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

:root {
  --bg-primary: #0a0e14;
  --bg-secondary: #0d1117;
  --bg-panel: #111820;
  --bg-input: #0d1117;
  --border: #1e2a3a;
  --border-bright: #2a3a4e;
  --text-primary: #c5cdd8;
  --text-dim: #5a6a7a;
  --text-bright: #e8edf3;
  --accent-cyan: #00d4ff;
  --accent-green: #00ff41;
  --accent-yellow: #ffd700;
  --accent-orange: #ff8c00;
  --accent-red: #ff4444;
  --accent-blue: #4a9eff;
  --accent-purple: #b48eff;
  --font-mono: 'IBM Plex Mono', 'Consolas', 'Courier New', monospace;
  --font-display: 'Share Tech Mono', monospace;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.5;
  overflow: hidden;
  height: 100vh;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 16px;
  background: linear-gradient(180deg, #141c26 0%, #0d1117 100%);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  min-height: 42px;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-title {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--accent-cyan);
  letter-spacing: 2px;
  text-shadow: 0 0 12px rgba(0,212,255,0.3);
}

.header-subtitle {
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing: 0.5px;
}

.cpu-status {
  font-family: var(--font-display);
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 3px;
  letter-spacing: 1px;
  border: 1px solid;
}

.cpu-status.halted { color: var(--text-dim); border-color: #333; background: #1a1a1a; }
.cpu-status.running { color: var(--accent-green); border-color: #0a4a0a; background: #0a1a0a; animation: pulse-green 1s infinite; }
.cpu-status.paused { color: var(--accent-yellow); border-color: #4a4a0a; background: #1a1a0a; }
.cpu-status.error { color: var(--accent-red); border-color: #4a0a0a; background: #1a0a0a; }

@keyframes pulse-green {
  0%, 100% { box-shadow: 0 0 4px rgba(0,255,65,0.2); }
  50% { box-shadow: 0 0 8px rgba(0,255,65,0.4); }
}

/* Main layout */
.main-container {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.left-panel {
  width: 48%;
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border);
  min-width: 400px;
}

.right-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Toolbar */
.toolbar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  flex-shrink: 0;
}

.toolbar-btn {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  padding: 4px 12px;
  border: 1px solid var(--border-bright);
  background: var(--bg-panel);
  color: var(--text-primary);
  cursor: pointer;
  border-radius: 3px;
  transition: all 0.15s;
  letter-spacing: 0.3px;
  white-space: nowrap;
}

.toolbar-btn:hover {
  background: #1a2430;
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.toolbar-btn.primary {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

.toolbar-btn.run {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

.toolbar-btn.danger {
  border-color: var(--accent-red);
  color: var(--accent-red);
}

.toolbar-btn:active {
  transform: scale(0.97);
}

.toolbar-sep {
  width: 1px;
  height: 20px;
  background: var(--border);
  margin: 0 4px;
}

.speed-control {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: 4px;
}

.speed-control label {
  font-size: 10px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.speed-slider {
  width: 80px;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 2px;
  outline: none;
}

.speed-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-cyan);
  cursor: pointer;
}

.example-select {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 3px 8px;
  background: var(--bg-panel);
  color: var(--text-primary);
  border: 1px solid var(--border-bright);
  border-radius: 3px;
  cursor: pointer;
  outline: none;
}

.example-select:focus {
  border-color: var(--accent-cyan);
}

/* Editor area */
.editor-container {
  flex: 1;
  position: relative;
  overflow: hidden;
  display: flex;
}

.line-numbers {
  width: 44px;
  background: #080c12;
  border-right: 1px solid var(--border);
  overflow: hidden;
  flex-shrink: 0;
  padding-top: 8px;
  user-select: none;
}

.line-num {
  display: block;
  height: 20px;
  line-height: 20px;
  text-align: right;
  padding-right: 8px;
  font-size: 11px;
  color: var(--text-dim);
  cursor: pointer;
  position: relative;
}

.line-num:hover { color: var(--text-primary); }

.line-num.current {
  color: var(--accent-yellow);
  background: rgba(255,215,0,0.06);
}

.line-num.breakpoint::before {
  content: '●';
  position: absolute;
  left: 4px;
  color: var(--accent-red);
  font-size: 10px;
}

.code-textarea {
  flex: 1;
  background: var(--bg-input);
  color: var(--text-bright);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 20px;
  padding: 8px 12px;
  border: none;
  outline: none;
  resize: none;
  tab-size: 4;
  white-space: pre;
  overflow: auto;
}

.code-textarea::selection {
  background: rgba(0,212,255,0.2);
}

/* Assembler output */
.asm-output {
  height: 100px;
  min-height: 60px;
  background: #060a0e;
  border-top: 1px solid var(--border);
  overflow-y: auto;
  padding: 6px 10px;
  font-size: 11px;
  flex-shrink: 0;
}

.asm-output .msg-success { color: var(--accent-green); }
.asm-output .msg-error { color: var(--accent-red); }
.asm-output .msg-info { color: var(--accent-cyan); }
.asm-output .msg-hex { color: var(--accent-orange); }

/* Right panel sections */
.right-scroll {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.panel-section {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.panel-header {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-dim);
  padding: 5px 10px;
  background: rgba(0,0,0,0.3);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.panel-body {
  padding: 8px 10px;
}

/* Registers */
.registers-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
}

.reg-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 2px 6px;
  border-radius: 2px;
  transition: background 0.3s;
}

.reg-item.changed {
  background: rgba(255,215,0,0.12);
  animation: flash-yellow 0.6s;
}

@keyframes flash-yellow {
  0% { background: rgba(255,215,0,0.3); }
  100% { background: rgba(255,215,0,0.05); }
}

.reg-name {
  font-size: 11px;
  font-weight: 600;
  color: var(--accent-cyan);
  min-width: 22px;
}

.reg-val {
  font-size: 12px;
  color: var(--text-bright);
  font-weight: 500;
}

.reg-dec {
  font-size: 10px;
  color: var(--text-dim);
}

/* Flags */
.flags-grid {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.flag-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 32px;
  padding: 4px 0;
  border-radius: 3px;
  border: 1px solid var(--border);
  transition: all 0.3s;
}

.flag-item.set {
  border-color: var(--accent-green);
  background: rgba(0,255,65,0.08);
}

.flag-item.changed {
  animation: flash-flag 0.6s;
}

@keyframes flash-flag {
  0% { box-shadow: 0 0 8px rgba(255,215,0,0.5); }
  100% { box-shadow: none; }
}

.flag-label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.flag-item.set .flag-label { color: var(--accent-green); }
.flag-item:not(.set) .flag-label { color: #444; }

.flag-val {
  font-size: 9px;
  margin-top: 1px;
}

.flag-item.set .flag-val { color: var(--accent-green); }
.flag-item:not(.set) .flag-val { color: #333; }

/* Stack */
.stack-list {
  max-height: 120px;
  overflow-y: auto;
  font-size: 11px;
}

.stack-entry {
  display: flex;
  gap: 12px;
  padding: 1px 4px;
  border-radius: 2px;
}

.stack-entry.top {
  background: rgba(0,212,255,0.08);
  color: var(--accent-cyan);
}

.stack-addr { color: var(--text-dim); min-width: 50px; }
.stack-val { color: var(--text-bright); }

/* Memory view */
.memory-controls {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-bottom: 6px;
}

.mem-addr-input {
  font-family: var(--font-mono);
  font-size: 11px;
  width: 80px;
  padding: 2px 6px;
  background: var(--bg-input);
  color: var(--text-bright);
  border: 1px solid var(--border-bright);
  border-radius: 3px;
  outline: none;
}

.mem-addr-input:focus { border-color: var(--accent-cyan); }

.memory-dump {
  max-height: 160px;
  overflow-y: auto;
  font-size: 11px;
  line-height: 18px;
}

.mem-row {
  display: flex;
  white-space: pre;
}

.mem-addr-col { color: var(--accent-blue); min-width: 60px; }
.mem-hex-col { color: var(--text-primary); }
.mem-ascii-col { color: var(--text-dim); margin-left: 12px; }

.mem-byte { padding: 0 1px; }
.mem-byte.highlight-ip { background: rgba(0,255,65,0.15); color: var(--accent-green); }
.mem-byte.highlight-write { background: rgba(255,140,0,0.2); color: var(--accent-orange); }

/* Trace */
.trace-list {
  max-height: 120px;
  overflow-y: auto;
  font-size: 11px;
}

.trace-entry {
  display: flex;
  gap: 8px;
  padding: 1px 4px;
  border-radius: 2px;
}

.trace-entry.next {
  background: rgba(0,255,65,0.08);
}

.trace-addr { color: var(--accent-blue); min-width: 50px; }
.trace-hex { color: var(--text-dim); min-width: 80px; }
.trace-dis { color: var(--text-bright); }

/* Console output */
.console-output {
  min-height: 60px;
  max-height: 100px;
  background: #000;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 18px;
  padding: 6px 10px;
  color: #33ff33;
  overflow-y: auto;
  white-space: pre-wrap;
  word-break: break-all;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
  text-shadow: 0 0 4px rgba(51,255,51,0.3);
}

/* Stats bar */
.stats-bar {
  display: flex;
  gap: 16px;
  padding: 4px 10px;
  font-size: 10px;
  color: var(--text-dim);
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.stats-bar span { letter-spacing: 0.3px; }
.stats-bar .stat-val { color: var(--accent-cyan); }

/* Footer */
.footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 4px 16px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  font-size: 10px;
  color: var(--text-dim);
  flex-shrink: 0;
}

.footer a {
  color: var(--accent-cyan);
  text-decoration: none;
}

.footer a:hover { text-decoration: underline; }

/* Scrollbar styling */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: #2a3a4e; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #3a4a5e; }

/* CRT scanline effect (subtle) */
.crt-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  pointer-events: none;
  z-index: 9999;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0,0,0,0.03) 2px,
    rgba(0,0,0,0.03) 4px
  );
}