:root {
  --green: #00ff41;
  --cyan: #00d4ff;
  --amber: #ffb000;
  --magenta: #ff79c6;
  --red: #ff3333;
  --bg-dark: #0a0a14;
  --bg-panel: #0d0d1a;
  --bg-header: #1a1a2e;
  --bg-input: #08080f;
  --border: #1e1e3a;
  --text-dim: #4a4a6a;
  --text-mid: #8888aa;
}

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

body {
  background: var(--bg-dark);
  color: #c0c0d0;
  font-family: 'Fira Code', monospace;
  min-height: 100vh;
  overflow-x: hidden;
}

/* CRT Scanline Overlay */
.crt-overlay {
  pointer-events: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: 9999;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0, 0, 0, 0.08) 2px,
    rgba(0, 0, 0, 0.08) 4px
  );
}
.crt-overlay.off { display: none; }

/* Compile button + electrical surge animation */
.btn-compile {
  background: linear-gradient(135deg, #003300, #005500);
  border: 1px solid var(--green);
  color: var(--green);
  text-shadow: 0 0 8px var(--green);
  box-shadow: 0 0 15px rgba(0, 255, 65, 0.2), inset 0 0 15px rgba(0, 255, 65, 0.05);
  transition: all 0.2s;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}
.btn-compile:hover {
  background: linear-gradient(135deg, #004400, #007700);
  box-shadow: 0 0 25px rgba(0, 255, 65, 0.4), inset 0 0 20px rgba(0, 255, 65, 0.1);
}
.btn-compile:active { transform: scale(0.97); }

@keyframes surge {
  0% { box-shadow: 0 0 15px rgba(0, 255, 65, 0.2); }
  20% { box-shadow: 0 0 40px rgba(0, 255, 65, 0.8), 0 0 80px rgba(0, 255, 65, 0.4); }
  40% { box-shadow: 0 0 20px rgba(0, 212, 255, 0.6), 0 0 60px rgba(0, 212, 255, 0.3); }
  60% { box-shadow: 0 0 50px rgba(0, 255, 65, 0.7), 0 0 100px rgba(0, 255, 65, 0.3); }
  100% { box-shadow: 0 0 15px rgba(0, 255, 65, 0.2); }
}
.btn-compile.surge {
  animation: surge 0.6s ease-out;
}

/* Code textarea */
.code-editor {
  background: var(--bg-input);
  color: var(--green);
  font-family: 'Fira Code', monospace;
  font-size: 13px;
  line-height: 1.6;
  border: 1px solid var(--border);
  resize: none;
  outline: none;
  caret-color: var(--green);
  tab-size: 2;
}
.code-editor::placeholder { color: var(--text-dim); }
.code-editor:focus {
  border-color: rgba(0, 255, 65, 0.3);
  box-shadow: inset 0 0 20px rgba(0, 255, 65, 0.03);
}

/* Tab styling */
.tab-btn {
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-dim);
  font-family: 'Fira Code', monospace;
  font-size: 11px;
  padding: 8px 12px;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}
.tab-btn:hover { color: var(--text-mid); }
.tab-btn.active {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
  text-shadow: 0 0 8px rgba(0, 212, 255, 0.3);
}

/* Output panels */
.output-panel {
  background: var(--bg-input);
  border: 1px solid var(--border);
  font-family: 'Fira Code', monospace;
  font-size: 12px;
  line-height: 1.7;
  overflow: auto;
}

/* Register display */
.register-cell {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  padding: 4px 8px;
  font-size: 11px;
  text-align: center;
  transition: all 0.3s;
}
.register-cell.changed {
  border-color: var(--amber);
  box-shadow: 0 0 8px rgba(255, 176, 0, 0.3);
  color: var(--amber);
}

/* Hex dump colors */
.hex-load { color: #6688ff; }
.hex-arith { color: var(--green); }
.hex-jump { color: var(--amber); }
.hex-io { color: #ff66aa; }
.hex-misc { color: var(--text-mid); }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-dim); }

/* Animated chip */
@keyframes chipPulse {
  0%, 100% { opacity: 0.7; }
  50% { opacity: 1; }
}
.chip-icon { animation: chipPulse 2s ease-in-out infinite; }

/* Error styling */
.error-msg {
  color: var(--red);
  font-size: 12px;
}

/* Memory grid */
.mem-cell {
  width: 22px;
  height: 18px;
  font-size: 9px;
  text-align: center;
  line-height: 18px;
  color: var(--text-dim);
}
.mem-cell.written {
  color: var(--cyan);
  background: rgba(0, 212, 255, 0.08);
}

/* Status bar */
.status-bar {
  border-top: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg-panel), var(--bg-dark));
}

/* Responsive */
@media (max-width: 768px) {
  .main-split { flex-direction: column !important; }
  .left-panel, .right-panel { width: 100% !important; }
}

/* Button base */
.btn-small {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  color: var(--text-mid);
  font-family: 'Fira Code', monospace;
  font-size: 11px;
  padding: 4px 12px;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-small:hover {
  border-color: var(--text-mid);
  color: #c0c0d0;
}

/* Line numbers */
.line-numbers {
  color: var(--text-dim);
  font-size: 12px;
  line-height: 1.6;
  text-align: right;
  padding-right: 8px;
  user-select: none;
  font-family: 'Fira Code', monospace;
  border-right: 1px solid var(--border);
}

/* Footer */
.footer-link {
  color: var(--cyan);
  text-decoration: none;
}
.footer-link:hover {
  text-shadow: 0 0 8px rgba(0, 212, 255, 0.5);
}

/* Simulator buttons */
.btn-sim {
  background: linear-gradient(135deg, #1a1a00, #333300);
  border: 1px solid var(--amber);
  color: var(--amber);
  font-family: 'Fira Code', monospace;
  font-size: 11px;
  padding: 5px 14px;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-sim:hover {
  box-shadow: 0 0 12px rgba(255, 176, 0, 0.3);
}
.btn-sim:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

/* Select dropdown */
.retro-select {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  color: var(--text-mid);
  font-family: 'Fira Code', monospace;
  font-size: 11px;
  padding: 4px 8px;
  cursor: pointer;
  outline: none;
}
.retro-select:focus { border-color: var(--cyan); }

/* Syntax highlight */
.syn-keyword { color: #ff79c6; }
.syn-number { color: #bd93f9; }
.syn-string { color: #f1fa8c; }
.syn-comment { color: #6272a4; font-style: italic; }
.syn-operator { color: var(--amber); }
.syn-ident { color: var(--green); }

/* Toggle switch */
.toggle-track {
  width: 32px;
  height: 16px;
  background: var(--border);
  border-radius: 8px;
  cursor: pointer;
  position: relative;
  transition: background 0.2s;
}
.toggle-track.on { background: rgba(0, 255, 65, 0.3); }
.toggle-thumb {
  width: 12px;
  height: 12px;
  background: var(--text-mid);
  border-radius: 50%;
  position: absolute;
  top: 2px;
  left: 2px;
  transition: all 0.2s;
}
.toggle-track.on .toggle-thumb {
  left: 18px;
  background: var(--green);
}