:root{
  --pixel-size: 10px; /* adjust visual size */
  --gap: 2px;
}
body{font-family: system-ui,Segoe UI,Roboto,Arial;display:flex;flex-direction:column;align-items:center;margin:24px;color:#222}
h1{margin:0 0 12px}
.board-wrap{background:#111;padding:12px;border-radius:8px}
canvas#led{image-rendering: pixelated; width: calc(64 * var(--pixel-size)); height: calc(8 * var(--pixel-size)); display:block;}
.hint{margin-top:12px;color:#444}

.controls{display:flex;align-items:center;gap:8px;margin-top:12px;color:#ddd}
.controls label{color:#ddd}
.controls input[type=range]{width:240px}
.controls #speedLabel{min-width:48px;text-align:right}

/* LED look */
canvas{background:#000;border:6px solid #222}