/* Interactive Styles for PDA-CFG Equivalence Experiment 
 * 
 * Enhanced Features (Updated with exp7 theme):
 * - Shadow highlights for current PDA states with pulsing animation
 * - Drop-shadow effects for start and accept states
 * - Enhanced visual feedback for active transitions
 * - Smooth transitions and animations with reduced motion support
 * - Browser compatibility fallbacks for older browsers
 * - Color scheme updated to match exp7 theme
 */

/* Animation classes */
.fade-in {
  animation: fadeIn 0.3s ease-in;
}

.fade-out {
  animation: fadeOut 0.3s ease-out;
}

.slide-in {
  animation: slideIn 0.4s ease-out;
}

.pulse {
  animation: pulse 1s infinite;
}

.bounce {
  animation: bounce 0.5s ease-out;
}

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

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

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

@keyframes pulse {
  0%, 100% { 
    transform: scale(1);
    opacity: 1;
  }
  50% { 
    transform: scale(1.02);
    opacity: 0.9;
  }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-5px);
  }
  60% {
    transform: translateY(-3px);
  }
}

@keyframes currentStatePulse {
  0%, 100% {
    filter: drop-shadow(0 0 12px rgba(124, 58, 237, 0.6)) drop-shadow(0 0 20px rgba(124, 58, 237, 0.4));
    transform: scale(1);
  }
  50% {
    filter: drop-shadow(0 0 20px rgba(124, 58, 237, 0.8)) drop-shadow(0 0 30px rgba(124, 58, 237, 0.6));
    transform: scale(1.05);
  }
}

@keyframes transitionPulse {
  0%, 100% {
    filter: drop-shadow(0 0 8px rgba(124, 58, 237, 0.6));
    stroke-width: 4;
  }
  50% {
    filter: drop-shadow(0 0 12px rgba(124, 58, 237, 0.8));
    stroke-width: 5;
  }
}

/* Button interaction animations */
@keyframes correctAnswer {
  0% {
    background: rgba(140, 90, 255, 0.18);
    color: #5b21b6;
    transform: scale(1);
    box-shadow: 0 2px 8px 0 rgba(124, 58, 237, 0.04);
  }
  50% {
    transform: scale(1.15);
    box-shadow: 0 0 25px rgba(16, 185, 129, 0.6);
    background: rgba(16, 185, 129, 0.7);
  }
  100% {
    background: rgba(16, 185, 129, 0.9);
    color: #ffffff;
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
  }
}

@keyframes incorrectAnswer {
  0% {
    background: rgba(140, 90, 255, 0.18);
    color: #5b21b6;
    transform: translateX(0) scale(1);
  }
  25% {
    transform: translateX(-10px) scale(1.05);
    background: rgba(239, 68, 68, 0.5);
    box-shadow: 0 0 15px rgba(239, 68, 68, 0.3);
  }
  75% {
    transform: translateX(10px) scale(1.05);
    background: rgba(239, 68, 68, 0.7);
  }
  100% {
    background: rgba(239, 68, 68, 0.9);
    color: #ffffff;
    transform: translateX(0) scale(1.05);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
  }
}

@keyframes buttonSelect {
  0% {
    background: #fff;
    color: #374151;
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    background: #3B82F6;
    color: #fff;
    transform: scale(1.02);
  }
}

/* PDA Visualization Specific Styles */
.pda-state {
  cursor: pointer;
  transition: all 0.3s ease;
}

.pda-state circle {
  stroke-width: 2;
  stroke: #4b5563;
  fill: #f9fafb;
  transition: all 0.5s ease;
}

.pda-state circle.start {
  stroke: #7c3aed;
  stroke-width: 3;
  fill: #faf5ff;
  filter: drop-shadow(0 0 8px rgba(124, 58, 237, 0.3));
}

.pda-state circle.accept {
  stroke: #10b981;
  stroke-width: 3;
  fill: #f0fdf4;
  filter: drop-shadow(0 0 8px rgba(16, 185, 129, 0.3));
}

.pda-state circle.current {
  fill: #7c3aed;
  stroke: #5b21b6;
  stroke-width: 4;
  filter: drop-shadow(0 0 12px rgba(124, 58, 237, 0.6)) drop-shadow(0 0 20px rgba(124, 58, 237, 0.4));
  animation: currentStatePulse 2s infinite ease-in-out;
}

/* SVG-specific selectors for D3.js generated elements with higher specificity */
svg .pda-state circle.state-circle.start {
  stroke: #7c3aed !important;
  stroke-width: 3 !important;
  fill: #faf5ff !important;
  filter: drop-shadow(0 0 8px rgba(124, 58, 237, 0.3)) !important;
}

svg .pda-state circle.state-circle.accept {
  stroke: #10b981 !important;
  stroke-width: 3 !important;
  fill: #f0fdf4 !important;
  filter: drop-shadow(0 0 8px rgba(16, 185, 129, 0.3)) !important;
}

svg .pda-state circle.state-circle.current {
  fill: #7c3aed !important;
  stroke: #5b21b6 !important;
  stroke-width: 4 !important;
  filter: drop-shadow(0 0 12px rgba(124, 58, 237, 0.6)) drop-shadow(0 0 20px rgba(124, 58, 237, 0.4)) !important;
  animation: currentStatePulse 2s infinite ease-in-out !important;
}

/* Alternative approach - target any circle with these classes */
circle.state-circle.start {
  stroke: #7c3aed !important;
  stroke-width: 3 !important;
  fill: #faf5ff !important;
  filter: drop-shadow(0 0 8px rgba(124, 58, 237, 0.3)) !important;
}

circle.state-circle.accept {
  stroke: #10b981 !important;
  stroke-width: 3 !important;
  fill: #f0fdf4 !important;
  filter: drop-shadow(0 0 8px rgba(16, 185, 129, 0.3)) !important;
}

circle.state-circle.current {
  fill: #7c3aed !important;
  stroke: #5b21b6 !important;
  stroke-width: 4 !important;
  filter: drop-shadow(0 0 12px rgba(124, 58, 237, 0.6)) drop-shadow(0 0 20px rgba(124, 58, 237, 0.4)) !important;
  animation: currentStatePulse 2s infinite ease-in-out !important;
}

.pda-state.current text {
  fill: white;
  font-weight: bold;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.3));
}

/* Enhanced hover effects for states */
.pda-state:hover circle:not(.current) {
  filter: drop-shadow(0 0 6px rgba(124, 58, 237, 0.2));
  transform: scale(1.02);
}

/* Enhanced current state when it's also start or accept */
.pda-state.current.start circle,
.pda-state.current.accept circle {
  filter: drop-shadow(0 0 12px rgba(124, 58, 237, 0.6)) 
          drop-shadow(0 0 20px rgba(124, 58, 237, 0.4))
          drop-shadow(0 0 25px rgba(124, 58, 237, 0.2));
}

/* Accept state inner circle styling */
.accept-inner-circle {
  transition: all 0.5s ease;
}

.accept-inner-circle.current {
  filter: drop-shadow(0 0 8px rgba(124, 58, 237, 0.4));
}

.pda-state text {
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  font-weight: 500;
  text-anchor: middle;
  dominant-baseline: central;
  fill: #374151;
}

.pda-transition {
  cursor: pointer;
  transition: all 0.3s ease;
}

.pda-transition path, .pda-transition line {
  stroke: #6b7280;
  stroke-width: 2;
  fill: none;
  marker-end: url(#arrowhead);
}

.pda-transition.active path, .pda-transition.active line {
  stroke: #7c3aed;
  stroke-width: 4;
  filter: drop-shadow(0 0 8px rgba(124, 58, 237, 0.6));
  animation: transitionPulse 1.5s infinite ease-in-out;
}

/* Enhanced transition hover effects */
.pda-transition:hover path:not(.active),
.pda-transition:hover line:not(.active) {
  stroke: #9333ea;
  stroke-width: 3;
  filter: drop-shadow(0 0 4px rgba(147, 51, 234, 0.3));
  opacity: 0.9;
}

.pda-transition:hover text:not(.active) {
  fill: #9333ea;
  font-weight: 600;
}

.pda-transition text {
  font-family: 'Courier New', monospace;
  font-size: 12px;
  fill: #374151;
  text-anchor: middle;
  transition: all 0.3s ease;
}

.pda-transition.active text {
  fill: #7c3aed;
  font-weight: bold;
  filter: drop-shadow(0 1px 2px rgba(124, 58, 237, 0.4));
}

/* Stack visualization */
.stack-visualization {
  margin-top: 20px;
}

.stack-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.stack-item {
  width: 60px;
  height: 30px;
  background: #f3f4f6;
  border: 2px solid #d1d5db;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Courier New', monospace;
  font-weight: bold;
  font-size: 14px;
  color: #374151;
  transition: all 0.3s ease;
}

.stack-item.top {
  background: rgba(99, 102, 241, 0.12);
  border-color: #6366F1;
  color: #3B82F6;
  filter: drop-shadow(0 2px 4px rgba(99, 102, 241, 0.2));
}

.stack-item.new {
  animation: slideIn 0.5s ease-out;
  background: #dcfce7;
  border-color: #10b981;
  filter: drop-shadow(0 2px 4px rgba(16, 185, 129, 0.2));
}

.stack-item.removing {
  animation: fadeOut 0.3s ease-in;
}

/* PDA Legend enhancements */
.pda-legend .legend-item circle {
  transition: all 0.3s ease;
}

.pda-legend .legend-item:hover circle {
  filter: drop-shadow(0 2px 4px rgba(124, 58, 237, 0.3));
  transform: scale(1.1);
}

/* CFG Derivation Tree Styles */
.cfg-node {
  cursor: pointer;
  transition: all 0.3s ease;
}

.cfg-node circle {
  fill: #f9fafb;
  stroke: #6b7280;
  stroke-width: 2;
}

.cfg-node.non-terminal circle {
  fill: #ddd6fe;
  stroke: #7c3aed;
}

.cfg-node.terminal circle {
  fill: #dcfce7;
  stroke: #10b981;
}

.cfg-node.current circle {
  fill: #7c3aed;
  stroke: #5b21b6;
  stroke-width: 3;
  animation: pulse 1s infinite;
}

.cfg-node text {
  font-family: 'Courier New', monospace;
  font-size: 14px;
  font-weight: bold;
  text-anchor: middle;
  dominant-baseline: central;
  fill: #374151;
}

.cfg-node.current text {
  fill: white;
}

.cfg-edge {
  stroke: #6b7280;
  stroke-width: 2;
  fill: none;
}

.cfg-edge.new {
  stroke: #6366F1;
  stroke-width: 3;
  animation: slideIn 0.5s ease-out;
}

/* Production rule highlighting */
.production-rule.highlighted {
  background: rgba(99, 102, 241, 0.12);
  border-color: #6366F1;
  color: #3B82F6;
  font-weight: bold;
  animation: pulse 1s infinite;
}

.production-rule.applied {
  background: #dcfce7;
  border-color: #10b981;
  color: #065f46;
}

/* Choice interaction styles - Matching exp7 rule styling exactly */
.choice-button {
  position: relative;
  padding: 8px 12px !important;
  background: rgba(140, 90, 255, 0.18) !important;
  border: none !important;
  border-radius: 6px !important;
  font-family: monospace !important;
  font-size: 1.1rem !important;
  color: #5b21b6 !important;
  font-weight: 500 !important;
  box-shadow: 0 2px 8px 0 rgba(124, 58, 237, 0.04) !important;
  transition: all 0.2s !important;
  cursor: pointer !important;
  display: inline-block !important;
  margin: 0 !important;
  text-align: center !important;
  line-height: 1.3 !important;
}

.choice-button:hover {
  background: rgba(140, 90, 255, 0.25) !important;
  box-shadow: 0 3px 6px rgba(124, 58, 237, 0.1) !important;
  transform: translateY(-2px) !important;
}

.choice-button::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.1) 50%, transparent 70%);
  transform: translateX(-100%);
  transition: none;
  border-radius: 8px;
  pointer-events: none;
}

.choice-button:hover::before {
  transform: translateX(-100%);
}

.choice-button.correct {
  background: rgba(16, 185, 129, 0.9) !important;
  color: #ffffff !important;
  border: 2px solid #10B981 !important;
  transform: translateY(-1px) scale(1.05) !important;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4) !important;
  animation: correctAnswer 0.6s ease-out !important;
}

.choice-button.incorrect {
  background: rgba(239, 68, 68, 0.9) !important;
  color: #ffffff !important;
  border: 2px solid #EF4444 !important;
  transform: translateY(-1px) scale(1.05) !important;
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4) !important;
  animation: incorrectAnswer 0.6s ease-out !important;
}

.choice-button.selected {
  background: rgba(140, 90, 255, 0.35) !important;
  color: #5b21b6 !important;
  transform: translateY(-1px) !important;
  box-shadow: 0 4px 8px rgba(124, 58, 237, 0.15) !important;
  animation: buttonSelect 0.3s ease-out !important;
}

/* Progress indicators */
.progress-bar {
  width: 100%;
  height: 6px;
  background: #e5e7eb;
  border-radius: 3px;
  overflow: hidden;
  margin: 16px 0;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #3B82F6, #6366F1);
  border-radius: 3px;
  transition: width 0.5s ease;
  position: relative;
}

.progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent 30%, rgba(255,255,255,0.3) 50%, transparent 70%);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* Step navigation styles */
.step-navigation {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 20px;
  padding-top: 16px;
  border-top: 2px solid #e5e7eb;
}

.step-counter {
  font-size: 0.875rem;
  color: #6b7280;
  font-weight: 500;
}

.step-counter .current {
  color: #7c3aed;
  font-weight: bold;
}

/* Tooltip styles */
.tooltip {
  position: absolute;
  background: #1f2937;
  color: white;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 500;
  z-index: 1000;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.tooltip.visible {
  opacity: 1;
}

.tooltip::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: #1f2937 transparent transparent transparent;
}

/* Loading states */
.loading {
  position: relative;
  overflow: hidden;
}

.loading::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  animation: loading 1.5s infinite;
}

@keyframes loading {
  0% { left: -100%; }
  100% { left: 100%; }
}

/* Success/Error states */
.success-state {
  background: #f0fdf4;
  border-color: #10b981;
  animation: bounce 0.5s ease-out;
}

.error-state {
  background: #fef2f2;
  border-color: #ef4444;
  animation: shake 0.5s ease-out;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
  20%, 40%, 60%, 80% { transform: translateX(5px); }
}

/* Focus states for accessibility */
.choice-button:focus,
.button:focus {
  outline: 2px solid #7c3aed;
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  .pda-state circle,
  .cfg-node circle {
    stroke-width: 3;
  }
  
  .choice-button {
    border-width: 3px;
  }
  
  .feedback-area {
    border-left-width: 6px;
  }
}

/* PDA Visualization Layout */
.visualization-container {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  min-height: 300px;
}

.pda-diagram-area {
  flex: 1;
  min-height: 300px;
}

.pda-stack-area {
  flex: 0 0 150px; /* Fixed width for stack area */
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stack-header {
  font-size: 14px;
  font-weight: bold;
  color: #374151;
  margin-bottom: 10px;
  text-align: center;
  padding: 5px 10px;
  background: #f3f4f6;
  border-radius: 4px;
  border: 1px solid #d1d5db;
}

/* Visual Stack Styles */
.visual-stack {
  display: flex;
  flex-direction: column-reverse; /* Stack grows upward */
  align-items: center;
  min-height: 200px;
  width: 120px;
  padding: 15px 10px;
  border: 3px solid #e5e7eb;
  border-radius: 12px;
  background: linear-gradient(to bottom, #f9fafb 0%, #f3f4f6 100%);
  position: relative;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

.visual-stack::after {
  content: "BOTTOM";
  position: absolute;
  bottom: 5px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 10px;
  color: #6b7280;
  font-weight: bold;
}

.visual-stack::before {
  content: "TOP";
  position: absolute;
  top: 5px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 10px;
  color: #6b7280;
  font-weight: bold;
}

.stack-element {
  background: linear-gradient(135deg, #6366F1 0%, #3B82F6 100%);
  color: white;
  padding: 8px 12px;
  margin: 3px 0;
  border-radius: 8px;
  font-weight: bold;
  font-size: 14px;
  min-width: 50px;
  text-align: center;
  box-shadow: 0 3px 6px rgba(0, 0, 0, 0.15);
  border: 2px solid #4c1d95;
  animation: stackPush 0.4s ease-out;
  position: relative;
}

.stack-element.top {
  background: linear-gradient(135deg, #EF4444 0%, #DC2626 100%);
  border-color: #991b1b;
  transform: scale(1.1);
  box-shadow: 0 4px 12px rgba(220, 38, 38, 0.4);
  animation: stackTopHighlight 0.5s ease-out;
}

.stack-element.top::after {
  content: "← TOP";
  position: absolute;
  left: 100%;
  top: 50%;
  transform: translateY(-50%);
  margin-left: 8px;
  font-size: 10px;
  color: #dc2626;
  font-weight: bold;
  white-space: nowrap;
}

.stack-element.empty-indicator {
  background: transparent;
  color: #9ca3af;
  border: 2px dashed #d1d5db;
  font-style: italic;
  animation: none;
  transform: none;
  box-shadow: none;
}

@keyframes stackPush {
  0% {
    transform: translateY(30px) scale(0.7);
    opacity: 0;
  }
  100% {
    transform: translateY(0) scale(1);
    opacity: 1;
  }
}

@keyframes stackTopHighlight {
  0% {
    transform: scale(1);
    box-shadow: 0 3px 6px rgba(0, 0, 0, 0.15);
  }
  50% {
    transform: scale(1.15);
    box-shadow: 0 6px 20px rgba(220, 38, 38, 0.6);
  }
  100% {
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(220, 38, 38, 0.4);
  }
}

@keyframes stackPop {
  0% {
    transform: translateY(0) scale(1);
    opacity: 1;
  }
  100% {
    transform: translateY(-30px) scale(0.7);
    opacity: 0;
  }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  /* Disable shadow effects for reduced motion */
  .pda-state.current circle,
  .pda-state.start circle,
  .pda-state.accept circle,
  .accept-inner-circle.current,
  .pda-transition.active path,
  .pda-transition.active line {
    filter: none !important;
  }
}

/* Browser compatibility fallbacks */
@supports not (filter: drop-shadow(0 0 4px rgba(0,0,0,0.5))) {
  /* Fallback for browsers that don't support drop-shadow */
  .pda-state.current circle {
    box-shadow: 0 0 12px rgba(124, 58, 237, 0.6);
  }
  
  .pda-state.start circle,
  .pda-state.accept circle {
    box-shadow: 0 0 8px rgba(124, 58, 237, 0.3);
  }
}