:root {
  --bg-dark: #0d0d1a;
  --bg-panel: #131325;
  --bg-header: #1a1a30;
  --bg-input: #0a0a18;
  --border: #252545;
  --green: #00FF41;
  --green-dim: #00aa2a;
  --cyan: #00d4ff;
  --red: #ff4444;
  --yellow: #ffcc00;
  --text: #c8c8e0;
  --text-dim: #6a6a8a;
  --text-bright: #e8e8ff;
}

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

body {
  background: var(--bg-dark);
  color: var(--text);
  font-family: 'IBM Plex Sans', sans-serif;
  overflow: hidden;
  height: 100vh;
}

.font-mono { font-family: 'Fira Code', monospace !important; }
.font-sans { font-family: 'IBM Plex Sans', sans-serif !important; }

/* 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: #3a3a5a; }

/* Animations */
@keyframes pulse-green {
  0%, 100% { box-shadow: 0 0 0px var(--green); }
  50% { box-shadow: 0 0 8px var(--green); }
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

@keyframes flash-reg {
  0% { background: rgba(0, 255, 65, 0.3); }
  100% { background: transparent; }
}

.animate-blink { animation: blink 1s step-end infinite; }
.animate-pulse-green { animation: pulse-green 2s ease-in-out infinite; }
.flash-register { animation: flash-reg 0.6s ease-out; }

/* CRT scanline effect */
.crt-effect {
  position: relative;
  overflow: hidden;
}
.crt-effect::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0, 0, 0, 0.08) 2px,
    rgba(0, 0, 0, 0.08) 4px
  );
  pointer-events: none;
  z-index: 1;
}

/* LED indicator */
.led {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
  transition: all 0.2s;
}
.led-on {
  background: var(--green);
  box-shadow: 0 0 6px var(--green), 0 0 12px rgba(0, 255, 65, 0.3);
}
.led-off {
  background: #1a2a1a;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.5);
}

/* Line highlight */
.line-highlight {
  background: rgba(0, 255, 65, 0.1) !important;
  border-left: 2px solid var(--green) !important;
}

.line-breakpoint {
  position: relative;
}
.line-breakpoint::after {
  content: '';
  position: absolute;
  left: 4px;
  top: 50%;
  transform: translateY(-50%);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 4px var(--red);
}

/* Button styles */
.btn-toolbar {
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
  border: 1px solid var(--border);
  background: var(--bg-header);
  color: var(--text);
  cursor: pointer;
  transition: all 0.15s;
  font-family: 'IBM Plex Sans', sans-serif;
  white-space: nowrap;
}
.btn-toolbar:hover {
  background: #252545;
  border-color: var(--cyan);
  color: var(--cyan);
}
.btn-toolbar:active { transform: scale(0.97); }
.btn-primary {
  background: rgba(0, 255, 65, 0.1);
  border-color: var(--green);
  color: var(--green);
}
.btn-primary:hover {
  background: rgba(0, 255, 65, 0.2);
  border-color: var(--green);
  color: var(--green);
}
.btn-danger {
  border-color: var(--red);
  color: var(--red);
}
.btn-danger:hover {
  background: rgba(255, 68, 68, 0.1);
}

/* Status badges */
.status-badge {
  padding: 2px 8px;
  border-radius: 3px;
  font-size: 11px;
  font-weight: 600;
  font-family: 'Fira Code', monospace;
  letter-spacing: 0.5px;
}

/* Tooltip */
.tooltip-container { position: relative; }
.tooltip-container .tooltip-text {
  visibility: hidden;
  opacity: 0;
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: #2a2a4a;
  color: var(--text-bright);
  padding: 6px 10px;
  border-radius: 4px;
  font-size: 11px;
  white-space: nowrap;
  z-index: 100;
  transition: opacity 0.15s;
  border: 1px solid var(--border);
  pointer-events: none;
}
.tooltip-container:hover .tooltip-text {
  visibility: visible;
  opacity: 1;
}

/* Memory highlight */
.mem-program { background: rgba(0, 212, 255, 0.08); }
.mem-stack { background: rgba(255, 204, 0, 0.08); }
.mem-access { background: rgba(0, 255, 65, 0.25); }

/* Tab styles */
.tab-active {
  border-bottom: 2px solid var(--green);
  color: var(--green);
}
.tab-inactive {
  border-bottom: 2px solid transparent;
  color: var(--text-dim);
}

/* Select */
select.styled-select {
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 12px;
  font-family: 'IBM Plex Sans', sans-serif;
  cursor: pointer;
  outline: none;
}
select.styled-select:focus { border-color: var(--cyan); }

/* Responsive */
@media (max-width: 1024px) {
  .desktop-layout { flex-direction: column !important; }
  .panel-left, .panel-right { width: 100% !important; max-width: 100% !important; }
}