/* ====================================================================
   TREE REALMS - Main Stylesheet
   A complete educational adventure game for tree data structures
   ==================================================================== */

/* CSS Variables - Dark Forest Theme */
:root {
  /* Primary Colors */
  --bg-dark: #0a0f0d;
  --bg-medium: #141f1a;
  --bg-light: #1e2d27;
  --bg-card: #243530;

  /* Accent Colors */
  --primary: #4ade80;
  --primary-dark: #22c55e;
  --primary-glow: rgba(74, 222, 128, 0.3);
  --secondary: #60a5fa;
  --secondary-dark: #3b82f6;
  --accent-gold: #fbbf24;
  --accent-purple: #a78bfa;
  --accent-red: #f87171;
  --accent-cyan: #22d3d3;

  /* Text Colors */
  --text-primary: #e8f5e9;
  --text-secondary: #a7c4bc;
  --text-muted: #6b8f82;

  /* Node Colors */
  --node-default: #2dd4bf;
  --node-selected: #fbbf24;
  --node-correct: #4ade80;
  --node-wrong: #f87171;
  --node-highlight: #a78bfa;
  --node-visited: #60a5fa;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #4ade80 0%, #22d3d3 100%);
  --gradient-gold: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
  --gradient-dark: linear-gradient(180deg, #0a0f0d 0%, #141f1a 100%);
  --gradient-card: linear-gradient(145deg, #243530 0%, #1e2d27 100%);

  /* Shadows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 20px var(--primary-glow);

  /* Borders */
  --border-subtle: 1px solid rgba(74, 222, 128, 0.1);
  --border-accent: 2px solid var(--primary);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Fonts */
  --font-display: 'Cinzel', serif;
  --font-body: 'Rajdhani', sans-serif;
  --font-pixel: 'Press Start 2P', cursive;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 50%;
}

/* Reset & Base Styles */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.5;
  color: var(--text-primary);
  background: var(--bg-dark);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Screen Management */
.screen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  visibility: hidden;
  transition:
    opacity var(--transition-slow),
    visibility var(--transition-slow);
  overflow: hidden;
}

.screen.active {
  opacity: 1;
  visibility: visible;
  z-index: 10;
}

/* ====================================================================
   LOADING SCREEN
   ==================================================================== */
#loading-screen {
  background: var(--gradient-dark);
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.tree-logo {
  font-size: 6rem;
  animation:
    float 3s ease-in-out infinite,
    glow-pulse 2s ease-in-out infinite;
  filter: drop-shadow(0 0 30px var(--primary-glow));
}

.game-title {
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-top: var(--spacing-lg);
  letter-spacing: 0.1em;
}

.subtitle {
  font-family: var(--font-display);
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-top: var(--spacing-sm);
  letter-spacing: 0.3em;
  text-transform: uppercase;
}

.loading-bar {
  width: 300px;
  height: 6px;
  background: var(--bg-light);
  border-radius: var(--radius-full);
  margin: var(--spacing-xl) auto var(--spacing-md);
  overflow: hidden;
}

.loading-progress {
  width: 0%;
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width 0.3s ease;
  box-shadow: var(--shadow-glow);
}

.loading-text {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ====================================================================
   MAIN MENU
   ==================================================================== */
#main-menu {
  background: var(--gradient-dark);
}

.menu-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

.floating-nodes {
  position: absolute;
  width: 100%;
  height: 100%;
}

.floating-node {
  position: absolute;
  width: 40px;
  height: 40px;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  opacity: 0.1;
  animation: float-random 10s ease-in-out infinite;
}

.menu-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: var(--spacing-xl);
}

.logo-container {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.tree-symbol {
  font-size: 5rem;
  animation: float 3s ease-in-out infinite;
  filter: drop-shadow(0 0 40px var(--primary-glow));
}

.main-title {
  font-family: var(--font-display);
  font-size: 4rem;
  font-weight: 900;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 0.15em;
  text-shadow: none;
  margin-top: var(--spacing-md);
}

.main-subtitle {
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: var(--text-secondary);
  letter-spacing: 0.4em;
  text-transform: uppercase;
  margin-top: var(--spacing-sm);
}

.menu-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  width: 300px;
}

.menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md) var(--spacing-xl);
  background: var(--gradient-card);
  border: var(--border-subtle);
  border-radius: var(--radius-lg);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.menu-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(74, 222, 128, 0.1),
    transparent
  );
  transition: left var(--transition-slow);
}

.menu-btn:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

.menu-btn:hover::before {
  left: 100%;
}

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

.btn-icon {
  font-size: 1.3rem;
}

.player-stats {
  display: flex;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-2xl);
  padding: var(--spacing-md) var(--spacing-xl);
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-lg);
  border: var(--border-subtle);
}

.stat-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

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

.stat-value {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--primary);
}

/* ====================================================================
   STORY INTRO
   ==================================================================== */
#story-intro {
  background: var(--bg-dark);
}

.story-overlay {
  position: absolute;
  width: 100%;
  height: 100%;
  background: radial-gradient(
    ellipse at center,
    transparent 0%,
    var(--bg-dark) 70%
  );
}

.story-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: var(--spacing-2xl);
  max-width: 800px;
  margin: 0 auto;
}

.story-text {
  font-family: var(--font-display);
  font-size: 1.4rem;
  line-height: 2;
  color: var(--text-primary);
  text-align: center;
  opacity: 0;
  animation: fade-in 1s ease forwards;
}

.story-continue-btn {
  margin-top: var(--spacing-2xl);
  padding: var(--spacing-md) var(--spacing-xl);
  background: transparent;
  border: var(--border-accent);
  border-radius: var(--radius-lg);
  color: var(--primary);
  font-family: var(--font-body);
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition-normal);
}

.story-continue-btn:hover {
  background: var(--primary);
  color: var(--bg-dark);
}

/* ====================================================================
   REALM SELECT
   ==================================================================== */
#realm-select {
  background: var(--gradient-dark);
  display: flex;
  flex-direction: column;
}

.realm-header,
.level-header,
.achievements-header,
.codex-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg) var(--spacing-xl);
  background: rgba(0, 0, 0, 0.3);
  border-bottom: var(--border-subtle);
}

.realm-header h1,
.level-header h1,
.achievements-header h1,
.codex-header h1 {
  font-family: var(--font-display);
  font-size: 1.8rem;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.back-btn {
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--bg-card);
  border: var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.player-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.stars {
  font-size: 1.2rem;
  color: var(--accent-gold);
}

.realms-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  padding: var(--spacing-xl);
  overflow-y: auto;
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.realm-card {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
  padding: var(--spacing-lg);
  background: var(--gradient-card);
  border: var(--border-subtle);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
}

.realm-card:hover {
  transform: translateX(8px);
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

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

.realm-card.locked:hover {
  transform: none;
  border-color: rgba(74, 222, 128, 0.1);
  box-shadow: none;
}

.realm-icon {
  font-size: 3rem;
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-lg);
}

.realm-info {
  flex: 1;
}

.realm-info h2 {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.2em;
}

.realm-info h3 {
  font-size: 1.4rem;
  color: var(--text-primary);
  margin: var(--spacing-xs) 0;
}

.realm-info p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.realm-progress {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-sm);
}

.progress-bar {
  flex: 1;
  height: 6px;
  background: var(--bg-dark);
  border-radius: var(--radius-full);
  overflow: hidden;
}

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

.progress-text {
  font-size: 0.85rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.realm-status {
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  border-radius: var(--radius-full);
  font-size: 1.5rem;
  color: var(--bg-dark);
}

.realm-status.locked {
  background: var(--bg-dark);
  color: var(--text-muted);
}

/* ====================================================================
   LEVEL SELECT
   ==================================================================== */
#level-select {
  background: var(--gradient-dark);
  display: flex;
  flex-direction: column;
}

.levels-container {
  flex: 1;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-lg);
  padding: var(--spacing-xl);
  overflow-y: auto;
}

.level-card {
  background: var(--gradient-card);
  border: var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.level-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-normal);
}

.level-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-glow);
}

.level-card:hover::before {
  transform: scaleX(1);
}

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

.level-card.locked:hover {
  transform: none;
  border-color: rgba(74, 222, 128, 0.1);
  box-shadow: none;
}

.level-card.locked::before {
  display: none;
}

.level-card.completed {
  border-color: var(--primary-dark);
}

.level-number {
  font-family: var(--font-display);
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.2em;
}

.level-title {
  font-size: 1.3rem;
  color: var(--text-primary);
  margin: var(--spacing-xs) 0 var(--spacing-sm);
}

.level-description {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.level-stars {
  display: flex;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-md);
}

.level-star {
  font-size: 1.2rem;
  color: var(--text-muted);
}

.level-star.earned {
  color: var(--accent-gold);
}

.level-lock {
  position: absolute;
  top: 50%;
  right: var(--spacing-lg);
  transform: translateY(-50%);
  font-size: 2rem;
  opacity: 0.5;
}

/* ====================================================================
   OVERLAYS
   ==================================================================== */
.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.overlay.active {
  opacity: 1;
  visibility: visible;
}

.overlay-content {
  background: var(--gradient-card);
  border: var(--border-accent);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  text-align: center;
  max-width: 500px;
  width: 90%;
  animation: scale-in 0.3s ease;
}

.overlay-content h2 {
  font-family: var(--font-display);
  font-size: 2rem;
  margin-bottom: var(--spacing-lg);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.pause-buttons,
.victory-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

/* Victory Screen */
.overlay-content.victory {
  border-color: var(--accent-gold);
}

.victory-icon {
  font-size: 4rem;
  animation: bounce 0.5s ease infinite;
}

.level-results {
  margin: var(--spacing-lg) 0;
}

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

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

.result-value {
  color: var(--primary);
  font-weight: 600;
}

.stars-earned {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg) 0;
  border-bottom: none;
}

.stars-earned .star {
  font-size: 2.5rem;
  color: var(--text-muted);
  transition: all var(--transition-normal);
}

.stars-earned .star.earned {
  color: var(--accent-gold);
  animation: star-pop 0.5s ease;
}

.concept-learned {
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  margin: var(--spacing-lg) 0;
}

.concept-learned h3 {
  font-size: 0.9rem;
  color: var(--accent-cyan);
  margin-bottom: var(--spacing-sm);
}

.concept-learned p {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.menu-btn.secondary {
  background: transparent;
  border: 1px solid var(--text-muted);
}

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

/* Modal */
.modal-content {
  background: var(--gradient-card);
  border: var(--border-accent);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  width: 90%;
  max-width: 400px;
}

.modal-content h3 {
  font-family: var(--font-display);
  margin-bottom: var(--spacing-lg);
}

.modal-content input {
  width: 100%;
  padding: var(--spacing-md);
  background: var(--bg-dark);
  border: var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1.1rem;
  text-align: center;
}

.modal-content input:focus {
  outline: none;
  border-color: var(--primary);
}

.modal-buttons {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.modal-btn {
  flex: 1;
  padding: var(--spacing-md);
  background: var(--bg-light);
  border: var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-body);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.modal-btn.primary {
  background: var(--primary);
  color: var(--bg-dark);
  border-color: var(--primary);
}

/* Toast Notifications */
#toast-container {
  position: fixed;
  bottom: var(--spacing-xl);
  right: var(--spacing-xl);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  z-index: 1000;
}

.toast {
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--bg-card);
  border: var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  animation: slide-in-right 0.3s ease;
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.toast.success {
  border-color: var(--node-correct);
}

.toast.error {
  border-color: var(--node-wrong);
}

.toast.info {
  border-color: var(--secondary);
}

/* ====================================================================
   SCROLLBAR STYLING
   ==================================================================== */
::-webkit-scrollbar {
  width: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--bg-light);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

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

.invisible {
  visibility: hidden;
}

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

.text-primary {
  color: var(--primary);
}

.text-gold {
  color: var(--accent-gold);
}

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