<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      user-select: none;
    }

    body {
      background: transparent;
      color: #1e2945;
      padding: 8px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      min-height: 100%;
    }

    .panels-row {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      width: 100%;
    }

    .knee-panel {
      flex: 1 1 calc(50% - 4px);
      min-width: 280px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    .panel-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      margin-bottom: 4px;
      padding: 0 4px;
    }

    .panel-title {
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
    }

    .panel-tag {
      font-size: 11px;
      font-weight: 600;
      padding: 2px 6px;
      border-radius: 4px;
      background: #e2e8f0;
      color: #475569;
    }

    .panel-tag.soft {
      background: #e0f2fe;
      color: #0369a1;
    }

    .svg-container {
      width: 100%;
      max-width: 320px;
      aspect-ratio: 1.15;
    }

    svg {
      width: 100%;
      height: 100%;
      overflow: visible;
    }

    .ctrl-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 6px 12px;
      font-size: 13px;
      font-weight: 600;
    }

    .slider-wrap {
      flex: 1;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    input[type="range"] {
      flex: 1;
      accent-color: #22b7ff;
      cursor: pointer;
      height: 6px;
    }

    .val-badge {
      display: inline-block;
      min-width: 68px;
      text-align: right;
      font-variant-numeric: tabular-nums;
      color: #0369a1;
    }

    .gr-text {
      font-size: 12px;
      color: #64748b;
      font-variant-numeric: tabular-nums;
    }

    .gr-val {
      font-weight: 700;
      color: #d97706;
    }

    .grid-line {
      stroke: #e2e8f0;
      stroke-dasharray: 2, 2;
      stroke-width: 1;
    }

    .axis-text {
      font-size: 9px;
      fill: #64748b;
      font-weight: 500;
    }

    .axis-title {
      font-size: 10px;
      fill: #334155;
      font-weight: 700;
    }
  </style>
</head>
<body>

  <div class="ctrl-bar">
    <div class="slider-wrap">
      <span style="white-space:nowrap;font-size:12px;">Input Level:</span>
      <input type="range" id="inSlider" min="-36" max="0" value="-16" step="0.5">
      <span class="val-badge" id="inVal">-16.0 dB</span>
    </div>
  </div>

  <div class="panels-row">
    
    <div class="knee-panel">
      <div class="panel-header">
        <span class="panel-title">Hard Knee</span>
        <span class="gr-text">GR: <span class="gr-val" id="hardGR">0.0 dB</span></span>
      </div>
      <div class="svg-container">
        <svg viewBox="0 0 240 210" id="hardSvg">
          
          <line x1="35" y1="20" x2="225" y2="20" class="grid-line" />
          <line x1="35" y1="67" x2="225" y2="67" class="grid-line" />
          <line x1="35" y1="115" x2="225" y2="115" class="grid-line" />
          <line x1="35" y1="162" x2="225" y2="162" class="grid-line" />
          <line x1="35" y1="210" x2="225" y2="210" class="grid-line" />

          <line x1="35" y1="20" x2="35" y2="210" class="grid-line" />
          <line x1="82.5" y1="20" x2="82.5" y2="210" class="grid-line" />
          <line x1="130" y1="20" x2="130" y2="210" class="grid-line" />
          <line x1="177.5" y1="20" x2="177.5" y2="210" class="grid-line" />
          <line x1="225" y1="20" x2="225" y2="210" class="grid-line" />

          
          <line x1="130" y1="20" x2="130" y2="210" stroke="#94a3b8" stroke-dasharray="3,3" stroke-width="1.2" />

          
          <line x1="35" y1="210" x2="225" y2="20" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="4,4" />
          <text x="75" y="150" fill="#94a3b8" font-size="10" font-weight="600" transform="rotate(-45 75 150)">1:1 (No GR)</text>

          
          
          <polyline points="35,210 130,115 225,91.25" fill="none" stroke="#1e2945" stroke-width="3" stroke-linecap="round" stroke-linejoin="round" />

          
          <circle cx="130" cy="115" r="4" fill="#0f172a" />
          <text x="130" y="132" text-anchor="middle" font-size="10" font-weight="700" fill="#0f172a">Threshold: -18 dB</text>
          <text x="195" y="78" fill="#0f172a" font-size="10" font-weight="700">4:1 Ratio</text>

          
          <text x="30" y="213" text-anchor="end" class="axis-text">-36</text>
          <text x="30" y="118" text-anchor="end" class="axis-text">-18</text>
          <text x="30" y="24" text-anchor="end" class="axis-text">0</text>
          <text x="35" y="222" text-anchor="middle" class="axis-text">-36</text>
          <text x="130" y="222" text-anchor="middle" class="axis-text">-18</text>
          <text x="225" y="222" text-anchor="middle" class="axis-text">0</text>

          <text x="130" y="234" text-anchor="middle" class="axis-title">Input (dBFS)</text>
          <text x="12" y="115" text-anchor="middle" class="axis-title" transform="rotate(-90 12 115)">Output (dBFS)</text>

          
          <circle id="hardMarker" cx="130" cy="115" r="5" fill="#22b7ff" stroke="#ffffff" stroke-width="2" />
        </svg>
      </div>
    </div>

    
    <div class="knee-panel">
      <div class="panel-header">
        <span class="panel-title">Soft Knee</span>
        <span class="gr-text">GR: <span class="gr-val" id="softGR">0.0 dB</span></span>
      </div>
      <div class="svg-container">
        <svg viewBox="0 0 240 210" id="softSvg">
          
          
          <rect x="98.33" y="20" width="63.34" height="190" fill="#22b7ff" fill-opacity="0.12" />
          <line x1="98.33" y1="20" x2="98.33" y2="210" stroke="#22b7ff" stroke-width="1" stroke-dasharray="2,2" />
          <line x1="161.67" y1="20" x2="161.67" y2="210" stroke="#22b7ff" stroke-width="1" stroke-dasharray="2,2" />

          
          <line x1="35" y1="20" x2="225" y2="20" class="grid-line" />
          <line x1="35" y1="67" x2="225" y2="67" class="grid-line" />
          <line x1="35" y1="115" x2="225" y2="115" class="grid-line" />
          <line x1="35" y1="162" x2="225" y2="162" class="grid-line" />
          <line x1="35" y1="210" x2="225" y2="210" class="grid-line" />

          <line x1="35" y1="20" x2="35" y2="210" class="grid-line" />
          <line x1="82.5" y1="20" x2="82.5" y2="210" class="grid-line" />
          <line x1="130" y1="20" x2="130" y2="210" class="grid-line" />
          <line x1="177.5" y1="20" x2="177.5" y2="210" class="grid-line" />
          <line x1="225" y1="20" x2="225" y2="210" class="grid-line" />

          
          <line x1="130" y1="20" x2="130" y2="210" stroke="#94a3b8" stroke-dasharray="3,3" stroke-width="1" />

          
          <line x1="35" y1="210" x2="225" y2="20" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="4,4" />

          
          <path id="softCurvePath" d="" fill="none" stroke="#0284c7" stroke-width="3" stroke-linecap="round" />

          
          <text x="130" y="32" text-anchor="middle" font-size="9.5" font-weight="700" fill="#0284c7">12 dB Knee Width</text>
          <text x="130" y="44" text-anchor="middle" font-size="8.5" font-weight="600" fill="#0369a1">(-24 to -12 dBFS)</text>

          <text x="195" y="78" fill="#0284c7" font-size="10" font-weight="700">4:1 Ratio</text>

          
          <text x="30" y="213" text-anchor="end" class="axis-text">-36</text>
          <text x="30" y="118" text-anchor="end" class="axis-text">-18</text>
          <text x="30" y="24" text-anchor="end" class="axis-text">0</text>
          <text x="35" y="222" text-anchor="middle" class="axis-text">-36</text>
          <text x="130" y="222" text-anchor="middle" class="axis-text">-18</text>
          <text x="225" y="222" text-anchor="middle" class="axis-text">0</text>

          <text x="130" y="234" text-anchor="middle" class="axis-title">Input (dBFS)</text>
          <text x="12" y="115" text-anchor="middle" class="axis-title" transform="rotate(-90 12 115)">Output (dBFS)</text>

          
          <circle id="softMarker" cx="130" cy="115" r="5" fill="#0284c7" stroke="#ffffff" stroke-width="2" />
        </svg>
      </div>
    </div>
  </div>

  <script>
    const T = -18;      // Threshold (dBFS)
    const R = 4;        // Ratio (4:1)
    const W = 12;       // Knee width (dB)
    const W2 = W / 2;   // 6 dB

    // Coordinates mapping
    // x range: -36 to 0 dBFS -> px 35 to 225 (span 190)
    // y range: -36 to 0 dBFS -> px 210 to 20 (span 190)
    function dbToPxX(db) {
      return 35 + ((db + 36) / 36) * 190;
    }
    function dbToPxY(db) {
      return 210 - ((db + 36) / 36) * 190;
    }

    // Hard Knee function
    function getHardKneeOut(x) {
      if (x <= T) return x;
      return T + (x - T) / R;
    }

    // Soft Knee function (Standard DSP Quadratic Knee)
    function getSoftKneeOut(x) {
      if (x <= T - W2) {
        return x;
      } else if (x >= T + W2) {
        return T + (x - T) / R;
      } else {
        // Quadratic blend zone
        const slopeDiff = (1 / R) - 1;
        const delta = x - T + W2;
        return x + (slopeDiff * delta * delta) / (2 * W);
      }
    }

    // Render continuous soft knee SVG path
    function buildSoftPath() {
      let d = "";
      for (let db = -36; db <= 0; db += 0.5) {
        const out = getSoftKneeOut(db);
        const px = dbToPxX(db);
        const py = dbToPxY(out);
        d += (db === -36 ? `M ${px.toFixed(2)},${py.toFixed(2)}` : ` L ${px.toFixed(2)},${py.toFixed(2)}`);
      }
      document.getElementById('softCurvePath').setAttribute('d', d);
    }
    buildSoftPath();

    // Update markers and readouts on slider input
    const inSlider = document.getElementById('inSlider');
    const inVal = document.getElementById('inVal');
    const hardGR = document.getElementById('hardGR');
    const softGR = document.getElementById('softGR');
    const hardMarker = document.getElementById('hardMarker');
    const softMarker = document.getElementById('softMarker');

    function update() {
      const inDb = parseFloat(inSlider.value);
      inVal.textContent = (inDb >= 0 ? "+" : "") + inDb.toFixed(1) + " dB";

      // Hard Knee
      const hardOut = getHardKneeOut(inDb);
      const hardReduction = inDb - hardOut;
      hardGR.textContent = hardReduction.toFixed(1) + " dB";
      hardMarker.setAttribute('cx', dbToPxX(inDb).toFixed(2));
      hardMarker.setAttribute('cy', dbToPxY(hardOut).toFixed(2));

      // Soft Knee
      const softOut = getSoftKneeOut(inDb);
      const softReduction = inDb - softOut;
      softGR.textContent = softReduction.toFixed(1) + " dB";
      softMarker.setAttribute('cx', dbToPxX(inDb).toFixed(2));
      softMarker.setAttribute('cy', dbToPxY(softOut).toFixed(2));
    }

    inSlider.addEventListener('input', update);
    update();
  </script>
</body>
</html>

Compressor Parameters: Threshold, Ratio, Attack, and Release

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="1:1">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #ffffff;
      color: #1e2945;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      user-select: none;
    }

    .toggles {
      display: flex;
      width: 100%;
      max-width: 440px;
      gap: 6px;
      margin-bottom: 8px;
    }

    .toggle-btn {
      flex: 1;
      border: 1px solid #d1d5db;
      background: #f8fafc;
      padding: 7px 6px;
      border-radius: 6px;
      font-size: 11px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      text-align: center;
      line-height: 1.3;
      transition: background 0.2s, border-color 0.2s, color 0.2s;
    }

    .toggle-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
    }

    .diagram-area {
      position: relative;
      width: 100%;
      max-width: 440px;
      flex: 1;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 6px 8px;
    }

    .track {
      position: relative;
      width: 100%;
      height: 30%;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    .track-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 11px;
      font-weight: 700;
      color: #64748b;
      margin-bottom: 2px;
      padding: 0 4px;
    }

    .track-header .badge {
      font-size: 10px;
      padding: 1px 5px;
      border-radius: 4px;
      font-weight: 600;
    }

    .badge-blue { background: #e0f2fe; color: #0284c7; }
    .badge-orange { background: #ffedd5; color: #ea580c; }
    .badge-green { background: #dcfce7; color: #16a34a; }

    svg.wave-canvas {
      width: 100%;
      height: 60px;
      overflow: visible;
    }

    .center-line {
      stroke: #cbd5e1;
      stroke-dasharray: 3 3;
      stroke-width: 1;
    }

    .thresh-line {
      stroke: #ef4444;
      stroke-dasharray: 2 2;
      stroke-width: 1;
    }

    .playhead-line {
      position: absolute;
      top: 0;
      bottom: 0;
      width: 1.5px;
      background: #2563eb;
      box-shadow: 0 0 4px rgba(37,99,235,0.4);
      pointer-events: none;
      z-index: 10;
      left: 10%;
    }

    .time-scale {
      display: flex;
      justify-content: space-between;
      font-size: 9px;
      color: #94a3b8;
      padding: 2px 4px 0;
      border-top: 1px solid #e2e8f0;
      margin-top: 2px;
    }

    .visual-note {
      font-size: 11px;
      font-weight: 600;
      text-align: center;
      color: #334155;
      margin-top: 6px;
      height: 18px;
    }
  </style>
</head>
<body>

  <div class="toggles">
    <button id="btnSlow" class="toggle-btn active" onclick="setMode('slow')">
      Slow Attack (30ms)<br>Fast Release (50ms)
    </button>
    <button id="btnFast" class="toggle-btn" onclick="setMode('fast')">
      Fast Attack (0.5ms)<br>Fast Release (20ms)
    </button>
  </div>

  <div class="diagram-area" id="stage">
    <div class="playhead-line" id="playhead"></div>

    
    <div class="track">
      <div class="track-header">
        <span>Raw Input (Snare Hit)</span>
        <span class="badge badge-blue">Transient + Body</span>
      </div>
      <svg class="wave-canvas" viewBox="0 0 400 60" preserveAspectRatio="none">
        <line x1="0" y1="30" x2="400" y2="30" class="center-line" />
        <line x1="0" y1="12" x2="400" y2="12" class="thresh-line" />
        <line x1="0" y1="48" x2="400" y2="48" class="thresh-line" />
        <path id="rawWave" fill="rgba(2, 132, 199, 0.2)" stroke="#0284c7" stroke-width="1.5" />
      </svg>
    </div>

    
    <div class="track">
      <div class="track-header">
        <span>Gain Reduction (GR)</span>
        <span class="badge badge-orange" id="grBadge">Slow clamp</span>
      </div>
      <svg class="wave-canvas" viewBox="0 0 400 60" preserveAspectRatio="none">
        <line x1="0" y1="8" x2="400" y2="8" stroke="#cbd5e1" stroke-width="1" />
        <text x="5" y="18" fill="#94a3b8" font-size="8" font-weight="600">0 dB</text>
        <text x="5" y="52" fill="#ea580c" font-size="8" font-weight="600">-12 dB</text>
        <path id="grWave" fill="rgba(234, 88, 12, 0.15)" stroke="#ea580c" stroke-width="2" />
      </svg>
    </div>

    
    <div class="track">
      <div class="track-header">
        <span>Output Waveform</span>
        <span class="badge badge-green" id="outBadge">Punch preserved</span>
      </div>
      <svg class="wave-canvas" viewBox="0 0 400 60" preserveAspectRatio="none">
        <line x1="0" y1="30" x2="400" y2="30" class="center-line" />
        <line x1="0" y1="12" x2="400" y2="12" class="thresh-line" />
        <line x1="0" y1="48" x2="400" y2="48" class="thresh-line" />
        <path id="outWave" fill="rgba(22, 163, 74, 0.2)" stroke="#16a34a" stroke-width="1.5" />
      </svg>
    </div>

    <div class="time-scale">
      <span>0 ms (Hit)</span>
      <span>50 ms</span>
      <span>100 ms</span>
      <span>150 ms</span>
      <span>200 ms</span>
    </div>
  </div>

  <div class="visual-note" id="noteText">Transient punches through; body is controlled.</div>

  <script>
    let currentMode = 'slow';
    const N = 200;
    const width = 400;
    const midY = 30;

    // Generate Drum Waveform Envelope & Oscillation
    // Transient at x = 30..60 (peak ~26px amp), Ring/Body x = 60..250
    function getInputEnvelope(x) {
      if (x < 25) return 0;
      if (x <= 40) return (x - 25) / 15; // fast rising transient
      if (x <= 75) return 1.0 - 0.65 * ((x - 40) / 35); // drops to body level (0.35)
      if (x <= 320) return 0.35 * Math.exp(-(x - 75) / 110); // ring decay
      return 0;
    }

    function getAudioSample(x) {
      const env = getInputEnvelope(x);
      if (env === 0) return 0;
      // High frequency transient pop morphing into fundamental ring
      const freq = x < 55 ? 0.9 : 0.45;
      return env * Math.sin((x - 25) * freq);
    }

    function getGainReduction(x, mode) {
      if (x < 25) return 0; // 0 = no reduction (0dB), 1 = max reduction (-12dB)

      if (mode === 'slow') {
        // Slow attack: lets peak slip through (peaks around x=80), fast release
        if (x < 45) {
          return 0.05 * ((x - 25) / 20); // barely reacts during initial spike
        } else if (x <= 95) {
          return 0.05 + 0.7 * ((x - 45) / 50); // clamps down on sustained body
        } else {
          return Math.max(0, 0.75 * Math.exp(-(x - 95) / 55)); // releases quickly
        }
      } else {
        // Fast attack: immediately clamps down peak (x=27), releases immediately on tail
        if (x < 30) {
          return 0.95 * ((x - 25) / 5); // instant clamp
        } else if (x <= 85) {
          return 0.95 * Math.exp(-(x - 30) / 40); // very fast release pumping
        } else {
          return Math.max(0, 0.25 * Math.exp(-(x - 85) / 35));
        }
      }
    }

    function renderWaves() {
      let rawTop = [], rawBot = [];
      let grPts = [];
      let outTop = [], outBot = [];

      for (let i = 0; i <= N; i++) {
        const x = (i / N) * width;
        const rawAmp = getAudioSample(x) * 26; // max +-26px
        rawTop.push(`${x.toFixed(1)},${(midY - rawAmp).toFixed(1)}`);
        rawBot.unshift(`${x.toFixed(1)},${(midY + rawAmp).toFixed(1)}`);

        // GR curve: top is 8px (0dB), bottom is 50px (-12dB)
        const grFactor = getGainReduction(x, currentMode); // 0..1
        const grY = 8 + grFactor * 42;
        grPts.push(`${x.toFixed(1)},${grY.toFixed(1)}`);

        // Output wave: amplitude multiplied by (1 - grFactor * 0.75)
        const compMultiplier = 1.0 - (grFactor * 0.78);
        const outAmp = rawAmp * compMultiplier;
        outTop.push(`${x.toFixed(1)},${(midY - outAmp).toFixed(1)}`);
        outBot.unshift(`${x.toFixed(1)},${(midY + outAmp).toFixed(1)}`);
      }

      document.getElementById('rawWave').setAttribute('d', `M ${rawTop.join(' L ')} L ${rawBot.join(' L ')} Z`);
      document.getElementById('grWave').setAttribute('d', `M 0,8 L ${grPts.join(' L ')} L 400,8 Z`);
      document.getElementById('outWave').setAttribute('d', `M ${outTop.join(' L ')} L ${outBot.join(' L ')} Z`);
    }

    function setMode(mode) {
      currentMode = mode;
      document.getElementById('btnSlow').classList.toggle('active', mode === 'slow');
      document.getElementById('btnFast').classList.toggle('active', mode === 'fast');

      const grBadge = document.getElementById('grBadge');
      const outBadge = document.getElementById('outBadge');
      const note = document.getElementById('noteText');

      if (mode === 'slow') {
        grBadge.textContent = 'Lagged clamp';
        outBadge.textContent = 'Transient punches through';
        note.textContent = 'Slow attack lets the initial spike pass untouched.';
      } else {
        grBadge.textContent = 'Instant clamp';
        outBadge.textContent = 'Transient flattened';
        note.textContent = 'Fast attack shaves the spike flat; causes pumping.';
      }
      renderWaves();
    }

    // Playhead animation
    let startTime = null;
    const playhead = document.getElementById('playhead');

    function animatePlayhead(ts) {
      if (!startTime) startTime = ts;
      const elapsed = (ts - startTime) % 2400; // 2.4s cycle
      const progress = elapsed / 2400;
      
      // Progress over waveform width
      const pct = Math.min(100, Math.max(0, progress * 100));
      playhead.style.left = `${pct}%`;

      requestAnimationFrame(animatePlayhead);
    }

    renderWaves();
    requestAnimationFrame(animatePlayhead);
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>Compressor Dynamics: 3 Stages</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      width: 100%;
      background: #f8fafc;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      padding: 12px;
    }
    .app {
      display: flex;
      flex-direction: column;
      gap: 10px;
      max-width: 580px;
      margin: 0 auto;
    }

    /* Step Navigation */
    .controls {
      display: flex;
      gap: 6px;
      justify-content: center;
      align-items: center;
    }
    .step-btn {
      flex: 1;
      padding: 7px 4px;
      font-size: 12px;
      font-weight: 600;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #64748b;
      border-radius: 6px;
      cursor: pointer;
      text-align: center;
      transition: all 0.25s ease;
      white-space: nowrap;
    }
    .step-btn.active {
      background: #22b7ff;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(34, 183, 255, 0.35);
    }
    .play-btn {
      width: 32px;
      height: 32px;
      display: flex;
      align-items: center;
      justify-content: center;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #1e2945;
      border-radius: 6px;
      cursor: pointer;
      font-size: 13px;
      flex-shrink: 0;
    }

    /* Main Display Box */
    .stage-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 12px 14px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    /* Diagram visual layout */
    .viz-grid {
      display: grid;
      grid-template-columns: 46px 1fr 42px;
      gap: 10px;
      height: 220px;
      position: relative;
    }

    /* dB Scale */
    .scale {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      font-size: 11px;
      font-weight: 600;
      color: #64748b;
      text-align: right;
      padding-right: 4px;
      border-right: 1px dashed #cbd5e1;
      user-select: none;
    }
    .scale .mark-thresh {
      color: #d97706;
      font-weight: 700;
    }

    /* Waveform Canvas Area */
    .waveform-area {
      position: relative;
      background: #f1f5f9;
      border-radius: 6px;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    /* Grid lines */
    .grid-line {
      position: absolute;
      left: 0;
      right: 0;
      border-top: 1px dashed #e2e8f0;
      pointer-events: none;
    }
    .thresh-line {
      position: absolute;
      left: 0;
      right: 0;
      top: 44.4%; /* -16 dBFS mapped to 0..-36 range: 16/36 = 44.4% */
      border-top: 2px dashed #f59e0b;
      z-index: 2;
      display: flex;
      justify-content: flex-end;
      padding-right: 6px;
    }
    .thresh-badge {
      background: #fef3c7;
      color: #b45309;
      font-size: 10px;
      font-weight: 700;
      padding: 1px 5px;
      border-radius: 4px;
      transform: translateY(-50%);
    }

    /* Waveform visual */
    svg.wave-svg {
      width: 100%;
      height: 100%;
      position: absolute;
      inset: 0;
    }
    .wave-fill {
      fill: rgba(34, 183, 255, 0.22);
      transition: d 0.35s ease;
    }
    .wave-line {
      fill: none;
      stroke: #0284c7;
      stroke-width: 2.2;
      stroke-linecap: round;
      stroke-linejoin: round;
      transition: d 0.35s ease;
    }
    .wave-gr-overlay {
      fill: rgba(239, 68, 68, 0.25);
      stroke: #ef4444;
      stroke-width: 1.5;
      stroke-dasharray: 3 3;
      transition: opacity 0.35s ease, d 0.35s ease;
    }

    /* Right Meter */
    .meter-col {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 3px;
    }
    .meter-track {
      flex: 1;
      width: 18px;
      background: #e2e8f0;
      border-radius: 4px;
      position: relative;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
    }
    .meter-fill {
      width: 100%;
      background: linear-gradient(0deg, #10b981 60%, #22b7ff 80%, #ef4444 100%);
      border-radius: 3px;
      transition: height 0.35s ease;
    }
    .meter-peak-line {
      position: absolute;
      left: 0;
      right: 0;
      height: 2px;
      background: #1e2945;
      transition: bottom 0.35s ease;
    }
    .meter-lbl {
      font-size: 10px;
      font-weight: 700;
      color: #64748b;
      text-transform: uppercase;
    }

    /* Metric Badges Row */
    .metrics-row {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
      margin-top: 2px;
    }
    .metric-box {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 6px;
      padding: 6px 8px;
      text-align: center;
    }
    .metric-label {
      font-size: 10px;
      color: #64748b;
      text-transform: uppercase;
      font-weight: 600;
      margin-bottom: 2px;
    }
    .metric-val {
      font-size: 14px;
      font-weight: 700;
      color: #1e2945;
    }
    .metric-val.highlight {
      color: #0284c7;
    }
    .metric-val.accent {
      color: #10b981;
    }
  </style>
</head>
<body>
  <div class="app">
    
    <div class="controls">
      <button class="step-btn active" id="btn0">1. Original</button>
      <button class="step-btn" id="btn1">2. Compressed</button>
      <button class="step-btn" id="btn2">3. Make-up Gain</button>
      <button class="play-btn" id="playBtn" title="Auto Play">▶</button>
    </div>

    
    <div class="stage-card">
      <div class="viz-grid">
        
        <div class="scale">
          <span>0 dB</span>
          <span>-6 dB</span>
          <span>-12 dB</span>
          <span class="mark-thresh">-16 dB</span>
          <span>-24 dB</span>
          <span>-30 dB</span>
          <span>-36 dB</span>
        </div>

        
        <div class="waveform-area">
          <div class="thresh-line" id="threshLine">
            <span class="thresh-badge">Threshold -16 dB</span>
          </div>

          <svg class="wave-svg" viewBox="0 0 400 200" preserveAspectRatio="none">
            
            <path id="waveFill" class="wave-fill" d="" />
            
            <path id="grFill" class="wave-gr-overlay" d="" opacity="0" />
            
            <path id="waveLine" class="wave-line" d="" />
            
            <line x1="0" y1="100" x2="400" y2="100" stroke="#cbd5e1" stroke-width="1" stroke-dasharray="2 2" />
          </svg>
        </div>

        
        <div class="meter-col">
          <div class="meter-track">
            <div class="meter-fill" id="meterFill" style="height: 100%;"></div>
            <div class="meter-peak-line" id="peakLine" style="bottom: 100%;"></div>
          </div>
          <span class="meter-lbl" id="meterDb">0 dB</span>
        </div>
      </div>

      
      <div class="metrics-row">
        <div class="metric-box">
          <div class="metric-label">Peak Level</div>
          <div class="metric-val" id="valPeak">0 dBFS</div>
        </div>
        <div class="metric-box">
          <div class="metric-label">Quiet Level</div>
          <div class="metric-val highlight" id="valBody">-30 dBFS</div>
        </div>
        <div class="metric-box">
          <div class="metric-label">Dynamic Range</div>
          <div class="metric-val accent" id="valRange">30 dB</div>
        </div>
      </div>
    </div>
  </div>

  <script src="{{VENDOR_CDN}}/classace-diagram.js"></script>
  <script>
    // Stage configurations:
    // Scale: 0 dBFS = 100% amp (y = 0/200), -36 dBFS = 0% amp (y = 100)
    // dB to amp amplitude mapping (linearized for visual clarity):
    // 0 dBFS -> amp: 94
    // -6 dBFS -> amp: 78
    // -16 dBFS -> amp: 52 (Threshold)
    // -24 dBFS -> amp: 32
    // -30 dBFS -> amp: 16
    // -36 dBFS -> amp: 2

    const stages = [
      {
        peakAmp: 94, // 0 dBFS
        bodyAmp: 16, // -30 dBFS
        grAmp: 0,
        meterPct: 100,
        peakDb: "0 dBFS",
        bodyDb: "-30 dBFS",
        rangeDb: "30 dB",
        meterLabel: "0 dB"
      },
      {
        peakAmp: 78, // -6 dBFS (-6 dB Gain Reduction)
        bodyAmp: 16, // -30 dBFS (quiet unchanged)
        grAmp: 94,   // ghost of original peak
        meterPct: 83,
        peakDb: "-6 dBFS",
        bodyDb: "-30 dBFS",
        rangeDb: "24 dB",
        meterLabel: "-6 dB"
      },
      {
        peakAmp: 94, // 0 dBFS (+6 dB makeup gain)
        bodyAmp: 32, // -24 dBFS (lifted body!)
        grAmp: 0,
        meterPct: 100,
        peakDb: "0 dBFS",
        bodyDb: "-24 dBFS",
        rangeDb: "24 dB",
        meterLabel: "0 dB"
      }
    ];

    function buildWavePath(peakA, bodyA) {
      // Symmetrical envelope across 400px width:
      // Quiet start (0..100), Chorus Peak (130..270), Quiet end (300..400)
      const topPts = [
        [0, 100 - bodyA * 0.9],
        [40, 100 - bodyA * 1.1],
        [80, 100 - bodyA * 0.95],
        [115, 100 - (bodyA + (peakA - bodyA) * 0.4)],
        [150, 100 - peakA * 0.95],
        [180, 100 - peakA],
        [200, 100 - peakA * 0.98],
        [225, 100 - peakA],
        [255, 100 - peakA * 0.92],
        [285, 100 - (bodyA + (peakA - bodyA) * 0.35)],
        [320, 100 - bodyA * 1.05],
        [360, 100 - bodyA * 0.9],
        [400, 100 - bodyA]
      ];

      const botPts = topPts.map(p => [p[0], 200 - p[1]]).reverse();

      // Top line path string
      let topPath = `M ${topPts[0][0]} ${topPts[0][1]}`;
      for (let i = 1; i < topPts.length; i++) {
        topPath += ` L ${topPts[i][0]} ${topPts[i][1]}`;
      }

      // Fill polygon path
      let fillPath = topPath;
      for (let i = 0; i < botPts.length; i++) {
        fillPath += ` L ${botPts[i][0]} ${botPts[i][1]}`;
      }
      fillPath += " Z";

      return { line: topPath, fill: fillPath };
    }

    function buildGRPath(origPeakA, compPeakA) {
      // Shows shaved peak region in Stage 2
      const topO = [
        [125, 100 - compPeakA * 0.9],
        [150, 100 - origPeakA * 0.95],
        [180, 100 - origPeakA],
        [200, 100 - origPeakA * 0.98],
        [225, 100 - origPeakA],
        [255, 100 - origPeakA * 0.92],
        [275, 100 - compPeakA * 0.9]
      ];
      const botC = [
        [275, 100 - compPeakA * 0.9],
        [255, 100 - compPeakA * 0.92],
        [225, 100 - compPeakA],
        [200, 100 - compPeakA * 0.98],
        [180, 100 - compPeakA],
        [150, 100 - compPeakA * 0.95],
        [125, 100 - compPeakA * 0.9]
      ];

      let path = `M ${topO[0][0]} ${topO[0][1]}`;
      for (let i = 1; i < topO.length; i++) path += ` L ${topO[i][0]} ${topO[i][1]}`;
      for (let i = 0; i < botC.length; i++) path += ` L ${botC[i][0]} ${botC[i][1]}`;
      return path + " Z";
    }

    let currentStep = 0;
    let timer = null;

    function renderStage(idx) {
      currentStep = idx;
      const s = stages[idx];

      // Update buttons
      [0, 1, 2].forEach(i => {
        const btn = document.getElementById('btn' + i);
        if (btn) btn.classList.toggle('active', i === idx);
      });

      // Waveform shapes
      const paths = buildWavePath(s.peakAmp, s.bodyAmp);
      document.getElementById('waveLine').setAttribute('d', paths.line);
      document.getElementById('waveFill').setAttribute('d', paths.fill);

      // Gain reduction shaded cap in stage 2
      const grEl = document.getElementById('grFill');
      if (idx === 1) {
        grEl.setAttribute('d', buildGRPath(stages[0].peakAmp, s.peakAmp));
        grEl.setAttribute('opacity', '1');
      } else {
        grEl.setAttribute('opacity', '0');
      }

      // Meter & labels
      document.getElementById('meterFill').style.height = s.meterPct + '%';
      document.getElementById('peakLine').style.bottom = s.meterPct + '%';
      document.getElementById('meterDb').textContent = s.meterLabel;

      document.getElementById('valPeak').textContent = s.peakDb;
      document.getElementById('valBody').textContent = s.bodyDb;
      document.getElementById('valRange').textContent = s.rangeDb;
    }

    function startAuto() {
      if (timer) clearInterval(timer);
      timer = setInterval(() => {
        renderStage((currentStep + 1) % 3);
      }, 3200);
      document.getElementById('playBtn').textContent = '⏸';
    }

    function stopAuto() {
      if (timer) {
        clearInterval(timer);
        timer = null;
      }
      document.getElementById('playBtn').textContent = '▶';
    }

    // Interactive wiring
    [0, 1, 2].forEach(i => {
      const btn = document.getElementById('btn' + i);
      btn.addEventListener('click', () => {
        stopAuto();
        renderStage(i);
      });
    });

    document.getElementById('playBtn').addEventListener('click', () => {
      if (timer) stopAuto();
      else startAuto();
    });

    // Initialize stage 1 and start gentle auto-cycle
    renderStage(0);
    startAuto();
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="1:1">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #f8fafc;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      user-select: none;
    }
    .wrapper {
      width: 100%;
      max-width: 440px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 10px;
    }
    /* Ratio Tabs */
    .tabs {
      display: flex;
      gap: 6px;
      width: 100%;
      justify-content: center;
      flex-wrap: wrap;
    }
    .tab-btn {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      padding: 6px 12px;
      font-size: 13px;
      font-weight: 600;
      color: #64748b;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .tab-btn.active {
      background: #22b7ff;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 4px rgba(34, 183, 255, 0.25);
    }
    /* Graph Container */
    .graph-box {
      width: 100%;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 8px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.04);
    }
    svg {
      width: 100%;
      height: auto;
      display: block;
    }
    /* Readout Card */
    .readout {
      width: 100%;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 8px 12px;
      font-size: 13px;
      line-height: 1.4;
      display: flex;
      justify-content: space-between;
      align-items: center;
      box-shadow: 0 1px 2px rgba(0,0,0,0.03);
    }
    .readout-item {
      display: flex;
      flex-direction: column;
    }
    .readout-label {
      font-size: 10px;
      font-weight: 700;
      color: #64748b;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .readout-val {
      font-weight: 700;
      color: #1e2945;
      font-size: 13px;
    }
    .gr-val {
      color: #d97706;
    }
  </style>
</head>
<body>
  <div class="wrapper">
    
    <div class="tabs" role="tablist">
      <button class="tab-btn" onclick="selectRatio('2:1')">2:1</button>
      <button class="tab-btn active" onclick="selectRatio('4:1')">4:1</button>
      <button class="tab-btn" onclick="selectRatio('8:1')">8:1</button>
      <button class="tab-btn" onclick="selectRatio('20:1')">20:1 (Limiter)</button>
    </div>

    
    <div class="graph-box">
      <svg viewBox="0 0 360 330" id="graphSvg">
        <defs>
          
          <marker id="arrow" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="4" markerHeight="4" orient="auto-start-reverse">
            <path d="M 0 1.5 L 8 5 L 0 8.5 z" fill="#d97706" />
          </marker>
        </defs>

        
        
        
        <g stroke="#f1f5f9" stroke-width="1.5">
          <line x1="45" y1="215" x2="325" y2="215" />
          <line x1="45" y1="145" x2="325" y2="145" />
          <line x1="45" y1="75" x2="325" y2="75" />
          
          <line x1="115" y1="5" x2="115" y2="285" />
          <line x1="185" y1="5" x2="185" y2="285" />
          <line x1="255" y1="5" x2="255" y2="285" />
        </g>

        
        <rect x="185" y="5" width="140" height="280" fill="#22b7ff" fill-opacity="0.04" />

        
        <line x1="45" y1="285" x2="325" y2="285" stroke="#94a3b8" stroke-width="1.5" />
        <line x1="45" y1="5" x2="45" y2="285" stroke="#94a3b8" stroke-width="1.5" />

        
        <line x1="185" y1="5" x2="185" y2="285" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="4 3" />

        
        <g font-size="11" fill="#64748b" text-anchor="middle" font-family="system-ui">
          
          <text x="45" y="302">-40</text>
          <text x="115" y="302">-30</text>
          <text x="185" y="302" font-weight="700" fill="#1e2945">-20</text>
          <text x="255" y="302">-10</text>
          <text x="325" y="302">0</text>
          <text x="185" y="322" font-weight="600" fill="#1e2945">Input Level (dBFS)</text>

          
          <text x="38" y="289" text-anchor="end">-40</text>
          <text x="38" y="219" text-anchor="end">-30</text>
          <text x="38" y="149" text-anchor="end" font-weight="700" fill="#1e2945">-20</text>
          <text x="38" y="79" text-anchor="end">-10</text>
          <text x="38" y="9" text-anchor="end">0</text>
        </g>
        <text transform="rotate(-90)" x="-145" y="12" font-size="11" font-weight="600" fill="#1e2945" text-anchor="middle" font-family="system-ui">Output (dBFS)</text>

        
        <line x1="45" y1="285" x2="325" y2="5" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="5 4" />
        <text x="300" y="22" font-size="10" fill="#94a3b8" font-weight="600">1:1</text>

        
        
        <line x1="45" y1="285" x2="185" y2="145" stroke="#64748b" stroke-width="2.5" />

        
        <line id="curve-2:1" x1="185" y1="145" x2="325" y2="75" stroke="#cbd5e1" stroke-width="2" />
        <line id="curve-4:1" x1="185" y1="145" x2="325" y2="110" stroke="#cbd5e1" stroke-width="2" />
        <line id="curve-8:1" x1="185" y1="145" x2="325" y2="127.5" stroke="#cbd5e1" stroke-width="2" />
        <line id="curve-20:1" x1="185" y1="145" x2="325" y2="138" stroke="#cbd5e1" stroke-width="2" />

        
        <line id="active-curve" x1="185" y1="145" x2="325" y2="110" stroke="#22b7ff" stroke-width="4" stroke-linecap="round" />

        
        <circle cx="185" cy="145" r="4.5" fill="#1e2945" />
        <text x="180" y="135" font-size="10" font-weight="700" fill="#1e2945" text-anchor="end">Threshold (-20 dBFS)</text>

        
        
        <g id="indicatorGroup">
          
          <line x1="269" y1="285" x2="269" y2="61" stroke="#cbd5e1" stroke-width="1" stroke-dasharray="2 2" />
          
          
          <circle cx="269" cy="61" r="3" fill="#94a3b8" />
          
          
          <line id="grLine" x1="269" y1="61" x2="269" y2="124" stroke="#d97706" stroke-width="2.5" marker-end="url(#arrow)" />

          
          <line id="outLine" x1="45" y1="124" x2="269" y2="124" stroke="#22b7ff" stroke-width="1" stroke-dasharray="3 3" />

          
          <circle id="activePoint" cx="269" cy="124" r="5" fill="#22b7ff" stroke="#ffffff" stroke-width="2" />
        </g>
      </svg>
    </div>

    
    <div class="readout" id="readoutBox">
      <div class="readout-item">
        <span class="readout-label">Input (+12 dB over)</span>
        <span class="readout-val">-8 dBFS</span>
      </div>
      <div class="readout-item">
        <span class="readout-label">Output</span>
        <span class="readout-val" id="outVal" style="color:#0284c7">-17 dBFS</span>
      </div>
      <div class="readout-item" style="text-align: right;">
        <span class="readout-label">Gain Reduction</span>
        <span class="readout-val gr-val" id="grVal">-9 dB</span>
      </div>
    </div>
  </div>

  <script>
    const ratioData = {
      '2:1': {
        slope: 0.5,
        endY: 75,       // y = -20 + 20 * 0.5 = -10 dBFS -> SVG Y = 5 + 10 * 7 = 75
        testY: 103,     // y = -20 + 12 * 0.5 = -14 dBFS -> SVG Y = 5 + 14 * 7 = 103
        outText: '-14 dBFS',
        grText: '-6 dB'
      },
      '4:1': {
        slope: 0.25,
        endY: 110,      // y = -20 + 20 * 0.25 = -15 dBFS -> SVG Y = 5 + 15 * 7 = 110
        testY: 124,     // y = -20 + 12 * 0.25 = -17 dBFS -> SVG Y = 5 + 17 * 7 = 124
        outText: '-17 dBFS',
        grText: '-9 dB'
      },
      '8:1': {
        slope: 0.125,
        endY: 127.5,    // y = -20 + 20 * 0.125 = -17.5 dBFS -> SVG Y = 5 + 17.5 * 7 = 127.5
        testY: 134.5,   // y = -20 + 12 * 0.125 = -18.5 dBFS -> SVG Y = 5 + 18.5 * 7 = 134.5
        outText: '-18.5 dBFS',
        grText: '-10.5 dB'
      },
      '20:1': {
        slope: 0.05,
        endY: 138,      // y = -20 + 20 * 0.05 = -19 dBFS -> SVG Y = 5 + 19 * 7 = 138
        testY: 140.8,   // y = -20 + 12 * 0.05 = -19.4 dBFS -> SVG Y = 5 + 19.4 * 7 = 140.8
        outText: '-19.4 dBFS',
        grText: '-11.4 dB'
      }
    };

    function selectRatio(ratioKey) {
      // Update Tab Styles
      const buttons = document.querySelectorAll('.tab-btn');
      buttons.forEach(btn => {
        if (btn.textContent.startsWith(ratioKey)) {
          btn.classList.add('active');
        } else {
          btn.classList.remove('active');
        }
      });

      // Update Curve Coordinates
      const data = ratioData[ratioKey];
      const activeCurve = document.getElementById('active-curve');
      activeCurve.setAttribute('x2', '325');
      activeCurve.setAttribute('y2', data.endY);

      // Update Test Point & Gain Reduction Arrow
      const activePoint = document.getElementById('activePoint');
      activePoint.setAttribute('cy', data.testY);

      const outLine = document.getElementById('outLine');
      outLine.setAttribute('y1', data.testY);
      outLine.setAttribute('y2', data.testY);

      const grLine = document.getElementById('grLine');
      grLine.setAttribute('y2', data.testY);

      // Update Readouts
      document.getElementById('outVal').textContent = data.outText;
      document.getElementById('grVal').textContent = data.grText;
    }
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #f8fafc;
      color: #0f172a;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 12px;
      user-select: none;
      -webkit-user-select: none;
    }

    .toolbar {
      width: 100%;
      max-width: 680px;
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      align-items: center;
      gap: 10px;
      margin-bottom: 12px;
    }

    .btn {
      background: #0284c7;
      color: #ffffff;
      border: 1px solid #0369a1;
      border-radius: 6px;
      padding: 7px 14px;
      font-size: 13px;
      font-weight: 700;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: background 0.3s ease, opacity 0.3s ease, box-shadow 0.3s ease;
    }
    .btn:hover { background: #0369a1; }
    .btn:active { opacity: 0.85; }

    .controls-wrapper {
      display: flex;
      align-items: center;
      gap: 12px;
      flex-wrap: wrap;
    }

    .slider-group {
      display: flex;
      align-items: center;
      gap: 8px;
      background: #f1f5f9;
      padding: 6px 10px;
      border-radius: 6px;
      border: 1px solid #cbd5e1;
      font-size: 13px;
      font-weight: 700;
      color: #0f172a;
    }

    .slider-group label {
      color: #0f172a;
      font-weight: 700;
    }

    .slider-group input[type="range"] {
      cursor: pointer;
      accent-color: #0284c7;
      width: 105px;
    }

    .damper-status {
      font-size: 11px;
      font-weight: 600;
      color: #475569;
      background: #e2e8f0;
      padding: 2px 6px;
      border-radius: 4px;
      transition: background-color 0.3s ease, color 0.3s ease;
    }

    .schematic-box {
      position: relative;
      width: 100%;
      max-width: 680px;
      aspect-ratio: 700 / 460;
      background: transparent;
      overflow: hidden;
    }

    canvas {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
      z-index: 1;
      cursor: pointer;
    }

    svg {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
      z-index: 2;
      pointer-events: none;
    }

    .label-badge {
      position: absolute;
      background: #ffffff;
      border: 1.5px solid #64748b;
      padding: 2px 6px;
      border-radius: 4px;
      font-size: 11px;
      font-weight: 700;
      color: #0f172a;
      white-space: nowrap;
      pointer-events: none;
      z-index: 3;
      box-shadow: 0 1px 3px rgba(0,0,0,0.08);
      max-width: 48%;
      overflow: hidden;
      text-overflow: ellipsis;
    }

    @media (max-width: 480px) {
      .toolbar {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
      }
      .controls-wrapper {
        justify-content: space-between;
      }
      .slider-group {
        flex: 1;
        justify-content: space-between;
      }
      .label-badge {
        font-size: 9px;
        padding: 1px 4px;
      }
    }
  </style>
</head>
<body>

  <div class="toolbar">
    <button class="btn" id="playBtn">▶ Excite Plate</button>
    <div class="controls-wrapper">
      <div class="slider-group">
        <label for="damperSlider">Decay Time:</label>
        <input type="range" id="damperSlider" min="0.5" max="5.0" step="0.1" value="3.2">
        <span id="decayVal" style="min-width: 32px; color:#0369a1; font-weight:800;">3.2s</span>
      </div>
      <div class="damper-status" id="damperStatus">Felt Gap: 18mm</div>
    </div>
  </div>

  <div class="schematic-box" id="box">
    <canvas id="waveCanvas"></canvas>
    
    <svg viewBox="0 0 700 460">
      <defs>
        
        <linearGradient id="frameGrad" x1="0" y1="0" x2="1" y2="1">
          <stop offset="0%" stop-color="#334155"/>
          <stop offset="100%" stop-color="#0f172a"/>
        </linearGradient>
        
        <linearGradient id="plateGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#f8fafc"/>
          <stop offset="100%" stop-color="#e2e8f0"/>
        </linearGradient>

        <pattern id="feltTexture" width="8" height="8" patternUnits="userSpaceOnUse">
          <rect width="8" height="8" fill="#991b1b"/>
          <circle cx="2" cy="2" r="1" fill="#7f1d1d" opacity="0.6"/>
          <circle cx="6" cy="6" r="1" fill="#7f1d1d" opacity="0.6"/>
          <path d="M0 4 h8 M4 0 v8" stroke="#b91c1c" stroke-width="0.5" opacity="0.4"/>
        </pattern>

        <filter id="feltShadow" x="-5%" y="-5%" width="115%" height="115%">
          <feDropShadow dx="3" dy="4" stdDeviation="3" flood-color="#0f172a" flood-opacity="0.25"/>
        </filter>
      </defs>

      
      <rect x="20" y="20" width="660" height="420" rx="4" fill="none" stroke="url(#frameGrad)" stroke-width="14"/>
      <rect x="27" y="27" width="646" height="406" fill="none" stroke="#475569" stroke-width="1"/>

      
      
      <g stroke="#64748b" stroke-width="2" fill="none" stroke-linecap="round" stroke-linejoin="round">
        <path d="M 115 27 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 225 27 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 350 27 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 475 27 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 585 27 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        
        
        <path d="M 115 391 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 225 391 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 350 391 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 475 391 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        <path d="M 585 391 v 8 l 4 3 l -8 5 l 8 5 l -8 5 l 8 5 l -4 3 v 8" />
        
        
        <path d="M 27 125 h 8 l 3 4 l 5 -8 l 5 8 l 5 -8 l 5 8 l 3 -4 h 8" />
        <path d="M 27 230 h 8 l 3 4 l 5 -8 l 5 8 l 5 -8 l 5 8 l 3 -4 h 8" />
        <path d="M 27 335 h 8 l 3 4 l 5 -8 l 5 8 l 5 -8 l 5 8 l 3 -4 h 8" />
        
        
        <path d="M 633 125 h 8 l 3 4 l 5 -8 l 5 8 l 5 -8 l 5 8 l 3 -4 h 8" />
        <path d="M 633 230 h 8 l 3 4 l 5 -8 l 5 8 l 5 -8 l 5 8 l 3 -4 h 8" />
        <path d="M 633 335 h 8 l 3 4 l 5 -8 l 5 8 l 5 -8 l 5 8 l 3 -4 h 8" />
      </g>

      
      <rect x="65" y="65" width="570" height="330" rx="1" fill="url(#plateGrad)" stroke="#475569" stroke-width="2"/>

      
      <g id="damperAssembly" filter="url(#feltShadow)">
        
        <line id="motorRodTop" x1="530" y1="27" x2="530" y2="85" stroke="#475569" stroke-width="3" stroke-dasharray="2 2"/>
        <line id="motorRodBot" x1="530" y1="375" x2="530" y2="433" stroke="#475569" stroke-width="3" stroke-dasharray="2 2"/>
        <rect x="522" y="20" width="16" height="12" rx="2" fill="#0f172a" stroke="#334155" stroke-width="1"/>
        <rect x="522" y="428" width="16" height="12" rx="2" fill="#0f172a" stroke="#334155" stroke-width="1"/>

        
        <rect id="damperBacking" x="90" y="85" width="520" height="290" rx="3" fill="#cbd5e1" stroke="#94a3b8" stroke-width="1.5"/>
        
        
        <rect id="feltPad" x="95" y="90" width="510" height="280" rx="2" fill="url(#feltTexture)" stroke="#7f1d1d" stroke-width="1.5" opacity="0.65"/>
        
        
        <line x1="100" y1="85" x2="600" y2="85" stroke="#64748b" stroke-width="2"/>
        <line x1="100" y1="375" x2="600" y2="375" stroke="#64748b" stroke-width="2"/>
      </g>

      
      <g id="driverNode">
        <circle cx="310" cy="235" r="17" fill="#0284c7" stroke="#0369a1" stroke-width="2.5"/>
        <circle cx="310" cy="235" r="7" fill="#ffffff" stroke="#0369a1" stroke-width="1.5"/>
        <circle cx="310" cy="235" r="2.5" fill="#0284c7"/>
      </g>

      
      <g id="pickupL">
        <rect x="495" y="135" width="22" height="22" rx="4" fill="#059669" stroke="#047857" stroke-width="2"/>
        <circle cx="506" cy="146" r="4" fill="#ffffff"/>
      </g>

      
      <g id="pickupR">
        <rect x="175" y="295" width="22" height="22" rx="4" fill="#059669" stroke="#047857" stroke-width="2"/>
        <circle cx="186" cy="306" r="4" fill="#ffffff"/>
      </g>

      
      <path d="M 225 35 L 225 15" stroke="#475569" stroke-width="1.2" fill="none"/>
      <path d="M 310 235 L 310 190 L 260 190" stroke="#0284c7" stroke-width="1.5" stroke-dasharray="3 3" fill="none"/>
      <path d="M 506 135 L 506 92 L 545 92" stroke="#059669" stroke-width="1.5" stroke-dasharray="3 3" fill="none"/>
      <path d="M 186 317 L 186 345 L 140 345" stroke="#059669" stroke-width="1.5" stroke-dasharray="3 3" fill="none"/>
      <path d="M 570 350 L 615 375" stroke="#b91c1c" stroke-width="1.5" stroke-dasharray="3 3" fill="none"/>
    </svg>

    
    <div class="label-badge" style="top: 3%; left: 24%; border-color:#64748b;">Tension Springs</div>
    <div class="label-badge" style="top: 17%; left: 11%; border-color:#475569; color:#0f172a;">Suspended Steel Plate</div>
    <div class="label-badge" style="top: 36%; left: 20%; border-color:#0284c7; color:#0369a1;">Driver Transducer (Input)</div>
    <div class="label-badge" style="top: 16%; right: 4%; border-color:#059669; color:#065f46;">Pickup L (Stereo Out)</div>
    <div class="label-badge" style="top: 73%; left: 8%; border-color:#059669; color:#065f46;">Pickup R (Stereo Out)</div>
    <div class="label-badge" style="bottom: 12%; right: 4%; border-color:#b91c1c; color:#991b1b;">Motorized Felt Damper</div>
  </div>

  <script>
    const canvas = document.getElementById('waveCanvas');
    const ctx = canvas.getContext('2d');
    const playBtn = document.getElementById('playBtn');
    const damperSlider = document.getElementById('damperSlider');
    const decayVal = document.getElementById('decayVal');
    const damperStatus = document.getElementById('damperStatus');
    const damperAssembly = document.getElementById('damperAssembly');
    const feltPad = document.getElementById('feltPad');

    let decayTime = parseFloat(damperSlider.value);
    let ripples = [];
    let audioCtx = null;

    function resizeCanvas() {
      const rect = canvas.getBoundingClientRect();
      canvas.width = rect.width;
      canvas.height = rect.height;
    }
    window.addEventListener('resize', resizeCanvas);
    resizeCanvas();

    function updateDamperVisual() {
      decayTime = parseFloat(damperSlider.value);
      decayVal.textContent = decayTime.toFixed(1) + 's';
      
      // Normalized: 0 = shortest decay (damper pressed close/touching), 1 = max decay (damper withdrawn)
      const norm = (decayTime - 0.5) / 4.5;
      
      // Realistic gap distance readout in mm
      const gapMm = Math.round(1 + norm * 35);
      damperStatus.textContent = norm < 0.15 
        ? `Felt Gap: ${gapMm}mm (Max Damping)` 
        : (norm > 0.85 ? `Felt Gap: ${gapMm}mm (Min Damping)` : `Felt Gap: ${gapMm}mm`);

      // Mechanical translation & opacity:
      // When close (decay low): high opacity, shift toward plate center
      // When far (decay high): shifted away (up and right), low opacity, light shadow
      const shiftX = (norm * 18).toFixed(1);
      const shiftY = (-norm * 14).toFixed(1);
      const scale = (1 - norm * 0.05).toFixed(3);
      const opacity = (0.95 - norm * 0.7).toFixed(2);
      
      damperAssembly.setAttribute('transform', `translate(${shiftX}, ${shiftY}) scale(${scale})`);
      damperAssembly.setAttribute('transform-origin', '350 230');
      feltPad.setAttribute('opacity', opacity);
    }

    damperSlider.addEventListener('input', updateDamperVisual);
    updateDamperVisual();

    // Wave ripple simulation modeling high modal density
    class Wavefront {
      constructor(x, y, speed, amp, freq) {
        this.x = x;
        this.y = y;
        this.r = 0;
        this.speed = speed;
        this.amp = amp;
        this.freq = freq;
        this.life = 1.0;
      }
      update(dampingRate) {
        this.r += this.speed;
        this.life -= dampingRate;
      }
    }

    function excite(xNorm = 310/700, yNorm = 235/460) {
      const px = xNorm * canvas.width;
      const py = yNorm * canvas.height;
      
      for (let i = 0; i < 16; i++) {
        ripples.push(new Wavefront(
          px, 
          py, 
          1.7 + i * 0.4, 
          1.0 - i * 0.04, 
          0.05 + i * 0.02
        ));
      }

      // Plate reverb sound synthesis via Web Audio API
      try {
        if (!audioCtx) audioCtx = new (window.AudioContext || window.webkitAudioContext)();
        if (audioCtx.state === 'suspended') audioCtx.resume();

        const t = audioCtx.currentTime;
        const freqs = [290, 470, 720, 1080, 1550, 2240, 3180, 4200];
        freqs.forEach((f, idx) => {
          const osc = audioCtx.createOscillator();
          const gain = audioCtx.createGain();
          osc.type = idx % 2 === 0 ? 'sine' : 'triangle';
          osc.frequency.setValueAtTime(f, t);
          
          const dTime = decayTime * (1 - idx * 0.07);
          gain.gain.setValueAtTime(0.035 / (idx + 1), t);
          gain.gain.exponentialRampToValueAtTime(0.0001, t + Math.max(0.15, dTime));

          osc.connect(gain);
          gain.connect(audioCtx.destination);
          osc.start(t);
          osc.stop(t + dTime);
        });
      } catch (e) {}
    }

    playBtn.addEventListener('click', () => excite());
    canvas.addEventListener('pointerdown', (e) => {
      const rect = canvas.getBoundingClientRect();
      excite((e.clientX - rect.left) / rect.width, (e.clientY - rect.top) / rect.height);
    });

    // Render loop
    function animate() {
      ctx.clearRect(0, 0, canvas.width, canvas.height);

      // Plate bounds in canvas coordinates
      const px = (65 / 700) * canvas.width;
      const py = (65 / 460) * canvas.height;
      const pw = (570 / 700) * canvas.width;
      const ph = (330 / 460) * canvas.height;

      // Clip ripples strictly inside the sheet metal boundary
      ctx.save();
      ctx.beginPath();
      ctx.rect(px, py, pw, ph);
      ctx.clip();

      const dampingRate = 0.006 / (decayTime * 0.65);

      for (let i = ripples.length - 1; i >= 0; i--) {
        const w = ripples[i];
        w.update(dampingRate);

        if (w.life <= 0 || w.r > Math.max(canvas.width, canvas.height) * 1.3) {
          ripples.splice(i, 1);
          continue;
        }

        ctx.beginPath();
        ctx.arc(w.x, w.y, w.r, 0, Math.PI * 2);
        ctx.strokeStyle = `rgba(2, 132, 199, ${(w.life * 0.5).toFixed(3)})`;
        ctx.lineWidth = 2;
        ctx.stroke();

        // Secondary high-frequency dispersion ring
        if (w.r > 24) {
          ctx.beginPath();
          ctx.arc(w.x, w.y, w.r * 0.72, 0, Math.PI * 2);
          ctx.strokeStyle = `rgba(5, 150, 105, ${(w.life * 0.35).toFixed(3)})`;
          ctx.lineWidth = 1.3;
          ctx.stroke();
        }
      }

      ctx.restore();

      // Gentle auto-trigger if idle
      if (ripples.length === 0 && Math.random() < 0.012) {
        excite();
      }

      requestAnimationFrame(animate);
    }

    setTimeout(() => excite(), 350);
    animate();
  </script>
</body>
</html>

Reverberation Types: Spring, Plate, Chamber, and Hall

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Acoustic Echo Chamber</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 8px 10px;
      width: 100%;
      min-height: 100vh;
      max-height: 580px;
      user-select: none;
      overflow-x: hidden;
    }

    /* Signal flow pipeline - wraps cleanly on small screens */
    .flow-bar {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px 6px;
      width: 100%;
      max-width: 520px;
      margin-bottom: 4px;
      flex-wrap: wrap;
    }
    .flow-node {
      padding: 4px 8px;
      font-size: 11px;
      font-weight: 700;
      text-align: center;
      background: #f1f5f9;
      color: #64748b;
      border-radius: 6px;
      border: 1px solid #e2e8f0;
      transition: background-color 0.4s ease, color 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
      white-space: nowrap;
      cursor: pointer;
    }
    .flow-node.active-dry {
      background: #eff6ff;
      color: #1d4ed8;
      border-color: #93c5fd;
      box-shadow: 0 0 0 2px rgba(37,99,235,0.2);
    }
    .flow-node.active-room {
      background: #fffbeb;
      color: #b45309;
      border-color: #fcd34d;
      box-shadow: 0 0 0 2px rgba(217,119,6,0.2);
    }
    .flow-node.active-wet {
      background: #ecfdf5;
      color: #047857;
      border-color: #6ee7b7;
      box-shadow: 0 0 0 2px rgba(5,150,105,0.2);
    }
    .flow-arrow {
      font-size: 10px;
      color: #94a3b8;
      font-weight: bold;
      user-select: none;
    }

    @media (max-width: 380px) {
      .flow-node {
        font-size: 9.5px;
        padding: 3px 6px;
      }
      .flow-arrow {
        font-size: 8px;
      }
    }

    /* Diagram container */
    .svg-wrap {
      width: 100%;
      max-width: 520px;
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
    }
    svg {
      width: 100%;
      height: auto;
      max-height: 340px;
    }

    /* Interactive controls */
    .controls {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      width: 100%;
      margin-top: 4px;
    }
    .btn {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      color: #334155;
      padding: 5px 14px;
      border-radius: 18px;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: background-color 0.2s, border-color 0.2s;
    }
    .btn:hover {
      background: #f1f5f9;
      border-color: #94a3b8;
    }
    .stepper {
      display: flex;
      gap: 6px;
    }
    .step-dot {
      width: 22px;
      height: 22px;
      border-radius: 50%;
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      color: #64748b;
      font-size: 11px;
      font-weight: bold;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: background-color 0.3s, color 0.3s, border-color 0.3s;
    }
    .step-dot.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #2563eb;
    }

    /* Smooth animated wave rays and pulses */
    .ray-path {
      stroke-dasharray: 8 6;
      animation: dash 2.8s linear infinite;
    }
    @keyframes dash {
      to { stroke-dashoffset: -28; }
    }
    .wave-pulse {
      animation: waveExpand 3.2s cubic-bezier(0.1, 0.5, 0.4, 1) infinite;
      transform-origin: 100px 105px;
    }
    @keyframes waveExpand {
      0% { opacity: 0.8; r: 10; }
      100% { opacity: 0; r: 95; }
    }
    .layer-transition {
      transition: opacity 0.6s ease;
    }
  </style>
</head>
<body>

  
  <div class="flow-bar">
    <div id="node1" class="flow-node active-dry" onclick="setStep(0)">1. Dry Aux Send</div>
    <div class="flow-arrow">➔</div>
    <div id="node2" class="flow-node" onclick="setStep(1)">2. Speaker</div>
    <div class="flow-arrow">➔</div>
    <div id="node3" class="flow-node" onclick="setStep(2)">3. Reflections</div>
    <div class="flow-arrow">➔</div>
    <div id="node4" class="flow-node" onclick="setStep(3)">4. Mics</div>
    <div class="flow-arrow">➔</div>
    <div id="node5" class="flow-node" onclick="setStep(4)">5. Wet Return</div>
  </div>

  
  <div class="svg-wrap">
    <svg viewBox="0 0 520 340" aria-label="Floor plan of an acoustic echo chamber">
      <defs>
        
        <pattern id="concreteHatch" width="12" height="12" patternTransform="rotate(45 0 0)" patternUnits="userSpaceOnUse">
          <line x1="0" y1="0" x2="0" y2="12" stroke="#cbd5e1" stroke-width="3" />
        </pattern>
        
        <radialGradient id="roomGlow" cx="45%" cy="45%" r="55%">
          <stop offset="0%" stop-color="#ffffff"/>
          <stop offset="100%" stop-color="#f8fafc"/>
        </radialGradient>
        
        <marker id="arrowAmber" markerWidth="6" markerHeight="6" refX="4" refY="3" orient="auto">
          <polygon points="0 0, 6 3, 0 6" fill="#f59e0b" />
        </marker>
        <marker id="arrowBlue" markerWidth="6" markerHeight="6" refX="4" refY="3" orient="auto">
          <polygon points="0 0, 6 3, 0 6" fill="#2563eb" />
        </marker>
        <marker id="arrowGreen" markerWidth="6" markerHeight="6" refX="4" refY="3" orient="auto">
          <polygon points="0 0, 6 3, 0 6" fill="#059669" />
        </marker>
      </defs>

      
      <polygon points="50,42 460,24 485,296 75,316" fill="none" stroke="url(#concreteHatch)" stroke-width="20" stroke-linejoin="round"/>
      <polygon points="50,42 460,24 485,296 75,316" fill="none" stroke="#64748b" stroke-width="2.5" stroke-linejoin="round"/>
      <polygon points="50,42 460,24 485,296 75,316" fill="url(#roomGlow)" />

      
      <g transform="translate(255, 42)">
        <rect x="-115" y="-11" width="230" height="22" rx="11" fill="#ffffff" stroke="#cbd5e1" stroke-width="1.2" opacity="0.96"/>
        <text x="0" y="4" text-anchor="middle" fill="#334155" font-size="10" font-weight="700" letter-spacing="0.5">NON-PARALLEL REFLECTIVE WALLS</text>
      </g>

      
      <g id="layerWaves" class="layer-transition" opacity="1">
        <circle cx="100" cy="105" r="14" fill="none" stroke="#f59e0b" stroke-width="2" opacity="0.8" class="wave-pulse"/>
        <circle cx="100" cy="105" r="28" fill="none" stroke="#f59e0b" stroke-width="2" opacity="0.6" class="wave-pulse" style="animation-delay: 1.0s;"/>
        <circle cx="100" cy="105" r="48" fill="none" stroke="#f59e0b" stroke-width="1.5" opacity="0.4" class="wave-pulse" style="animation-delay: 2.0s;"/>
      </g>

      
      <g id="layerRays" class="layer-transition" opacity="1">
        
        <path class="ray-path" d="M 115,100 L 320,38 L 470,160 L 365,225" fill="none" stroke="#f59e0b" stroke-width="2" marker-mid="url(#arrowAmber)"/>
        
        <path class="ray-path" d="M 115,110 L 450,90 L 420,285 L 290,245" fill="none" stroke="#f59e0b" stroke-width="2" style="animation-delay: -0.7s;"/>
        
        <path class="ray-path" d="M 105,120 L 220,305 L 475,220 L 365,235" fill="none" stroke="#f59e0b" stroke-width="2" style="animation-delay: -1.4s;"/>
        
        <path class="ray-path" d="M 120,95 L 455,48 L 150,300 L 285,250" fill="none" stroke="#d97706" stroke-width="1.5" stroke-opacity="0.75" style="animation-delay: -2.1s;"/>
      </g>

      
      <g transform="translate(195, 140) rotate(42)">
        <rect x="-7" y="-36" width="14" height="72" rx="4" fill="#334155" stroke="#0f172a" stroke-width="1.5"/>
        <line x1="-3" y1="-30" x2="-3" y2="30" stroke="#94a3b8" stroke-width="2" stroke-dasharray="3 3"/>
      </g>

      
      <g transform="translate(145, 175)">
        <rect x="-58" y="-15" width="116" height="30" rx="6" fill="#ffffff" stroke="#cbd5e1" stroke-width="1" opacity="0.94"/>
        <text x="0" y="-1" text-anchor="middle" fill="#1e293b" font-size="10.5" font-weight="700">Acoustic Baffle</text>
        <text x="0" y="11" text-anchor="middle" fill="#64748b" font-size="8.5">(Blocks direct sound)</text>
      </g>

      
      
      <path d="M 14,105 L 75,105" fill="none" stroke="#2563eb" stroke-width="2.5" stroke-dasharray="4 3" marker-end="url(#arrowBlue)"/>
      <g transform="translate(95, 105) rotate(35)">
        
        <rect x="-18" y="-13" width="20" height="26" rx="2" fill="#1e2945"/>
        
        <polygon points="2,-13 13,-20 13,20 2,13" fill="#2563eb"/>
        <circle cx="-8" cy="0" r="4.5" fill="#94a3b8"/>
      </g>
      
      <g transform="translate(85, 68)">
        <rect x="-42" y="-10" width="84" height="20" rx="5" fill="#eff6ff" stroke="#93c5fd" stroke-width="1"/>
        <text x="0" y="4" text-anchor="middle" fill="#1d4ed8" font-size="10.5" font-weight="700">Loudspeaker</text>
      </g>

      
      
      <g transform="translate(365, 225) rotate(-65)">
        <rect x="-4" y="-12" width="8" height="20" rx="3" fill="#059669"/>
        <circle cx="0" cy="-14" r="6" fill="#10b981" stroke="#047857" stroke-width="1"/>
        <line x1="0" y1="8" x2="0" y2="18" stroke="#64748b" stroke-width="2"/>
      </g>
      
      <g transform="translate(285, 240) rotate(115)">
        <rect x="-4" y="-12" width="8" height="20" rx="3" fill="#059669"/>
        <circle cx="0" cy="-14" r="6" fill="#10b981" stroke="#047857" stroke-width="1"/>
        <line x1="0" y1="8" x2="0" y2="18" stroke="#64748b" stroke-width="2"/>
      </g>

      
      <g transform="translate(330, 280)">
        <rect x="-72" y="-13" width="144" height="28" rx="6" fill="#ffffff" stroke="#a7f3d0" stroke-width="1.2" opacity="0.96"/>
        <text x="0" y="0" text-anchor="middle" fill="#065f46" font-size="10.5" font-weight="700">Microphones (M/S or A/B)</text>
        <text x="0" y="11" text-anchor="middle" fill="#059669" font-size="8.5">(Captures wet reverb only)</text>
      </g>

      
      <path d="M 378,225 Q 430,250 505,250" fill="none" stroke="#059669" stroke-width="2.5" stroke-dasharray="4 3" marker-end="url(#arrowGreen)"/>
      <text x="490" y="240" text-anchor="end" fill="#047857" font-size="9" font-weight="700">Wet Return</text>

    </svg>
  </div>

  
  <div class="controls">
    <button id="playBtn" class="btn" onclick="togglePlay()"><span>⏸</span> Pause</button>
    <div class="stepper">
      <div class="step-dot active" onclick="setStep(0)">1</div>
      <div class="step-dot" onclick="setStep(1)">2</div>
      <div class="step-dot" onclick="setStep(2)">3</div>
      <div class="step-dot" onclick="setStep(3)">4</div>
      <div class="step-dot" onclick="setStep(4)">5</div>
    </div>
  </div>

  <script>
    const nodes = [
      { el: document.getElementById('node1'), cls: 'active-dry' },
      { el: document.getElementById('node2'), cls: 'active-dry' },
      { el: document.getElementById('node3'), cls: 'active-room' },
      { el: document.getElementById('node4'), cls: 'active-wet' },
      { el: document.getElementById('node5'), cls: 'active-wet' }
    ];
    const dots = document.querySelectorAll('.step-dot');
    const playBtn = document.getElementById('playBtn');
    const layerWaves = document.getElementById('layerWaves');
    const layerRays = document.getElementById('layerRays');

    let currentStep = 0;
    let isPlaying = true;
    let timer = null;

    function setStep(idx) {
      currentStep = idx;
      nodes.forEach((n, i) => {
        n.el.className = 'flow-node' + (i === idx ? ' ' + n.cls : '');
      });
      dots.forEach((d, i) => {
        d.className = 'step-dot' + (i === idx ? ' active' : '');
      });

      // Visual focus for each step in signal flow
      if (idx === 0) { // Dry aux send
        layerWaves.style.opacity = '0.25';
        layerRays.style.opacity = '0.2';
      } else if (idx === 1) { // Speaker emits
        layerWaves.style.opacity = '1';
        layerRays.style.opacity = '0.35';
      } else if (idx === 2) { // Room reflections dense field
        layerWaves.style.opacity = '0.85';
        layerRays.style.opacity = '1';
      } else if (idx === 3) { // Mics capture
        layerWaves.style.opacity = '0.5';
        layerRays.style.opacity = '0.9';
      } else { // Wet return
        layerWaves.style.opacity = '0.35';
        layerRays.style.opacity = '0.6';
      }
    }

    function nextStep() {
      setStep((currentStep + 1) % 5);
    }

    function startTimer() {
      if (timer) clearInterval(timer);
      timer = setInterval(nextStep, 3200); // 3.2s per step ensures comfortable reading
    }

    function togglePlay() {
      isPlaying = !isPlaying;
      if (isPlaying) {
        playBtn.innerHTML = '<span>⏸</span> Pause';
        startTimer();
      } else {
        playBtn.innerHTML = '<span>▶</span> Play';
        clearInterval(timer);
      }
    }

    // Initialize
    setStep(0);
    startTimer();
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      background: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 12px;
      min-height: 100%;
      user-select: none;
    }

    .controls {
      display: flex;
      gap: 8px;
      width: 100%;
      max-width: 540px;
      justify-content: center;
      margin-bottom: 8px;
    }

    .btn-toggle {
      flex: 1;
      padding: 8px 14px;
      font-size: 14px;
      font-weight: 600;
      border: 2px solid #e2e8f0;
      background: #f8fafc;
      color: #64748b;
      border-radius: 8px;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      transition: all 0.2s ease;
    }
    .btn-toggle.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.25);
    }

    .btn-audio {
      padding: 8px 14px;
      font-size: 14px;
      font-weight: 600;
      border: 2px solid #e2e8f0;
      background: #f8fafc;
      color: #1e2945;
      border-radius: 8px;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: background 0.2s;
    }
    .btn-audio:active {
      background: #e2e8f0;
    }

    .chart-container {
      position: relative;
      width: 100%;
      max-width: 540px;
      height: 250px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      overflow: hidden;
    }

    svg {
      width: 100%;
      height: 100%;
      display: block;
    }

    .stage-legend {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 6px;
      width: 100%;
      max-width: 540px;
      margin-top: 8px;
    }

    .legend-card {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 8px;
      padding: 6px 8px;
      text-align: center;
      transition: border-color 0.2s, background-color 0.2s;
    }
    .legend-card.highlight {
      border-color: #0284c7;
      background: #f0f9ff;
    }
    .legend-title {
      font-size: 12px;
      font-weight: 700;
      color: #0f172a;
      display: block;
    }
    .legend-sub {
      font-size: 11px;
      color: #64748b;
      font-weight: 500;
    }
  </style>
</head>
<body>

  <div class="controls">
    <button class="btn-toggle active" id="btnHall" onclick="setType('hall')">
      <span>🏛️</span> Hall Reverb
    </button>
    <button class="btn-toggle" id="btnPlate" onclick="setType('plate')">
      <span>⚡</span> Plate Reverb
    </button>
    <button class="btn-audio" onclick="playCurrentReverb()">
      <span>🔊</span> Play
    </button>
  </div>

  <div class="chart-container">
    <svg id="svgChart" viewBox="0 0 540 250">
      
      <line x1="45" y1="210" x2="520" y2="210" stroke="#cbd5e1" stroke-width="1.5" />
      <line x1="45" y1="25" x2="45" y2="210" stroke="#cbd5e1" stroke-width="1.5" />

      
      <text x="25" y="35" font-size="11" fill="#64748b" font-weight="600" text-anchor="middle">Amp</text>
      <text x="25" y="214" font-size="11" fill="#64748b" font-weight="600" text-anchor="middle">0</text>
      <text x="45" y="226" font-size="11" fill="#64748b" text-anchor="middle">0ms</text>
      <text x="110" y="226" font-size="11" fill="#64748b" text-anchor="middle">20ms</text>
      <text x="200" y="226" font-size="11" fill="#64748b" text-anchor="middle">80ms</text>
      <text x="360" y="226" font-size="11" fill="#64748b" text-anchor="middle">1.0s</text>
      <text x="500" y="226" font-size="11" fill="#64748b" text-anchor="middle">2.5s</text>

      
      <rect id="zonePreDelay" x="48" y="25" width="62" height="185" fill="#fef3c7" opacity="0.4" />
      <rect id="zoneEarly" x="110" y="25" width="90" height="185" fill="#e0f2fe" opacity="0.4" />
      <rect id="zoneLate" x="200" y="25" width="315" height="185" fill="#f1f5f9" opacity="0.5" />

      
      <path id="decayEnvelope" fill="rgba(2, 132, 199, 0.08)" stroke="#0284c7" stroke-width="1.5" stroke-dasharray="3,3" />

      
      <g id="spikesGroup"></g>

      
      <g id="stageMarkers"></g>
    </svg>
  </div>

  <div class="stage-legend">
    <div class="legend-card" id="card1">
      <span class="legend-title" id="title1">1. Direct Sound</span>
      <span class="legend-sub" id="sub1">0ms (Dry Signal)</span>
    </div>
    <div class="legend-card" id="card2">
      <span class="legend-title" id="title2">2. Pre-Delay Gap</span>
      <span class="legend-sub" id="sub2">20–80ms Early Walls</span>
    </div>
    <div class="legend-card" id="card3">
      <span class="legend-title" id="title3">3. Diffuse Tail</span>
      <span class="legend-sub" id="sub3">Exponential Decay</span>
    </div>
  </div>

  <script>
    let currentType = 'hall';
    let audioCtx = null;

    function renderDiagram(type) {
      const g = document.getElementById('spikesGroup');
      const env = document.getElementById('decayEnvelope');
      const zonePre = document.getElementById('zonePreDelay');
      const zoneEarly = document.getElementById('zoneEarly');
      const zoneLate = document.getElementById('zoneLate');
      const markers = document.getElementById('stageMarkers');

      g.innerHTML = '';
      markers.innerHTML = '';

      if (type === 'hall') {
        // Zone configurations
        zonePre.setAttribute('x', '48');
        zonePre.setAttribute('width', '62');
        zonePre.setAttribute('opacity', '0.45');

        zoneEarly.setAttribute('x', '110');
        zoneEarly.setAttribute('width', '90');

        zoneLate.setAttribute('x', '200');
        zoneLate.setAttribute('width', '315');

        // Direct Sound (0ms)
        addSpike(g, 45, 35, '#ef4444', 3);

        // Pre-delay marker
        markers.innerHTML += `
          <line x1="48" y1="170" x2="108" y2="170" stroke="#d97706" stroke-width="1.5" marker-end="url(#arrow)" />
          <text x="78" y="162" font-size="10" fill="#b45309" font-weight="700" text-anchor="middle">Pre-delay</text>
        `;

        // Early Reflections (20ms to 80ms)
        const earlySpikes = [
          { x: 112, h: 80 }, { x: 128, h: 105 }, { x: 145, h: 95 },
          { x: 165, h: 120 }, { x: 182, h: 110 }, { x: 198, h: 130 }
        ];
        earlySpikes.forEach(s => addSpike(g, s.x, s.h, '#0284c7', 2));

        // Diffuse Tail (80ms to 510ms)
        let pathD = 'M 200 125 ';
        for (let x = 202; x <= 510; x += 3.5) {
          const progress = (x - 200) / 310;
          const maxAmp = 125 + (205 - 125) * Math.pow(progress, 0.65);
          const randAmp = maxAmp + Math.random() * (210 - maxAmp);
          addSpike(g, x, randAmp, '#64748b', 1, 0.5);
          pathD += `L ${x} ${maxAmp} `;
        }
        pathD += 'L 510 210 L 200 210 Z';
        env.setAttribute('d', pathD);

        // Update Legend
        document.getElementById('title2').textContent = '2. Pre-Delay & Early';
        document.getElementById('sub2').textContent = '20–80ms Sparse Spikes';
        document.getElementById('title3').textContent = '3. Diffuse Tail';
        document.getElementById('sub3').textContent = 'Smooth Hall Decay';
      } else {
        // Plate Reverb: No Pre-Delay, immediate dense diffusion
        zonePre.setAttribute('width', '0');
        zoneEarly.setAttribute('x', '48');
        zoneEarly.setAttribute('width', '40');
        zoneLate.setAttribute('x', '88');
        zoneLate.setAttribute('width', '425');

        // Direct Sound
        addSpike(g, 45, 35, '#ef4444', 3);

        // Immediate dense reflections
        let pathD = 'M 48 55 ';
        for (let x = 48; x <= 505; x += 2.5) {
          const progress = (x - 48) / 457;
          const maxAmp = 55 + (206 - 55) * Math.pow(progress, 0.7);
          const randAmp = maxAmp + Math.random() * (210 - maxAmp);
          addSpike(g, x, randAmp, '#0284c7', 1, 0.6);
          pathD += `L ${x} ${maxAmp} `;
        }
        pathD += 'L 505 210 L 48 210 Z';
        env.setAttribute('d', pathD);

        markers.innerHTML += `
          <text x="140" y="50" font-size="11" fill="#0284c7" font-weight="700">⚡ Immediate Dense Onset (0ms Pre-Delay)</text>
        `;

        // Update Legend
        document.getElementById('title2').textContent = '2. Zero Pre-Delay';
        document.getElementById('sub2').textContent = 'Immediate Reflection';
        document.getElementById('title3').textContent = '3. Dense Plate Tail';
        document.getElementById('sub3').textContent = 'High-Density Metallic';
      }
    }

    function addSpike(parent, x, topY, color, width, opacity = 1) {
      const line = document.createElementNS('http://www.w3.org/2000/svg', 'line');
      line.setAttribute('x1', x);
      line.setAttribute('y1', 210);
      line.setAttribute('x2', x);
      line.setAttribute('y2', topY);
      line.setAttribute('stroke', color);
      line.setAttribute('stroke-width', width);
      line.setAttribute('stroke-linecap', 'round');
      line.setAttribute('opacity', opacity);
      parent.appendChild(line);
    }

    function setType(type) {
      currentType = type;
      document.getElementById('btnHall').classList.toggle('active', type === 'hall');
      document.getElementById('btnPlate').classList.toggle('active', type === 'plate');
      renderDiagram(type);
    }

    function playCurrentReverb() {
      if (!audioCtx) audioCtx = new (window.AudioContext || window.webkitAudioContext)();
      if (audioCtx.state === 'suspended') audioCtx.resume();

      const now = audioCtx.currentTime;
      const sr = audioCtx.sampleRate;
      const dur = currentType === 'hall' ? 2.0 : 1.4;
      const buf = audioCtx.createBuffer(1, sr * dur, sr);
      const data = buf.getChannelData(0);

      // Direct sound impulse
      data[0] = 1.0;

      if (currentType === 'hall') {
        const preDelaySamples = Math.floor(0.04 * sr);
        // Sparse early reflections
        const delays = [0.04, 0.055, 0.07, 0.09, 0.11];
        delays.forEach((d, i) => {
          const idx = Math.floor(d * sr);
          data[idx] = (Math.random() > 0.5 ? 0.6 : -0.6) * Math.pow(0.8, i);
        });
        // Late exponential decay
        for (let i = Math.floor(0.1 * sr); i < data.length; i++) {
          const t = (i - 0.1 * sr) / sr;
          data[i] = (Math.random() * 2 - 1) * Math.exp(-3.2 * t) * 0.45;
        }
      } else {
        // Plate: immediate dense onset
        for (let i = 1; i < data.length; i++) {
          const t = i / sr;
          data[i] = (Math.random() * 2 - 1) * Math.exp(-4.5 * t) * 0.7;
        }
      }

      // Play through a warm filter
      const src = audioCtx.createBufferSource();
      src.buffer = buf;
      const filter = audioCtx.createBiquadFilter();
      filter.type = currentType === 'hall' ? 'lowpass' : 'bandpass';
      filter.frequency.value = currentType === 'hall' ? 3500 : 2500;

      src.connect(filter);
      filter.connect(audioCtx.destination);
      src.start(now);
    }

    renderDiagram('hall');
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: #ffffff;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      user-select: none;
    }

    .matrix-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 8px;
      width: 100%;
    }

    .card-col {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      display: flex;
      flex-direction: column;
      overflow: hidden;
      cursor: pointer;
      transition: box-shadow 0.2s ease, background-color 0.2s ease;
    }

    .card-col.active {
      background: #ffffff;
      box-shadow: 0 0 0 2px var(--accent-color, #22b7ff);
    }

    .spring-col { --accent-color: #d97706; }
    .plate-col { --accent-color: #0284c7; }
    .chamber-col { --accent-color: #059669; }
    .hall-col { --accent-color: #7c3aed; }

    .header-block {
      background: #f1f5f9;
      padding: 8px 4px;
      text-align: center;
      border-bottom: 2px solid var(--accent-color);
    }

    .title-badge {
      font-size: 13px;
      font-weight: 700;
      color: var(--accent-color);
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .cell-section {
      padding: 8px 6px;
      border-bottom: 1px solid #e2e8f0;
      display: flex;
      flex-direction: column;
      gap: 4px;
      flex: 1;
    }

    .cell-section:last-child {
      border-bottom: none;
    }

    .dim-label {
      font-size: 10px;
      font-weight: 700;
      text-transform: uppercase;
      color: #64748b;
      letter-spacing: 0.3px;
    }

    .val-text {
      font-size: 12px;
      font-weight: 600;
      color: #1e2945;
      line-height: 1.25;
    }

    .sub-text {
      font-size: 11px;
      color: #64748b;
      line-height: 1.2;
    }

    .visual-box {
      height: 38px;
      width: 100%;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 4px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-top: 2px;
      position: relative;
      overflow: hidden;
    }

    .card-col.active .visual-box {
      background: #f8fafc;
    }

    .tag-bubble {
      display: inline-block;
      padding: 3px 6px;
      border-radius: 4px;
      font-size: 11px;
      font-weight: 600;
      background: #e2e8f0;
      color: #334155;
      text-align: center;
      margin-top: 2px;
    }

    .spring-col.active .tag-bubble { background: #fef3c7; color: #92400e; }
    .plate-col.active .tag-bubble { background: #e0f2fe; color: #075985; }
    .chamber-col.active .tag-bubble { background: #d1fae5; color: #065f46; }
    .hall-col.active .tag-bubble { background: #ede9fe; color: #5b21b6; }

    /* Visual Wave / Envelope SVGs */
    svg.spec {
      width: 100%;
      height: 100%;
    }

    /* Sound Trigger Bar */
    .controls {
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 6px 12px;
    }

    .status-text {
      font-size: 12px;
      font-weight: 600;
      color: #475569;
    }

    .status-text span {
      color: #0f172a;
      font-weight: 700;
    }

    .btn-audio {
      background: #2563eb;
      color: #ffffff;
      border: none;
      border-radius: 6px;
      padding: 6px 12px;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .btn-audio:hover {
      background: #1d4ed8;
    }

    @media (max-width: 500px) {
      .matrix-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .val-text { font-size: 11px; }
      .sub-text { font-size: 10px; }
    }
  </style>
</head>
<body>

  <div class="matrix-grid">
    
    <div class="card-col spring-col active" onclick="selectCol(0)">
      <div class="header-block">
        <div class="title-badge">Spring</div>
      </div>
      
      <div class="cell-section">
        <div class="dim-label">1. Mechanism</div>
        <div class="val-text">Torsion Wire</div>
        <div class="sub-text">Coiled metal spring + pickup</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">2. Transient</div>
        <div class="visual-box">
          <svg class="spec" viewBox="0 0 80 30">
            
            <path d="M 5 25 Q 10 5, 15 25 T 25 25 T 35 20 T 45 18 T 55 16 T 65 15 T 75 15" fill="none" stroke="#d97706" stroke-width="2" />
            <circle cx="10" cy="15" r="2" fill="#d97706" />
          </svg>
        </div>
        <div class="sub-text">Boing / Dispersed</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">3. Frequency</div>
        <div class="val-text">Dark / Bandpass</div>
        <div class="sub-text">Lo-Fi Mid Peak (~1kHz)</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">4. Best For</div>
        <div class="tag-bubble">Guitars &amp; Dub</div>
      </div>
    </div>

    
    <div class="card-col plate-col" onclick="selectCol(1)">
      <div class="header-block">
        <div class="title-badge">Plate</div>
      </div>
      
      <div class="cell-section">
        <div class="dim-label">1. Mechanism</div>
        <div class="val-text">Suspended Sheet</div>
        <div class="sub-text">1×2m steel sheet driver</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">2. Transient</div>
        <div class="visual-box">
          <svg class="spec" viewBox="0 0 80 30">
            
            <path d="M 5 5 L 15 15 L 25 10 L 35 18 L 45 20 L 55 23 L 65 25 L 75 27" fill="none" stroke="#0284c7" stroke-width="2" />
            <line x1="5" y1="5" x2="5" y2="28" stroke="#0284c7" stroke-width="1.5" stroke-dasharray="2,2"/>
          </svg>
        </div>
        <div class="sub-text">0-Predelay Rapid Bloom</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">3. Frequency</div>
        <div class="val-text">Bright &amp; Smooth</div>
        <div class="sub-text">High-end shimmer (>5kHz)</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">4. Best For</div>
        <div class="tag-bubble">Vocals &amp; Snares</div>
      </div>
    </div>

    
    <div class="card-col chamber-col" onclick="selectCol(2)">
      <div class="header-block">
        <div class="title-badge">Chamber</div>
      </div>
      
      <div class="cell-section">
        <div class="dim-label">1. Mechanism</div>
        <div class="val-text">Concrete Bunker</div>
        <div class="sub-text">Speaker + mic in hard room</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">2. Transient</div>
        <div class="visual-box">
          <svg class="spec" viewBox="0 0 80 30">
            
            <line x1="5" y1="28" x2="5" y2="8" stroke="#059669" stroke-width="2"/>
            <line x1="18" y1="28" x2="18" y2="12" stroke="#059669" stroke-width="1.5"/>
            <line x1="28" y1="28" x2="28" y2="16" stroke="#059669" stroke-width="1.5"/>
            <path d="M 32 20 Q 50 22, 75 28" fill="none" stroke="#059669" stroke-width="1.5"/>
          </svg>
        </div>
        <div class="sub-text">Organic Early Blend</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">3. Frequency</div>
        <div class="val-text">Warm &amp; Dense</div>
        <div class="sub-text">Neutral / natural acoustic</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">4. Best For</div>
        <div class="tag-bubble">Acoustic &amp; Pop</div>
      </div>
    </div>

    
    <div class="card-col hall-col" onclick="selectCol(3)">
      <div class="header-block">
        <div class="title-badge">Hall</div>
      </div>
      
      <div class="cell-section">
        <div class="dim-label">1. Mechanism</div>
        <div class="val-text">Architectural</div>
        <div class="sub-text">Large concert auditorium</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">2. Transient</div>
        <div class="visual-box">
          <svg class="spec" viewBox="0 0 80 30">
            
            <line x1="5" y1="28" x2="5" y2="6" stroke="#7c3aed" stroke-width="2"/>
            <rect x="7" y="24" width="16" height="4" fill="#ede9fe"/>
            <path d="M 25 12 Q 45 16, 75 28" fill="none" stroke="#7c3aed" stroke-width="2"/>
          </svg>
        </div>
        <div class="sub-text">Distinct Pre-Delay (~40ms)</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">3. Frequency</div>
        <div class="val-text">Lush &amp; Balanced</div>
        <div class="sub-text">Extended low &amp; high decay</div>
      </div>

      <div class="cell-section">
        <div class="dim-label">4. Best For</div>
        <div class="tag-bubble">Strings &amp; Pads</div>
      </div>
    </div>
  </div>

  <div class="controls">
    <div class="status-text">Selected: <span id="selectedLabel">Spring Reverb</span></div>
    <button class="btn-audio" onclick="playAudition()">
      <span>Audition Profile</span> 🔊
    </button>
  </div>

  <script>
    const types = [
      { name: "Spring Reverb", freq: 440, decay: 0.6, type: 'bandpass', mod: true },
      { name: "Plate Reverb", freq: 1200, decay: 1.4, type: 'highpass', mod: false },
      { name: "Chamber Reverb", freq: 600, decay: 1.0, type: 'peaking', mod: false },
      { name: "Hall Reverb", freq: 350, decay: 2.2, type: 'lowpass', mod: false }
    ];

    let currentIndex = 0;
    const cols = document.querySelectorAll('.card-col');
    const selectedLabel = document.getElementById('selectedLabel');

    function selectCol(index) {
      currentIndex = index;
      cols.forEach((col, i) => {
        if (i === index) {
          col.classList.add('active');
        } else {
          col.classList.remove('active');
        }
      });
      selectedLabel.textContent = types[index].name;
    }

    function playAudition() {
      const cfg = types[currentIndex];
      const AudioContext = window.AudioContext || window.webkitAudioContext;
      if (!AudioContext) return;
      
      const ctx = new AudioContext();
      const now = ctx.currentTime;

      // Transient Burst
      const osc = ctx.createOscillator();
      const gain = ctx.createGain();
      const filter = ctx.createBiquadFilter();

      osc.type = currentIndex === 0 ? 'sawtooth' : 'triangle';
      osc.frequency.setValueAtTime(cfg.freq, now);

      if (cfg.mod) {
        // Dispersive twang pitch drop
        osc.frequency.exponentialRampToValueAtTime(120, now + 0.3);
      }

      filter.type = cfg.type === 'peaking' ? 'allpass' : cfg.type;
      filter.frequency.setValueAtTime(cfg.freq, now);

      // Decay Envelope
      gain.gain.setValueAtTime(0.35, now);
      if (currentIndex === 3) {
        // Hall pre-delay simulation
        gain.gain.setValueAtTime(0.01, now);
        gain.gain.setValueAtTime(0.35, now + 0.05);
      }
      gain.gain.exponentialRampToValueAtTime(0.001, now + cfg.decay);

      osc.connect(filter);
      filter.connect(gain);
      gain.connect(ctx.destination);

      osc.start(now);
      osc.stop(now + cfg.decay);
    }
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      background-color: #f8f9fa;
      color: #1e2945;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }
    .grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 12px;
      width: 100%;
      max-width: 600px;
    }
    .reverb-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      box-shadow: 0 1px 3px rgba(0,0,0,0.04);
      transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
      user-select: none;
      -webkit-tap-highlight-color: transparent;
    }
    .reverb-card:hover {
      border-color: #cbd5e1;
      box-shadow: 0 4px 12px rgba(34, 183, 255, 0.08);
    }
    .reverb-card.active {
      border-color: #22b7ff;
      box-shadow: 0 0 0 2px rgba(34, 183, 255, 0.25);
      background-color: #f0f9ff;
    }
    .visual-box {
      width: 100%;
      height: 64px;
      background: #f1f5f9;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 8px;
      position: relative;
      overflow: hidden;
    }
    .card-title {
      font-size: 15px;
      font-weight: 700;
      color: #1e2945;
      margin-bottom: 2px;
    }
    .badge-medium {
      font-size: 11px;
      font-weight: 600;
      color: #64748b;
      background: #e2e8f0;
      padding: 2px 6px;
      border-radius: 4px;
      margin-bottom: 6px;
      text-transform: uppercase;
      letter-spacing: 0.3px;
    }
    .vibe-tag {
      font-size: 12px;
      font-weight: 600;
      color: #0284c7;
      display: flex;
      align-items: center;
      gap: 4px;
    }
    .sound-btn {
      margin-top: 6px;
      font-size: 11px;
      font-weight: 600;
      color: #475569;
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      border-radius: 12px;
      padding: 3px 8px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: background 0.15s ease, color 0.15s ease;
    }
    .reverb-card.active .sound-btn {
      background: #22b7ff;
      color: #ffffff;
      border-color: #22b7ff;
    }
    
    /* Schematic SVGs */
    svg {
      width: 100%;
      height: 100%;
    }
    .stroke-main {
      stroke: #334155;
      stroke-width: 2;
      fill: none;
      stroke-linecap: round;
      stroke-linejoin: round;
    }
    .fill-accent {
      fill: #38bdf8;
    }
    .stroke-accent {
      stroke: #0284c7;
      stroke-width: 2;
      stroke-linecap: round;
    }

    @media (max-width: 380px) {
      .grid {
        grid-template-columns: 1fr;
        gap: 8px;
      }
      .visual-box {
        height: 52px;
      }
      body {
        padding: 8px;
      }
    }
  </style>
</head>
<body>

  <div class="grid">
    
    <div class="reverb-card" data-type="spring" role="button" tabindex="0">
      <div class="visual-box">
        <svg viewBox="0 0 120 50">
          
          <rect x="15" y="16" width="10" height="18" rx="2" fill="#94a3b8" />
          <rect x="95" y="16" width="10" height="18" rx="2" fill="#94a3b8" />
          
          <path d="M 25 25 Q 30 12, 35 25 T 45 25 T 55 25 T 65 25 T 75 25 T 85 25 T 95 25" 
                class="stroke-accent" fill="none" stroke-width="2.5"/>
          
          <line x1="10" y1="42" x2="110" y2="42" stroke="#cbd5e1" stroke-width="2" />
        </svg>
      </div>
      <div class="card-title">Spring</div>
      <div class="badge-medium">Mechanical</div>
      <div class="vibe-tag">✦ Twangy</div>
      <div class="sound-btn"><span>▶</span> Tap to Hear</div>
    </div>

    
    <div class="reverb-card" data-type="plate" role="button" tabindex="0">
      <div class="visual-box">
        <svg viewBox="0 0 120 50">
          
          <rect x="15" y="6" width="90" height="38" rx="2" fill="none" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="3 3"/>
          
          <rect x="25" y="11" width="70" height="28" rx="1" fill="#bae6fd" stroke="#0284c7" stroke-width="1.5"/>
          
          <line x1="15" y1="6" x2="25" y2="11" stroke="#64748b" stroke-width="1.5"/>
          <line x1="105" y1="6" x2="95" y2="11" stroke="#64748b" stroke-width="1.5"/>
          <line x1="15" y1="44" x2="25" y2="39" stroke="#64748b" stroke-width="1.5"/>
          <line x1="105" y1="44" x2="95" y2="39" stroke="#64748b" stroke-width="1.5"/>
          
          <circle cx="60" cy="25" r="3" fill="#0369a1" />
        </svg>
      </div>
      <div class="card-title">Plate</div>
      <div class="badge-medium">Electromechanical</div>
      <div class="vibe-tag">✦ Lush / Bright</div>
      <div class="sound-btn"><span>▶</span> Tap to Hear</div>
    </div>

    
    <div class="reverb-card" data-type="chamber" role="button" tabindex="0">
      <div class="visual-box">
        <svg viewBox="0 0 120 50">
          
          <rect x="20" y="8" width="80" height="34" rx="2" fill="#f8fafc" stroke="#64748b" stroke-width="2"/>
          
          <polygon points="30,21 37,17 37,33 30,29" fill="#0284c7" />
          <rect x="27" y="21" width="3" height="8" fill="#0284c7"/>
          
          <path d="M 43 21 Q 47 25 43 29" stroke="#38bdf8" stroke-width="1.5" fill="none" />
          <path d="M 48 18 Q 54 25 48 32" stroke="#38bdf8" stroke-width="1.5" fill="none" />
          
          <path d="M 52 20 L 70 10 L 80 38 L 88 25" stroke="#94a3b8" stroke-width="1" stroke-dasharray="2 2" fill="none"/>
          
          <line x1="90" y1="21" x2="90" y2="29" stroke="#1e2945" stroke-width="3" stroke-linecap="round"/>
          <circle cx="90" cy="20" r="2.5" fill="#1e2945"/>
        </svg>
      </div>
      <div class="card-title">Chamber</div>
      <div class="badge-medium">Physical Room</div>
      <div class="vibe-tag">✦ Warm / Natural</div>
      <div class="sound-btn"><span>▶</span> Tap to Hear</div>
    </div>

    
    <div class="reverb-card" data-type="hall" role="button" tabindex="0">
      <div class="visual-box">
        <svg viewBox="0 0 120 50">
          
          <path d="M 15 42 L 25 14 Q 60 6 95 14 L 105 42 Z" fill="#f1f5f9" stroke="#64748b" stroke-width="1.5"/>
          
          <rect x="42" y="36" width="36" height="6" rx="1" fill="#0284c7"/>
          
          <path d="M 50 32 Q 60 22 70 32" stroke="#38bdf8" stroke-width="1.5" fill="none"/>
          <path d="M 40 26 Q 60 12 80 26" stroke="#38bdf8" stroke-width="1.5" fill="none"/>
          <path d="M 30 20 Q 60 2 90 20" stroke="#0284c7" stroke-width="1.5" fill="none"/>
        </svg>
      </div>
      <div class="card-title">Hall</div>
      <div class="badge-medium">Architectural</div>
      <div class="vibe-tag">✦ Expansive</div>
      <div class="sound-btn"><span>▶</span> Tap to Hear</div>
    </div>
  </div>

  <script>
    let audioCtx = null;

    function getAudioContext() {
      if (!audioCtx) {
        audioCtx = new (window.AudioContext || window.webkitAudioContext)();
      }
      if (audioCtx.state === 'suspended') {
        audioCtx.resume();
      }
      return audioCtx;
    }

    function playReverbSim(type) {
      const ctx = getAudioContext();
      const now = ctx.currentTime;

      // Dry impulse click
      const imp = ctx.createBufferSource();
      const impBuf = ctx.createBuffer(1, ctx.sampleRate * 0.03, ctx.sampleRate);
      const data = impBuf.getChannelData(0);
      for (let i = 0; i < data.length; i++) {
        data[i] = (Math.random() * 2 - 1) * Math.exp(-i / (ctx.sampleRate * 0.005));
      }
      imp.buffer = impBuf;

      const masterGain = ctx.createGain();
      masterGain.connect(ctx.destination);
      masterGain.gain.setValueAtTime(0.5, now);

      imp.connect(masterGain);
      imp.start(now);

      if (type === 'spring') {
        // Twangy / boing: modulated resonant bandpass with rapid dispersion flutter
        const osc = ctx.createOscillator();
        const oscGain = ctx.createGain();
        osc.type = 'sawtooth';
        osc.frequency.setValueAtTime(140, now);
        osc.frequency.exponentialRampToValueAtTime(70, now + 0.35);

        // Chirp modulation
        const mod = ctx.createOscillator();
        mod.frequency.setValueAtTime(45, now);
        const modGain = ctx.createGain();
        modGain.gain.setValueAtTime(30, now);
        mod.connect(osc.frequency);

        oscGain.gain.setValueAtTime(0.3, now);
        oscGain.gain.exponentialRampToValueAtTime(0.001, now + 0.6);

        mod.start(now);
        osc.start(now);
        mod.stop(now + 0.6);
        osc.stop(now + 0.6);

        osc.connect(oscGain);
        oscGain.connect(masterGain);

      } else if (type === 'plate') {
        // Lush / bright high-density shimmer (filtered bright burst + long tail)
        const dur = 1.4;
        const pBuf = ctx.createBuffer(1, ctx.sampleRate * dur, ctx.sampleRate);
        const pData = pBuf.getChannelData(0);
        for (let i = 0; i < pData.length; i++) {
          pData[i] = (Math.random() * 2 - 1) * Math.exp(-i / (ctx.sampleRate * 0.35));
        }
        const pSrc = ctx.createBufferSource();
        pSrc.buffer = pBuf;

        const hp = ctx.createBiquadFilter();
        hp.type = 'highpass';
        hp.frequency.setValueAtTime(1200, now);

        const lp = ctx.createBiquadFilter();
        lp.type = 'highshelf';
        lp.frequency.setValueAtTime(4000, now);
        lp.gain.setValueAtTime(4, now);

        pSrc.connect(hp);
        hp.connect(lp);
        lp.connect(masterGain);
        pSrc.start(now);

      } else if (type === 'chamber') {
        // Warm / natural room: early reflections + moderate warm decay
        const dur = 0.9;
        const cBuf = ctx.createBuffer(1, ctx.sampleRate * dur, ctx.sampleRate);
        const cData = cBuf.getChannelData(0);
        for (let i = 0; i < cData.length; i++) {
          cData[i] = (Math.random() * 2 - 1) * Math.exp(-i / (ctx.sampleRate * 0.18));
        }
        const cSrc = ctx.createBufferSource();
        cSrc.buffer = cBuf;

        const lp = ctx.createBiquadFilter();
        lp.type = 'lowpass';
        lp.frequency.setValueAtTime(2200, now);

        cSrc.connect(lp);
        lp.connect(masterGain);
        cSrc.start(now);

      } else if (type === 'hall') {
        // Expansive: deep, delayed build, long diffuse 2.2s decay
        const dur = 2.4;
        const hBuf = ctx.createBuffer(1, ctx.sampleRate * dur, ctx.sampleRate);
        const hData = hBuf.getChannelData(0);
        const predelay = Math.floor(ctx.sampleRate * 0.04);
        for (let i = 0; i < hData.length; i++) {
          if (i < predelay) {
            hData[i] = 0;
          } else {
            hData[i] = (Math.random() * 2 - 1) * Math.exp(-(i - predelay) / (ctx.sampleRate * 0.65));
          }
        }
        const hSrc = ctx.createBufferSource();
        hSrc.buffer = hBuf;

        const lp = ctx.createBiquadFilter();
        lp.type = 'lowpass';
        lp.frequency.setValueAtTime(3200, now);
        lp.frequency.exponentialRampToValueAtTime(800, now + dur);

        hSrc.connect(lp);
        lp.connect(masterGain);
        hSrc.start(now);
      }
    }

    const cards = document.querySelectorAll('.reverb-card');
    cards.forEach(card => {
      const trigger = () => {
        cards.forEach(c => c.classList.remove('active'));
        card.classList.add('active');
        const type = card.getAttribute('data-type');
        playReverbSim(type);
      };

      card.addEventListener('click', trigger);
      card.addEventListener('keydown', (e) => {
        if (e.key === 'Enter' || e.key === ' ') {
          e.preventDefault();
          trigger();
        }
      });
    });
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: #ffffff;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      padding: 10px 12px;
      user-select: none;
    }

    .header-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 620px;
      margin-bottom: 6px;
    }

    .title-tag {
      font-size: 13px;
      font-weight: 700;
      letter-spacing: 0.5px;
      text-transform: uppercase;
      color: #64748b;
    }

    .btn-trigger {
      background: #2563eb;
      color: #ffffff;
      border: none;
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
      border-radius: 6px;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: background 0.2s, opacity 0.2s;
    }
    .btn-trigger:hover { background: #1d4ed8; }
    .btn-trigger:active { opacity: 0.85; }

    .svg-container {
      width: 100%;
      max-width: 620px;
      height: auto;
    }

    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
    }

    .label-tag {
      font-size: 11px;
      font-weight: 700;
      fill: #475569;
    }

    .signal-title {
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.3px;
    }

    /* Animation highlights */
    .pulse-glow {
      transition: stroke-width 0.2s, filter 0.2s;
    }
  </style>
</head>
<body>

  <div class="header-bar">
    <span class="title-tag">Spring Reverb Tank</span>
    <button id="triggerBtn" class="btn-trigger">Trigger Impulse 🔊</button>
  </div>

  <div class="svg-container">
    <svg viewBox="0 0 620 400">
      <defs>
        
        <linearGradient id="foamGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#475569" />
          <stop offset="100%" stop-color="#334155" />
        </linearGradient>
        <linearGradient id="driveGrad" x1="0" y1="0" x2="1" y2="0">
          <stop offset="0%" stop-color="#3b82f6" />
          <stop offset="100%" stop-color="#2563eb" />
        </linearGradient>
        <linearGradient id="pickupGrad" x1="0" y1="0" x2="1" y2="0">
          <stop offset="0%" stop-color="#6366f1" />
          <stop offset="100%" stop-color="#4f46e5" />
        </linearGradient>
      </defs>

      
      <rect x="20" y="24" width="580" height="236" rx="8" fill="#f8fafc" stroke="#94a3b8" stroke-width="2" stroke-dasharray="6,4" />
      <text x="32" y="42" class="label-tag" fill="#94a3b8">Outer Chassis</text>

      
      <rect x="36" y="222" width="46" height="24" rx="3" fill="url(#foamGrad)" />
      <rect x="538" y="222" width="46" height="24" rx="3" fill="url(#foamGrad)" />
      <text x="59" y="238" fill="#ffffff" font-size="9" font-weight="700" text-anchor="middle">Foam</text>
      <text x="561" y="238" fill="#ffffff" font-size="9" font-weight="700" text-anchor="middle">Foam</text>
      <text x="60" y="258" class="label-tag" text-anchor="middle">Damping Foam</text>

      
      
      <path d="M 58 48 L 58 54 L 54 58 L 62 64 L 54 70 L 62 76 L 58 80 L 58 86" fill="none" stroke="#64748b" stroke-width="2" />
      
      <path d="M 562 48 L 562 54 L 558 58 L 566 64 L 558 70 L 566 76 L 562 80 L 562 86" fill="none" stroke="#64748b" stroke-width="2" />
      
      <path d="M 58 190 L 58 196 L 54 200 L 62 206 L 54 212 L 62 218 L 58 222" fill="none" stroke="#64748b" stroke-width="2" />
      
      <path d="M 562 190 L 562 196 L 558 200 L 566 206 L 558 212 L 566 218 L 562 222" fill="none" stroke="#64748b" stroke-width="2" />
      <text x="562" y="44" class="label-tag" text-anchor="middle">Suspension Springs</text>

      
      <rect x="50" y="86" width="520" height="104" rx="6" fill="#ffffff" stroke="#cbd5e1" stroke-width="2" />

      
      <g id="driveCoilGroup">
        <rect x="80" y="104" width="36" height="68" rx="4" fill="url(#driveGrad)" />
        
        <line x1="80" y1="116" x2="116" y2="116" stroke="#93c5fd" stroke-width="2" />
        <line x1="80" y1="126" x2="116" y2="126" stroke="#93c5fd" stroke-width="2" />
        <line x1="80" y1="138" x2="116" y2="138" stroke="#93c5fd" stroke-width="2" />
        <line x1="80" y1="150" x2="116" y2="150" stroke="#93c5fd" stroke-width="2" />
        <line x1="80" y1="160" x2="116" y2="160" stroke="#93c5fd" stroke-width="2" />
        
        <rect x="116" y="132" width="14" height="12" rx="2" fill="#1e2945" />
      </g>
      <text x="98" y="74" class="label-tag" fill="#2563eb" text-anchor="middle">Drive Coil</text>
      <path d="M 98 78 L 98 98" stroke="#2563eb" stroke-width="1.5" stroke-dasharray="2,2" />

      
      <g id="pickupCoilGroup">
        <rect x="504" y="104" width="36" height="68" rx="4" fill="url(#pickupGrad)" />
        
        <line x1="504" y1="116" x2="540" y2="116" stroke="#c7d2fe" stroke-width="2" />
        <line x1="504" y1="126" x2="540" y2="126" stroke="#c7d2fe" stroke-width="2" />
        <line x1="504" y1="138" x2="540" y2="138" stroke="#c7d2fe" stroke-width="2" />
        <line x1="504" y1="150" x2="540" y2="150" stroke="#c7d2fe" stroke-width="2" />
        <line x1="504" y1="160" x2="540" y2="160" stroke="#c7d2fe" stroke-width="2" />
        
        <rect x="490" y="132" width="14" height="12" rx="2" fill="#1e2945" />
      </g>
      <text x="522" y="74" class="label-tag" fill="#4f46e5" text-anchor="middle">Pickup Coil</text>
      <path d="M 522 78 L 522 98" stroke="#4f46e5" stroke-width="1.5" stroke-dasharray="2,2" />

      
      <g id="springsGroup">
        
        <path id="spring1" d="" fill="none" stroke="#d97706" stroke-width="3" stroke-linecap="round" stroke-linejoin="round" />
        
        <path id="spring2" d="" fill="none" stroke="#f59e0b" stroke-width="3" stroke-linecap="round" stroke-linejoin="round" />
      </g>

      
      <g id="dispersionLabel" opacity="0.95">
        <rect x="235" y="93" width="150" height="20" rx="4" fill="#fef3c7" stroke="#f59e0b" stroke-width="1" />
        <text x="310" y="107" font-size="10" font-weight="700" fill="#b45309" text-anchor="middle">Physical Wave Dispersion</text>
      </g>

      
      
      <rect x="20" y="280" width="220" height="100" rx="8" fill="#eff6ff" stroke="#bfdbfe" stroke-width="1.5" />
      <text x="32" y="300" class="signal-title" fill="#1d4ed8">Input: Dry Pulse</text>
      
      <line x1="32" y1="350" x2="228" y2="350" stroke="#93c5fd" stroke-width="1.5" />
      <path id="inputWave" d="M 32 350 L 95 350 L 105 308 L 115 372 L 125 350 L 228 350" fill="none" stroke="#2563eb" stroke-width="2.5" stroke-linecap="round" />

      
      <g transform="translate(258, 330)">
        <circle cx="22" cy="0" r="18" fill="#fef3c7" stroke="#fde68a" stroke-width="1.5" />
        <path d="M 14 -5 L 26 0 L 14 5" fill="none" stroke="#d97706" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round" />
      </g>

      
      <rect x="320" y="280" width="280" height="100" rx="8" fill="#eef2ff" stroke="#c7d2fe" stroke-width="1.5" />
      <text x="332" y="300" class="signal-title" fill="#4338ca">Output: Dispersed "Boing"</text>
      <line x1="332" y1="350" x2="588" y2="350" stroke="#c7d2fe" stroke-width="1.5" />
      
      <path id="outputWave" d="M 332 350 L 350 350" fill="none" stroke="#4f46e5" stroke-width="2" stroke-linecap="round" />
    </svg>
  </div>

  <script>
    // Exact helical spring path generator
    function buildSpringPath(x1, y1, x2, y2, coils, radius, wavePhase = 0, waveAmp = 0) {
      const len = x2 - x1;
      const step = len / (coils * 4);
      let d = `M ${x1} ${y1}`;
      
      for (let i = 0; i <= coils * 4; i++) {
        const progress = i / (coils * 4);
        const x = x1 + i * step;
        const phase = (i % 4);
        
        // Base helical coil offset
        let dy = 0;
        if (phase === 1) dy = -radius;
        else if (phase === 3) dy = radius;
        
        // Dispersion wave packet perturbation
        const waveOffset = Math.sin(progress * Math.PI * 4 - wavePhase) * waveAmp * Math.sin(progress * Math.PI);
        
        d += ` L ${x.toFixed(1)} ${(y1 + dy + waveOffset).toFixed(1)}`;
      }
      return d;
    }

    // Static spring resting render
    const spring1 = document.getElementById('spring1');
    const spring2 = document.getElementById('spring2');
    const outputWave = document.getElementById('outputWave');

    function renderRestingSprings() {
      spring1.setAttribute('d', buildSpringPath(130, 126, 490, 126, 26, 9));
      spring2.setAttribute('d', buildSpringPath(130, 150, 490, 150, 24, 9));
    }
    renderRestingSprings();

    // Render output dispersed chirp waveform
    function buildOutputChirp() {
      const startX = 350;
      const endX = 585;
      let d = `M 332 350 L ${startX} 350`;
      
      for (let x = startX; x <= endX; x += 1.5) {
        const t = (x - startX) / (endX - startX); // 0 to 1
        // Lows early (low freq), high frequency chirp wash arrives later
        const freq = 6 + t * 42; 
        const env = Math.exp(-t * 2.8) * Math.sin(t * Math.PI * 0.95);
        const y = 350 - Math.sin(t * freq * Math.PI) * (env * 34);
        d += ` L ${x.toFixed(1)} ${y.toFixed(1)}`;
      }
      return d;
    }
    outputWave.setAttribute('d', buildOutputChirp());

    // Sound Synthesis on interaction
    function playSpringBoingSound() {
      try {
        const AudioContext = window.AudioContext || window.webkitAudioContext;
        if (!AudioContext) return;
        const ctx = new AudioContext();
        const now = ctx.currentTime;

        // Metallic resonance dispersion modes (chirp frequencies)
        const modes = [180, 290, 440, 680, 1100, 1650, 2200];
        modes.forEach((freq, idx) => {
          const osc = ctx.createOscillator();
          const gain = ctx.createGain();
          
          // Frequency sweeps slightly upward to mimic physical dispersion
          osc.frequency.setValueAtTime(freq * 0.9, now);
          osc.frequency.exponentialRampToValueAtTime(freq * 1.12, now + 0.12 + idx * 0.04);
          
          const amp = 0.08 / (idx + 1);
          gain.gain.setValueAtTime(amp, now);
          gain.gain.exponentialRampToValueAtTime(0.0001, now + 1.1 - idx * 0.08);

          osc.connect(gain);
          gain.connect(ctx.destination);
          osc.start(now);
          osc.stop(now + 1.2);
        });
      } catch (e) {
        // Fallback silently if audio context is blocked
      }
    }

    // Animation state
    let animId = null;
    let startTime = null;

    function animatePulse(timestamp) {
      if (!startTime) startTime = timestamp;
      const progress = (timestamp - startTime) / 1400; // 1.4s duration

      if (progress < 1) {
        const wavePhase = progress * Math.PI * 6;
        const amp = Math.sin(progress * Math.PI) * 8;
        
        spring1.setAttribute('d', buildSpringPath(130, 126, 490, 126, 26, 9, wavePhase, amp));
        spring2.setAttribute('d', buildSpringPath(130, 150, 490, 150, 24, 9, wavePhase + 0.5, amp * 0.9));

        // Highlight drive coil early, pickup coil late
        const driveGroup = document.getElementById('driveCoilGroup');
        const pickupGroup = document.getElementById('pickupCoilGroup');
        
        if (progress < 0.25) {
          driveGroup.setAttribute('filter', 'drop-shadow(0 0 6px #3b82f6)');
        } else {
          driveGroup.removeAttribute('filter');
        }

        if (progress > 0.65 && progress < 0.95) {
          pickupGroup.setAttribute('filter', 'drop-shadow(0 0 6px #6366f1)');
        } else {
          pickupGroup.removeAttribute('filter');
        }

        animId = requestAnimationFrame(animatePulse);
      } else {
        renderRestingSprings();
        document.getElementById('driveCoilGroup').removeAttribute('filter');
        document.getElementById('pickupCoilGroup').removeAttribute('filter');
        animId = null;
      }
    }

    const triggerBtn = document.getElementById('triggerBtn');
    triggerBtn.addEventListener('click', () => {
      playSpringBoingSound();
      if (animId) cancelAnimationFrame(animId);
      startTime = null;
      animId = requestAnimationFrame(animatePulse);
    });
  </script>
</body>
</html>

MUSTECH-2.1

Aligned learning resources

Related diagrams