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

    .selector-bar {
      display: flex;
      flex-wrap: wrap;
      gap: 6px;
      justify-content: center;
      width: 100%;
      max-width: 580px;
      margin-bottom: 6px;
    }

    .iso-btn {
      appearance: none;
      border: 1.5px solid #cbd5e1;
      background: #f8fafc;
      color: #334155;
      padding: 4px 9px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      transition: background-color 0.15s, border-color 0.15s, color 0.15s;
    }

    .iso-btn:hover {
      background: #e2e8f0;
      border-color: #94a3b8;
    }

    .iso-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 1px 3px rgba(2, 132, 199, 0.3);
    }

    .chart-container {
      position: relative;
      width: 100%;
      max-width: 580px;
      margin: 0 auto;
    }

    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
      user-select: none;
    }

    .axis-label {
      font-size: 11.5px;
      font-weight: 700;
      fill: #334155;
    }

    .tick-label {
      font-size: 9.5px;
      fill: #64748b;
    }

    .region-label {
      font-size: 10.5px;
      font-weight: 700;
      text-anchor: middle;
      pointer-events: none;
    }

    .region-sub {
      font-size: 9px;
      font-weight: 500;
      text-anchor: middle;
      pointer-events: none;
    }

    .iso-marker {
      cursor: pointer;
    }

    .iso-marker:hover circle.marker-dot {
      stroke-width: 2.5;
      stroke: #0284c7;
    }

    .info-card {
      width: 100%;
      max-width: 580px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 8px 12px;
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: space-between;
      gap: 6px 12px;
      margin-top: 6px;
      font-size: 12.5px;
    }

    .info-title {
      font-weight: 800;
      color: #0f172a;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .badge {
      display: inline-block;
      padding: 2px 7px;
      border-radius: 4px;
      font-size: 11px;
      font-weight: 700;
    }

    .badge-stable { background: #dcfce7; color: #15803d; }
    .badge-beta-minus { background: #dbeafe; color: #1d4ed8; }
    .badge-beta-plus { background: #ffedd5; color: #c2410c; }
    .badge-alpha { background: #f3e8ff; color: #7e22ce; }

    .info-stats {
      color: #475569;
      font-size: 12px;
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
    }

    .info-stats strong {
      color: #0f172a;
    }

    @media (max-width: 420px) {
      .info-card {
        flex-direction: column;
        align-items: flex-start;
      }
      .axis-label {
        font-size: 10.5px;
      }
    }
  </style>
</head>
<body>

  <div class="selector-bar" id="buttonGroup">
    <button class="iso-btn active" data-id="c12">¹²C (Stable)</button>
    <button class="iso-btn" data-id="c14">¹⁴C (β⁻)</button>
    <button class="iso-btn" data-id="c11">¹¹C (β⁺)</button>
    <button class="iso-btn" data-id="pb208">²⁰⁸Pb (Stable)</button>
    <button class="iso-btn" data-id="u238">²³⁸U (α)</button>
  </div>

  <div class="chart-container">
    <svg viewBox="0 0 560 375" id="stabilityChart">
      <defs>
        <linearGradient id="bgGrad" x1="0" y1="0" x2="1" y2="1">
          <stop offset="0%" stop-color="#ffffff"/>
          <stop offset="100%" stop-color="#f8fafc"/>
        </linearGradient>
      </defs>

      
      <rect x="55" y="25" width="480" height="310" fill="url(#bgGrad)" stroke="#cbd5e1" stroke-width="1"/>

      
      <g stroke="#f1f5f9" stroke-width="1">
        <line x1="55" y1="276.9" x2="535" y2="276.9"/>
        <line x1="55" y1="218.8" x2="535" y2="218.8"/>
        <line x1="55" y1="160.6" x2="535" y2="160.6"/>
        <line x1="55" y1="102.5" x2="535" y2="102.5"/>
        <line x1="55" y1="44.4" x2="535" y2="44.4"/>
        
        <line x1="151" y1="25" x2="151" y2="335"/>
        <line x1="247" y1="25" x2="247" y2="335"/>
        <line x1="343" y1="25" x2="343" y2="335"/>
        <line x1="439" y1="25" x2="439" y2="335"/>
      </g>

      
      <rect x="448.6" y="25" width="86.4" height="310" fill="#faf5ff" opacity="0.85"/>
      <line x1="448.6" y1="25" x2="448.6" y2="335" stroke="#a855f7" stroke-width="1.5" stroke-dasharray="3 3"/>

      
      
      <path d="M 55 335 L 55 25 L 448.6 25 L 448.6 82 C 380 145, 290 220, 200 270 C 120 310, 80 325, 55 335 Z" fill="#eff6ff" opacity="0.85"/>
      
      <path d="M 55 335 C 80 328, 120 316, 200 280 C 290 234, 380 165, 448.6 100 L 448.6 335 Z" fill="#fff7ed" opacity="0.85"/>

      
      <line x1="55" y1="335" x2="535" y2="141.25" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="5 4"/>
      <text x="530" y="133" fill="#64748b" font-size="10" font-weight="700" text-anchor="end">N = Z</text>

      
      <path id="stableBand" d="
        M 55 335 
        C 90 324, 155 292, 230 245
        C 310 195, 385 140, 448.6 83
        L 448.6 99
        C 385 154, 310 208, 230 257
        C 155 302, 90 331, 55 335 Z" 
        fill="#10b981" stroke="#059669" stroke-width="1.5" opacity="0.9"/>

      
      <g>
        
        <text x="215" y="110" class="region-label" fill="#1d4ed8">Neutron-Rich</text>
        <text x="215" y="124" class="region-sub" fill="#3b82f6">β⁻ Decay (n → p + e⁻)</text>
        
        
        <text x="325" y="285" class="region-label" fill="#c2410c">Proton-Rich</text>
        <text x="325" y="299" class="region-sub" fill="#ea580c">β⁺ Decay / Electron Capture</text>
        
        
        <text x="492" y="175" class="region-label" fill="#7e22ce">Z &gt; 82</text>
        <text x="492" y="189" class="region-sub" fill="#9333ea">Heavy (α Decay)</text>

        
        <text x="270" y="222" fill="#065f46" font-size="10" font-weight="800" transform="rotate(-33 270 222)">Band of Stability</text>
      </g>

      
      <line x1="55" y1="25" x2="55" y2="335" stroke="#334155" stroke-width="1.5"/>
      <line x1="55" y1="335" x2="535" y2="335" stroke="#334155" stroke-width="1.5"/>

      
      
      <text x="47" y="339" class="tick-label" text-anchor="end">0</text>
      <text x="47" y="280.5" class="tick-label" text-anchor="end">30</text>
      <line x1="51" y1="276.9" x2="55" y2="276.9" stroke="#334155"/>
      <text x="47" y="222.5" class="tick-label" text-anchor="end">60</text>
      <line x1="51" y1="218.8" x2="55" y2="218.8" stroke="#334155"/>
      <text x="47" y="164.2" class="tick-label" text-anchor="end">90</text>
      <line x1="51" y1="160.6" x2="55" y2="160.6" stroke="#334155"/>
      <text x="47" y="106" class="tick-label" text-anchor="end">120</text>
      <line x1="51" y1="102.5" x2="55" y2="102.5" stroke="#334155"/>
      <text x="47" y="48" class="tick-label" text-anchor="end">150</text>
      <line x1="51" y1="44.4" x2="55" y2="44.4" stroke="#334155"/>

      
      
      <text x="55" y="348" class="tick-label" text-anchor="middle">0</text>
      <text x="151" y="348" class="tick-label" text-anchor="middle">20</text>
      <line x1="151" y1="335" x2="151" y2="339" stroke="#334155"/>
      <text x="247" y="348" class="tick-label" text-anchor="middle">40</text>
      <line x1="247" y1="335" x2="247" y2="339" stroke="#334155"/>
      <text x="343" y="348" class="tick-label" text-anchor="middle">60</text>
      <line x1="343" y1="335" x2="343" y2="339" stroke="#334155"/>
      <text x="439" y="348" class="tick-label" text-anchor="middle">80</text>
      <line x1="439" y1="335" x2="439" y2="339" stroke="#334155"/>
      <text x="448.6" y="360" class="tick-label" text-anchor="middle" font-weight="700" fill="#7e22ce">Pb-82</text>
      <line x1="448.6" y1="335" x2="448.6" y2="342" stroke="#7e22ce" stroke-width="1.5"/>
      <text x="535" y="348" class="tick-label" text-anchor="middle">100</text>
      <line x1="535" y1="335" x2="535" y2="339" stroke="#334155"/>

      
      <text x="295" y="368" class="axis-label" text-anchor="middle">Protons (Z)</text>
      <text x="15" y="180" class="axis-label" text-anchor="middle" transform="rotate(-90 15 180)">Neutrons (N)</text>

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

  
  <div class="info-card" id="infoCard">
    <div class="info-title">
      <span id="cardName">Carbon-12 (¹²C)</span>
      <span class="badge badge-stable" id="cardBadge">Stable</span>
    </div>
    <div class="info-stats">
      <span>Z: <strong id="cardZ">6</strong></span>
      <span>N: <strong id="cardN">6</strong></span>
      <span>N/Z Ratio: <strong id="cardRatio">1.00</strong></span>
    </div>
  </div>

  <script>
    const isotopes = {
      c14: { 
        name: 'Carbon-14 (¹⁴C)', 
        short: '¹⁴C',
        z: 6, n: 8, 
        mode: 'β⁻ Decay', 
        type: 'beta-minus',
        labelPos: { lx: 64, ly: 295, tx: 60, ty: 292, anchor: 'end' }
      },
      c12: { 
        name: 'Carbon-12 (¹²C)', 
        short: '¹²C',
        z: 6, n: 6, 
        mode: 'Stable', 
        type: 'stable',
        labelPos: { lx: 106, ly: 318, tx: 110, ty: 321, anchor: 'start' }
      },
      c11: { 
        name: 'Carbon-11 (¹¹C)', 
        short: '¹¹C',
        z: 6, n: 5, 
        mode: 'β⁺ Decay / EC', 
        type: 'beta-plus',
        labelPos: { lx: 80, ly: 348, tx: 76, ty: 356, anchor: 'end' }
      },
      pb208: { 
        name: 'Lead-208 (²⁰⁸Pb)', 
        short: '²⁰⁸Pb',
        z: 82, n: 126, 
        mode: 'Stable (Band End)', 
        type: 'stable',
        labelPos: { lx: 432, ly: 90.9, tx: 428, ty: 88, anchor: 'end' }
      },
      u238: { 
        name: 'Uranium-238 (²³⁸U)', 
        short: '²³⁸U',
        z: 92, n: 146, 
        mode: 'α Decay', 
        type: 'alpha',
        labelPos: { lx: 485, ly: 52.1, tx: 480, ty: 49, anchor: 'end' }
      }
    };

    function mapZ(z) { return 55 + (z / 100) * 480; }
    function mapN(n) { return 335 - (n / 160) * 310; }

    const isoGroup = document.getElementById('isoPoints');

    Object.keys(isotopes).forEach(key => {
      const d = isotopes[key];
      const cx = mapZ(d.z);
      const cy = mapN(d.n);

      const g = document.createElementNS('http://www.w3.org/2000/svg', 'g');
      g.setAttribute('class', 'iso-marker');
      g.setAttribute('id', 'marker-' + key);
      g.onclick = () => selectIsotope(key);

      // Leader line for collision avoidance if defined
      if (d.labelPos.lx !== undefined) {
        const line = document.createElementNS('http://www.w3.org/2000/svg', 'line');
        line.setAttribute('x1', cx);
        line.setAttribute('y1', cy);
        line.setAttribute('x2', d.labelPos.lx);
        line.setAttribute('y2', d.labelPos.ly);
        line.setAttribute('stroke', '#64748b');
        line.setAttribute('stroke-width', '1');
        line.setAttribute('stroke-dasharray', '2 2');
        g.appendChild(line);
      }

      // Pulse ring for selection
      const ring = document.createElementNS('http://www.w3.org/2000/svg', 'circle');
      ring.setAttribute('cx', cx);
      ring.setAttribute('cy', cy);
      ring.setAttribute('r', '9');
      ring.setAttribute('fill', 'none');
      ring.setAttribute('stroke', '#0284c7');
      ring.setAttribute('stroke-width', '2');
      ring.setAttribute('opacity', key === 'c12' ? '1' : '0');
      ring.setAttribute('class', 'marker-ring');

      // Center dot
      const dot = document.createElementNS('http://www.w3.org/2000/svg', 'circle');
      dot.setAttribute('cx', cx);
      dot.setAttribute('cy', cy);
      dot.setAttribute('r', '4.5');
      dot.setAttribute('class', 'marker-dot');
      const dotColor = d.type === 'stable' ? '#059669' : (d.type === 'beta-minus' ? '#2563eb' : (d.type === 'beta-plus' ? '#ea580c' : '#9333ea'));
      dot.setAttribute('fill', dotColor);
      dot.setAttribute('stroke', '#ffffff');
      dot.setAttribute('stroke-width', '1.5');

      // Text label with distinct position
      const txt = document.createElementNS('http://www.w3.org/2000/svg', 'text');
      txt.setAttribute('x', d.labelPos.tx);
      txt.setAttribute('y', d.labelPos.ty);
      txt.setAttribute('font-size', '10.5');
      txt.setAttribute('font-weight', '700');
      txt.setAttribute('fill', '#0f172a');
      txt.setAttribute('text-anchor', d.labelPos.anchor);
      txt.textContent = d.short;

      g.appendChild(ring);
      g.appendChild(dot);
      g.appendChild(txt);
      isoGroup.appendChild(g);
    });

    function selectIsotope(id) {
      const data = isotopes[id];
      if (!data) return;

      // Update button styles
      document.querySelectorAll('.iso-btn').forEach(btn => {
        btn.classList.toggle('active', btn.dataset.id === id);
      });

      // Update marker highlight rings
      Object.keys(isotopes).forEach(key => {
        const marker = document.getElementById('marker-' + key);
        const ring = marker.querySelector('.marker-ring');
        ring.setAttribute('opacity', key === id ? '1' : '0');
      });

      // Update badge card
      document.getElementById('cardName').textContent = data.name;
      document.getElementById('cardZ').textContent = data.z;
      document.getElementById('cardN').textContent = data.n;
      document.getElementById('cardRatio').textContent = (data.n / data.z).toFixed(2);
      
      const badge = document.getElementById('cardBadge');
      badge.textContent = data.mode;
      badge.className = 'badge badge-' + data.type;
    }

    document.querySelectorAll('.iso-btn').forEach(btn => {
      btn.onclick = () => selectIsotope(btn.dataset.id);
    });
  </script>
</body>
</html>

Nuclear Stability and the Band of Stability

<!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: #f8f9fa;
      font-family: system-ui, -apple-system, sans-serif;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .controls {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 8px 14px;
    }

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

    .slider-label {
      font-size: 13px;
      font-weight: 700;
      white-space: nowrap;
    }

    input[type=range] {
      flex: 1;
      accent-color: #2563eb;
      cursor: pointer;
    }

    .status-badge {
      font-size: 12px;
      font-weight: 800;
      letter-spacing: 0.5px;
      padding: 4px 10px;
      border-radius: 20px;
      transition: background 0.2s, color 0.2s;
    }
    .status-badge.stable {
      background: #dcfce7;
      color: #166534;
    }
    .status-badge.unstable {
      background: #fee2e2;
      color: #991b1b;
    }

    .card-grid {
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .force-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 14px;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .card-header {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
      font-size: 13px;
      font-weight: 700;
    }

    .card-subtitle {
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
    }

    .canvas-box {
      width: 100%;
      height: 100px;
      position: relative;
    }

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

    .nucleon {
      transition: cx 0.15s ease-out;
    }

    .force-arrow, .force-spring {
      transition: all 0.15s ease-out;
    }
  </style>
</head>
<body>

  <div class="controls">
    <div class="slider-row">
      <span class="slider-label">Separation: <span id="distVal">1.5</span> fm</span>
      <input type="range" id="distSlider" min="1.0" max="4.5" step="0.1" value="1.5">
    </div>
    <span id="statusBadge" class="status-badge stable">STABLE</span>
  </div>

  <div class="card-grid">
    
    <div class="force-card">
      <div class="card-header">
        <span style="color: #dc2626;">Electrostatic Repulsion</span>
        <span class="card-subtitle">Long-range (active)</span>
      </div>
      <div class="canvas-box">
        <svg viewBox="0 0 400 90" id="svgElectro">
          <defs>
            <marker id="arrRedL" markerWidth="8" markerHeight="8" refX="2" refY="4" orient="auto">
              <path d="M7,1 L2,4 L7,7 Z" fill="#ef4444"/>
            </marker>
            <marker id="arrRedR" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
              <path d="M1,1 L6,4 L1,7 Z" fill="#ef4444"/>
            </marker>
          </defs>

          
          <line id="repelLeft" x1="150" y1="45" x2="80" y2="45" stroke="#ef4444" stroke-width="4" marker-end="url(#arrRedL)"/>
          <line id="repelRight" x1="250" y1="45" x2="320" y2="45" stroke="#ef4444" stroke-width="4" marker-end="url(#arrRedR)"/>

          
          <g id="p1Group" transform="translate(160, 45)">
            <circle r="22" fill="#fee2e2" stroke="#ef4444" stroke-width="3"/>
            <text text-anchor="middle" dy="6" font-size="18" font-weight="bold" fill="#dc2626">p⁺</text>
          </g>

          <g id="p2Group" transform="translate(240, 45)">
            <circle r="22" fill="#fee2e2" stroke="#ef4444" stroke-width="3"/>
            <text text-anchor="middle" dy="6" font-size="18" font-weight="bold" fill="#dc2626">p⁺</text>
          </g>
        </svg>
      </div>
    </div>

    
    <div class="force-card">
      <div class="card-header">
        <span style="color: #16a34a;">Strong Nuclear Force</span>
        <span id="strongSub" class="card-subtitle" style="color: #16a34a;">Active (&lt; 3 fm)</span>
      </div>
      <div class="canvas-box">
        <svg viewBox="0 0 400 90" id="svgStrong">
          <defs>
            <marker id="arrGrnInL" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
              <path d="M1,1 L6,4 L1,7 Z" fill="#16a34a"/>
            </marker>
            <marker id="arrGrnInR" markerWidth="8" markerHeight="8" refX="2" refY="4" orient="auto">
              <path d="M7,1 L2,4 L7,7 Z" fill="#16a34a"/>
            </marker>
          </defs>

          
          <path id="springPath" d="" fill="none" stroke="#16a34a" stroke-width="4" stroke-linecap="round" stroke-linejoin="round"/>
          
          
          <line id="attrLeft" x1="110" y1="45" x2="135" y2="45" stroke="#16a34a" stroke-width="3" marker-end="url(#arrGrnInL)"/>
          <line id="attrRight" x1="290" y1="45" x2="265" y2="45" stroke="#16a34a" stroke-width="3" marker-end="url(#arrGrnInR)"/>

          
          <g id="spGroup" transform="translate(160, 45)">
            <circle r="22" fill="#fee2e2" stroke="#ef4444" stroke-width="3"/>
            <text text-anchor="middle" dy="6" font-size="18" font-weight="bold" fill="#dc2626">p⁺</text>
          </g>

          
          <g id="snGroup" transform="translate(240, 45)">
            <circle r="22" fill="#e0f2fe" stroke="#0284c7" stroke-width="3"/>
            <text text-anchor="middle" dy="6" font-size="18" font-weight="bold" fill="#0369a1">n⁰</text>
          </g>
        </svg>
      </div>
    </div>
  </div>

  <script>
    const slider = document.getElementById('distSlider');
    const distVal = document.getElementById('distVal');
    const statusBadge = document.getElementById('statusBadge');
    const strongSub = document.getElementById('strongSub');

    const p1Group = document.getElementById('p1Group');
    const p2Group = document.getElementById('p2Group');
    const repelLeft = document.getElementById('repelLeft');
    const repelRight = document.getElementById('repelRight');

    const spGroup = document.getElementById('spGroup');
    const snGroup = document.getElementById('snGroup');
    const springPath = document.getElementById('springPath');
    const attrLeft = document.getElementById('attrLeft');
    const attrRight = document.getElementById('attrRight');

    function update(d) {
      distVal.textContent = d.toFixed(1);

      // Center is at X=200. Nucleons shift symmetrically with distance
      // d ranges 1.0 to 4.5 -> gap ranges ~48px to ~230px
      const halfGap = 24 + (d - 1.0) * 28;
      const xLeft = 200 - halfGap;
      const xRight = 200 + halfGap;

      // Update Electrostatic positions
      p1Group.setAttribute('transform', `translate(${xLeft}, 45)`);
      p2Group.setAttribute('transform', `translate(${xRight}, 45)`);

      const arrowLen = Math.max(30, 75 - (d - 1.0) * 8);
      repelLeft.setAttribute('x1', xLeft - 24);
      repelLeft.setAttribute('x2', xLeft - 24 - arrowLen);
      repelRight.setAttribute('x1', xRight + 24);
      repelRight.setAttribute('x2', xRight + 24 + arrowLen);

      // Update Strong force positions
      spGroup.setAttribute('transform', `translate(${xLeft}, 45)`);
      snGroup.setAttribute('transform', `translate(${xRight}, 45)`);

      const isBound = d <= 3.0;

      if (isBound) {
        statusBadge.textContent = "STABLE";
        statusBadge.className = "status-badge stable";
        strongSub.textContent = "Active (< 3 fm)";
        strongSub.style.color = "#16a34a";

        // Draw active green spring coils
        const startX = xLeft + 22;
        const endX = xRight - 22;
        const w = endX - startX;
        const coils = 5;
        let p = `M ${startX} 45 `;
        for (let i = 1; i <= coils; i++) {
          const cx = startX + (w * (i - 0.5)) / coils;
          const cy = (i % 2 === 1) ? 33 : 57;
          p += `L ${cx} ${cy} `;
        }
        p += `L ${endX} 45`;
        springPath.setAttribute('d', p);
        springPath.setAttribute('stroke', '#16a34a');
        springPath.setAttribute('stroke-dasharray', 'none');

        attrLeft.style.display = 'block';
        attrRight.style.display = 'block';
        attrLeft.setAttribute('x1', xLeft - 24 - arrowLen * 0.7);
        attrLeft.setAttribute('x2', xLeft - 24);
        attrRight.setAttribute('x1', xRight + 24 + arrowLen * 0.7);
        attrRight.setAttribute('x2', xRight + 24);
      } else {
        statusBadge.textContent = "UNSTABLE";
        statusBadge.className = "status-badge unstable";
        strongSub.textContent = "Inactive (> 3 fm)";
        strongSub.style.color = "#94a3b8";

        // Draw inactive gray dashed line
        const startX = xLeft + 22;
        const endX = xRight - 22;
        springPath.setAttribute('d', `M ${startX} 45 L ${endX} 45`);
        springPath.setAttribute('stroke', '#94a3b8');
        springPath.setAttribute('stroke-dasharray', '5 4');

        attrLeft.style.display = 'none';
        attrRight.style.display = 'none';
      }
    }

    slider.addEventListener('input', (e) => {
      update(parseFloat(e.target.value));
    });

    update(1.5);
  </script>
</body>
</html>

OGS.11.PS.AT.4

Aligned learning resources

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