/* ============== CSS VARIABLES ============== */
:root {
  --primary: #6C63FF;
  --primary-dark: #5A52D5;
  --secondary: #FF6B6B;
  --success: #4ECB71;
  --warning: #FFB830;
  --danger: #FF4757;

  --bg-light: #F8F9FF;
  --bg-card: #FFFFFF;
  --bg-dark: #2D3436;

  --text-primary: #2D3436;
  --text-muted: #636E72;
  --text-light: #B2BEC3;

  --math-color: #00B894;
  --science-color: #0984E3;

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 50%;

  --shadow-sm: 0 2px 8px rgba(108, 99, 255, 0.1);
  --shadow-md: 0 8px 32px rgba(108, 99, 255, 0.15);
  --shadow-lg: 0 16px 48px rgba(108, 99, 255, 0.2);

  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-bounce: 500ms cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* ============== RESET & BASE ============== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Quicksand', sans-serif;
  background: var(--bg-light);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: 'Nunito', sans-serif;
  font-weight: 700;
}

button {
  font-family: 'Quicksand', sans-serif;
  cursor: pointer;
  border: none;
  outline: none;
}

input {
  font-family: 'Quicksand', sans-serif;
}

/* ============== SCREENS ============== */
.screen {
  display: none;
  min-height: 100vh;
  padding: 20px;
  animation: fadeIn 0.3s ease;
}

.screen.active {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

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

/* ============== WELCOME SCREEN ============== */
.welcome-container {
  text-align: center;
  max-width: 400px;
  padding: 40px 20px;
}

.logo-bounce {
  animation: bounce 2s infinite;
}

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

.logo-icon {
  font-size: 80px;
  display: block;
  margin-bottom: 10px;
}

.logo-text {
  font-size: 48px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  font-size: 20px;
  color: var(--text-muted);
  margin: 20px 0 40px;
}

.mascot {
  position: relative;
  margin: 30px 0;
}

.mascot-emoji {
  font-size: 100px;
  animation: wave 1s infinite;
}

@keyframes wave {
  0%, 100% { transform: rotate(0deg); }
  25% { transform: rotate(15deg); }
  75% { transform: rotate(-15deg); }
}

.speech-bubble {
  position: absolute;
  top: 10px;
  right: -20px;
  background: var(--bg-card);
  padding: 10px 20px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  font-weight: 600;
  animation: pulse 2s infinite;
}

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

.speech-bubble::after {
  content: '';
  position: absolute;
  left: -10px;
  top: 50%;
  transform: translateY(-50%);
  border: 10px solid transparent;
  border-right-color: var(--bg-card);
}

/* ============== BUTTONS ============== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-lg);
  font-size: 16px;
  font-weight: 600;
  transition: all var(--transition-fast);
}

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

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

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

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

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

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

.btn-danger:hover {
  background: #E74C3C;
}

.btn-link {
  background: transparent;
  color: var(--text-muted);
  margin-top: 20px;
}

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

.btn-large {
  padding: 16px 40px;
  font-size: 18px;
}

.btn-icon-only {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-full);
  background: var(--bg-card);
  font-size: 18px;
}

.btn-icon-only:hover {
  background: var(--bg-light);
}

.btn-icon {
  font-size: 14px;
}

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

/* ============== PROFILE SCREEN ============== */
.profile-container {
  width: 100%;
  max-width: 400px;
  background: var(--bg-card);
  padding: 40px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

.back-btn {
  color: var(--text-muted);
  cursor: pointer;
  margin-bottom: 20px;
  font-weight: 600;
}

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

.screen-title {
  font-size: 28px;
  margin-bottom: 30px;
  text-align: center;
}

.form-group {
  margin-bottom: 30px;
}

.form-label {
  display: block;
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.form-input {
  width: 100%;
  padding: 16px 20px;
  font-size: 18px;
  border: 2px solid var(--text-light);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.form-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(108, 99, 255, 0.1);
}

.form-input::placeholder {
  color: var(--text-light);
}

.age-slider {
  width: 100%;
  height: 8px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  -webkit-appearance: none;
  appearance: none;
  cursor: pointer;
}

.age-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-full);
  background: var(--primary);
  box-shadow: var(--shadow-md);
  cursor: pointer;
}

.age-hints {
  display: flex;
  justify-content: space-between;
  margin-top: 10px;
  color: var(--text-muted);
  font-size: 14px;
}

/* ============== SUBJECT SCREEN ============== */
.subjects-container {
  width: 100%;
  max-width: 600px;
  text-align: center;
}

.screen-subtitle {
  font-size: 18px;
  color: var(--text-muted);
  margin-bottom: 30px;
}

.subject-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
}

.subject-card {
  background: var(--bg-card);
  padding: 30px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
}

.subject-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.math-card:hover {
  border: 2px solid var(--math-color);
}

.science-card:hover {
  border: 2px solid var(--science-color);
}

.subject-icon {
  font-size: 60px;
  margin-bottom: 15px;
}

.subject-card h3 {
  font-size: 24px;
  margin-bottom: 10px;
}

.subject-card p {
  color: var(--text-muted);
  margin-bottom: 15px;
}

.subject-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.topic-tag {
  background: var(--bg-light);
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 12px;
  color: var(--text-muted);
}

/* ============== HOME SCREEN (DASHBOARD) ============== */
.home-container {
  width: 100%;
  max-width: 600px;
}

.home-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

.home-header-buttons {
  display: flex;
  gap: 8px;
}

.logout-btn {
  color: var(--secondary);
}

.home-user-info {
  display: flex;
  align-items: center;
  gap: 15px;
}

.home-avatar {
  width: 60px;
  height: 60px;
  background: var(--primary);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 30px;
}

.home-greeting h2 {
  font-size: 24px;
  color: var(--text-primary);
}

.home-date {
  font-size: 14px;
  color: var(--text-muted);
}

.stats-overview {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 15px;
  margin-bottom: 30px;
}

.stat-card {
  background: var(--bg-card);
  padding: 20px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.stat-card .stat-icon {
  font-size: 30px;
}

.stat-card .stat-info {
  display: flex;
  flex-direction: column;
}

.stat-card .stat-value {
  font-family: 'Fredoka One', cursive;
  font-size: 28px;
  color: var(--primary);
}

.stat-card .stat-label {
  font-size: 12px;
  color: var(--text-muted);
}

.subject-progress-section {
  margin-bottom: 30px;
}

.section-title {
  font-size: 20px;
  margin-bottom: 15px;
  color: var(--text-primary);
}

.subject-progress-card {
  background: var(--bg-card);
  padding: 20px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  margin-bottom: 15px;
  display: flex;
  align-items: center;
  gap: 15px;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.subject-progress-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.subject-progress-icon {
  font-size: 40px;
}

.subject-progress-info {
  flex: 1;
}

.subject-progress-info h4 {
  font-size: 18px;
  margin-bottom: 8px;
}

.progress-bar-small {
  height: 8px;
  background: var(--bg-light);
  border-radius: 10px;
  overflow: hidden;
  margin-bottom: 5px;
}

.progress-fill-small {
  height: 100%;
  background: var(--primary);
  border-radius: 10px;
  transition: width var(--transition-normal);
}

.progress-text {
  font-size: 12px;
  color: var(--text-muted);
}

.subject-stars {
  font-size: 18px;
  font-weight: bold;
  color: var(--warning);
}

.math-progress {
  border-left: 4px solid var(--math-color);
}

.science-progress {
  border-left: 4px solid var(--science-color);
}

.quick-play-section {
  margin-bottom: 20px;
}

.btn-full {
  width: 100%;
}

.recent-score-card {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  padding: 20px;
  border-radius: var(--radius-md);
  color: white;
}

.recent-score-header {
  font-size: 14px;
  opacity: 0.9;
  margin-bottom: 10px;
}

.recent-score-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.recent-game-name {
  font-size: 16px;
}

.recent-score-value {
  font-family: 'Fredoka One', cursive;
  font-size: 32px;
}

/* ============== HUB SCREEN ============== */
.hub-container {
  width: 100%;
  max-width: 800px;
}

.hub-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-card);
  padding: 20px;
  border-radius: var(--radius-md);
  margin-bottom: 30px;
  box-shadow: var(--shadow-sm);
}

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

.user-avatar {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.user-name {
  font-weight: 700;
  font-size: 18px;
}

.user-subject {
  font-size: 14px;
  color: var(--text-muted);
}

.header-buttons {
  display: flex;
  gap: 10px;
}

.progress-section {
  background: var(--bg-card);
  padding: 20px;
  border-radius: var(--radius-md);
  margin-bottom: 30px;
  box-shadow: var(--shadow-sm);
}

.progress-label {
  display: flex;
  justify-content: space-between;
  margin-bottom: 10px;
  font-weight: 600;
}

.progress-bar {
  height: 12px;
  background: var(--bg-light);
  border-radius: 6px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 6px;
  transition: width var(--transition-normal);
}

.levels-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

/* ============== LEVEL CARD ============== */
.level-card {
  background: var(--bg-card);
  padding: 25px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

.level-card:not(.locked):hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.level-card.locked {
  opacity: 0.6;
  cursor: not-allowed;
  filter: grayscale(50%);
}

.level-number {
  font-family: 'Fredoka One', cursive;
  font-size: 48px;
  color: var(--primary);
  margin-bottom: 10px;
}

.level-card.locked .level-number {
  color: var(--text-light);
}

.level-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 5px;
}

.level-concept {
  font-size: 14px;
  color: var(--text-muted);
}

.level-stars {
  margin-top: 10px;
  font-size: 20px;
}

.lock-overlay {
  position: absolute;
  top: 10px;
  right: 10px;
  font-size: 24px;
}

.current-indicator {
  position: absolute;
  bottom: -5px;
  left: 50%;
  transform: translateX(-50%);
  width: 50px;
  height: 4px;
  background: var(--primary);
  border-radius: 2px;
  animation: glow 1.5s infinite;
}

@keyframes glow {
  0%, 100% { box-shadow: 0 0 5px var(--primary); }
  50% { box-shadow: 0 0 20px var(--primary); }
}

/* ============== GAME SCREEN ============== */
.game-container {
  width: 100%;
  max-width: 100%;
  min-height: 700px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.game-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 20px;
  background: var(--bg-light);
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.game-info {
  display: flex;
  flex-direction: column;
}

.game-title {
  font-weight: 700;
  font-size: 18px;
}

.game-level {
  font-size: 14px;
  color: var(--text-muted);
}

.game-stats {
  display: flex;
  gap: 20px;
}

.stat {
  display: flex;
  align-items: center;
  gap: 5px;
  font-family: 'Fredoka One', cursive;
  font-size: 20px;
}

.stat-icon {
  font-size: 20px;
}

.game-area {
  min-height: 600px;
  padding: 0;
  display: flex;
  align-items: stretch;
  justify-content: stretch;
}

.game-instructions {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(248, 249, 255, 0.95);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
}

.instructions-content {
  background: var(--bg-card);
  padding: 40px;
  border-radius: var(--radius-md);
  text-align: center;
  max-width: 400px;
  box-shadow: var(--shadow-lg);
}

.instructions-content h3 {
  font-size: 24px;
  margin-bottom: 15px;
}

.instructions-content p {
  color: var(--text-muted);
  margin-bottom: 25px;
  line-height: 1.6;
}

/* ============== RESULTS SCREEN ============== */
.results-container {
  width: 100%;
  max-width: 500px;
  text-align: center;
  background: var(--bg-card);
  padding: 40px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

.results-header {
  margin-bottom: 30px;
}

.result-icon {
  font-size: 80px;
  margin-bottom: 20px;
}

.result-title {
  font-size: 32px;
  margin-bottom: 10px;
}

.result-message {
  color: var(--text-muted);
  font-size: 18px;
}

.score-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  margin-bottom: 30px;
}

.score-circle {
  width: 150px;
  height: 150px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: var(--shadow-lg);
}

.score-number {
  font-family: 'Fredoka One', cursive;
  font-size: 48px;
}

.score-label {
  font-size: 16px;
  opacity: 0.9;
}

.stars-display {
  display: flex;
  gap: 10px;
  font-size: 40px;
}

.star {
  transition: all var(--transition-bounce);
}

.star.earned {
  animation: starPop 0.5s ease forwards;
}

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

.result-details {
  background: var(--bg-light);
  padding: 20px;
  border-radius: var(--radius-md);
  margin-bottom: 30px;
}

.detail-item {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

.detail-item:last-child {
  border-bottom: none;
}

.status-badge {
  padding: 5px 15px;
  border-radius: 20px;
  font-weight: 600;
}

.status-badge.passed {
  background: var(--success);
  color: white;
}

.status-badge.failed {
  background: var(--secondary);
  color: white;
}

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

/* ============== MODAL ============== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal-overlay.active {
  display: flex;
}

.modal {
  background: var(--bg-card);
  padding: 30px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-width: 400px;
  width: 90%;
  animation: modalSlide 0.3s ease;
}

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

.modal-content p {
  font-size: 18px;
  margin-bottom: 25px;
  text-align: center;
}

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

/* ============== CONFETTI ============== */
.confetti-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 999;
  overflow: hidden;
}

.confetti {
  position: absolute;
  width: 10px;
  height: 10px;
  animation: confettiFall 3s linear forwards;
}

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

/* ============== RESPONSIVE ============== */
@media (max-width: 600px) {
  .logo-text {
    font-size: 36px;
  }

  .logo-icon {
    font-size: 60px;
  }

  .mascot-emoji {
    font-size: 70px;
  }

  .subject-cards {
    grid-template-columns: 1fr;
  }

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

  .hub-header {
    flex-direction: column;
    gap: 15px;
  }

  .game-header {
    flex-wrap: wrap;
    gap: 10px;
  }

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

/* ============== UTILITIES ============== */
.hidden {
  display: none !important;
}

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

.mt-20 {
  margin-top: 20px;
}

/* ============== GAME SPECIFIC ============== */
.game-area {
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
}

.game-question {
  font-family: 'Fredoka One', cursive;
  font-size: 72px;
  color: var(--primary);
  margin-bottom: 30px;
}

.game-choices {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 15px;
  max-width: 400px;
}

.choice-btn {
  padding: 20px 30px;
  font-size: 28px;
  font-family: 'Fredoka One', cursive;
  background: var(--bg-card);
  border: 3px solid var(--text-light);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.choice-btn:hover {
  border-color: var(--primary);
  transform: scale(1.05);
}

.choice-btn.correct {
  background: var(--success);
  border-color: var(--success);
  color: white;
  animation: correctPulse 0.5s ease;
}

.choice-btn.wrong {
  background: var(--secondary);
  border-color: var(--secondary);
  color: white;
  animation: shake 0.5s ease;
}

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

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

/* Match Game Styles */
.match-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 500px;
}

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

.match-item {
  padding: 15px 20px;
  background: var(--bg-card);
  border: 2px solid var(--text-light);
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
}

.match-item:hover {
  border-color: var(--primary);
}

.match-item.selected {
  border-color: var(--primary);
  background: rgba(108, 99, 255, 0.1);
}

.match-item.matched {
  border-color: var(--success);
  background: rgba(78, 203, 113, 0.2);
  pointer-events: none;
}