Files
code-sinth/web/sandbox/studio.html
Jose Luis Montañes 249e2a2b96 sandbox/studio: knob now has large metallic disc filling the body
Reading the close-up: the knob is dominated by a big metallic chrome
disc that occupies most of its surface. The dark part is just a thin
outer rim. The indicator is a small dark notch on the disc that
rotates with the value (the disc itself stays vertically lit).

- Thin dark rim around the outside (~3px @ 56).
- Large metallic disc fills the inside (radial gradient, brushed-metal
  striations from center outward, top crescent highlight).
- Indicator is a small dark triangular notch on the disc, base near
  the center, tip toward the rim, rotated to the value angle.
- Amber arc kept outside everything as a value-progress meter.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-01 18:06:08 +02:00

637 lines
23 KiB
HTML

<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>code-sinth — studio hardware emulation</title>
<style>
:root {
--bg: #131210;
--hw-bg: #1a1916; /* panel: neutral dark, very faint warm tint */
--hw-bg-hi: #232220;
--hw-bg-lo: #0e0d0b;
--hw-edge: #050505;
--hw-screw: #5a5550;
--hw-amber: #e8a050; /* used ONLY for arcs / LEDs / labels */
--hw-amber-hi: #f4c890;
--hw-amber-mut: rgba(232, 160, 80, 0.18);
--hw-amber-glow: rgba(232, 160, 80, 0.45);
--hw-amber-off: #28201a;
--hw-fg: #a8a39a; /* general text: warm-neutral cream */
--hw-fg-hi: #d8d0c0;
--hw-fg-dim: #6c6660;
--hw-engrave: #8a847a;
--hw-screen: #161412;
--hw-led-red: #c84838;
--hw-led-green: #6aca8a;
--hw-syn-com: #5a554f;
--hw-syn-kw: #d68868;
--hw-syn-num: #d6a268;
--hw-syn-fn: #c8a878;
--hw-syn-id: #b8b0a0;
--hw-syn-op: #6c6660;
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; background: var(--bg); color: var(--hw-fg);
font-family: 'JetBrains Mono', 'Cascadia Code', Consolas, monospace;
font-size: 12px; }
body { padding: 32px; min-height: 100vh; display: flex; align-items: flex-start; justify-content: center; }
/* ===================================================================== */
/* Outer layout: sidebar (description) + hardware unit */
/* ===================================================================== */
.layout {
width: 100%;
max-width: 980px;
}
/* ===================================================================== */
/* Hardware unit — single large rounded panel containing everything */
/* ===================================================================== */
.hardware {
position: relative;
background:
radial-gradient(ellipse at 30% 0%, var(--hw-bg-hi) 0%, var(--hw-bg) 50%, var(--hw-bg-lo) 100%);
border: 1px solid var(--hw-edge);
border-radius: 10px;
box-shadow:
inset 0 1px 0 rgba(255, 220, 180, 0.05),
inset 0 -1px 0 rgba(0, 0, 0, 0.7),
inset 0 0 0 1px rgba(232, 160, 80, 0.04),
0 1px 0 rgba(255, 220, 180, 0.02),
0 8px 24px rgba(0, 0, 0, 0.55);
padding: 14px;
display: grid;
grid-template-columns: 1fr 220px;
gap: 12px;
}
.left-stack { display: grid; grid-template-rows: auto 1fr auto; gap: 8px; min-width: 0; }
.right-stack { display: grid; grid-template-rows: auto auto; gap: 8px; min-width: 0; }
/* corner screws — only on the outermost frame */
.screw {
position: absolute;
width: 8px; height: 8px; border-radius: 50%;
background:
radial-gradient(circle at 30% 25%, #8a7d6a 0%, #3a3025 60%, #100c08 100%);
box-shadow:
inset 0 -1px 1px rgba(0,0,0,0.7),
inset 0 1px 0 rgba(255,220,180,0.18),
0 1px 1px rgba(0,0,0,0.6);
pointer-events: none;
z-index: 5;
}
.screw::after {
content: ''; position: absolute; inset: 0;
background: linear-gradient(45deg, transparent 44%, rgba(0,0,0,0.55) 47%,
rgba(0,0,0,0.55) 53%, transparent 56%);
border-radius: 50%;
}
.hardware > .screw.tl { top: 8px; left: 8px; }
.hardware > .screw.tr { top: 8px; right: 8px; }
.hardware > .screw.bl { bottom: 8px; left: 8px; }
.hardware > .screw.br { bottom: 8px; right: 8px; }
/* ===================================================================== */
/* Header bar inside the hardware unit */
/* ===================================================================== */
.top-bar, .bottom-bar {
height: 30px;
display: flex;
align-items: stretch;
gap: 10px;
padding: 3px 12px;
color: var(--hw-fg-dim);
font-size: 10px;
letter-spacing: 0.08em;
background:
linear-gradient(180deg, #1f1d1a 0%, #14130f 100%);
border: 1px solid var(--hw-edge);
border-radius: 4px;
box-shadow:
inset 0 1px 0 rgba(255,220,180,0.05),
inset 0 -1px 0 rgba(0,0,0,0.6);
}
.top-bar > *, .bottom-bar > * { align-self: center; }
.top-bar .btn-group { align-self: stretch; }
.btn-group { display: flex; align-items: stretch; height: 100%; }
.btn-group .hw-btn { border-radius: 0; border-right-width: 0; }
.btn-group .hw-btn:first-child { border-radius: 3px 0 0 3px; }
.btn-group .hw-btn:last-child { border-radius: 0 3px 3px 0; border-right-width: 1px; }
.hw-btn {
background: linear-gradient(180deg, #2c261f 0%, #14110d 100%);
border: 1px solid var(--hw-edge);
color: var(--hw-fg-hi);
padding: 0 14px;
font-family: inherit;
font-size: 10px;
cursor: pointer;
letter-spacing: 0.12em;
text-transform: uppercase;
box-shadow:
inset 0 1px 0 rgba(255,220,180,0.10),
inset 0 -1px 0 rgba(0,0,0,0.55),
0 1px 1px rgba(0,0,0,0.4);
display: inline-flex; align-items: center; gap: 6px;
transition: color 80ms;
}
.hw-btn:hover { color: var(--hw-amber); }
.hw-btn:active { transform: translateY(1px);
box-shadow: inset 0 1px 3px rgba(0,0,0,0.6); }
.hw-btn .led-red {
width: 6px; height: 6px; border-radius: 50%;
background: var(--hw-led-red);
box-shadow: 0 0 4px var(--hw-led-red);
animation: led-pulse 2.2s ease-in-out infinite;
}
.hw-btn .ico-play {
width: 0; height: 0;
border-left: 6px solid var(--hw-led-green);
border-top: 4px solid transparent;
border-bottom: 4px solid transparent;
filter: drop-shadow(0 0 3px var(--hw-led-green));
}
@keyframes led-pulse {
0%, 100% { box-shadow: 0 0 3px var(--hw-led-red); }
50% { box-shadow: 0 0 8px var(--hw-led-red); }
}
.hw-header .num { color: var(--hw-amber); font-variant-numeric: tabular-nums; }
.hw-header .right { margin-left: auto; color: var(--hw-engrave); letter-spacing: 0.18em; }
/* ===================================================================== */
/* Code "screen" — left, big */
/* ===================================================================== */
/* the code area is *recessed* into the rack — no separate bordered panel.
Achieved with deep inset shadow + slightly darker bg than the rack. */
.screen {
background: var(--hw-screen);
border-radius: 4px;
padding: 12px 18px;
box-shadow:
inset 0 2px 4px rgba(0,0,0,0.7),
inset 0 -1px 0 rgba(255,220,180,0.03),
inset 0 0 0 1px var(--hw-edge),
inset 0 6px 14px rgba(0,0,0,0.5);
display: flex; flex-direction: column;
min-height: 300px;
overflow: hidden;
}
.glass {
flex: 1; overflow: auto;
font-size: 12px; line-height: 19px;
}
.code-line { display: flex; gap: 14px; white-space: pre; }
.ln { color: var(--hw-syn-com); user-select: none; min-width: 16px; text-align: right; }
.syn-com { color: var(--hw-syn-com); font-style: italic; }
.syn-kw { color: var(--hw-syn-kw); }
.syn-num { color: var(--hw-syn-num); }
.syn-fn { color: var(--hw-syn-fn); }
.syn-id { color: var(--hw-syn-id); }
.syn-op { color: var(--hw-syn-op); }
.syn-arrow { color: var(--hw-amber); }
.running-label {
color: var(--hw-amber);
font-size: 10px;
letter-spacing: 0.18em;
text-shadow: 0 0 5px var(--hw-amber-glow);
}
.running-dot {
display: inline-block;
width: 6px; height: 6px; border-radius: 50%;
background: var(--hw-amber);
box-shadow: 0 0 5px var(--hw-amber-glow);
margin-right: 6px; vertical-align: middle;
animation: led-pulse 2.2s ease-in-out infinite;
}
.blink { animation: blink 1.1s step-end infinite; }
@keyframes blink { 50% { opacity: 0; } }
/* ===================================================================== */
/* Right column */
/* ===================================================================== */
/* knobs sub-panel inside hardware */
.knobs {
background: linear-gradient(180deg, #1f1a14 0%, #14110d 100%);
border: 1px solid var(--hw-edge);
border-radius: 6px;
padding: 14px 12px;
box-shadow:
inset 0 1px 0 rgba(255,220,180,0.04),
inset 0 -1px 0 rgba(0,0,0,0.6);
display: grid;
grid-template-columns: 1fr 1fr;
gap: 12px 10px;
}
.knob-cell {
display: flex; flex-direction: column; align-items: center; gap: 4px;
}
.knob-cell .label {
font-size: 9px; letter-spacing: 0.16em; text-transform: uppercase;
color: var(--hw-engrave);
text-shadow: 0 1px 0 rgba(0,0,0,0.6), 0 -1px 0 rgba(255,220,180,0.04);
}
.knob-cell .value {
font-size: 10px; font-variant-numeric: tabular-nums;
color: var(--hw-fg-hi); letter-spacing: 0.05em;
background: transparent;
padding: 0; min-width: 46px; text-align: center;
}
.hw-knob { cursor: grab; touch-action: none; }
.hw-knob.dragging { cursor: grabbing; }
/* sequencer sub-panel */
.seq {
background: linear-gradient(180deg, #1f1a14 0%, #14110d 100%);
border: 1px solid var(--hw-edge);
border-radius: 6px;
padding: 8px 10px;
box-shadow:
inset 0 1px 0 rgba(255,220,180,0.04),
inset 0 -1px 0 rgba(0,0,0,0.6);
display: flex; flex-direction: column; gap: 5px;
}
.seq-row {
display: flex; align-items: center; gap: 8px;
}
.seq-row .label {
width: 44px;
font-size: 8px; letter-spacing: 0.16em; text-transform: uppercase;
color: var(--hw-engrave);
text-shadow: 0 1px 0 rgba(0,0,0,0.6);
}
.leds {
display: grid; grid-template-columns: repeat(16, 1fr); gap: 2px;
flex: 1;
}
.led {
height: 12px; border-radius: 1px;
background: linear-gradient(180deg, #0a0805 0%, var(--hw-amber-off) 100%);
border: 1px solid var(--hw-edge);
box-shadow: inset 0 1px 1px rgba(0,0,0,0.7);
cursor: pointer; position: relative;
transition: background 60ms;
}
.led:hover { background: linear-gradient(180deg, #181208 0%, #382818 100%); }
.led.on {
background:
radial-gradient(circle at 50% 25%, var(--hw-amber-hi) 0%,
var(--hw-amber) 55%, #a06820 100%);
box-shadow:
inset 0 0 2px rgba(255,255,255,0.4),
0 0 5px var(--hw-amber-glow);
}
.led.beat::before {
content: ''; position: absolute; left: -1px; top: -3px; bottom: -3px;
width: 1px; background: var(--hw-amber-mut);
}
.led.playhead {
outline: 1px solid rgba(232, 160, 80, 0.6);
outline-offset: 1px;
}
</style>
</head>
<body>
<div class="layout">
<!-- ===================== hardware unit ===================== -->
<div class="hardware">
<span class="screw tl"></span>
<span class="screw tr"></span>
<span class="screw bl"></span>
<span class="screw br"></span>
<!-- left stack: top-bar / screen / bottom-bar -->
<div class="left-stack">
<div class="top-bar">
<div class="btn-group">
<button class="hw-btn"><span class="led-red"></span>STOP</button>
<button class="hw-btn"><span class="ico-play"></span>RUN</button>
</div>
<span>48 KHZ</span>
<span>TAPS: <span class="num">14</span></span>
<span>CPU: <span class="num">9%</span></span>
<span class="right">CODE · SINTH</span>
</div>
<section class="screen">
<div class="glass" id="glass"></div>
</section>
<div class="bottom-bar">
<span class="running-label"><span class="running-dot"></span>RUNNING<span class="blink">_</span></span>
</div>
</div>
<!-- right column with knobs + seq -->
<div class="right-stack">
<section class="knobs">
<div class="knob-cell">
<span class="label">tempo</span>
<canvas class="hw-knob" data-min="60" data-max="200" data-value="120" data-decimals="1"></canvas>
<span class="value">120.0</span>
</div>
<div class="knob-cell">
<span class="label">res</span>
<canvas class="hw-knob" data-min="0.5" data-max="8" data-value="2.5" data-decimals="2"></canvas>
<span class="value">2.50</span>
</div>
<div class="knob-cell">
<span class="label">cutoff</span>
<canvas class="hw-knob" data-min="200" data-max="4000" data-value="800" data-decimals="0"></canvas>
<span class="value">800</span>
</div>
<div class="knob-cell">
<span class="label">drive</span>
<canvas class="hw-knob" data-min="0" data-max="1" data-value="0.35" data-decimals="2"></canvas>
<span class="value">0.35</span>
</div>
</section>
<section class="seq">
<div class="seq-row" data-pattern="1000100010001000">
<span class="label">kicks</span>
<div class="leds"></div>
</div>
<div class="seq-row" data-pattern="0010001000100010">
<span class="label">hat</span>
<div class="leds"></div>
</div>
<div class="seq-row" data-pattern="1001010001010010">
<span class="label">melody</span>
<div class="leds"></div>
</div>
</section>
</div>
</div>
</div>
<script>
// ===========================================================================
// static syntax-highlighted code (matches reference layout)
// ===========================================================================
const PATCH = [
['# studio hardware emulation — visual exploration', 'com'],
null,
[['kw','node'], ['id','kick'], ['op','='], ['fn','step_seq'], ['op','('],
['id','rate'], ['op','='], ['id','tempo'], ['op',','], ['id','steps'], ['op','='], ['num','16'], ['op',',']],
[['op',' '], ['id','default'], ['op','='], ['op','['],
['num','1'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',', '],
['num','1'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',', '],
['num','1'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',', '],
['num','1'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',','], ['num','0'], ['op',']'], ['op',')']],
null,
[['kw','node'], ['id','bass'], ['op','='], ['fn','osc'], ['op','('],
['id','saw'], ['op',','], ['id','freq'], ['op','='], ['num','55'], ['op',')']],
[['kw','node'], ['id','lp'], ['op','='], ['fn','filter'], ['op','('],
['id','bass'], ['op',','], ['id','cutoff'], ['op','='], ['num','800'], ['op',','],
['id','q'], ['op','='], ['num','2.5'], ['op',')']],
null,
[['kw','out'], ['arrow','← '], ['id','bass'], ['op','*'], ['num','0.6'],
['op','+'], ['id','kick'], ['op','*'], ['num','0.4']],
null,
[['kw','node'], ['id','melody'], ['op','='], ['fn','piano_roll'], ['op','('],
['id','voice'], ['op','='], ['id','synth'], ['op',',']],
[['op',' '], ['id','rate'], ['op','='], ['id','tempo'], ['op',','],
['id','length'], ['op','='], ['num','16'], ['op',',']],
[['op',' '], ['id','octaves'], ['op','='], ['num','2'], ['op',','],
['id','gate'], ['op','='], ['num','0.18'], ['op',')']],
];
const glass = document.getElementById('glass');
let lineNum = 0;
for (const line of PATCH) {
const div = document.createElement('div');
div.className = 'code-line';
if (line === null) {
lineNum++;
div.innerHTML = `<span class="ln">${lineNum}</span><span> </span>`;
} else if (Array.isArray(line) && typeof line[0] === 'string' && line[1] === 'com') {
lineNum++;
div.innerHTML = `<span class="ln">${lineNum}</span><span class="syn-com">${line[0]}</span>`;
} else {
lineNum++;
let html = `<span class="ln">${lineNum}</span><span>`;
for (const [cls, txt] of line) {
const sep = cls === 'op' ? '' : ' ';
const klass = cls === 'arrow' ? 'syn-arrow' : `syn-${cls}`;
html += `<span class="${klass}">${txt}</span>${sep}`;
}
html += `</span>`;
div.innerHTML = html;
}
glass.appendChild(div);
}
// ===========================================================================
// knob — restrained: dark gradient + thin amber arc + single tickmark.
// No knurled ridges, no brushed metal. Closer to the reference image.
// ===========================================================================
const KNOB_SIZE = 56;
function setupCanvas(canvas, size) {
const dpr = window.devicePixelRatio || 1;
canvas.style.width = size + 'px';
canvas.style.height = size + 'px';
canvas.width = Math.round(size * dpr);
canvas.height = Math.round(size * dpr);
const ctx = canvas.getContext('2d');
ctx.scale(dpr, dpr);
return ctx;
}
function drawKnob(ctx, size, norm) {
const cx = size / 2, cy = size / 2 + 1;
const totalR = size * 0.46; // outer edge of the whole knob
const rimW = size * 0.045; // dark rim thickness (thin)
const discR = totalR - rimW; // metallic disc fills most of inside
ctx.clearRect(0, 0, size, size);
// (1) drop shadow under the whole knob
ctx.save();
ctx.shadowColor = 'rgba(0,0,0,0.7)';
ctx.shadowBlur = 6;
ctx.shadowOffsetY = 2;
ctx.fillStyle = '#000';
ctx.beginPath();
ctx.arc(cx, cy, totalR + 0.5, 0, Math.PI * 2);
ctx.fill();
ctx.restore();
// (2) amber value arc OUTSIDE everything (faint full track + bright active)
const startA = Math.PI * 0.78, endA = Math.PI * 2.22;
ctx.lineCap = 'round';
ctx.lineWidth = 1.5;
ctx.strokeStyle = 'rgba(232,160,80,0.10)';
ctx.beginPath();
ctx.arc(cx, cy, totalR + 4, startA, endA);
ctx.stroke();
ctx.strokeStyle = '#e8a050';
ctx.shadowBlur = 3;
ctx.shadowColor = 'rgba(232,160,80,0.55)';
ctx.beginPath();
ctx.arc(cx, cy, totalR + 4, startA, startA + norm * (endA - startA));
ctx.stroke();
ctx.shadowBlur = 0;
// (3) thin DARK RIM around the outside (the body of the knob)
const rim = ctx.createLinearGradient(0, cy - totalR, 0, cy + totalR);
rim.addColorStop(0, '#2a2826');
rim.addColorStop(0.5, '#0a0908');
rim.addColorStop(1, '#040404');
ctx.strokeStyle = rim;
ctx.lineWidth = rimW;
ctx.beginPath();
ctx.arc(cx, cy, totalR - rimW / 2, 0, Math.PI * 2);
ctx.stroke();
// (4) BIG METALLIC DISC — fills most of the inside (the "circulito metalico
// que ocupa casi todo"). Radial gradient, brushed-metal feel.
const disc = ctx.createRadialGradient(
cx, cy - discR * 0.25, 0,
cx, cy + discR * 0.4, discR * 1.4
);
disc.addColorStop(0, '#b6b0a6'); // lit upper-center
disc.addColorStop(0.45, '#8a847a');
disc.addColorStop(0.85, '#46423d');
disc.addColorStop(1, '#2a2722'); // bottom dark
ctx.fillStyle = disc;
ctx.beginPath();
ctx.arc(cx, cy, discR, 0, Math.PI * 2);
ctx.fill();
// (5) brushed-metal radial striations (very subtle, deterministic)
ctx.save();
ctx.beginPath();
ctx.arc(cx, cy, discR - 0.5, 0, Math.PI * 2);
ctx.clip();
for (let i = 0; i < 96; i++) {
const a = (i / 96) * Math.PI * 2;
const alpha = 0.025 + ((i * 9301 + 49297) % 233) / 233 * 0.04;
ctx.strokeStyle = `rgba(255, 240, 220, ${alpha.toFixed(3)})`;
ctx.lineWidth = 0.5;
ctx.beginPath();
ctx.moveTo(cx, cy);
ctx.lineTo(cx + Math.cos(a) * discR, cy + Math.sin(a) * discR);
ctx.stroke();
}
ctx.restore();
// (6) thin shadow line where disc meets rim (depth)
ctx.strokeStyle = 'rgba(0,0,0,0.55)';
ctx.lineWidth = 0.7;
ctx.beginPath();
ctx.arc(cx, cy, discR + 0.4, 0, Math.PI * 2);
ctx.stroke();
// (7) bright highlight crescent on the top edge of the disc
ctx.strokeStyle = 'rgba(255,255,255,0.30)';
ctx.lineWidth = 0.8;
ctx.beginPath();
ctx.arc(cx, cy, discR - 0.5, Math.PI * 1.18, Math.PI * 1.82);
ctx.stroke();
// (8) small DARK NOTCH indicator on the disc, rotates with value
const ang = startA + norm * (endA - startA);
const tipR = discR * 0.86;
const baseR = discR * 0.55;
const perp = ang + Math.PI / 2;
const half = size * 0.028;
const tipX = cx + Math.cos(ang) * tipR;
const tipY = cy + Math.sin(ang) * tipR;
const bX = cx + Math.cos(ang) * baseR;
const bY = cy + Math.sin(ang) * baseR;
ctx.fillStyle = 'rgba(8,7,6,0.95)';
ctx.beginPath();
ctx.moveTo(tipX, tipY);
ctx.lineTo(bX + Math.cos(perp) * half, bY + Math.sin(perp) * half);
ctx.lineTo(bX - Math.cos(perp) * half, bY - Math.sin(perp) * half);
ctx.closePath();
ctx.fill();
}
document.querySelectorAll('canvas.hw-knob').forEach((canvas) => {
const min = parseFloat(canvas.dataset.min);
const max = parseFloat(canvas.dataset.max);
const dec = canvas.dataset.decimals !== undefined ? +canvas.dataset.decimals : 1;
const valueEl = canvas.parentNode.querySelector('.value');
let value = parseFloat(canvas.dataset.value);
const ctx = setupCanvas(canvas, KNOB_SIZE);
const fmt = (v) => v.toFixed(dec);
const redraw = () => {
const norm = Math.max(0, Math.min(1, (value - min) / (max - min)));
drawKnob(ctx, KNOB_SIZE, norm);
if (valueEl) valueEl.textContent = fmt(value);
};
redraw();
canvas.addEventListener('pointerdown', (e) => {
e.preventDefault();
canvas.setPointerCapture(e.pointerId);
canvas.classList.add('dragging');
document.body.style.cursor = 'grabbing';
const startY = e.clientY;
const startV = value;
const span = max - min;
const onMove = (ev) => {
const dy = startY - ev.clientY;
const factor = ev.shiftKey ? 4 : 1;
const delta = (dy / 200) * span / factor;
value = Math.max(min, Math.min(max, startV + delta));
redraw();
};
const onUp = () => {
canvas.classList.remove('dragging');
document.body.style.cursor = '';
canvas.removeEventListener('pointermove', onMove);
canvas.removeEventListener('pointerup', onUp);
canvas.removeEventListener('pointercancel', onUp);
};
canvas.addEventListener('pointermove', onMove);
canvas.addEventListener('pointerup', onUp);
canvas.addEventListener('pointercancel', onUp);
});
canvas.addEventListener('dblclick', () => {
value = parseFloat(canvas.dataset.value);
redraw();
});
});
// ===========================================================================
// step LEDs
// ===========================================================================
document.querySelectorAll('.seq-row').forEach((row) => {
const pattern = row.dataset.pattern.split('').map((c) => c === '1' ? 1 : 0);
const container = row.querySelector('.leds');
const cells = [];
for (let i = 0; i < 16; i++) {
const led = document.createElement('div');
led.className = 'led' + (pattern[i] ? ' on' : '') + (i % 4 === 0 ? ' beat' : '');
led.addEventListener('click', () => {
pattern[i] = pattern[i] ? 0 : 1;
led.classList.toggle('on', !!pattern[i]);
});
container.appendChild(led);
cells.push(led);
}
row._cells = cells;
});
let phStep = 0;
const allRows = document.querySelectorAll('.seq-row');
setInterval(() => {
allRows.forEach((row) => {
row._cells.forEach((c, i) => c.classList.toggle('playhead', i === phStep));
});
phStep = (phStep + 1) % 16;
}, 125);
</script>
</body>
</html>