 12px 30px;
  border: 2px solid var(--text-dim);
  border-radius: var(--border-radius);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.3s ease;
  text-transform: uppercase;
  letter-spacing: 1px;
}

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

/* Action Buttons Grid */
.action-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  justify-content: center;
  margin: 30px 0;
}

.action-btn {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.2rem;
  padding: 15px 25px;
  border: 2px solid var(--text-dim);
  border-radius: var(--border-radius);
  background: var(--bg-card);
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.2s ease;
  min-width: 80px;
}

.action-btn:hover {
  border-color: var(--neon-cyan);
  background: rgba(0, 245, 255, 0.1);
  transform: translateY(-2px);
}

.action-btn.selected {
  border-color: var(--neon-green);
  background: rgba(57, 255, 20, 0.2);
  color: var(--neon-green);
}

.action-btn.correct {
  border-color: var(--neon-green);
  background: rgba(57, 255, 20, 0.3);
  color: var(--neon-green);
  animation: correctPulse 0.5s ease;
}

.action-btn.wrong {
  border-color: var(--neon-red);
  background: rgba(255, 51, 102, 0.3);
  color: var(--neon-red);
  animation: wrongShake 0.5s ease;
}

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

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

/* Power-of-2 Tiles */
.power-tiles {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  justify-content: center;
  margin: 30px 0;
}

.power-tile {
  width: 80px;
  height: 80px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
  border: 2px solid var(--text-dim);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all 0.2s ease;
}

.power-tile:hover {
  border-color: var(--neon-cyan);
  transform: scale(1.05);
}

.power-tile.collected {
  border-color: var(--neon-green);
  background: rgba(57, 255, 20, 0.2);
}

.power-tile .value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.5rem;
  color: var(--text-primary);
}

.power-tile .power {
  font-size: 0.7rem;
  color: var(--text-dim);
}

/* Truth Table */
.truth-table {
  margin: 30px auto;
  border-collapse: collapse;
  font-family: 'Share Tech Mono', monospace;
}

.truth-table th,
.truth-table td {
  padding: 12px 25px;
  border: 1px solid var(--text-dim);
  text-align: center;
}

.truth-table th {
  background: var(--bg-secondary);
  color: var(--neon-cyan);
  font-weight: normal;
}

.truth-table td {
  background: var(--bg-card);
}

.truth-table .result-1 {
  color: var(--neon-green);
}

.truth-table .result-0 {
  color: var(--neon-red);
}

/* Operation Display */
.operation-display {
  text-align: center;
  margin: 30px 0;
  padding: 25px;
  background: var(--bg-card);
  border-radius: var(--border-radius-lg);
  border: 1px solid rgba(0, 245, 255, 0.2);
}

.operation-display .operand {
  font-family: 'Share Tech Mono', monospace;
  font-size: 2rem;
  color: var(--text-primary);
  margin: 10px 0;
}

.operation-display .operator {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.5rem;
  color: var(--neon-magenta);
}

.operation-display .result-line {
  border-top: 2px solid var(--text-dim);
  margin-top: 15px;
  padding-top: 15px;
}

/* Message Display */
.message {
  text-align: center;
  padding: 15px 25px;
  border-radius: var(--border-radius);
  margin: 20px 0;
  font-size: 1.1rem;
}

.message.success {
  background: rgba(57, 255, 20, 0.1);
  border: 1px solid var(--neon-green);
  color: var(--neon-green);
}

.message.error {
  background: rgba(255, 51, 102, 0.1);
  border: 1px solid var(--neon-red);
  color: var(--neon-red);
}

.message.info {
  background: rgba(0, 245, 255, 0.1);
  border: 1px solid var(--neon-cyan);
  color: var(--neon-cyan);
}

/* Level Progress */
.level-progress {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin: 20px 0;
}

.level-indicator {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--text-dim);
  transition: all 0.3s ease;
}

.level-indicator.completed {
  background: var(--neon-green);
  box-shadow: var(--glow-green);
}

.level-indicator.current {
  background: var(--neon-cyan);
  box-shadow: var(--glow-cyan);
  animation: currentPulse 1.5s ease infinite;
}

@keyframes currentPulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.3);
  }
}

/* Tower/Stack Display */
.tower-container {
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  gap: 5px;
  margin: 30px auto;
  min-height: 300px;
}

.tower-block {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.5rem;
  padding: 10px 40px;
  background: var(--gradient-primary);
  color: var(--bg-primary);
  border-radius: var(--border-radius);
  animation: stackIn 0.3s ease;
}

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

/* Torch/Gate Visuals */
.gate-container {
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 60px;
  margin: 40px 0;
}

.torch {
  width: 40px;
  height: 100px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.torch-flame {
  width: 30px;
  height: 40px;
  border-radius: 50% 50% 50% 50%;
  background: var(--text-dim);
  transition: all 0.3s ease;
}

.torch.lit .torch-flame {
  background: linear-gradient(to top, var(--neon-orange), var(--neon-yellow));
  box-shadow: 0 0 30px rgba(255, 165, 0, 0.8);
  animation: flicker 0.5s ease infinite alternate;
}

@keyframes flicker {
  from {
    transform: scaleY(1);
  }
  to {
    transform: scaleY(1.1);
  }
}

.torch-base {
  width: 15px;
  height: 60px;
  background: linear-gradient(to right, #4a4a4a, #6a6a6a, #4a4a4a);
  border-radius: 0 0 5px 5px;
}

.gate {
  width: 120px;
  height: 150px;
  background: var(--bg-card);
  border: 3px solid var(--text-dim);
  border-radius: 60px 60px 0 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.5s ease;
}

.gate.open {
  border-color: var(--neon-green);
  background: rgba(57, 255, 20, 0.1);
  box-shadow: inset 0 0 50px rgba(57, 255, 20, 0.3);
}

.gate-status {
  font-family: 'Orbitron', sans-serif;
  font-size: 0.9rem;
  color: var(--text-dim);
}

.gate.open .gate-status {
  color: var(--neon-green);
}

/* Calculator Style */
.calculator {
  background: var(--bg-card);
  border: 2px solid rgba(0, 245, 255, 0.2);
  border-radius: var(--border-radius-lg);
  padding: 30px;
  max-width: 400px;
  margin: 30px auto;
}

.calc-display {
  background: var(--bg-primary);
  border: 1px solid var(--text-dim);
  border-radius: var(--border-radius);
  padding: 15px;
  margin-bottom: 20px;
  text-align: right;
}

.calc-display .main-value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 2rem;
  color: var(--neon-cyan);
}

.calc-display .sub-value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1rem;
  color: var(--text-secondary);
}

.calc-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.calc-btn {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.2rem;
  padding: 15px;
  border: 1px solid var(--text-dim);
  border-radius: var(--border-radius);
  background: var(--bg-secondary);
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.calc-btn:hover {
  border-color: var(--neon-cyan);
  background: rgba(0, 245, 255, 0.1);
}

.calc-btn.operator {
  background: rgba(255, 0, 255, 0.2);
  border-color: var(--neon-magenta);
  color: var(--neon-magenta);
}

.calc-btn.equals {
  background: var(--gradient-primary);
  border: none;
  color: var(--bg-primary);
  grid-column: span 2;
}

/* Array/Set Display */
.array-display {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin: 20px 0;
  padding: 20px;
  background: var(--bg-card);
  border-radius: var(--border-radius-lg);
}

.array-item {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.3rem;
  padding: 15px 20px;
  background: var(--bg-secondary);
  border: 2px solid var(--text-dim);
  border-radius: var(--border-radius);
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.array-item:hover {
  border-color: var(--neon-cyan);
}

.array-item.selected {
  border-color: var(--neon-green);
  background: rgba(57, 255, 20, 0.2);
}

.array-item.eliminated {
  opacity: 0.3;
  text-decoration: line-through;
}

/* Skill Tree */
.skill-tree {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 600px;
  margin: 30px auto;
}

.skill-node {
  aspect-ratio: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
  border: 2px solid var(--text-dim);
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s ease;
}

.skill-node:hover {
  border-color: var(--neon-cyan);
  transform: scale(1.05);
}

.skill-node.unlocked {
  border-color: var(--neon-green);
  background: rgba(57, 255, 20, 0.1);
  box-shadow: var(--glow-green);
}

.skill-node .skill-icon {
  font-size: 2rem;
  margin-bottom: 5px;
}

.skill-node .skill-name {
  font-size: 0.7rem;
  color: var(--text-secondary);
  text-align: center;
}

/* Gray Code Path */
.gray-code-path {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  justify-content: center;
  margin: 30px 0;
}

.path-node {
  width: 100px;
  padding: 15px;
  text-align: center;
  background: var(--bg-card);
  border: 2px solid var(--text-dim);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all 0.2s ease;
}

.path-node:hover {
  border-color: var(--neon-cyan);
}

.path-node.current {
  border-color: var(--neon-yellow);
  box-shadow: 0 0 20px rgba(255, 255, 0, 0.3);
}

.path-node.visited {
  border-color: var(--neon-green);
  background: rgba(57, 255, 20, 0.1);
}

.path-node .node-value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 1rem;
}

/* ==========================================
   MODALS
   ========================================== */

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  z-index: 2000;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.modal.active {
  display: flex;
  animation: modalIn 0.3s ease;
}

@keyframes modalIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.modal-content {
  background: var(--bg-card);
  border: 1px solid rgba(0, 245, 255, 0.2);
  border-radius: var(--border-radius-lg);
  padding: 40px;
  max-width: 600px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  animation: modalContentIn 0.3s ease;
}

@keyframes modalContentIn {
  from {
    transform: scale(0.9) translateY(20px);
  }
  to {
    transform: scale(1) translateY(0);
  }
}

.modal-content h2 {
  font-family: 'Orbitron', sans-serif;
  font-size: 1.8rem;
  color: var(--neon-cyan);
  margin-bottom: 20px;
  text-align: center;
}

.modal-content p {
  color: var(--text-secondary);
  margin-bottom: 15px;
  line-height: 1.7;
}

.modal-content code {
  font-family: 'Share Tech Mono', monospace;
  background: var(--bg-secondary);
  padding: 2px 8px;
  border-radius: 4px;
  color: var(--neon-green);
}

.modal-content .btn-primary {
  display: block;
  width: 100%;
  margin-top: 30px;
}

/* Result Modal */
.modal-content.result {
  text-align: center;
}

.result-icon {
  font-size: 4rem;
  margin-bottom: 20px;
  animation: bounce 1s ease infinite;
}

@keyframes bounce {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.result-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  margin: 30px 0;
}

.result-stat .value {
  font-family: 'Share Tech Mono', monospace;
  font-size: 2.5rem;
  color: var(--neon-cyan);
  display: block;
}

.result-stat .label {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.result-buttons {
  display: flex;
  gap: 15px;
  justify-content: center;
}

/* ==========================================
   RESPONSIVE
   ========================================== */

@media (max-width: 768px) {
  .hub-header h1 {
    font-size: 2rem;
    letter-spacing: 2px;
  }

  .hub-header h2 {
    font-size: 1.2rem;
    letter-spacing: 10px;
  }

  .bit-icon span {
    font-size: 2.5rem;
  }

  .hub-stats {
    flex-direction: column;
    align-items: center;
  }

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

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

  .binary-display {
    flex-wrap: wrap;
  }

  .bit-cell {
    width: 40px;
    height: 50px;
  }

  .bit-cell .bit-value {
    font-size: 1.4rem;
  }

  .gate-container {
    flex-direction: column;
    align-items: center;
    gap: 20px;
  }

  .result-buttons {
    flex-direction: column;
  }
}

/* ==========================================
   UTILITY CLASSES
   ========================================== */

.text-center {
  text-align: center;
}
.text-cyan {
  color: var(--neon-cyan);
}
.text-magenta {
  color: var(--neon-magenta);
}
.text-green {
  color: var(--neon-green);
}
.text-yellow {
  color: var(--neon-yellow);
}
.text-red {
  color: var(--neon-red);
}
.text-mono {
  font-family: 'Share Tech Mono', monospace;
}

.mt-1 {
  margin-top: 10px;
}
.mt-2 {
  margin-top: 20px;
}
.mt-3 {
  margin-top: 30px;
}
.mb-1 {
  margin-bottom: 10px;
}
.mb-2 {
  margin-bottom: 20px;
}
.mb-3 {
  margin-bottom: 30px;
}

.flex-center {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hidden {
  display: none !important;
}

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

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

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

::-webkit-scrollbar-thumb:hover {
  background: var(--neon-cyan);
}