:root {
  --bg: #060a06;
  --panel: #0c120c;
  --green: #39ff14;
  --amber: #ffb000;
  --blue: #4aa8ff;
  --dim: #2a3a2a;
  --text: #b8ffb0;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background:
    radial-gradient(ellipse at 50% -10%, #0f2410 0%, var(--bg) 60%),
    var(--bg);
  color: var(--text);
  font-family: 'Share Tech Mono', monospace;
  min-height: 100vh;
}
.scanlines {
  pointer-events: none;
  position: fixed; inset: 0; z-index: 999;
  background: repeating-linear-gradient(
    to bottom, rgba(0,0,0,0) 0px, rgba(0,0,0,0) 2px,
    rgba(0,0,0,0.18) 3px, rgba(0,0,0,0.18) 4px);
  mix-blend-mode: multiply;
}
.wrap { max-width: 1000px; margin: 0 auto; padding: 20px 16px 60px; }

header { text-align: center; margin-bottom: 22px; }
h1 {
  font-family: 'VT323', monospace;
  font-size: clamp(40px, 8vw, 72px);
  margin: 0; color: var(--green);
  letter-spacing: 2px;
  text-shadow: 0 0 12px rgba(57,255,20,0.6), 0 0 30px rgba(57,255,20,0.3);
}
.tag { color: var(--amber); font-size: 14px; margin: 4px 0 0; opacity: 0.85; }

.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 720px) { .grid { grid-template-columns: 1fr; } }

.panel {
  background: linear-gradient(180deg, var(--panel), #080d08);
  border: 1px solid var(--dim);
  border-radius: 6px;
  padding: 16px;
  box-shadow: inset 0 0 30px rgba(57,255,20,0.04);
}
.panel h2 {
  margin: 0 0 12px; font-size: 18px;
  font-family: 'VT323', monospace; letter-spacing: 1px;
}
.tx h2 { color: var(--green); }
.rx h2 { color: var(--amber); }
.scope h2, .proto h2 { color: var(--blue); }

.src-btns { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 12px; }
.src-btn {
  flex: 1; min-width: 90px;
  background: #0a100a; color: var(--text);
  border: 1px solid var(--dim); border-radius: 4px;
  padding: 8px 4px; cursor: pointer;
  font-family: inherit; font-size: 12px;
  transition: all 0.15s;
}
.src-btn:hover { border-color: var(--green); }
.src-btn.active { background: var(--green); color: #041004; border-color: var(--green); }

.preview-row { display: flex; gap: 10px; align-items: flex-end; flex-wrap: wrap; }
.canvas-box { position: relative; }
.canvas-box.big { margin: 10px auto; text-align: center; }
.canvas-box .lbl {
  display: block; font-size: 10px; color: var(--amber);
  margin-bottom: 3px; letter-spacing: 1px;
}
canvas {
  background: #000; border: 1px solid var(--dim); border-radius: 3px;
  image-rendering: pixelated;
  box-shadow: 0 0 12px rgba(57,255,20,0.15);
}
#rxCanvas { width: 100%; max-width: 256px; height: auto; }
#scopeCanvas { width: 100%; height: auto; display: block; }

.big-btn {
  width: 100%; padding: 14px; margin: 12px 0;
  background: #0a1a0a; color: var(--green);
  border: 2px solid var(--green); border-radius: 5px;
  font-family: 'VT323', monospace; font-size: 24px;
  letter-spacing: 2px; cursor: pointer;
  transition: all 0.2s;
}
.big-btn:hover { box-shadow: 0 0 18px rgba(57,255,20,0.5); }
.big-btn.on {
  background: var(--green); color: #041004;
  animation: pulse 1s infinite;
}
.big-btn.amber { color: var(--amber); border-color: var(--amber); }
.big-btn.amber:hover { box-shadow: 0 0 18px rgba(255,176,0,0.5); }
.big-btn.amber.on { background: var(--amber); color: #200e00; }
@keyframes pulse { 50% { opacity: 0.65; } }

.row { display: flex; align-items: center; gap: 8px; font-size: 13px; margin: 8px 0; }
.row input[type=range] { flex: 1; accent-color: var(--green); }
.switch { cursor: pointer; }
.switch input { accent-color: var(--green); }

.leds { display: flex; gap: 16px; justify-content: center; margin: 8px 0; }
.led { font-size: 13px; color: #333; letter-spacing: 1px; transition: all 0.2s; }
.led.on { color: var(--green); text-shadow: 0 0 10px var(--green); }
#ledH.on { color: var(--amber); text-shadow: 0 0 10px var(--amber); }

.meters { display: flex; justify-content: space-between; font-size: 13px; color: var(--blue); margin: 6px 0; }

.status-line {
  font-size: 12px; color: var(--amber);
  border-top: 1px dashed var(--dim); padding-top: 8px; margin-top: 10px;
  min-height: 16px;
}

.band-key { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 8px; font-size: 11px; }
.band-key .v { color: var(--green); }
.band-key .h { color: var(--amber); }
.band-key .p { color: var(--blue); }

.proto h2 { cursor: pointer; user-select: none; }
#protoBody {
  font-size: 12px; color: var(--text); line-height: 1.5;
  background: #040704; padding: 10px; border-radius: 4px;
  border: 1px solid var(--dim); overflow-x: auto;
}
.hidden { display: none; }

.scope, .proto { margin-top: 16px; }

footer {
  margin-top: 30px; text-align: center; font-size: 12px;
  color: #557755; display: flex; flex-direction: column; gap: 6px;
}
footer a { color: var(--green); text-decoration: none; border-bottom: 1px dotted var(--green); }
footer a:hover { text-shadow: 0 0 8px var(--green); }