/* ============================================================
   🎨 UNIFIED DESIGN SYSTEM
   Modern dark theme for both Manual Graph & Hanoi Map modes
   ============================================================ */

:root {
  /* Colors */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  
  --accent-blue: #3b82f6;
  --accent-green: #10b981;
  --accent-purple: #8b5cf6;
  --accent-red: #ef4444;
  
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  
  --border-color: rgba(255, 255, 255, 0.1);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  
  /* Font */
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

html, body {
  height: 100%;
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow: hidden;
}

/* ============================================================
   CANVAS CONTAINER
   ============================================================ */
.canvas-container {
  position: fixed;
  left: 340px;
  top: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 20px 20px, rgba(59, 130, 246, 0.03) 1px, transparent 1px),
    radial-gradient(circle at 20px 20px, rgba(59, 130, 246, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  background-position: 0 0, 20px 20px;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  cursor: crosshair;
}

/* Map mode - No canvas, has #map div */
#map {
  position: fixed;
  left: 340px;
  top: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
}

/* ============================================================
   SIDEBAR
   ============================================================ */
.sidebar {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  width: 340px;
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
  border-right: 1px solid var(--border-color);
  box-shadow: 4px 0 20px rgba(0, 0, 0, 0.5);
  padding: 24px;
  overflow-y: auto;
  z-index: 1000;
}

.sidebar::-webkit-scrollbar {
  width: 8px;
}

.sidebar::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

.sidebar::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 4px;
}

/* Sidebar Header */
.sidebar-header {
  margin-bottom: 24px;
}

.sidebar-header h2 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 8px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ============================================================
   NAVIGATION BUTTONS
   ============================================================ */
.nav-section {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
}

.nav-btn {
  flex: 1;
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.nav-btn:hover:not(:disabled) {
  background: var(--accent-blue);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.nav-btn.active {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: white;
  border-color: transparent;
}

.nav-btn:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

/* ============================================================
   TOOLBAR BUTTONS
   ============================================================ */
.toolbar-row {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}

button {
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
  flex: 1;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

button.primary {
  background: linear-gradient(135deg, var(--accent-green), #059669);
  color: white;
  border: none;
}

button.primary:hover {
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

button.secondary {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
}

button.secondary:hover {
  background: var(--accent-purple);
  border-color: var(--accent-purple);
  color: white;
}

button.danger {
  background: linear-gradient(135deg, var(--accent-red), #dc2626);
  color: white;
  border: none;
}

button.danger:hover {
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
}

/* ============================================================
   FORM CONTROLS
   ============================================================ */
.control-group {
  margin-bottom: 20px;
}

.label {
  display: flex;
  flex-direction: column;
  gap: 10px;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}

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

/* Select */
select {
  width: 100%;
  padding: 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
}

select:hover {
  border-color: var(--accent-blue);
}

select:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

select option {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

/* Range Slider */
input[type="range"] {
  width: 100%;
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.2);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  border-radius: 50%;
  border: none;
  cursor: pointer;
}

/* ============================================================
   LEGEND & INSTRUCTIONS
   ============================================================ */
.legend {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px;
  margin-top: 24px;
}

.legend strong {
  display: block;
  margin-bottom: 16px;
  color: var(--accent-blue);
  font-size: 15px;
}

.legend ul {
  list-style: none;
  padding: 0;
}

.legend li {
  padding: 10px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.legend li:last-child {
  border-bottom: none;
}

.legend li strong {
  display: inline;
  color: var(--text-primary);
  margin-bottom: 0;
  font-size: 13px;
}

/* ============================================================
   STATS PANEL
   ============================================================ */
.stats-panel {
  background: rgba(59, 130, 246, 0.05);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: 12px;
  padding: 20px;
  margin-top: 24px;
}

.stats-panel strong {
  display: block;
  margin-bottom: 16px;
  color: var(--accent-blue);
  font-size: 15px;
}

.stat-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 13px;
}

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

.stat-item span:first-child {
  color: var(--text-secondary);
}

.stat-item span:last-child {
  color: var(--text-primary);
  font-weight: 600;
}

/* ============================================================
   STATUS BAR
   ============================================================ */
.status-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 14px 24px;
  font-size: 14px;
  font-weight: 500;
  text-align: center;
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.2);
  z-index: 1000;
  transition: all 0.3s ease;
}

.status-bar:hover {
  padding: 16px 24px;
}

/* ============================================================
   CONTEXT MENU
   ============================================================ */
.context-menu {
  position: fixed;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 8px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  z-index: 2000;
  min-width: 180px;
}

.context-menu button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 12px 16px;
  margin: 0;
  background: transparent;
  border: none;
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.context-menu button:hover {
  background: var(--accent-blue);
  color: white;
  transform: none;
  box-shadow: none;
}

.context-menu.hidden {
  display: none;
}

/* ============================================================
   RESULT MODAL
   ============================================================ */
.result-modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  z-index: 3000;
  min-width: 400px;
  max-width: 600px;
  transition: all 0.3s ease;
}

.result-modal.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, -50%) scale(0.9);
}

.result-modal h3 {
  margin: 0 0 24px 0;
  font-size: 24px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--border-color);
}

.modal-content p {
  margin: 16px 0;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.8;
}

.modal-content p strong {
  color: var(--text-primary);
  font-weight: 600;
}

.result-modal .close-btn {
  position: absolute;
  top: 20px;
  right: 20px;
  background: var(--accent-red);
  color: white;
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  padding: 0;
}

.result-modal .close-btn:hover {
  background: #dc2626;
  transform: rotate(90deg) scale(1.1);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
}

/* ============================================================
   ANIMATIONS
   ============================================================ */

/* Marker Pulse */
.start-marker, .end-marker, .animation-marker {
  animation: markerPulse 2s ease-in-out infinite;
}

@keyframes markerPulse {
  0%, 100% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.1);
    opacity: 0.8;
  }
}

/* Loading Spinner */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(15, 23, 42, 0.9);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(8px);
}

.spinner {
  border: 4px solid rgba(255, 255, 255, 0.1);
  border-top: 4px solid var(--accent-blue);
  border-radius: 50%;
  width: 50px;
  height: 50px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.loading-overlay p {
  color: var(--text-primary);
  margin-top: 20px;
  font-size: 16px;
  font-weight: 500;
}

/* Smooth Transitions */
button, select, input {
  transition: all 0.2s ease;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  .sidebar {
    width: 100%;
    height: auto;
    max-height: 60vh;
    position: fixed;
    bottom: 0;
    top: auto;
    border-right: none;
    border-top: 1px solid var(--border-color);
  }

  .canvas-container,
  #map {
    left: 0;
    bottom: 60vh;
  }

  .status-bar {
    display: none;
  }

  .result-modal {
    min-width: 90%;
    max-width: 90%;
    padding: 24px;
  }

  .nav-section {
    flex-direction: column;
  }

  .toolbar-row {
    flex-direction: column;
  }

  button {
    width: 100%;
  }
  
  /* Mobile stats panel */
  .live-stats-panel {
    width: 90% !important;
    left: 5% !important;
    right: auto !important;
    top: 10px !important;
  }
}

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

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }

.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }

/* ============================================================
   🌊 LIVE STATS PANEL (Map Mode Visualization)
   ============================================================ */
@keyframes pulse {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.4); opacity: 0.6; }
    100% { transform: scale(1); opacity: 1; }
}

.pulse-marker {
    animation: pulse 1.5s ease-in-out infinite;
}

.live-stats-panel {
    position: fixed;
    top: 20px;
    right: 20px;
    width: 320px;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    z-index: 1000;
    color: #e2e8f0;
    font-family: 'Inter', -apple-system, sans-serif;
}

.live-stats-panel h3 {
    margin: 0 0 16px 0;
    font-size: 18px;
    color: #60a5fa;
    border-bottom: 2px solid #334155;
    padding-bottom: 8px;
}

.live-stats-panel .stat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    padding: 8px 0;
}

.stat-label {
    color: #94a3b8;
    font-size: 14px;
}

.live-stats-panel .stat-row strong {
    color: #fbbf24;
    font-size: 16px;
}

.progress-bar-wrapper {
    width: 100%;
    height: 8px;
    background: #1e293b;
    border-radius: 4px;
    overflow: hidden;
    margin-top: 4px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #3b82f6, #10b981);
    transition: width 0.3s ease;
    width: 0%;
}

.playback-controls {
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid #334155;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.control-btn {
    background: #3b82f6;
    color: white;
    border: none;
    padding: 10px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
    font-weight: 600;
}

.control-btn:hover {
    background: #2563eb;
    transform: translateY(-1px);
}

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

.speed-control {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
}

.speed-control label {
    color: #94a3b8;
    min-width: 50px;
}

.speed-control input[type="range"] {
    flex: 1;
}

.speed-control span {
    color: #fbbf24;
    min-width: 50px;
    text-align: right;
}

.modal-actions {
    margin-top: 20px;
    display: flex;
    gap: 12px;
}

.modal-actions button {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s;
}

.modal-actions .primary {
    background: #3b82f6;
    color: white;
}

.modal-actions .primary:hover {
    background: #2563eb;
    transform: translateY(-2px);
}

.modal-actions .secondary {
    background: #334155;
    color: #e2e8f0;
}

.modal-actions .secondary:hover {
    background: #475569;
}
/* ============================================================
   🎨 HANOI MAP MODE - ADDITIONAL STYLES
   ============================================================ */

/* Toggle buttons for map mode */
.toggle-btn {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  padding: 10px 16px;
  border-radius: 10px;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  transition: all 0.3s ease;
}

.toggle-btn:hover {
  background: var(--accent-blue);
  color: white;
  border-color: var(--accent-blue);
  transform: translateY(-2px);
}

.toggle-btn.active {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: white;
  border-color: transparent;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

/* Result modal content wrapper */
.modal-content {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.modal-content p {
  margin: 0;
  padding: 12px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 8px;
  border-left: 3px solid var(--accent-blue);
}

/* Right panel styles for canvas mode */
.right-panel {
  position: fixed;
  right: 0;
  top: 0;
  bottom: 0;
  width: 420px;
  background: var(--bg-primary);
  border-left: 1px solid var(--border-color);
  box-shadow: -4px 0 20px rgba(0, 0, 0, 0.5);
  padding: 20px;
  overflow-y: auto;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.right-panel::-webkit-scrollbar {
  width: 8px;
}

.right-panel::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

.right-panel::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 4px;
}

/* Viz sections */
.viz-section {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 16px;
}

.viz-section h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--accent-blue);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 8px;
}

/* Distance Table */
#distanceTable {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

#distanceTable thead th {
  background: var(--bg-primary);
  padding: 10px 8px;
  text-align: left;
  font-weight: 600;
  color: var(--text-secondary);
  border-bottom: 2px solid var(--border-color);
}

#distanceTable tbody td {
  padding: 10px 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
}

#distanceTable tbody tr:hover {
  background: rgba(255, 255, 255, 0.03);
}

#distanceTable td.updating {
  background: #fef3c7 !important;
  color: #92400e;
  animation: pulse-table 0.6s;
  font-weight: 600;
}

#distanceTable td.improved {
  background: #dcfce7 !important;
  color: #166534;
}

@keyframes pulse-table {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

/* Priority Queue */
#pqContainer {
  min-height: 40px;
  max-height: 180px;
  overflow-y: auto;
}

.pq-items {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.pq-item {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  padding: 8px 14px;
  border-radius: 16px;
  font-size: 12px;
  font-weight: 600;
  display: inline-block;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.pq-item.popping {
  background: #fbbf24;
  color: #78350f;
  animation: pop-item 0.4s;
  border-color: #f59e0b;
}

@keyframes pop-item {
  0% { transform: scale(1); }
  50% { transform: scale(1.15); }
  100% { transform: scale(1); }
}

/* Explanation box */
.explanation-box {
  background: rgba(255, 255, 255, 0.03);
  padding: 14px;
  border-radius: 8px;
  border-left: 3px solid var(--accent-blue);
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.explanation-box strong {
  color: var(--accent-blue);
}

.relaxation-calc {
  margin-top: 10px;
  padding: 10px;
  background: var(--bg-primary);
  border-radius: 6px;
  font-family: 'Courier New', monospace;
}

.relaxation-calc code {
  color: var(--accent-purple);
  font-size: 12px;
}

/* Pseudocode */
#pseudocodeDisplay {
  background: var(--bg-primary);
  padding: 14px;
  border-radius: 8px;
  font-family: 'Courier New', monospace;
  font-size: 12px;
  line-height: 1.8;
  overflow-x: auto;
  max-height: 300px;
  overflow-y: auto;
  color: var(--text-secondary);
}

.code-line {
  padding: 2px 8px;
  border-radius: 4px;
}

.code-line.highlight {
  background: var(--accent-blue);
  color: white;
  font-weight: 600;
  animation: highlight-flash 0.5s;
}

@keyframes highlight-flash {
  0% { background: #60a5fa; }
  100% { background: var(--accent-blue); }
}

/* Playback Controls */
.playback-controls {
  position: sticky;
  bottom: 0;
  background: var(--bg-secondary);
  padding: 16px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  margin-top: auto;
}

.playback-buttons {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.playback-buttons button {
  flex: 1;
  padding: 10px;
  font-size: 16px;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
}

.playback-buttons button:hover {
  background: var(--accent-blue);
  color: white;
  border-color: var(--accent-blue);
}

#stepSlider {
  margin-top: 10px;
}

#stepCounter {
  display: block;
  text-align: center;
  margin-top: 10px;
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 600;
}

/* Adjust canvas container for right panel */
body:not(.map-mode) .canvas-container {
  right: 420px;
}