:root {
  --crt-green: #33ff33;
  --crt-green-dim: #1a9c1a;
  --crt-green-glow: #33ff3380;
  --crt-bg: #0a0a0a;
  --bezel-color: #3d3225;
  --bezel-light: #5a4a38;
  --bezel-dark: #2a2118;
  --panel-bg: #1a1a1a;
  --panel-border: #333;
  --text-dim: #888;
  --red: #ff4444;
  --yellow: #ffcc00;
  --blue: #4488ff;
  --cyan: #33ffff;
  --amber: #FFB833;
  --dim-green: #227722;
}

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

body {
  background: #111;
  background-image: radial-gradient(ellipse at 50% 0%, #1a1a1a 0%, #0a0a0a 70%);
  color: #ccc;
  font-family: 'IBM Plex Mono', monospace;
  min-height: 100vh;
  overflow-x: hidden;
}

.app-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px;
}

.header {
  text-align: center;
  padding: 20px 0 12px;
}

.header h1 {
  font-family: 'VT323', monospace;
  font-size: 36px;
  color: var(--crt-green);
  text-shadow: 0 0 10px var(--crt-green-glow), 0 0 20px var(--crt-green-glow);
  letter-spacing: 3px;
}

.header .subtitle {
  font-size: 13px;
  color: var(--text-dim);
  margin-top: 2px;
  letter-spacing: 1px;
}

.monitor-frame {
  background: linear-gradient(145deg, var(--bezel-light), var(--bezel-dark));
  border-radius: 18px;
  padding: 24px;
  margin: 12px auto;
  max-width: 760px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.6), inset 0 1px 0 rgba(255,255,255,0.08), inset 0 -1px 0 rgba(0,0,0,0.3);
  position: relative;
}

.monitor-label {
  position: absolute;
  bottom: 6px;
  left: 50%;
  transform: translateX(-50%);
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  color: #6b5d4d;
  letter-spacing: 4px;
  font-weight: 700;
  text-transform: uppercase;
}

.screen-bezel {
  background: #050505;
  border-radius: 10px;
  padding: 8px;
  box-shadow: inset 0 2px 8px rgba(0,0,0,0.9);
}

.crt-screen {
  position: relative;
  background: var(--crt-bg);
  border-radius: 6px;
  overflow: hidden;
  cursor: text;
}

.crt-screen canvas {
  display: block;
  width: 100%;
  height: auto;
  image-rendering: pixelated;
}

.scanlines {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: repeating-linear-gradient(0deg, transparent, transparent 2px, rgba(0,0,0,0.15) 2px, rgba(0,0,0,0.15) 4px);
  pointer-events: none;
  z-index: 2;
}

.vignette {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(ellipse at center, transparent 60%, rgba(0,0,0,0.4) 100%);
  pointer-events: none;
  z-index: 3;
}

.crt-flicker {
  animation: flicker 0.1s infinite alternate;
}

@keyframes flicker {
  0% { opacity: 1; }
  100% { opacity: 0.985; }
}

.controls-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 16px;
}

.panel-section {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 6px;
  padding: 14px;
}

.panel-section h3 {
  font-family: 'VT323', monospace;
  font-size: 18px;
  color: var(--crt-green);
  margin-bottom: 10px;
  border-bottom: 1px solid var(--panel-border);
  padding-bottom: 6px;
  letter-spacing: 1px;
}

.btn {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  font-weight: 700;
  padding: 6px 14px;
  border: 2px solid;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  transition: all 0.1s;
  background: transparent;
}

.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-green { border-color: var(--crt-green-dim); color: var(--crt-green); }
.btn-green:hover:not(:disabled) { background: rgba(51, 255, 51, 0.1); box-shadow: 0 0 8px var(--crt-green-glow); }

.btn-red { border-color: #992222; color: var(--red); }
.btn-red:hover:not(:disabled) { background: rgba(255, 68, 68, 0.1); }

.btn-yellow { border-color: #997700; color: var(--yellow); }
.btn-yellow:hover:not(:disabled) { background: rgba(255, 204, 0, 0.1); }

.btn-blue { border-color: #2255aa; color: var(--blue); }
.btn-blue:hover:not(:disabled) { background: rgba(68, 136, 255, 0.1); }

.btn-cyan { border-color: #1a9999; color: var(--cyan); }
.btn-cyan:hover:not(:disabled) { background: rgba(51, 255, 255, 0.1); }

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

.registers {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
  margin-bottom: 10px;
}

.reg-box {
  text-align: center;
  background: #0d0d0d;
  border: 1px solid #2a2a2a;
  border-radius: 3px;
  padding: 4px;
}

.reg-label { font-size: 10px; color: var(--text-dim); letter-spacing: 1px; }

.reg-value {
  font-family: 'VT323', monospace;
  font-size: 20px;
  color: var(--crt-green);
  text-shadow: 0 0 4px var(--crt-green-glow);
}

.flags-row { display: flex; gap: 4px; justify-content: center; }

.flag-indicator {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'VT323', monospace;
  font-size: 16px;
  border-radius: 3px;
  border: 1px solid #2a2a2a;
  background: #0d0d0d;
  color: #444;
  transition: all 0.15s;
}

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

.file-row {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 8px;
}

.hex-input {
  font-family: 'VT323', monospace;
  font-size: 18px;
  width: 80px;
  background: #0d0d0d;
  border: 1px solid #2a2a2a;
  color: var(--crt-green);
  padding: 4px 8px;
  border-radius: 3px;
  text-align: center;
}

.hex-input:focus {
  outline: none;
  border-color: var(--crt-green-dim);
  box-shadow: 0 0 4px var(--crt-green-glow);
}

.file-input-wrapper { position: relative; }

.file-input-wrapper input[type="file"] {
  position: absolute;
  opacity: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

.file-label {
  display: inline-block;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  padding: 6px 14px;
  border: 2px solid var(--panel-border);
  color: #aaa;
  cursor: pointer;
  letter-spacing: 1px;
}
.file-label:hover { border-color: #555; color: #ddd; }

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

.status-msg.error { color: var(--red); }

.speed-control {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 8px;
}

.speed-control input[type="range"] {
  flex: 1;
  accent-color: var(--crt-green);
  height: 4px;
}

.speed-label {
  font-family: 'VT323', monospace;
  font-size: 16px;
  color: var(--crt-green);
  min-width: 100px;
  text-align: right;
}

.stats-row {
  display: flex;
  gap: 16px;
  margin-top: 8px;
  font-size: 11px;
  color: var(--text-dim);
}

.stats-row span { color: var(--crt-green-dim); }

.memory-toggle {
  cursor: pointer;
  user-select: none;
  display: flex;
  align-items: center;
  gap: 6px;
}

.memory-toggle .arrow {
  transition: transform 0.2s;
  display: inline-block;
  font-size: 10px;
}

.memory-toggle .arrow.open { transform: rotate(90deg); }

.memory-viewer {
  background: #0a0a0a;
  border: 1px solid #222;
  border-radius: 3px;
  padding: 8px;
  margin-top: 8px;
  overflow-x: auto;
  font-family: 'VT323', monospace;
  font-size: 14px;
  color: var(--crt-green-dim);
  line-height: 1.6;
  max-height: 260px;
  overflow-y: auto;
}

.mem-page-select {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 6px;
}

/* Assembler Panel */
.assembler-panel {
  margin-top: 16px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 6px;
  overflow: hidden;
}

.assembler-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  background: #1e1e1e;
  border-bottom: 1px solid var(--panel-border);
  cursor: pointer;
  user-select: none;
}

.assembler-header h3 {
  font-family: 'VT323', monospace;
  font-size: 20px;
  color: var(--cyan);
  letter-spacing: 2px;
  margin: 0;
  border: none;
  padding: 0;
}

.assembler-header .toggle-arrow {
  color: var(--cyan);
  font-size: 14px;
  transition: transform 0.2s;
}

.assembler-header .toggle-arrow.open {
  transform: rotate(90deg);
}

.assembler-body {
  padding: 14px;
  display: none;
}

.assembler-body.open {
  display: block;
}

.asm-toolbar {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 10px;
}

.asm-toolbar select {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 12px;
  background: #0d0d0d;
  color: var(--crt-green);
  border: 1px solid #2a2a2a;
  padding: 5px 8px;
  border-radius: 3px;
  cursor: pointer;
}

.asm-toolbar select:focus {
  outline: none;
  border-color: var(--crt-green-dim);
}

.asm-editor-wrap {
  display: flex;
  border: 1px solid #2a2a2a;
  border-radius: 4px;
  overflow: hidden;
  background: #0a0a0a;
  max-height: 400px;
}

.asm-line-numbers {
  padding: 10px 8px;
  background: #0d0d0d;
  color: #555;
  font-family: 'VT323', monospace;
  font-size: 14px;
  line-height: 1.5;
  text-align: right;
  border-right: 1px solid #222;
  user-select: none;
  overflow: hidden;
  min-width: 40px;
}

.asm-editor {
  flex: 1;
  background: #0a0a0a;
  color: var(--crt-green);
  font-family: 'VT323', monospace;
  font-size: 14px;
  line-height: 1.5;
  padding: 10px;
  border: none;
  outline: none;
  resize: none;
  overflow-y: auto;
  tab-size: 8;
  white-space: pre;
  min-height: 200px;
}

.asm-output {
  margin-top: 10px;
  background: #0a0a0a;
  border: 1px solid #222;
  border-radius: 4px;
  padding: 10px;
  max-height: 250px;
  overflow-y: auto;
  font-family: 'VT323', monospace;
  font-size: 13px;
  line-height: 1.5;
  color: var(--crt-green-dim);
}

.asm-output .error-line { color: var(--red); }
.asm-output .success-line { color: var(--crt-green); }
.asm-output .info-line { color: var(--cyan); }
.asm-output .addr-line { color: var(--amber); }

/* Test Suite Panel */
.test-panel {
  margin-top: 16px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 6px;
  overflow: hidden;
}

.test-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  background: #1e1e1e;
  border-bottom: 1px solid var(--panel-border);
  cursor: pointer;
  user-select: none;
}

.test-header h3 {
  font-family: 'VT323', monospace;
  font-size: 20px;
  color: var(--amber);
  letter-spacing: 2px;
  margin: 0;
}

.test-body {
  padding: 14px;
  display: none;
}

.test-body.open { display: block; }

.test-controls {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.test-results {
  background: #0a0a0a;
  border: 1px solid #222;
  border-radius: 4px;
  padding: 10px;
  max-height: 400px;
  overflow-y: auto;
  font-family: 'VT323', monospace;
  font-size: 14px;
  line-height: 1.6;
}

.test-result-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 2px 0;
}

.test-pass { color: var(--crt-green); }
.test-fail { color: var(--red); }
.test-category {
  color: var(--amber);
  font-size: 16px;
  margin-top: 8px;
  margin-bottom: 4px;
  border-bottom: 1px solid #333;
  padding-bottom: 2px;
}

.test-summary-bar {
  display: flex;
  gap: 16px;
  align-items: center;
  padding: 8px 12px;
  background: #0d0d0d;
  border: 1px solid #222;
  border-radius: 4px;
  margin-bottom: 10px;
  font-family: 'VT323', monospace;
  font-size: 18px;
}

.test-summary-bar .led {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 1px solid #333;
}

.led-green { background: var(--crt-green); box-shadow: 0 0 6px var(--crt-green); }
.led-red { background: var(--red); box-shadow: 0 0 6px var(--red); }
.led-off { background: #333; }

/* On-Screen Keyboard */
.onscreen-keyboard {
  max-width: 1200px;
  margin: 20px auto;
  padding: 16px;
  background: linear-gradient(145deg, #2a2218, #1a1610);
  border: 2px solid #3d3225;
  border-radius: 10px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.5), inset 0 1px 0 rgba(255,255,255,0.05);
}

.kb-row { display: flex; justify-content: center; gap: 4px; margin-bottom: 4px; }
.kb-row:last-child { margin-bottom: 0; }

.kb-key {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 11px;
  font-weight: 700;
  padding: 8px 10px;
  min-width: 38px;
  height: 38px;
  border: 1px solid #555;
  border-bottom: 3px solid #333;
  border-radius: 4px;
  background: linear-gradient(180deg, #3a3a3a, #2a2a2a);
  color: #ddd;
  cursor: pointer;
  text-align: center;
  letter-spacing: 0.5px;
  transition: all 0.08s;
  user-select: none;
  display: flex;
  align-items: center;
  justify-content: center;
}

.kb-key:hover {
  background: linear-gradient(180deg, #4a4a4a, #3a3a3a);
  border-color: var(--crt-green-dim);
  color: var(--crt-green);
}

.kb-key:active {
  background: linear-gradient(180deg, #222, #1a1a1a);
  border-bottom-width: 1px;
  transform: translateY(2px);
  color: var(--crt-green);
  box-shadow: 0 0 6px var(--crt-green-glow);
}

.kb-wide { min-width: 68px; padding: 8px 6px; font-size: 9px; }
.kb-space { min-width: 320px; flex: 0 0 auto; }

.example-btns { display: flex; gap: 6px; margin-top: 8px; flex-wrap: wrap; }

.footer {
  text-align: center;
  padding: 20px 0;
  font-size: 12px;
  color: #555;
}

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

.footer a:hover { text-decoration: underline; color: var(--crt-green); }

@media (max-width: 768px) {
  .controls-panel { grid-template-columns: 1fr; }
  .monitor-frame { padding: 12px; border-radius: 12px; }
  .registers { grid-template-columns: repeat(3, 1fr); }
  .header h1 { font-size: 28px; }
  .onscreen-keyboard { padding: 8px; }
  .kb-key { min-width: 28px; height: 32px; padding: 4px 4px; font-size: 9px; }
  .kb-wide { min-width: 48px; font-size: 7px; }
  .kb-space { min-width: 180px; }
  .kb-row { gap: 2px; margin-bottom: 2px; }
}