:root {
  --bg-page: #0c0414; /* Deep synthwave dark space */
  --bg-panel: #16082b; /* Deep indigo arcade cabinet frame */
  --bg-input: #07010f; /* Void black screen inside cabinet */
  
  /* Retro Arcade Neon Theme */
  --retro-cyan: #00f0ff;
  --retro-magenta: #ff007f;
  --retro-yellow: #fffb00;
  --retro-purple: #9a00ff;
  
  --cyan-glow: rgba(0, 240, 255, 0.3);
  --magenta-glow: rgba(255, 0, 127, 0.3);
  --yellow-glow: rgba(255, 251, 0, 0.3);
  --purple-glow: rgba(154, 0, 255, 0.2);
  
  --text-main: #cebee6;
  --text-bright: #00f0ff;
  --text-magenta: #ff007f;
  --text-yellow: #fffb00;
  --text-muted: #8b6ca8;
  --text-soft: #4a3666;
  
  --success: #00ff66;
  --danger: #ff0055;
  
  --font-game: 'Press Start 2P', monospace;
  --font-pixel: 'VT323', monospace;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, "SF Mono", Menlo, Monaco, Consolas, monospace;
  
  --border-radius: 0px; /* Sharp 8-bit game pixel styling */
  --transition: 0.1s ease-in-out;
}

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

body {
  font-family: var(--font-pixel);
  background-color: var(--bg-page);
  background-image: 
    linear-gradient(rgba(154, 0, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(154, 0, 255, 0.05) 1px, transparent 1px);
  background-size: 32px 32px;
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  position: relative;
  text-shadow: 0 0 2px var(--cyan-glow);
}

/* CRT Screen Scanline Overlay Effect */
body::after {
  content: "";
  display: block;
  position: fixed;
  top: 0; left: 0; bottom: 0; right: 0;
  background: linear-gradient(rgba(18, 16, 16, 0) 50%, rgba(0, 0, 0, 0.25) 50%);
  background-size: 100% 4px;
  z-index: 99999;
  pointer-events: none;
  opacity: 0.4;
}

/* Retro CRT Glow Vignette + Cyber Gradient */
body::before {
  content: "";
  display: block;
  position: fixed;
  top: 0; left: 0; bottom: 0; right: 0;
  background: 
    radial-gradient(circle, transparent 65%, rgba(12, 4, 20, 0.85) 100%),
    linear-gradient(180deg, rgba(255, 0, 127, 0.04) 0%, transparent 35%, rgba(0, 240, 255, 0.04) 100%);
  z-index: 99998;
  pointer-events: none;
}

/* Retro Arcade Header */
.header {
  padding: 1.5rem 2.5rem;
  border-bottom: 4px solid var(--retro-magenta);
  background: var(--bg-panel);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  box-shadow: 0 4px 0 var(--retro-purple), 0 0 15px var(--magenta-glow);
  position: relative;
}

.header::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--retro-magenta), var(--retro-cyan), var(--retro-yellow));
}

.header-logo-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.header-glowing-dot {
  width: 12px;
  height: 12px;
  background-color: var(--retro-cyan);
  box-shadow: 0 0 10px var(--retro-cyan);
  animation: pulse 1s infinite alternate;
}

@keyframes pulse {
  from { opacity: 0.4; transform: scale(0.8); }
  to { opacity: 1; transform: scale(1.2); }
}

.header h1 {
  font-family: var(--font-game);
  font-size: 1.75rem;
  font-weight: 700;
  color: #fff;
  text-shadow: 3px 3px 0 var(--retro-magenta), -1px -1px 0 var(--retro-cyan);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.header .tagline {
  font-family: var(--font-pixel);
  font-size: 1.25rem;
  color: var(--text-main);
  letter-spacing: 0.02em;
  text-shadow: 1px 1px 0 rgba(0, 0, 0, 0.5);
}

/* Retro Main Layout Grid */
.main {
  flex: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr);
  gap: 2rem;
  padding: 2.5rem;
  max-width: 1600px;
  width: 100%;
  margin: 0 auto;
  z-index: 1;
}

/* Retro Arcade Cabinet Panel */
.panel {
  background: var(--bg-panel);
  border-radius: var(--border-radius);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  position: relative;
}

.input-panel {
  border: 4px solid var(--retro-cyan);
  box-shadow: 4px 4px 0 var(--retro-purple), 0 0 15px var(--cyan-glow);
}

.output-panel {
  border: 4px solid var(--retro-magenta);
  box-shadow: 4px 4px 0 var(--retro-purple), 0 0 15px var(--magenta-glow);
}

.panel h2 {
  font-family: var(--font-game);
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text-yellow);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-shadow: 2px 2px 0 rgba(0, 0, 0, 0.5);
}

.panel h2::before {
  content: "🕹️ ";
}

/* Retro Editor Textarea */
textarea#code-input {
  width: 100%;
  flex: 1;
  min-height: 480px;
  resize: vertical;
  background: var(--bg-input);
  color: #fff;
  border-radius: var(--border-radius);
  border: 2px solid var(--retro-purple);
  padding: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.6;
  outline: none;
  transition: all var(--transition);
  box-shadow: inset 0 0 12px rgba(0, 0, 0, 0.95);
}

textarea#code-input:focus {
  border-color: var(--retro-cyan);
  box-shadow: inset 0 0 12px rgba(0, 0, 0, 0.95), 0 0 8px var(--cyan-glow);
}

textarea#code-input::placeholder {
  color: var(--text-soft);
}

/* Controls */
.controls {
  margin-top: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

/* 3D Physical Push-down Arcade Button */
button#generate-btn {
  padding: 0.75rem 1.75rem;
  border-radius: var(--border-radius);
  border: none;
  background: var(--retro-cyan);
  color: #000;
  border-bottom: 5px solid #009eb7;
  font-family: var(--font-game);
  font-size: 0.68rem;
  font-weight: 900;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: all 0.05s ease-in-out;
  box-shadow: 0 4px 0 rgba(0, 0, 0, 0.4), 0 0 10px var(--cyan-glow);
}

button#generate-btn:hover:not(:disabled) {
  background: #2ef3ff;
  transform: translateY(1px);
  border-bottom-width: 4px;
}

button#generate-btn:active:not(:disabled) {
  transform: translateY(4px);
  border-bottom-width: 1px;
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.4), 0 0 5px var(--cyan-glow);
}

button#generate-btn:disabled {
  opacity: 0.35;
  background: var(--text-soft);
  border-bottom-color: #1e1330;
  color: var(--text-muted);
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.status {
  font-family: var(--font-game);
  font-size: 0.55rem;
  color: var(--text-bright);
}

.status::before {
  content: "SYS: ";
}

.status.error {
  color: var(--danger);
  text-shadow: 0 0 4px rgba(255, 0, 85, 0.5);
}

.note {
  margin-top: 1rem;
  font-family: var(--font-pixel);
  font-size: 1.1rem;
  color: var(--text-soft);
}

/* Terminal Tab System */
.tabs-header {
  display: flex;
  border-bottom: 3px solid var(--retro-magenta);
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
}

.tab-btn {
  padding: 0.5rem 1.25rem;
  background: transparent;
  border: 2px solid var(--retro-purple);
  border-radius: var(--border-radius);
  color: var(--text-muted);
  font-family: var(--font-game);
  font-size: 0.55rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.05s ease-in-out;
  border-bottom-width: 4px;
}

.tab-btn:hover {
  color: #fff;
  border-color: var(--retro-magenta);
}

.tab-btn.active {
  color: #fff;
  background: var(--retro-magenta);
  border-color: var(--retro-magenta);
  border-bottom: 4px solid #a3004f;
  text-shadow: 1px 1px 0 rgba(0, 0, 0, 0.8);
  box-shadow: 0 0 10px var(--magenta-glow);
}

.tab-btn.active:active {
  transform: translateY(2px);
  border-bottom-width: 2px;
}

.tabs-content {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.tab-content {
  display: none;
  flex: 1;
  flex-direction: column;
}

.tab-content.active {
  display: flex;
}

/* Action Controls */
.actions-row {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.action-btn {
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  border: 2px solid var(--retro-purple);
  background: var(--bg-input);
  color: var(--text-bright);
  font-family: var(--font-game);
  font-size: 0.5rem;
  font-weight: 500;
  cursor: pointer;
  border-bottom-width: 4px;
  transition: all 0.05s ease-in-out;
}

.action-btn:hover:not(:disabled) {
  border-color: var(--retro-cyan);
  color: #fff;
}

.action-btn:active:not(:disabled) {
  transform: translateY(2px);
  border-bottom-width: 2px;
}

.action-btn:disabled {
  opacity: 0.25;
  border-color: var(--text-soft);
  color: var(--text-soft);
  cursor: not-allowed;
  border-bottom-width: 2px;
  transform: none;
}

.action-btn.success {
  border-color: var(--success);
  color: var(--success);
  box-shadow: 0 0 5px rgba(0, 255, 102, 0.3);
}

/* Diagram Viewport & Synthwave Arcade Flowcharts */
.mermaid-viewport {
  flex: 1;
  min-height: 480px;
  background: var(--bg-input);
  border-radius: var(--border-radius);
  border: 2px solid var(--retro-magenta);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: auto;
  padding: 1.5rem;
  box-shadow: inset 0 0 15px rgba(0, 0, 0, 0.95);
  position: relative;
}

#mermaid-container {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

#mermaid-container svg {
  max-width: 100%;
  height: auto;
}

/* Cyber Synthwave Mermaid Color Scheme Override */
#mermaid-container svg .node rect,
#mermaid-container svg .node circle,
#mermaid-container svg .node polygon,
#mermaid-container svg .node path {
  fill: #16082b !important;
  stroke: var(--retro-cyan) !important;
  stroke-width: 2.5px !important;
  filter: drop-shadow(0 0 3px var(--cyan-glow)) !important;
}

/* Highlight diamond/decision nodes in glowing retro yellow */
#mermaid-container svg .node.decision rect,
#mermaid-container svg .node.decision polygon,
#mermaid-container svg .node.decision path,
#mermaid-container svg .node[id^="M"] polygon, 
#mermaid-container svg .node[id^="Q"] polygon {
  stroke: var(--retro-yellow) !important;
  filter: drop-shadow(0 0 3px var(--yellow-glow)) !important;
}

#mermaid-container svg .node .label {
  color: #fff !important;
  font-family: var(--font-pixel) !important;
  font-size: 14px !important;
  text-shadow: 1px 1px 0 #000 !important;
}

#mermaid-container svg .edgePath .path {
  stroke: var(--retro-magenta) !important;
  stroke-width: 2.5px !important;
  filter: drop-shadow(0 0 2px var(--magenta-glow)) !important;
}

#mermaid-container svg .marker {
  fill: var(--retro-magenta) !important;
  stroke: none !important;
}

#mermaid-container svg .edgeLabel rect {
  fill: var(--bg-input) !important;
  stroke: var(--retro-purple) !important;
  stroke-width: 1px !important;
}

#mermaid-container svg .edgeLabel span {
  color: var(--retro-yellow) !important;
  font-family: var(--font-pixel) !important;
  font-size: 12px !important;
}

/* Pre Output Elements */
.ascii-output,
.steps-output {
  flex: 1;
  background: var(--bg-input);
  border-radius: var(--border-radius);
  border: 2px solid var(--retro-magenta);
  padding: 1.25rem;
  min-height: 480px;
  white-space: pre;
  overflow: auto;
  font-family: var(--font-pixel);
  font-size: 1.35rem;
  line-height: 1.5;
  color: #fff;
  box-shadow: inset 0 0 15px rgba(0, 0, 0, 0.95);
  text-shadow: 1px 1px 0 rgba(0, 0, 0, 0.8);
}

.raw-mermaid-fallback {
  background: rgba(0, 0, 0, 0.4);
  border-radius: var(--border-radius);
  border: 2px solid var(--retro-purple);
  padding: 0.75rem;
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  text-align: left;
  white-space: pre-wrap;
  word-break: break-all;
}

/* States & Spinner */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  text-align: center;
  padding: 2rem;
  height: 100%;
  font-family: var(--font-game);
  font-size: 0.55rem;
  line-height: 1.8;
}

.empty-state-text {
  animation: blink 1.2s infinite steps(2);
}

@keyframes blink {
  to { opacity: 0.3; }
}

.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--retro-magenta);
  gap: 1.5rem;
  height: 100%;
  font-family: var(--font-game);
  font-size: 0.65rem;
  text-shadow: 2px 2px 0 #000;
}

/* Retro Jumping/Rotating Block Spinner */
.spinner {
  width: 32px;
  height: 32px;
  background: var(--retro-yellow);
  box-shadow: 0 0 10px var(--yellow-glow);
  animation: jump 0.8s steps(4) infinite;
}

@keyframes jump {
  0% { transform: scale(1) rotate(0deg); background: var(--retro-yellow); }
  50% { transform: scale(1.2) rotate(90deg); background: var(--retro-magenta); }
  100% { transform: scale(1) rotate(180deg); background: var(--retro-cyan); }
}

.error-text {
  color: var(--danger) !important;
  text-shadow: 0 0 4px rgba(255, 0, 85, 0.5);
}

/* Retro Arcade Footer */
.footer {
  padding: 1.5rem 2.5rem;
  border-top: 4px solid var(--retro-cyan);
  background: var(--bg-panel);
  font-family: var(--font-pixel);
  font-size: 1.15rem;
  color: var(--text-muted);
  text-align: center;
  letter-spacing: 0.02em;
  box-shadow: 0 -4px 0 var(--retro-purple), 0 0 15px var(--cyan-glow);
}

.footer span::before {
  content: "🕹️ ";
}

/* Responsive Layout */
@media (max-width: 1024px) {
  .main {
    grid-template-columns: 1fr;
    padding: 1.5rem;
    gap: 1.5rem;
  }

  .header {
    padding: 1.25rem 1.5rem;
  }

  .footer {
    padding: 1.25rem;
  }
  
  textarea#code-input,
  .ascii-output,
  .steps-output,
  .mermaid-viewport {
    min-height: 380px;
  }
}