<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
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      stroke-width: 3.5;
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      stroke-width: 2.5;
      stroke-dasharray: 6 5;
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      background: #f1f5f9;
      border-color: #cbd5e1;
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      color: #ffffff;
      border-color: transparent;
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    .btn-stimulus.active { background: #ea580c; }
    .btn-receptor.active { background: #0284c7; }
    .btn-control.active { background: #7c3aed; }
    .btn-effector.active { background: #059669; }

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      background: #0f172a;
      color: #ffffff;
      border-color: #0f172a;
      padding: 6px 10px;
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    .play-btn:hover {
      background: #334155;
    }
  </style>
</head>
<body>

  <div class="diagram-wrap">
    <svg viewBox="0 0 400 400">
      <defs>
        
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        </marker>
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        </marker>
      </defs>

      
      <g transform="translate(200, 200)">
        <circle r="46" fill="#ffffff" stroke="#e2e8f0" stroke-width="2" />
        <text y="-8" text-anchor="middle" font-size="11" font-weight="700" fill="#64748b" letter-spacing="0.5">SET POINT</text>
        <text y="12" text-anchor="middle" font-size="17" font-weight="800" fill="#0f172a">37°C</text>
      </g>

      
      
      <path id="path0" class="arrow-path" d="M 240 76 A 130 130 0 0 1 324 160" marker-end="url(#arrow-gray)" />

      
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        <textPath href="#textArc" startOffset="50%" text-anchor="middle">
          Corrective Response (–)
        </textPath>
      </text>

      
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        <circle class="bg" r="38" fill="#ea580c" stroke="#ffffff" stroke-width="2"/>
        <text y="-8" class="num">1</text>
        <text y="9" class="title">Stimulus</text>
      </g>

      
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        <circle class="bg" r="38" fill="#0284c7" stroke="#ffffff" stroke-width="2"/>
        <text y="-8" class="num">2</text>
        <text y="9" class="title">Receptor</text>
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        <circle class="bg" r="38" fill="#7c3aed" stroke="#ffffff" stroke-width="2"/>
        <text y="-12" class="num">3</text>
        <text y="3" class="title-sm">Control</text>
        <text y="17" class="title-sm">Center</text>
      </g>

      
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        <circle class="bg" r="38" fill="#059669" stroke="#ffffff" stroke-width="2"/>
        <text y="-8" class="num">4</text>
        <text y="9" class="title">Effector</text>
      </g>
    </svg>
  </div>

  
  <div class="controls">
    <button id="playBtn" class="btn play-btn" onclick="togglePlay()" aria-label="Play/Pause">⏸</button>
    <button class="btn btn-stimulus active" onclick="setStep(0)">1. Stimulus</button>
    <button class="btn btn-receptor" onclick="setStep(1)">2. Receptor</button>
    <button class="btn btn-control" onclick="setStep(2)">3. Control</button>
    <button class="btn btn-effector" onclick="setStep(3)">4. Effector</button>
  </div>

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</body>
</html>

System Interactions for Regulation and Homeostasis

<!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, sans-serif;
      background: #f8fafc;
      color: #1e293b;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      min-height: 100%;
    }

    .controls {
      display: flex;
      gap: 6px;
      margin-bottom: 12px;
      width: 100%;
      max-width: 440px;
      justify-content: center;
    }

    .btn {
      flex: 1;
      padding: 8px 6px;
      font-size: 13px;
      font-weight: 600;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      background: #ffffff;
      color: #475569;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      transition: all 0.2s ease;
    }

    .btn.active {
      background: #0ea5e9;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(14, 165, 233, 0.25);
    }
    .btn.active.hot-btn {
      background: #ef4444;
      border-color: #dc2626;
      box-shadow: 0 2px 6px rgba(239, 68, 68, 0.25);
    }
    .btn.active.cold-btn {
      background: #0284c7;
      border-color: #0369a1;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.25);
    }

    .diagram {
      position: relative;
      width: 100%;
      max-width: 440px;
      height: 380px;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    /* Center Target */
    .setpoint {
      position: absolute;
      top: 6px;
      left: 50%;
      transform: translateX(-50%);
      background: #ffffff;
      border: 2px solid #10b981;
      border-radius: 12px;
      padding: 6px 12px;
      text-align: center;
      box-shadow: 0 2px 8px rgba(16, 185, 129, 0.15);
      z-index: 10;
      width: 160px;
    }
    .setpoint .temp {
      font-size: 18px;
      font-weight: 800;
      color: #059669;
      line-height: 1.1;
    }
    .setpoint .label {
      font-size: 11px;
      font-weight: 700;
      color: #475569;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    /* Side Branches */
    .grid-container {
      position: absolute;
      top: 68px;
      width: 100%;
      height: 300px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
    }

    .branch {
      display: flex;
      flex-direction: column;
      gap: 6px;
      border-radius: 12px;
      padding: 8px 6px;
      transition: opacity 0.3s ease, filter 0.3s ease;
    }

    .branch.hot {
      background: rgba(254, 242, 242, 0.85);
      border: 1.5px solid #fecaca;
    }

    .branch.cold {
      background: rgba(240, 249, 255, 0.85);
      border: 1.5px solid #bae6fd;
    }

    .branch.dimmed {
      opacity: 0.25;
      filter: grayscale(0.8);
    }

    .card-item {
      background: #ffffff;
      border-radius: 8px;
      padding: 6px 8px;
      font-size: 12px;
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 6px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    }

    .hot .card-item {
      border-left: 3px solid #ef4444;
      color: #991b1b;
    }

    .cold .card-item {
      border-left: 3px solid #0284c7;
      color: #075985;
    }

    .stimulus {
      font-size: 13px;
      font-weight: 800;
      text-align: center;
      padding: 4px 6px;
      border-radius: 6px;
    }
    .hot .stimulus {
      background: #fee2e2;
      color: #b91c1c;
    }
    .cold .stimulus {
      background: #e0f2fe;
      color: #0369a1;
    }

    .sensor-tag {
      font-size: 10px;
      font-weight: 700;
      color: #64748b;
      text-align: center;
      margin: -2px 0;
    }

    .flow-arrow {
      text-align: center;
      font-size: 12px;
      line-height: 1;
      font-weight: 900;
    }
    .hot .flow-arrow { color: #ef4444; }
    .cold .flow-arrow { color: #0284c7; }

    .return-box {
      margin-top: auto;
      text-align: center;
      padding: 6px 4px;
      border-radius: 8px;
      font-size: 11px;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
    }
    .hot .return-box {
      background: #fef2f2;
      color: #b91c1c;
      border: 1px dashed #f87171;
    }
    .cold .return-box {
      background: #f0f9ff;
      color: #0369a1;
      border: 1px dashed #38bdf8;
    }
  </style>
</head>
<body>

  <div class="controls">
    <button class="btn active" id="btn-all" onclick="setMode('all')">⚖️ Both Loops</button>
    <button class="btn hot-btn" id="btn-hot" onclick="setMode('hot')">🔥 Temp Rises</button>
    <button class="btn cold-btn" id="btn-cold" onclick="setMode('cold')">❄️ Temp Falls</button>
  </div>

  <div class="diagram">
    <div class="setpoint">
      <div class="temp">37°C (98.6°F)</div>
      <div class="label">Set Point Normal</div>
    </div>

    <div class="grid-container">
      
      <div class="branch hot" id="branch-hot">
        <div class="stimulus">🔥 Temp Rises</div>
        <div class="sensor-tag">Hypothalamus 🧠</div>
        <div class="flow-arrow">▼</div>
        
        <div class="card-item">
          <span>💦</span>
          <div>Sweat Glands<br><span style="font-size:10px;font-weight:500;color:#64748b;">Evaporation</span></div>
        </div>

        <div class="card-item">
          <span>🩸</span>
          <div>Vasodilation<br><span style="font-size:10px;font-weight:500;color:#64748b;">Radiates Heat</span></div>
        </div>

        <div class="flow-arrow">▼</div>
        <div class="return-box">
          <span>❄️ Cools back to 37°C ↺</span>
        </div>
      </div>

      
      <div class="branch cold" id="branch-cold">
        <div class="stimulus">❄️ Temp Falls</div>
        <div class="sensor-tag">Hypothalamus 🧠</div>
        <div class="flow-arrow">▼</div>

        <div class="card-item">
          <span>🥶</span>
          <div>Shivering<br><span style="font-size:10px;font-weight:500;color:#64748b;">Muscle Friction</span></div>
        </div>

        <div class="card-item">
          <span>🛑</span>
          <div>Vasoconstriction<br><span style="font-size:10px;font-weight:500;color:#64748b;">Traps Core Heat</span></div>
        </div>

        <div class="flow-arrow">▼</div>
        <div class="return-box">
          <span>🔥 Warms back to 37°C ↺</span>
        </div>
      </div>
    </div>
  </div>

  <script>
    function setMode(mode) {
      const bHot = document.getElementById('branch-hot');
      const bCold = document.getElementById('branch-cold');
      const btnAll = document.getElementById('btn-all');
      const btnHot = document.getElementById('btn-hot');
      const btnCold = document.getElementById('btn-cold');

      btnAll.classList.remove('active');
      btnHot.classList.remove('active');
      btnCold.classList.remove('active');

      if (mode === 'all') {
        btnAll.classList.add('active');
        bHot.classList.remove('dimmed');
        bCold.classList.remove('dimmed');
      } else if (mode === 'hot') {
        btnHot.classList.add('active');
        bHot.classList.remove('dimmed');
        bCold.classList.add('dimmed');
      } else if (mode === 'cold') {
        btnCold.classList.add('active');
        bHot.classList.add('dimmed');
        bCold.classList.remove('dimmed');
      }
    }
  </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;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
    }

    .controls {
      display: flex;
      gap: 6px;
      width: 100%;
      max-width: 420px;
      justify-content: center;
      margin-bottom: 8px;
    }

    .btn {
      flex: 1;
      padding: 8px 4px;
      font-size: 13px;
      font-weight: 600;
      border: 1px solid #e2e8f0;
      background: #f8fafc;
      color: #475569;
      border-radius: 8px;
      cursor: pointer;
      text-align: center;
      transition: all 0.25s ease;
    }

    .btn.active-high {
      background: #ecfdf5;
      border-color: #10b981;
      color: #047857;
      box-shadow: 0 0 0 1px #10b981;
    }
    .btn.active-norm {
      background: #f0f9ff;
      border-color: #0284c7;
      color: #0369a1;
      box-shadow: 0 0 0 1px #0284c7;
    }
    .btn.active-low {
      background: #fffbeb;
      border-color: #f59e0b;
      color: #b45309;
      box-shadow: 0 0 0 1px #f59e0b;
    }

    /* Seesaw Stage */
    .scale-stage {
      position: relative;
      width: 100%;
      max-width: 360px;
      height: 150px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .seesaw-bar {
      position: absolute;
      width: 280px;
      height: 8px;
      background: #94a3b8;
      border-radius: 4px;
      top: 60px;
      transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
      transform-origin: center center;
    }

    .pan {
      position: absolute;
      width: 76px;
      height: 38px;
      border-radius: 6px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      font-size: 11px;
      font-weight: 700;
      top: -42px;
      box-shadow: 0 2px 4px rgba(0,0,0,0.06);
      transition: background 0.3s, border-color 0.3s;
    }

    .pan-left {
      left: 6px;
      background: #ffffff;
      border: 2px solid #cbd5e1;
      color: #047857;
    }
    .pan-right {
      right: 6px;
      background: #ffffff;
      border: 2px solid #cbd5e1;
      color: #b45309;
    }

    .pan-val {
      font-size: 13px;
      font-weight: 800;
    }

    .pivot {
      position: absolute;
      top: 64px;
      width: 0;
      height: 0;
      border-left: 20px solid transparent;
      border-right: 20px solid transparent;
      border-bottom: 34px solid #64748b;
      z-index: 1;
    }

    .target-badge {
      position: absolute;
      top: 102px;
      background: #0284c7;
      color: #ffffff;
      font-size: 12px;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 12px;
      letter-spacing: 0.2px;
    }

    /* Response Loop Flow */
    .flow-card {
      width: 100%;
      max-width: 420px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px 12px;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .flow-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 12px;
      font-weight: 700;
      color: #475569;
    }

    .badge-hormone {
      padding: 2px 8px;
      border-radius: 6px;
      font-size: 11px;
      font-weight: 800;
      text-transform: uppercase;
    }
    .badge-insulin { background: #d1fae5; color: #065f46; border: 1px solid #10b981; }
    .badge-glucagon { background: #fef3c7; color: #92400e; border: 1px solid #f59e0b; }
    .badge-stable { background: #e0f2fe; color: #0369a1; border: 1px solid #0284c7; }

    .steps-row {
      display: grid;
      grid-template-columns: 1fr auto 1fr auto 1fr;
      align-items: center;
      gap: 4px;
      text-align: center;
    }

    .step-box {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 6px;
      padding: 6px 4px;
      font-size: 11px;
      line-height: 1.25;
      min-height: 48px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      font-weight: 600;
      color: #334155;
    }

    .arrow {
      color: #94a3b8;
      font-size: 13px;
      font-weight: bold;
    }

    .highlight {
      font-weight: 800;
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="btn active-high" id="btnHigh" onclick="setState('high')">High (Post-Meal)</button>
    <button class="btn" id="btnNorm" onclick="setState('norm')">Target (Normal)</button>
    <button class="btn" id="btnLow" onclick="setState('low')">Low (Fasting)</button>
  </div>

  
  <div class="scale-stage">
    <div class="seesaw-bar" id="seesawBar">
      <div class="pan pan-left" id="panLeft">
        <span>Sugar</span>
        <span class="pan-val" id="valLeft">140</span>
      </div>
      <div class="pan pan-right" id="panRight">
        <span>Sugar</span>
        <span class="pan-val" id="valRight">--</span>
      </div>
    </div>
    <div class="pivot"></div>
    <div class="target-badge">Target: 90 mg/dL</div>
  </div>

  
  <div class="flow-card">
    <div class="flow-header">
      <span id="triggerText">High Blood Sugar Detected</span>
      <span class="badge-hormone badge-insulin" id="hormoneBadge">Insulin</span>
    </div>
    <div class="steps-row">
      <div class="step-box" id="step1">
        <span>Pancreas</span>
        <span class="highlight" id="cellType" style="color:#059669">Beta Cells</span>
      </div>
      <div class="arrow">➔</div>
      <div class="step-box" id="step2">
        <span>Liver Action</span>
        <span class="highlight" id="liverAction">Stores Glycogen</span>
      </div>
      <div class="arrow">➔</div>
      <div class="step-box" id="step3">
        <span>Result</span>
        <span class="highlight" id="resultAction" style="color:#059669">Sugar Falls ⬇</span>
      </div>
    </div>
  </div>

  <script>
    const data = {
      high: {
        rotate: '-14deg',
        leftVal: '140',
        rightVal: '--',
        leftBorder: '#10b981',
        rightBorder: '#cbd5e1',
        trigger: 'Blood Sugar Rises (Post-Meal)',
        badge: 'Insulin',
        badgeClass: 'badge-insulin',
        cell: 'Beta Cells',
        cellColor: '#059669',
        liver: 'Stores Glycogen',
        result: 'Sugar Falls ⬇',
        resultColor: '#059669'
      },
      norm: {
        rotate: '0deg',
        leftVal: '90',
        rightVal: '90',
        leftBorder: '#0284c7',
        rightBorder: '#0284c7',
        trigger: 'Homeostasis Maintained',
        badge: 'Balanced',
        badgeClass: 'badge-stable',
        cell: 'Sensor Cells',
        cellColor: '#0284c7',
        liver: 'Normal Output',
        result: 'Stable 90 mg/dL ✓',
        resultColor: '#0284c7'
      },
      low: {
        rotate: '14deg',
        leftVal: '--',
        rightVal: '60',
        leftBorder: '#cbd5e1',
        rightBorder: '#f59e0b',
        trigger: 'Blood Sugar Drops (Fasting)',
        badge: 'Glucagon',
        badgeClass: 'badge-glucagon',
        cell: 'Alpha Cells',
        cellColor: '#d97706',
        liver: 'Releases Glucose',
        result: 'Sugar Rises ⬆',
        resultColor: '#d97706'
      }
    };

    let curState = 'high';
    const states = ['high', 'norm', 'low'];
    let autoInterval = null;

    function setState(key, manual = true) {
      if (manual && autoInterval) {
        clearInterval(autoInterval);
        autoInterval = null;
      }
      curState = key;
      const s = data[key];

      // Update buttons
      document.getElementById('btnHigh').className = 'btn' + (key === 'high' ? ' active-high' : '');
      document.getElementById('btnNorm').className = 'btn' + (key === 'norm' ? ' active-norm' : '');
      document.getElementById('btnLow').className = 'btn' + (key === 'low' ? ' active-low' : '');

      // Update seesaw
      document.getElementById('seesawBar').style.transform = `rotate(${s.rotate})`;
      document.getElementById('valLeft').textContent = s.leftVal;
      document.getElementById('valRight').textContent = s.rightVal;
      document.getElementById('panLeft').style.borderColor = s.leftBorder;
      document.getElementById('panRight').style.borderColor = s.rightBorder;

      // Update pathway
      document.getElementById('triggerText').textContent = s.trigger;
      const badge = document.getElementById('hormoneBadge');
      badge.textContent = s.badge;
      badge.className = `badge-hormone ${s.badgeClass}`;

      const cell = document.getElementById('cellType');
      cell.textContent = s.cell;
      cell.style.color = s.cellColor;

      document.getElementById('liverAction').textContent = s.liver;

      const res = document.getElementById('resultAction');
      res.textContent = s.result;
      res.style.color = s.resultColor;
    }

    // Auto-cycle through states slowly for initial pedagogical demonstration
    let cycleIdx = 0;
    autoInterval = setInterval(() => {
      cycleIdx = (cycleIdx + 1) % states.length;
      setState(states[cycleIdx], false);
    }, 3800);

    // Initial render
    setState('high', false);
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Negative vs Positive Feedback</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      width: 100%;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #f8fafc;
      color: #1e293b;
      padding: 12px 8px;
    }
    .container {
      width: 100%;
      max-width: 680px;
      margin: 0 auto;
    }
    .grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 12px;
      width: 100%;
    }
    .feedback-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
    }
    .header-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      margin-bottom: 8px;
      gap: 6px;
    }
    .title {
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
    }
    .badge {
      font-size: 11px;
      font-weight: 700;
      padding: 2px 8px;
      border-radius: 999px;
      letter-spacing: 0.3px;
      white-space: nowrap;
    }
    .badge-neg {
      background: #e0f2fe;
      color: #0284c7;
      border: 1px solid #bae6fd;
    }
    .badge-pos {
      background: #fef3c7;
      color: #d97706;
      border: 1px solid #fde68a;
    }
    .graph-container {
      width: 100%;
      position: relative;
      background: #f8fafc;
      border-radius: 6px;
      border: 1px solid #e2e8f0;
      overflow: hidden;
    }
    svg {
      display: block;
      width: 100%;
      height: auto;
    }
    .info-footer {
      margin-top: 10px;
    }
    .main-label {
      font-size: 12.5px;
      font-weight: 700;
      color: #0f172a;
      display: flex;
      align-items: center;
      gap: 5px;
    }
    .examples {
      font-size: 11.5px;
      color: #64748b;
      margin-top: 2px;
      line-height: 1.35;
    }
    .controls {
      display: flex;
      justify-content: center;
      margin-top: 10px;
    }
    .btn-sim {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      padding: 6px 14px;
      font-size: 12.5px;
      font-weight: 600;
      color: #334155;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: background-color 0.15s, border-color 0.15s;
    }
    .btn-sim:hover {
      background-color: #f1f5f9;
      border-color: #94a3b8;
    }
    .btn-sim:active {
      background-color: #e2e8f0;
    }
  </style>
</head>
<body>

  <div class="container">
    <div class="grid">
      
      <div class="feedback-card">
        <div class="header-row">
          <span class="title">Negative Feedback</span>
          <span class="badge badge-neg">Stabilizing</span>
        </div>

        <div class="graph-container">
          <svg viewBox="0 0 300 135" id="negSvg" aria-label="Negative Feedback graph showing oscillation around a set point">
            
            <line x1="15" y1="20" x2="285" y2="20" stroke="#edf2f7" stroke-width="1" />
            <line x1="15" y1="115" x2="285" y2="115" stroke="#edf2f7" stroke-width="1" />
            
            
            <line x1="15" y1="68" x2="285" y2="68" stroke="#0284c7" stroke-width="1.5" stroke-dasharray="4 3" opacity="0.75" />
            
            
            <g transform="translate(18, 10)">
              <rect x="0" y="0" width="76" height="18" rx="4" fill="#e0f2fe" stroke="#38bdf8" stroke-width="1" />
              <text x="38" y="12.5" text-anchor="middle" fill="#0369a1" font-size="9" font-weight="700" letter-spacing="0.5">SET POINT</text>
            </g>
            
            
            <path id="negPath" d="M 15 68 Q 48.75 16, 82.5 68 T 150 68 T 217.5 68 T 285 68" fill="none" stroke="#0284c7" stroke-width="2.5" stroke-linecap="round" />
            
            
            <circle id="negDot" cx="15" cy="68" r="5" fill="#0284c7" stroke="#ffffff" stroke-width="1.5" />
          </svg>
        </div>

        <div class="info-footer">
          <div class="main-label">
            <span>🔄</span> Counteracts Change
          </div>
          <div class="examples">e.g., Body Temp, Blood Sugar, Blood Pressure</div>
        </div>
      </div>

      
      <div class="feedback-card">
        <div class="header-row">
          <span class="title">Positive Feedback</span>
          <span class="badge badge-pos">Amplifying</span>
        </div>

        <div class="graph-container">
          <svg viewBox="0 0 300 135" id="posSvg" aria-label="Positive Feedback graph showing exponential curve reaching final event">
            
            <line x1="15" y1="20" x2="285" y2="20" stroke="#edf2f7" stroke-width="1" />
            <line x1="15" y1="68" x2="285" y2="68" stroke="#edf2f7" stroke-width="1" />
            
            
            <line x1="15" y1="115" x2="285" y2="115" stroke="#94a3b8" stroke-width="1" stroke-dasharray="3 3" opacity="0.6" />
            
            
            <g transform="translate(18, 98)">
              <rect x="0" y="0" width="82" height="15" rx="3" fill="#f1f5f9" stroke="#cbd5e1" stroke-width="1" />
              <text x="41" y="11" text-anchor="middle" fill="#64748b" font-size="8.5" font-weight="600" letter-spacing="0.3">INITIAL STATE</text>
            </g>

            
            <path id="posPath" d="M 20 115 C 95 115, 175 110, 235 40" fill="none" stroke="#f59e0b" stroke-width="2.5" stroke-linecap="round" />
            
            
            <g transform="translate(180, 10)">
              <rect x="0" y="0" width="110" height="28" rx="6" fill="#fef3c7" stroke="#f59e0b" stroke-width="1.5" filter="drop-shadow(0 1px 2px rgba(245, 158, 11, 0.15))" />
              <text x="55" y="18" text-anchor="middle" fill="#b45309" font-size="9.5" font-weight="800" letter-spacing="0.5">FINAL EVENT ⚡</text>
              
              <circle cx="55" cy="29" r="2.5" fill="#f59e0b" />
            </g>
            
            
            <circle id="posDot" cx="20" cy="115" r="5" fill="#d97706" stroke="#ffffff" stroke-width="1.5" />
          </svg>
        </div>

        <div class="info-footer">
          <div class="main-label">
            <span>⚡</span> Amplifies Change toward an event
          </div>
          <div class="examples">e.g., Childbirth (Oxytocin), Blood Clotting</div>
        </div>
      </div>
    </div>

    <div class="controls">
      <button class="btn-sim" id="playToggle" onclick="toggleAnimation()" aria-label="Pause or Resume Animation">
        <span id="btnIcon">⏸</span> <span id="btnText">Pause Motion</span>
      </button>
    </div>
  </div>

  <script>
    let isPlaying = true;
    let progress = 0;
    let animId = null;

    const negPath = document.getElementById('negPath');
    const posPath = document.getElementById('posPath');
    const negDot = document.getElementById('negDot');
    const posDot = document.getElementById('posDot');
    const btnIcon = document.getElementById('btnIcon');
    const btnText = document.getElementById('btnText');

    const negLength = negPath.getTotalLength();
    const posLength = posPath.getTotalLength();

    function animateLoop() {
      if (!isPlaying) return;

      progress += 0.0035;
      if (progress > 1) {
        progress = 0;
      }

      // Update Negative Feedback Dot
      const pNeg = negPath.getPointAtLength(progress * negLength);
      negDot.setAttribute('cx', pNeg.x);
      negDot.setAttribute('cy', pNeg.y);

      // Update Positive Feedback Dot
      const pPos = posPath.getPointAtLength(progress * posLength);
      posDot.setAttribute('cx', pPos.x);
      posDot.setAttribute('cy', pPos.y);

      animId = requestAnimationFrame(animateLoop);
    }

    function toggleAnimation() {
      isPlaying = !isPlaying;
      if (isPlaying) {
        btnIcon.textContent = '⏸';
        btnText.textContent = 'Pause Motion';
        animId = requestAnimationFrame(animateLoop);
      } else {
        btnIcon.textContent = '▶';
        btnText.textContent = 'Resume Motion';
        if (animId) cancelAnimationFrame(animId);
      }
    }

    // Start motion loop
    animId = requestAnimationFrame(animateLoop);
  </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: #1e293b;
      background: transparent;
      padding: 6px;
      line-height: 1.35;
    }
    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      position: relative;
    }
    @media (max-width: 520px) {
      .comparison-grid {
        grid-template-columns: 1fr;
        gap: 16px;
      }
    }
    .system-panel {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .panel-nervous {
      border-top: 3px solid #2563eb;
    }
    .panel-endocrine {
      border-top: 3px solid #7c3aed;
    }
    .panel-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 6px;
    }
    .header-title {
      font-size: 15px;
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .nervous-title { color: #1d4ed8; }
    .endocrine-title { color: #6d28d9; }
    
    .badge {
      font-size: 11px;
      font-weight: 600;
      padding: 2px 7px;
      border-radius: 9999px;
      text-transform: uppercase;
      letter-spacing: 0.03em;
    }
    .badge-nervous {
      background: #dbeafe;
      color: #1e40af;
    }
    .badge-endocrine {
      background: #f3e8ff;
      color: #6b21a8;
    }

    .svg-container {
      width: 100%;
      background: #f8fafc;
      border-radius: 8px;
      border: 1px solid #f1f5f9;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .svg-container svg {
      width: 100%;
      height: auto;
      display: block;
    }

    /* Comparison rows */
    .data-list {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .data-row {
      display: flex;
      flex-direction: column;
      background: #f8fafc;
      padding: 6px 8px;
      border-radius: 6px;
      border-left: 2px solid #cbd5e1;
    }
    .panel-nervous .data-row { border-left-color: #93c5fd; }
    .panel-endocrine .data-row { border-left-color: #c4b5fd; }

    .data-label {
      font-size: 11px;
      font-weight: 700;
      color: #64748b;
      text-transform: uppercase;
      letter-spacing: 0.02em;
    }
    .data-val {
      font-size: 13px;
      font-weight: 600;
      color: #0f172a;
    }

    /* Nervous Animation */
    .nerve-spark {
      animation: pulseFly 1.4s ease-in-out infinite;
    }
    .target-nervous-cell {
      animation: targetFlash 1.4s ease-in-out infinite;
      transform-origin: 208px 50px;
    }

    @keyframes pulseFly {
      0% { cx: 40px; opacity: 0; }
      15% { opacity: 1; }
      75% { cx: 172px; opacity: 1; }
      85% { cx: 178px; opacity: 0; }
      100% { cx: 178px; opacity: 0; }
    }

    @keyframes targetFlash {
      0%, 72% {
        fill: #eff6ff;
        stroke: #60a5fa;
      }
      80%, 92% {
        fill: #fef08a;
        stroke: #eab308;
      }
      100% {
        fill: #eff6ff;
        stroke: #60a5fa;
      }
    }

    /* Endocrine Animation */
    .hormone-1 {
      animation: hormoneDrift1 3.6s ease-in-out infinite;
    }
    .hormone-2 {
      animation: hormoneDrift2 3.6s ease-in-out infinite;
    }
    .hormone-3 {
      animation: hormoneDrift3 3.6s ease-in-out infinite;
    }
    .target-endo-top {
      animation: receptorGlow1 3.6s ease-in-out infinite;
      transform-origin: 208px 30px;
    }
    .target-endo-bot {
      animation: receptorGlow2 3.6s ease-in-out infinite;
      transform-origin: 208px 70px;
    }

    @keyframes hormoneDrift1 {
      0% { transform: translate(0, 0); opacity: 0; }
      10% { opacity: 1; }
      50% { transform: translate(75px, 0); opacity: 1; }
      85% { transform: translate(148px, -18px); opacity: 1; }
      95%, 100% { transform: translate(154px, -18px); opacity: 0; }
    }

    @keyframes hormoneDrift2 {
      0%, 15% { transform: translate(0, 0); opacity: 0; }
      25% { opacity: 1; }
      60% { transform: translate(65px, 4px); opacity: 1; }
      88% { transform: translate(148px, 20px); opacity: 1; }
      98%, 100% { transform: translate(154px, 20px); opacity: 0; }
    }

    @keyframes hormoneDrift3 {
      0%, 30% { transform: translate(0, 0); opacity: 0; }
      40% { opacity: 1; }
      75% { transform: translate(70px, -2px); opacity: 1; }
      95% { transform: translate(120px, 0px); opacity: 0.8; }
      100% { transform: translate(130px, 0px); opacity: 0; }
    }

    @keyframes receptorGlow1 {
      0%, 75% {
        fill: #faf5ff;
        stroke: #c084fc;
      }
      85%, 95% {
        fill: #e9d5ff;
        stroke: #7c3aed;
      }
      100% {
        fill: #faf5ff;
        stroke: #c084fc;
      }
    }

    @keyframes receptorGlow2 {
      0%, 78% {
        fill: #faf5ff;
        stroke: #c084fc;
      }
      88%, 98% {
        fill: #e9d5ff;
        stroke: #7c3aed;
      }
      100% {
        fill: #faf5ff;
        stroke: #c084fc;
      }
    }
  </style>
</head>
<body>

  <div class="comparison-grid">
    
    <div class="system-panel panel-nervous">
      <div class="panel-header">
        <div class="header-title nervous-title">
          <span>⚡</span>
          <span>Nervous System</span>
        </div>
        <span class="badge badge-nervous">Direct Wire</span>
      </div>

      <div class="svg-container">
        <svg viewBox="0 0 240 100" aria-label="Neuron signaling directly to target cell">
          
          <path d="M 12 35 L 28 48 M 10 50 L 26 50 M 12 65 L 28 52" stroke="#2563eb" stroke-width="2" stroke-linecap="round"/>
          <circle cx="32" cy="50" r="12" fill="#dbeafe" stroke="#2563eb" stroke-width="2"/>
          <circle cx="32" cy="50" r="4" fill="#2563eb"/>
          
          
          <line x1="44" y1="50" x2="175" y2="50" stroke="#94a3b8" stroke-width="2.5"/>

          
          <rect x="52" y="43" width="22" height="14" rx="4" fill="#bfdbfe" stroke="#3b82f6" stroke-width="1.5"/>
          <rect x="82" y="43" width="22" height="14" rx="4" fill="#bfdbfe" stroke="#3b82f6" stroke-width="1.5"/>
          <rect x="112" y="43" width="22" height="14" rx="4" fill="#bfdbfe" stroke="#3b82f6" stroke-width="1.5"/>
          <rect x="142" y="43" width="22" height="14" rx="4" fill="#bfdbfe" stroke="#3b82f6" stroke-width="1.5"/>

          
          <path d="M 166 50 L 178 43 M 166 50 L 178 57" stroke="#2563eb" stroke-width="2" stroke-linecap="round"/>
          <circle cx="178" cy="43" r="2.5" fill="#2563eb"/>
          <circle cx="178" cy="57" r="2.5" fill="#2563eb"/>

          
          <circle id="nervousTarget" class="target-nervous-cell" cx="208" cy="50" r="16" fill="#eff6ff" stroke="#60a5fa" stroke-width="2"/>
          <circle cx="208" cy="50" r="5" fill="#93c5fd"/>
          
          
          <circle class="nerve-spark" cx="40" cy="50" r="4.5" fill="#eab308" filter="drop-shadow(0 0 3px #facc15)"/>
        </svg>
      </div>

      <div class="data-list">
        <div class="data-row">
          <span class="data-label">Signal Type</span>
          <span class="data-val">Electrical & Neurotransmitter</span>
        </div>
        <div class="data-row">
          <span class="data-label">Transmission Pathway</span>
          <span class="data-val">Direct neural axon wiring</span>
        </div>
        <div class="data-row">
          <span class="data-label">Speed & Duration</span>
          <span class="data-val">Milliseconds (Rapid / Brief)</span>
        </div>
        <div class="data-row">
          <span class="data-label">Specificity & Target</span>
          <span class="data-val">Single localized cell</span>
        </div>
      </div>
    </div>

    
    <div class="system-panel panel-endocrine">
      <div class="panel-header">
        <div class="header-title endocrine-title">
          <span>🧪</span>
          <span>Endocrine System</span>
        </div>
        <span class="badge badge-endocrine">Circulatory Broadcast</span>
      </div>

      <div class="svg-container">
        <svg viewBox="0 0 240 100" aria-label="Endocrine gland releasing hormones into bloodstream to targets">
          
          <g fill="#f3e8ff" stroke="#7c3aed" stroke-width="1.5">
            <circle cx="22" cy="40" r="8"/>
            <circle cx="28" cy="52" r="9"/>
            <circle cx="18" cy="58" r="7"/>
          </g>

          
          <rect x="42" y="34" width="140" height="32" rx="6" fill="#ffe4e6" stroke="#f43f5e" stroke-width="1.5" stroke-dasharray="4 2"/>
          
          
          <circle cx="70" cy="45" r="5" fill="#fb7185" opacity="0.6"/>
          <circle cx="115" cy="54" r="5" fill="#fb7185" opacity="0.6"/>
          <circle cx="150" cy="44" r="5" fill="#fb7185" opacity="0.6"/>

          
          
          <g class="target-endo-top">
            <circle cx="208" cy="30" r="14" fill="#faf5ff" stroke="#c084fc" stroke-width="2"/>
            <circle cx="208" cy="30" r="4" fill="#d8b4fe"/>
            
            <path d="M 194 30 L 199 27 L 199 33 Z" fill="#7c3aed"/>
          </g>

          
          <g class="target-endo-bot">
            <circle cx="208" cy="70" r="14" fill="#faf5ff" stroke="#c084fc" stroke-width="2"/>
            <circle cx="208" cy="70" r="4" fill="#d8b4fe"/>
            
            <path d="M 194 70 L 199 67 L 199 73 Z" fill="#7c3aed"/>
          </g>

          
          <g>
            <circle class="hormone-1" cx="36" cy="48" r="3.5" fill="#7c3aed"/>
            <circle class="hormone-2" cx="36" cy="52" r="3.5" fill="#9333ea"/>
            <circle class="hormone-3" cx="36" cy="46" r="3" fill="#6b21a8"/>
          </g>
        </svg>
      </div>

      <div class="data-list">
        <div class="data-row">
          <span class="data-label">Signal Type</span>
          <span class="data-val">Chemical hormones</span>
        </div>
        <div class="data-row">
          <span class="data-label">Transmission Pathway</span>
          <span class="data-val">Bloodstream circulation</span>
        </div>
        <div class="data-row">
          <span class="data-label">Speed & Duration</span>
          <span class="data-val">Minutes to Hours (Sustained)</span>
        </div>
        <div class="data-row">
          <span class="data-label">Specificity & Target</span>
          <span class="data-val">Widespread cells with receptors</span>
        </div>
      </div>
    </div>
  </div>

</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Neuroendocrine Bridge</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }
    body {
      background: #ffffff;
      color: #0f172a;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      width: 100%;
      padding: 8px;
      user-select: none;
    }

    .stepper-nav {
      display: flex;
      gap: 6px;
      width: 100%;
      max-width: 360px;
      margin-bottom: 4px;
    }

    .step-btn {
      flex: 1;
      border: 1.5px solid #cbd5e1;
      background: #f8fafc;
      color: #334155;
      font-size: 10.5px;
      font-weight: 700;
      padding: 6px 2px;
      border-radius: 6px;
      cursor: pointer;
      text-align: center;
      transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
      line-height: 1.2;
    }

    .step-btn:hover {
      background: #f1f5f9;
      border-color: #94a3b8;
    }

    .step-btn.active {
      background: #eff6ff;
      border-color: #1d4ed8;
      color: #1e40af;
      box-shadow: 0 0 0 1.5px #1d4ed8;
    }

    .step-btn.step-2-btn.active {
      background: #fffbeb;
      border-color: #b45309;
      color: #78350f;
      box-shadow: 0 0 0 1.5px #b45309;
    }

    .step-btn.step-3-btn.active {
      background: #fdf2f8;
      border-color: #be185d;
      color: #831843;
      box-shadow: 0 0 0 1.5px #be185d;
    }

    .diagram-svg {
      width: 100%;
      max-width: 360px;
      height: auto;
      display: block;
    }

    /* Interactive state styles */
    .neural-group, .hypo-group, .pituitary-group, .target-group {
      transition: opacity 0.25s ease, filter 0.25s ease;
    }

    .dimmed {
      opacity: 0.3;
    }

    .highlight-neural {
      filter: drop-shadow(0 0 4px #2563eb);
    }

    .highlight-hypo {
      filter: drop-shadow(0 0 5px #d97706);
    }

    .highlight-pituitary {
      filter: drop-shadow(0 0 5px #db2777);
    }

    /* Hormone pulse flow */
    @keyframes pulseHormone {
      0% { stroke-dashoffset: 24; }
      100% { stroke-dashoffset: 0; }
    }

    .hormone-flow {
      stroke-dasharray: 4, 4;
      animation: pulseHormone 1s linear infinite;
    }

    .hormone-flow.paused {
      animation-play-state: paused;
    }
  </style>
</head>
<body>

  
  <div class="stepper-nav">
    <button class="step-btn step-1-btn active" onclick="setStep(0)">1. Neural Detection</button>
    <button class="step-btn step-2-btn" onclick="setStep(1)">2. Hypothalamic Integration</button>
    <button class="step-btn step-3-btn" onclick="setStep(2)">3. Endocrine Command</button>
  </div>

  
  <svg class="diagram-svg" viewBox="0 0 360 295">
    
    <path d="M 75,100 C 65,40 135,18 180,18 C 240,18 285,48 280,108 C 275,138 235,152 215,152 L 215,170 L 195,170 L 195,138 C 160,138 95,138 75,100 Z"
          fill="#f1f5f9" stroke="#94a3b8" stroke-width="2" stroke-dasharray="none" />
    <text x="245" y="44" font-size="11" font-weight="700" fill="#475569">Brain</text>

    
    <g id="neuralGroup" class="neural-group">
      
      <path d="M 28,66 Q 85,66 142,82" fill="none" stroke="#2563eb" stroke-width="2.5" stroke-dasharray="4,3" />
      <path d="M 28,94 Q 85,92 142,88" fill="none" stroke="#2563eb" stroke-width="2.5" stroke-dasharray="4,3" />
      
      <circle cx="28" cy="66" r="4.5" fill="#1d4ed8" />
      <circle cx="28" cy="94" r="4.5" fill="#1d4ed8" />
      
      <text x="28" y="52" font-size="11.5" font-weight="800" fill="#1e40af">⚡ Sensory Nerves</text>
      <text x="134" y="74" font-size="12" font-weight="800" fill="#1d4ed8">→</text>
    </g>

    
    <g id="hypoGroup" class="hypo-group">
      <ellipse cx="170" cy="86" rx="28" ry="16" fill="#fef3c7" stroke="#b45309" stroke-width="2.5" />
      <text x="170" y="90" font-size="10" font-weight="800" fill="#78350f" text-anchor="middle">Hypothalamus</text>
      
      <line x1="170" y1="102" x2="170" y2="117" stroke="#b45309" stroke-width="3.5" stroke-linecap="round" />
    </g>

    
    <g id="pituitaryGroup" class="pituitary-group">
      <ellipse cx="170" cy="129" rx="19" ry="12" fill="#fce7f3" stroke="#be185d" stroke-width="2.5" />
      <text x="170" y="133" font-size="9.5" font-weight="800" fill="#831843" text-anchor="middle">Pituitary</text>
    </g>

    
    <g id="targetGroup" class="target-group">
      
      <path d="M 170,141 L 170,166" stroke="#e11d48" stroke-width="4" stroke-linecap="round" />
      
      
      <path d="M 170,166 C 170,190 65,185 65,214" fill="none" stroke="#e11d48" stroke-width="3" />
      <path d="M 170,166 L 170,214" fill="none" stroke="#e11d48" stroke-width="3" />
      <path d="M 170,166 C 170,190 275,185 275,214" fill="none" stroke="#e11d48" stroke-width="3" />

      
      <path id="flowLeft" class="hormone-flow" d="M 170,141 C 170,190 65,185 65,214" fill="none" stroke="#ffffff" stroke-width="2" />
      <path id="flowMid" class="hormone-flow" d="M 170,141 L 170,214" fill="none" stroke="#ffffff" stroke-width="2" />
      <path id="flowRight" class="hormone-flow" d="M 170,141 C 170,190 275,185 275,214" fill="none" stroke="#ffffff" stroke-width="2" />

      
      <rect x="115" y="155" width="110" height="20" rx="10" fill="#ffe4e6" stroke="#e11d48" stroke-width="1.5"/>
      <text x="170" y="169" font-size="10" font-weight="800" fill="#9f1239" text-anchor="middle">🩸 Bloodstream</text>

      
      
      <g transform="translate(23, 214)">
        <rect width="84" height="48" rx="7" fill="#f8fafc" stroke="#64748b" stroke-width="1.5" />
        <text x="42" y="21" font-size="15" text-anchor="middle">🦋</text>
        <text x="42" y="38" font-size="11" font-weight="800" fill="#0f172a" text-anchor="middle">Thyroid</text>
      </g>

      
      <g transform="translate(138, 214)">
        <rect width="84" height="48" rx="7" fill="#f8fafc" stroke="#64748b" stroke-width="1.5" />
        <text x="42" y="21" font-size="15" text-anchor="middle">⚡</text>
        <text x="42" y="38" font-size="11" font-weight="800" fill="#0f172a" text-anchor="middle">Adrenals</text>
      </g>

      
      <g transform="translate(253, 214)">
        <rect width="84" height="48" rx="7" fill="#f8fafc" stroke="#64748b" stroke-width="1.5" />
        <text x="42" y="21" font-size="15" text-anchor="middle">🫘</text>
        <text x="42" y="38" font-size="11" font-weight="800" fill="#0f172a" text-anchor="middle">Kidneys</text>
      </g>
      
      
      <text x="180" y="282" font-size="11" font-weight="700" fill="#1e293b" text-anchor="middle">Downstream Target Organs</text>
    </g>
  </svg>

  <script>
    let currentStep = 0;
    let timer = null;

    const neuralGroup = document.getElementById('neuralGroup');
    const hypoGroup = document.getElementById('hypoGroup');
    const pituitaryGroup = document.getElementById('pituitaryGroup');
    const targetGroup = document.getElementById('targetGroup');
    const stepBtns = document.querySelectorAll('.step-btn');
    const hormoneFlows = document.querySelectorAll('.hormone-flow');

    function updateView() {
      // Button states
      stepBtns.forEach((btn, idx) => {
        btn.classList.toggle('active', idx === currentStep);
      });

      // Clear highlights & dimmed classes
      neuralGroup.className = 'neural-group';
      hypoGroup.className = 'hypo-group';
      pituitaryGroup.className = 'pituitary-group';
      targetGroup.className = 'target-group';

      hormoneFlows.forEach(f => f.classList.remove('paused'));

      if (currentStep === 0) {
        // Step 1: Neural Detection
        neuralGroup.classList.add('highlight-neural');
        hypoGroup.classList.add('dimmed');
        pituitaryGroup.classList.add('dimmed');
        targetGroup.classList.add('dimmed');
        hormoneFlows.forEach(f => f.classList.add('paused'));
      } else if (currentStep === 1) {
        // Step 2: Hypothalamic Integration
        neuralGroup.classList.add('dimmed');
        hypoGroup.classList.add('highlight-hypo');
        pituitaryGroup.classList.add('dimmed');
        targetGroup.classList.add('dimmed');
        hormoneFlows.forEach(f => f.classList.add('paused'));
      } else if (currentStep === 2) {
        // Step 3: Pituitary & Endocrine Command
        neuralGroup.classList.add('dimmed');
        hypoGroup.classList.add('dimmed');
        pituitaryGroup.classList.add('highlight-pituitary');
      }
    }

    function setStep(idx) {
      currentStep = idx;
      updateView();
      resetTimer();
    }

    function nextStep() {
      currentStep = (currentStep + 1) % 3;
      updateView();
    }

    function resetTimer() {
      if (timer) clearInterval(timer);
      timer = setInterval(nextStep, 3500);
    }

    // Initialize
    updateView();
    resetTimer();
  </script>
</body>
</html>

112.43(b)(12)(A)

Aligned learning resources

Related diagrams