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

:root {
  --bg: #111110;
  --panel: #1a1a18;
  --panel-border: #333330;
  --green: #33ff33;
  --green-dim: #1a9a1a;
  --green-glow: rgba(51,255,51,0.15);
  --amber: #ffaa33;
  --bezel: #5c4a35;
  --bezel-dark: #3a2f22;
  --text: #c8c8b8;
  --text-dim: #777766;
  --red: #ff4444;
  --font-mono: 'IBM Plex Mono', 'Courier New', monospace;
  --font-display: 'VT323', 'Courier New', monospace;
}

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

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: 
    radial-gradient(ellipse at 50% 30%, rgba(51,255,51,0.03) 0%, transparent 60%),
    repeating-linear-gradient(0deg, transparent 0px, transparent 3px, rgba(255,255,255,0.008) 3px, rgba(255,255,255,0.008) 4px);
  pointer-events: none;
  z-index: 0;
}

#app {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 12px 16px;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 0 12px;
  border-bottom: 1px solid var(--panel-border);
  margin-bottom: 16px;
}

header h1 {
  font-family: var(--font-display);
  font-size: 28px;
  color: var(--green);
  letter-spacing: 2px;
  text-shadow: 0 0 10px var(--green-glow);
}

.subtitle {
  font-size: 11px;
  color: var(--text-dim);
  display: block;
  margin-top: 2px;
}

#main-layout {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

#monitor-section {
  flex-shrink: 0;
}

#monitor-bezel {
  background: linear-gradient(145deg, #6b5a45, #3a2f22);
  border-radius: 18px;
  padding: 18px 18px 8px;
  box-shadow: 
    0 4px 20px rgba(0,0,0,0.6),
    inset 0 1px 0 rgba(255,255,255,0.08);
}

#monitor-inner {
  position: relative;
  background: #000;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 
    inset 0 0 30px rgba(0,0,0,1),
    0 0 20px var(--green-glow),
    0 0 60px rgba(51,255,51,0.05);
}

#terminal {
  display: block;
  width: 560px;
  height: 384px;
  cursor: text;
  outline: none;
  image-rendering: pixelated;
}

#terminal:focus + #scanlines::after {
  content: '';
  position: absolute;
  bottom: 8px;
  right: 8px;
  width: 8px;
  height: 8px;
  background: var(--green);
  border-radius: 50%;
  box-shadow: 0 0 4px var(--green);
}

#scanlines {
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent 0px,
    transparent 1px,
    rgba(0,0,0,0.15) 1px,
    rgba(0,0,0,0.15) 2px
  );
  pointer-events: none;
  border-radius: 10px;
}

#monitor-label {
  text-align: center;
  padding: 8px 0 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: #aa9977;
  letter-spacing: 6px;
  text-transform: uppercase;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.led {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 4px var(--red);
  animation: ledPulse 2s ease-in-out infinite;
}

.led.running {
  background: var(--green);
  box-shadow: 0 0 6px var(--green);
  animation: ledPulseGreen 1s ease-in-out infinite;
}

@keyframes ledPulse {
  0%,100% { opacity: 0.6; }
  50% { opacity: 1; }
}

@keyframes ledPulseGreen {
  0%,100% { opacity: 0.8; }
  50% { opacity: 1; }
}

#focus-hint {
  text-align: center;
  font-size: 11px;
  color: var(--text-dim);
  margin-top: 6px;
}

#controls-section {
  flex: 1;
  min-width: 280px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 8px;
  padding: 10px 12px;
}

.panel h3 {
  font-family: var(--font-display);
  font-size: 16px;
  color: var(--amber);
  margin-bottom: 8px;
  letter-spacing: 1px;
}

.btn-row {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.btn {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  padding: 6px 12px;
  border: 1px solid var(--panel-border);
  border-radius: 4px;
  background: linear-gradient(180deg, #2a2a28, #1e1e1c);
  color: var(--text);
  cursor: pointer;
  transition: all 0.1s;
  box-shadow: 0 1px 2px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.05);
}

.btn:hover { 
  background: linear-gradient(180deg, #333330, #282826); 
  border-color: #555;
}

.btn:active { 
  transform: translateY(1px); 
  box-shadow: none; 
}

.btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.btn-primary {
  color: var(--green);
  border-color: var(--green-dim);
}

.btn-primary:hover {
  border-color: var(--green);
  box-shadow: 0 0 8px var(--green-glow);
}

.btn-small {
  padding: 4px 8px;
  font-size: 11px;
}

.speed-row {
  margin-top: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.speed-row label {
  font-size: 11px;
  color: var(--text-dim);
}

.speed-row select, select {
  font-family: var(--font-mono);
  font-size: 11px;
  background: #222;
  color: var(--text);
  border: 1px solid var(--panel-border);
  border-radius: 4px;
  padding: 4px 6px;
  flex: 1;
}

.reg-display {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--green);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
}

.reg-display b {
  color: #fff;
  font-weight: 400;
}

.flag-display {
  margin-top: 6px;
  display: flex;
  gap: 4px;
}

.flag {
  font-family: var(--font-display);
  font-size: 16px;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 3px;
  background: #222;
  border: 1px solid var(--panel-border);
  color: var(--text-dim);
  transition: all 0.15s;
}

.flag.active {
  color: var(--green);
  border-color: var(--green-dim);
  background: rgba(51,255,51,0.08);
  text-shadow: 0 0 4px var(--green-glow);
}

.flag.dim { opacity: 0.3; }

#dropzone {
  border: 2px dashed var(--panel-border);
  border-radius: 6px;
  padding: 12px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: 8px;
  position: relative;
}

#dropzone.dragover {
  border-color: var(--green);
  background: rgba(51,255,51,0.03);
}

#dropzone p {
  font-size: 11px;
  color: var(--text-dim);
  pointer-events: none;
}

#fileInput {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.load-row {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 6px 0;
}

.load-row label {
  font-size: 11px;
  color: var(--text-dim);
  white-space: nowrap;
}

.hex-prefix {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--amber);
}

.hex-input {
  font-family: var(--font-display);
  font-size: 16px;
  background: #1a1a18;
  color: var(--green);
  border: 1px solid var(--panel-border);
  border-radius: 4px;
  padding: 4px 6px;
  width: 64px;
  text-transform: uppercase;
}

.hex-input:focus {
  outline: none;
  border-color: var(--green-dim);
}

.status-msg {
  font-size: 11px;
  color: var(--green);
  min-height: 16px;
  margin-top: 4px;
}

.mem-dump {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--green);
  background: #0a0a08;
  border-radius: 4px;
  padding: 8px;
  overflow-x: auto;
  max-height: 160px;
  overflow-y: auto;
  line-height: 1.5;
  margin-top: 6px;
}

#examples-panel {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

#examples-panel h3 {
  margin-bottom: 0;
}

#examples-panel select {
  flex: 1;
  min-width: 140px;
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal.hidden { display: none; }

.modal-content {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  width: 90%;
  max-width: 520px;
  max-height: 80vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  border-bottom: 1px solid var(--panel-border);
}

.modal-header h2 {
  font-family: var(--font-display);
  font-size: 22px;
  color: var(--green);
}

.modal-body {
  padding: 16px;
  font-size: 12px;
  line-height: 1.6;
}

.modal-body h3 {
  color: var(--amber);
  font-family: var(--font-display);
  font-size: 16px;
  margin: 12px 0 4px;
}

.modal-body h3:first-child { margin-top: 0; }

.modal-body code {
  background: #222;
  padding: 2px 5px;
  border-radius: 3px;
  font-size: 12px;
  color: var(--green);
}

.modal-body code.block {
  display: block;
  padding: 8px 10px;
  margin: 6px 0;
  overflow-x: auto;
}

.modal-body ul {
  padding-left: 18px;
  margin: 4px 0;
}

footer {
  margin-top: 20px;
  padding: 12px 0;
  border-top: 1px solid var(--panel-border);
  text-align: center;
  font-size: 11px;
  color: var(--text-dim);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 6px 16px;
}

footer a {
  color: var(--green-dim);
  text-decoration: none;
}

footer a:hover {
  color: var(--green);
}

details summary {
  cursor: pointer;
  list-style: none;
}
details summary::-webkit-details-marker { display: none; }
details summary::before {
  content: '▸ ';
  color: var(--amber);
}
details[open] summary::before {
  content: '▾ ';
}

/* Responsive */
@media (max-width: 900px) {
  #main-layout {
    flex-direction: column;
    align-items: center;
  }
  #terminal {
    width: min(560px, calc(100vw - 72px));
    height: auto;
    aspect-ratio: 560/384;
  }
  #controls-section {
    width: 100%;
    max-width: 600px;
  }
}

@media (max-width: 480px) {
  #app { padding: 8px; }
  header h1 { font-size: 20px; }
  .subtitle { display: none; }
  #monitor-bezel { padding: 10px 10px 6px; border-radius: 12px; }
  .reg-display { font-size: 14px; gap: 4px 8px; }
}