<!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;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
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    body {
      background: #f8fafc;
      color: #0f172a;
      padding: 14px 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100vh;
    }

    .main-grid {
      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    /* Column Headers */
    .header-row {
      display: grid;
      grid-template-columns: 82px 1fr 1fr 1.05fr;
      align-items: center;
      text-align: center;
      font-weight: 700;
      font-size: 13px;
      color: #334155;
      padding: 0 8px;
    }

    /* Comparison Rows */
    .comp-row {
      display: grid;
      grid-template-columns: 82px 1fr 1fr 1.05fr;
      align-items: center;
      gap: 8px;
      background: #ffffff;
      padding: 10px 8px;
      border-radius: 12px;
      border: 1.5px solid #cbd5e1;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
      transition: opacity 0.3s ease, filter 0.3s ease, border-color 0.3s ease;
    }

    .base-tag {
      font-size: 13px;
      font-weight: 800;
      color: #1e40af;
      background: #dbeafe;
      border: 1px solid #bfdbfe;
      border-radius: 6px;
      padding: 6px 2px;
      text-align: center;
    }

    .power-cell {
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 17px;
      font-weight: 700;
      padding: 8px 2px;
      border-radius: 8px;
      background: #f1f5f9;
      color: #334155;
      border: 1.5px solid #cbd5e1;
      transition: all 0.3s ease;
    }

    .power-cell.selected {
      background: #d1fae5;
      color: #065f46;
      border: 2px solid #059669;
      box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.25);
      font-weight: 800;
    }

    .min-cell {
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 17px;
      font-weight: 800;
      padding: 8px 2px;
      border-radius: 8px;
      background: #0369a1;
      color: #ffffff;
      border: 1.5px solid #0284c7;
      box-shadow: 0 2px 4px rgba(3, 105, 161, 0.25);
    }

    .min-cell sup, .power-cell sup, .badge-p2 sup, .badge-p3 sup {
      font-size: 12px;
      margin-left: 1px;
    }

    /* Result Panel */
    .result-card {
      background: #ffffff;
      border: 1.5px solid #cbd5e1;
      border-radius: 12px;
      padding: 12px 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
      text-align: center;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
      transition: opacity 0.3s ease, filter 0.3s ease;
    }

    .calc-row {
      display: flex;
      align-items: center;
      justify-content: center;
      flex-wrap: wrap;
      gap: 6px 8px;
      font-size: 16px;
      font-weight: 700;
      color: #0f172a;
    }

    .badge-p2, .badge-p3 {
      background: #e0f2fe;
      color: #0369a1;
      padding: 3px 7px;
      border-radius: 6px;
      border: 1.5px solid #7dd3fc;
      font-weight: 800;
    }

    .badge-final {
      background: #d1fae5;
      color: #047857;
      padding: 4px 10px;
      border-radius: 8px;
      border: 2px solid #059669;
      font-size: 17px;
      font-weight: 800;
      box-shadow: 0 2px 5px rgba(5, 150, 105, 0.2);
    }

    /* Stepper Controls */
    .controls {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      margin-top: 4px;
    }

    .step-btn {
      background: #ffffff;
      border: 1.5px solid #94a3b8;
      color: #0f172a;
      padding: 6px 16px;
      font-size: 13px;
      font-weight: 700;
      border-radius: 20px;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: background-color 0.2s, border-color 0.2s;
    }

    .step-btn:hover {
      background: #f1f5f9;
      border-color: #64748b;
    }

    .dots {
      display: flex;
      gap: 8px;
    }

    .dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      background: #cbd5e1;
      cursor: pointer;
      transition: background-color 0.2s, outline 0.2s;
    }

    .dot.active {
      background: #0284c7;
      outline: 2px solid #bae6fd;
    }

    /* Readable Dimmed State with Sufficient Contrast */
    .dimmed {
      opacity: 0.58;
      filter: grayscale(0.25);
    }

    @media (max-width: 380px) {
      .header-row, .comp-row {
        grid-template-columns: 72px 1fr 1fr 1fr;
        gap: 5px;
        padding: 8px 4px;
      }
      .base-tag {
        font-size: 11px;
      }
      .power-cell, .min-cell {
        font-size: 15px;
      }
      .calc-row {
        font-size: 14px;
        gap: 4px 6px;
      }
      .badge-final {
        font-size: 15px;
        padding: 3px 8px;
      }
    }
  </style>
</head>
<body>

  <div class="main-grid">
    
    <div class="header-row">
      <span>Base</span>
      <span>72</span>
      <span>108</span>
      <span>Min Power</span>
    </div>

    
    <div class="comp-row" id="row-base2">
      <div class="base-tag">Base 2</div>
      <div class="power-cell" id="p72-2">2<sup>3</sup></div>
      <div class="power-cell selected" id="p108-2">2<sup>2</sup></div>
      <div class="min-cell" id="pick-2">2<sup>2</sup></div>
    </div>

    
    <div class="comp-row" id="row-base3">
      <div class="base-tag">Base 3</div>
      <div class="power-cell selected" id="p72-3">3<sup>2</sup></div>
      <div class="power-cell" id="p108-3">3<sup>3</sup></div>
      <div class="min-cell" id="pick-3">3<sup>2</sup></div>
    </div>

    
    <div class="result-card" id="res-card">
      <div class="calc-row">
        <span>GCF =</span>
        <span class="badge-p2">2<sup>2</sup></span>
        <span>×</span>
        <span class="badge-p3">3<sup>2</sup></span>
        <span>=</span>
        <span>4 × 9</span>
        <span>=</span>
        <span class="badge-final">36 Bags</span>
      </div>
    </div>

    
    <div class="controls">
      <button class="step-btn" id="playBtn">⏸ Pause</button>
      <div class="dots">
        <div class="dot active" data-step="0" title="Step 1: Compare Base 2"></div>
        <div class="dot" data-step="1" title="Step 2: Compare Base 3"></div>
        <div class="dot" data-step="2" title="Step 3: Calculate GCF"></div>
      </div>
    </div>
  </div>

  <script>
    let step = 0;
    let timer = null;
    let isPlaying = true;

    const row2 = document.getElementById('row-base2');
    const row3 = document.getElementById('row-base3');
    const resCard = document.getElementById('res-card');
    const playBtn = document.getElementById('playBtn');
    const dots = document.querySelectorAll('.dot');

    function renderStep(idx) {
      step = idx;

      // Update dots
      dots.forEach((d, i) => d.classList.toggle('active', i === step));

      // Step-specific emphasis with readable dimmed states
      if (step === 0) {
        row2.classList.remove('dimmed');
        row3.classList.add('dimmed');
        resCard.classList.add('dimmed');
      } else if (step === 1) {
        row2.classList.add('dimmed');
        row3.classList.remove('dimmed');
        resCard.classList.add('dimmed');
      } else {
        row2.classList.remove('dimmed');
        row3.classList.remove('dimmed');
        resCard.classList.remove('dimmed');
      }
    }

    function nextStep() {
      renderStep((step + 1) % 3);
    }

    function startTimer() {
      clearInterval(timer);
      timer = setInterval(nextStep, 3200);
      isPlaying = true;
      playBtn.textContent = '⏸ Pause';
    }

    function stopTimer() {
      clearInterval(timer);
      isPlaying = false;
      playBtn.textContent = '▶ Play';
    }

    playBtn.addEventListener('click', () => {
      if (isPlaying) {
        stopTimer();
      } else {
        nextStep();
        startTimer();
      }
    });

    dots.forEach((dot, i) => {
      dot.addEventListener('click', () => {
        renderStep(i);
        if (isPlaying) startTimer();
      });
    });

    renderStep(0);
    startTimer();
  </script>
</body>
</html>

Finding Greatest Common Factors Using Prime Powers

<!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: center;
      min-height: 100%;
    }

    .main-wrap {
      width: 100%;
      max-width: 520px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .controls {
      display: flex;
      justify-content: center;
      gap: 6px;
      flex-wrap: wrap;
    }

    .btn-step {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      border-radius: 20px;
      padding: 5px 12px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .btn-step.active {
      background: #22b7ff;
      color: #ffffff;
      border-color: #0ea5e9;
      box-shadow: 0 2px 6px rgba(34, 183, 255, 0.35);
    }

    .grid-table {
      display: grid;
      grid-template-columns: 1.1fr 1fr 1fr 1fr;
      gap: 6px;
      width: 100%;
    }

    .cell {
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 8px 4px;
      border-radius: 8px;
      font-size: 15px;
      font-weight: 600;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      transition: background 0.25s, box-shadow 0.25s, transform 0.25s;
    }

    .header-cell {
      background: #f1f5f9;
      color: #64748b;
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 0.5px;
      text-transform: uppercase;
      border: 1px solid #e2e8f0;
    }

    .num-cell {
      background: #f8fafc;
      color: #334155;
      font-weight: 700;
      font-size: 15px;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 3px 9px;
      border-radius: 12px;
      background: #e2e8f0;
      color: #334155;
      font-size: 15px;
      transition: all 0.25s ease;
    }

    .min-picked {
      background: #00e5ff !important;
      color: #003748 !important;
      font-weight: 800;
      box-shadow: 0 0 0 2px #00b4d8;
    }

    .col-dimmed {
      opacity: 0.35;
    }

    .col-highlight {
      background: #f0f9ff;
      border-color: #bae6fd;
    }

    .gcf-row .cell {
      background: #e0f7fa;
      border-color: #a5f3fc;
      color: #083344;
      font-weight: 700;
    }

    .gcf-label {
      font-size: 12px;
      line-height: 1.2;
      text-align: center;
      color: #0284c7;
      background: #f0f9ff !important;
    }

    .gcf-badge {
      background: #00e5ff;
      color: #003748;
      font-weight: 800;
      box-shadow: 0 0 0 2px #00b4d8;
    }

    .result-bar {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding: 10px 14px;
      background: #082f49;
      color: #ffffff;
      border-radius: 10px;
      font-size: 16px;
      font-weight: 700;
      flex-wrap: wrap;
    }

    .result-bar .tag {
      color: #38bdf8;
      font-weight: 600;
      font-size: 13px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .result-bar .calc {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      color: #e0f2fe;
    }

    .result-bar .ans {
      color: #00e5ff;
      font-size: 20px;
      font-weight: 800;
      margin-left: 2px;
    }

    sup {
      font-size: 10px;
      margin-left: 1px;
    }
  </style>
</head>
<body>
  <div class="main-wrap">
    <div class="controls">
      <button class="btn-step active" onclick="setStep(0)">All Primes</button>
      <button class="btn-step" onclick="setStep(1)">Prime 2</button>
      <button class="btn-step" onclick="setStep(2)">Prime 3</button>
      <button class="btn-step" onclick="setStep(3)">Prime 5</button>
      <button class="btn-step" onclick="setStep(4)">GCF Result</button>
    </div>

    <div class="grid-table" id="chart">
      
      <div class="cell header-cell">Number</div>
      <div class="cell header-cell" data-col="1">Prime 2</div>
      <div class="cell header-cell" data-col="2">Prime 3</div>
      <div class="cell header-cell" data-col="3">Prime 5</div>

      
      <div class="cell num-cell">60</div>
      <div class="cell" data-col="1"><span class="badge" id="c1-60">2²</span></div>
      <div class="cell" data-col="2"><span class="badge" id="c2-60">3¹</span></div>
      <div class="cell" data-col="3"><span class="badge" id="c3-60">5¹</span></div>

      
      <div class="cell num-cell">90</div>
      <div class="cell" data-col="1"><span class="badge" id="c1-90">2¹</span></div>
      <div class="cell" data-col="2"><span class="badge" id="c2-90">3²</span></div>
      <div class="cell" data-col="3"><span class="badge" id="c3-90">5¹</span></div>

      
      <div class="cell num-cell">150</div>
      <div class="cell" data-col="1"><span class="badge" id="c1-150">2¹</span></div>
      <div class="cell" data-col="2"><span class="badge" id="c2-150">3¹</span></div>
      <div class="cell" data-col="3"><span class="badge" id="c3-150">5²</span></div>

      
      <div class="cell gcf-label">Smallest<br>Power</div>
      <div class="cell gcf-row" data-col="1"><span class="badge gcf-badge">2¹</span></div>
      <div class="cell gcf-row" data-col="2"><span class="badge gcf-badge">3¹</span></div>
      <div class="cell gcf-row" data-col="3"><span class="badge gcf-badge">5¹</span></div>
    </div>

    <div class="result-bar">
      <span class="tag">GCF</span>
      <span>=</span>
      <span class="calc">2¹ × 3¹ × 5¹</span>
      <span>=</span>
      <span class="ans">30</span>
    </div>
  </div>

  <script>
    let currentStep = 0;
    const minBadges = {
      1: ['c1-90', 'c1-150'],
      2: ['c2-60', 'c2-150'],
      3: ['c3-60', 'c3-90']
    };

    function setStep(step) {
      currentStep = step;
      document.querySelectorAll('.btn-step').forEach((btn, idx) => {
        btn.classList.toggle('active', idx === step);
      });

      const cells = document.querySelectorAll('[data-col]');
      cells.forEach(cell => {
        const colId = parseInt(cell.getAttribute('data-col'));
        if (step === 0 || step === 4) {
          cell.classList.remove('col-dimmed', 'col-highlight');
        } else if (colId === step) {
          cell.classList.remove('col-dimmed');
          cell.classList.add('col-highlight');
        } else {
          cell.classList.add('col-dimmed');
          cell.classList.remove('col-highlight');
        }
      });

      // Clear all badge highlights
      document.querySelectorAll('.badge:not(.gcf-badge)').forEach(b => b.classList.remove('min-picked'));

      if (step === 0 || step === 4) {
        // Highlight all minimum powers
        Object.values(minBadges).flat().forEach(id => {
          const el = document.getElementById(id);
          if (el) el.classList.add('min-picked');
        });
      } else {
        // Highlight only active column's min powers
        minBadges[step].forEach(id => {
          const el = document.getElementById(id);
          if (el) el.classList.add('min-picked');
        });
      }
    }

    setStep(0);
  </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;
      background: #ffffff;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .btn-row {
      display: flex;
      justify-content: center;
      gap: 6px;
      flex-wrap: wrap;
    }

    .filter-btn {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      border-radius: 20px;
      padding: 4px 12px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .filter-btn.active {
      background: #2563eb;
      border-color: #2563eb;
      color: #ffffff;
      box-shadow: 0 2px 6px rgba(37, 99, 235, 0.3);
    }

    .cards-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
    }

    @media (max-width: 480px) {
      .cards-grid {
        grid-template-columns: 1fr;
      }
    }

    .panel-card {
      border-radius: 12px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .trap-card {
      background: #fef2f2;
      border: 1.5px solid #fecaca;
    }

    .correct-card {
      background: #f0fdf4;
      border: 1.5px solid #bbf7d0;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      padding: 3px 8px;
      border-radius: 6px;
      width: fit-content;
    }

    .trap-badge {
      background: #fee2e2;
      color: #dc2626;
    }

    .correct-badge {
      background: #dcfce7;
      color: #16a34a;
    }

    .math-box {
      background: #ffffff;
      border-radius: 8px;
      padding: 10px;
      font-size: 15px;
      line-height: 1.6;
      font-weight: 600;
      border: 1px solid rgba(0,0,0,0.06);
    }

    .factor-row {
      display: flex;
      align-items: center;
      gap: 4px;
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    }

    .num-label {
      width: 32px;
      color: #64748b;
      font-weight: 700;
    }

    .term {
      padding: 2px 5px;
      border-radius: 4px;
      transition: all 0.2s ease;
      display: inline-block;
    }

    .term-b2 { background: #e0f2fe; color: #0369a1; }
    .term-b5 { background: #fef3c7; color: #b45309; }
    .term-b7 { background: #f3e8ff; color: #7e22ce; }
    
    .term-zero {
      background: #f1f5f9;
      color: #94a3b8;
      border: 1px dashed #cbd5e1;
    }

    .dimmed {
      opacity: 0.25;
    }

    .highlight-focus {
      outline: 2px solid #2563eb;
      transform: translateY(-1px);
    }

    .summary-box {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 8px 10px;
      border-radius: 8px;
      font-weight: 700;
      font-size: 14px;
    }

    .trap-summary {
      background: #fee2e2;
      color: #991b1b;
    }

    .correct-summary {
      background: #dcfce7;
      color: #166534;
    }

    .status-icon {
      font-size: 18px;
    }

    .detail-hint {
      font-size: 12px;
      color: #475569;
      display: flex;
      justify-content: space-between;
      font-weight: 500;
      padding: 0 4px;
    }
  </style>
</head>
<body>

  
  <div class="btn-row">
    <button class="filter-btn active" onclick="setFilter('all')">All Primes</button>
    <button class="filter-btn" onclick="setFilter('b2')">Base 2</button>
    <button class="filter-btn" onclick="setFilter('b5')">Base 5</button>
    <button class="filter-btn" onclick="setFilter('b7')">Base 7</button>
  </div>

  <div class="cards-grid">
    
    <div class="panel-card trap-card">
      <div class="badge trap-badge">⚠️ Trap Alert</div>
      
      <div class="math-box">
        <div class="factor-row">
          <span class="num-label">40</span>
          <span>=</span>
          <span class="term term-b2">2³</span>
          <span>×</span>
          <span class="term term-b5">5</span>
        </div>
        <div class="factor-row">
          <span class="num-label">56</span>
          <span>=</span>
          <span class="term term-b2">2³</span>
          <span>×</span>
          <span class="term term-b7">7</span>
        </div>
      </div>

      <div class="detail-hint">
        <span>Includes non-shared 5 or 7</span>
      </div>

      <div class="summary-box trap-summary">
        <span>GCF ≠ 2³ × 5 × 7</span>
        <span class="status-icon">❌</span>
      </div>
    </div>

    
    <div class="panel-card correct-card">
      <div class="badge correct-badge">✓ Minimum Power Rule</div>

      <div class="math-box">
        <div class="factor-row">
          <span class="num-label">40</span>
          <span>=</span>
          <span class="term term-b2">2³</span>
          <span>×</span>
          <span class="term term-b5">5¹</span>
          <span>×</span>
          <span class="term term-b7 term-zero">7⁰</span>
        </div>
        <div class="factor-row">
          <span class="num-label">56</span>
          <span>=</span>
          <span class="term term-b2">2³</span>
          <span>×</span>
          <span class="term term-b5 term-zero">5⁰</span>
          <span>×</span>
          <span class="term term-b7">7¹</span>
        </div>
      </div>

      <div class="detail-hint">
        <span id="rule-detail">min(powers): 2³ · 5⁰ · 7⁰</span>
      </div>

      <div class="summary-box correct-summary">
        <span id="correct-result">GCF = 2³ × 1 × 1 = 8</span>
        <span class="status-icon">✅</span>
      </div>
    </div>
  </div>

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      const allTerms = document.querySelectorAll('.term');
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      const correctResult = document.getElementById('correct-result');

      if (type === 'b2') {
        ruleDetail.textContent = "min(2³, 2³) = 2³ = 8";
        correctResult.textContent = "Base 2 factor = 8";
      } else if (type === 'b5') {
        ruleDetail.textContent = "min(5¹, 5⁰) = 5⁰ = 1";
        correctResult.textContent = "Base 5 factor = 1";
      } else if (type === 'b7') {
        ruleDetail.textContent = "min(7⁰, 7¹) = 7⁰ = 1";
        correctResult.textContent = "Base 7 factor = 1";
      } else {
        ruleDetail.textContent = "min(powers): 2³ · 5⁰ · 7⁰";
        correctResult.textContent = "GCF = 2³ × 1 × 1 = 8";
      }
    }
  </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; }
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      flex-wrap: wrap;
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      gap: 6px;
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      width: 100%;
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      border: 1px solid #cbd5e1;
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      font-weight: 600;
      font-size: 12px;
      padding: 5px 10px;
      border-radius: 16px;
      cursor: pointer;
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      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
    }

    /* Top Terms Row */
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      border-radius: 10px;
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      border: 2px solid #cbd5e1;
      box-shadow: 0 2px 4px rgba(0,0,0,0.03);
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    .term-b { color: #0f766e; }
    .term-c { color: #b45309; }
    .op {
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      font-weight: 700;
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      text-align: center;
      font-size: 12px;
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      border: 2px solid #cbd5e1;
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      align-items: center;
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      align-items: center;
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      background: #ede9fe;
      color: #6d28d9;
      padding: 2px 7px;
      border-radius: 6px;
      border: 1.5px solid #c4b5fd;
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      color: #1e2945;
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      font-size: 11.5px;
      font-weight: 600;
      color: #374151;
      background: #f1f5f9;
      padding: 5px 8px;
      border-radius: 6px;
      border: 1px solid #cbd5e1;
      text-align: center;
      width: 100%;
      line-height: 1.35;
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        font-size: 11px;
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      .term-box {
        font-size: 16px;
        padding: 6px 2px;
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        padding: 4px 1px;
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        font-size: 17px;
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      .formula-bar {
        font-size: 10px;
        padding: 4px 6px;
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  </style>
</head>
<body>

  <div class="controls">
    <button class="btn-play" id="playBtn" title="Play / Pause" aria-label="Play / Pause">▶</button>
    <button class="btn-step active" data-step="0">1. Terms</button>
    <button class="btn-step" data-step="1">2. GCF</button>
    <button class="btn-step" data-step="2">3. Divide</button>
    <button class="btn-step" data-step="3">4. Factored</button>
  </div>

  <div class="stage">
    
    <div class="terms-row">
      <div class="term-box term-a" id="boxA">60</div>
      <div class="op">+</div>
      <div class="term-box term-b" id="boxB">90</div>
      <div class="op">+</div>
      <div class="term-box term-c" id="boxC">150</div>
    </div>

    
    <div class="branches-wrap">
      <svg class="svg-canvas" viewBox="0 0 300 38" preserveAspectRatio="none">
        <defs>
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      </svg>

      
      <div class="divisions-row">
        <div class="div-badge" id="divA">
          60 ÷ <span class="gcf-val">30</span> = <span class="res-val term-a">2</span>
        </div>
        <div class="div-badge" id="divB">
          90 ÷ <span class="gcf-val">30</span> = <span class="res-val term-b">3</span>
        </div>
        <div class="div-badge" id="divC">
          150 ÷ <span class="gcf-val">30</span> = <span class="res-val term-c">5</span>
        </div>
      </div>
    </div>

    
    <div class="bottom-result" id="resCard">
      <div class="factored-expr">
        <span class="gcf-highlight">30</span>
        <span class="paren-expr">(</span>
        <span class="term-a">2</span>
        <span class="op">+</span>
        <span class="term-b">3</span>
        <span class="op">+</span>
        <span class="term-c">5</span>
        <span class="paren-expr">)</span>
      </div>
      <div class="formula-bar">
        A + B + C = <strong>GCF</strong> · (A/GCF + B/GCF + C/GCF)
      </div>
    </div>
  </div>

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</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; }
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      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
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      color: #1e2945;
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      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px;
      user-select: none;
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    .toolbar {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      justify-content: center;
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    .btn-filter {
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
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      max-width: 640px;
      justify-content: space-between;
      gap: 12px;
      align-items: stretch;
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    .tree-card {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      background: #ffffff;
      border: 1px solid #e6e6e6;
      border-radius: 12px;
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    }

    .tree-title {
      font-size: 16px;
      font-weight: 700;
      color: #1e2945;
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      height: auto;
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    .line {
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      stroke-width: 2;
      stroke-linecap: round;
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      transition: transform 0.25s ease, fill 0.25s ease, stroke 0.25s ease, opacity 0.25s ease;
      cursor: pointer;
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      font-weight: 700;
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      pointer-events: none;
      font-family: inherit;
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      stroke: #94a3b8;
      stroke-width: 1.5;
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    .composite-text { fill: #475569; }

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    }
    .highlighted {
      stroke-width: 3.5;
      filter: drop-shadow(0 2px 4px rgba(0,0,0,0.15));
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    .power-box {
      margin-top: 8px;
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 16px;
      font-weight: 700;
      padding: 6px 12px;
      background: #f8f9fa;
      border-radius: 8px;
      border: 1px solid #e6e6e6;
    }

    .p-two {
      color: #1d4ed8;
      padding: 2px 6px;
      border-radius: 4px;
      transition: background 0.2s ease;
    }
    .p-three {
      color: #15803d;
      padding: 2px 6px;
      border-radius: 4px;
      transition: background 0.2s ease;
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    .p-two.active { background: #dbeafe; }
    .p-three.active { background: #dcfce7; }
    .op { color: #94a3b8; font-weight: 500; }
  </style>
</head>
<body>

  <div class="toolbar">
    <button class="btn-filter active" onclick="setFilter('all')">All Primes</button>
    <button class="btn-filter f-two" onclick="setFilter('2')">2's</button>
    <button class="btn-filter f-three" onclick="setFilter('3')">3's</button>
  </div>

  <div class="trees-container">
    
    <div class="tree-card">
      <div class="tree-title">72</div>
      <svg viewBox="0 0 240 220">
        
        <line class="line" x1="120" y1="20" x2="65" y2="70" />
        <line class="line" x1="120" y1="20" x2="175" y2="70" />

        <line class="line" x1="65" y1="70" x2="35" y2="125" />
        <line class="line" x1="65" y1="70" x2="95" y2="125" />

        <line class="line" x1="95" y1="125" x2="75" y2="185" />
        <line class="line" x1="95" y1="125" x2="115" y2="185" />

        <line class="line" x1="175" y1="70" x2="150" y2="185" />
        <line class="line" x1="175" y1="70" x2="200" y2="185" />

        
        
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        <g class="node composite" data-val="8">
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        <g class="node composite" data-val="9">
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        </g>

        
        <g class="node prime prime-2" data-prime="2">
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        <g class="node composite" data-val="4">
          <circle class="node-circle composite-circle" cx="95" cy="125" r="15" />
          <text class="node-text composite-text" x="95" cy="125">4</text>
        </g>

        
        <g class="node prime prime-2" data-prime="2">
          <circle class="node-circle prime-2-circle" cx="75" cy="185" r="15" />
          <text class="node-text prime-2-text" x="75" cy="185">2</text>
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        <g class="node prime prime-2" data-prime="2">
          <circle class="node-circle prime-2-circle" cx="115" cy="185" r="15" />
          <text class="node-text prime-2-text" x="115" cy="185">2</text>
        </g>

        <g class="node prime prime-3" data-prime="3">
          <circle class="node-circle prime-3-circle" cx="150" cy="185" r="15" />
          <text class="node-text prime-3-text" x="150" cy="185">3</text>
        </g>
        <g class="node prime prime-3" data-prime="3">
          <circle class="node-circle prime-3-circle" cx="200" cy="185" r="15" />
          <text class="node-text prime-3-text" x="200" cy="185">3</text>
        </g>
      </svg>
      <div class="power-box">
        <span class="p-two" id="p-72-2">2³</span>
        <span class="op">×</span>
        <span class="p-three" id="p-72-3">3²</span>
      </div>
    </div>

    
    <div class="tree-card">
      <div class="tree-title">108</div>
      <svg viewBox="0 0 240 220">
        
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        <line class="line" x1="120" y1="20" x2="175" y2="70" />

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        <line class="line" x1="200" y1="125" x2="215" y2="185" />

        
        
        <g class="node composite" data-val="108">
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          <text class="node-text composite-text" x="120" cy="20">108</text>
        </g>

        
        <g class="node composite" data-val="4">
          <circle class="node-circle composite-circle" cx="65" cy="70" r="15" />
          <text class="node-text composite-text" x="65" cy="70">4</text>
        </g>
        <g class="node composite" data-val="27">
          <circle class="node-circle composite-circle" cx="175" cy="70" r="15" />
          <text class="node-text composite-text" x="175" cy="70">27</text>
        </g>

        
        <g class="node prime prime-2" data-prime="2">
          <circle class="node-circle prime-2-circle" cx="40" cy="185" r="15" />
          <text class="node-text prime-2-text" x="40" cy="185">2</text>
        </g>
        <g class="node prime prime-2" data-prime="2">
          <circle class="node-circle prime-2-circle" cx="85" cy="185" r="15" />
          <text class="node-text prime-2-text" x="85" cy="185">2</text>
        </g>

        <g class="node prime prime-3" data-prime="3">
          <circle class="node-circle prime-3-circle" cx="140" cy="125" r="15" />
          <text class="node-text prime-3-text" x="140" cy="125">3</text>
        </g>
        <g class="node composite" data-val="9">
          <circle class="node-circle composite-circle" cx="200" cy="125" r="15" />
          <text class="node-text composite-text" x="200" cy="125">9</text>
        </g>

        
        <g class="node prime prime-3" data-prime="3">
          <circle class="node-circle prime-3-circle" cx="175" cy="185" r="15" />
          <text class="node-text prime-3-text" x="175" cy="185">3</text>
        </g>
        <g class="node prime prime-3" data-prime="3">
          <circle class="node-circle prime-3-circle" cx="215" cy="185" r="15" />
          <text class="node-text prime-3-text" x="215" cy="185">3</text>
        </g>
      </svg>
      <div class="power-box">
        <span class="p-two" id="p-108-2">2²</span>
        <span class="op">×</span>
        <span class="p-three" id="p-108-3">3³</span>
      </div>
    </div>
  </div>

  <script>
    function setFilter(type) {
      document.querySelectorAll('.btn-filter').forEach(btn => btn.classList.remove('active'));
      if (type === 'all') document.querySelector('.btn-filter:nth-child(1)').classList.add('active');
      if (type === '2') document.querySelector('.btn-filter.f-two').classList.add('active');
      if (type === '3') document.querySelector('.btn-filter.f-three').classList.add('active');

      const primes = document.querySelectorAll('.prime');
      const composites = document.querySelectorAll('.composite');
      const lines = document.querySelectorAll('.line');

      const p72_2 = document.getElementById('p-72-2');
      const p72_3 = document.getElementById('p-72-3');
      const p108_2 = document.getElementById('p-108-2');
      const p108_3 = document.getElementById('p-108-3');

      p72_2.classList.toggle('active', type === '2');
      p72_3.classList.toggle('active', type === '3');
      p108_2.classList.toggle('active', type === '2');
      p108_3.classList.toggle('active', type === '3');

      primes.forEach(p => {
        const val = p.getAttribute('data-prime');
        const circle = p.querySelector('circle');
        if (type === 'all') {
          p.classList.remove('dimmed');
          circle.classList.remove('highlighted');
        } else if (val === type) {
          p.classList.remove('dimmed');
          circle.classList.add('highlighted');
        } else {
          p.classList.add('dimmed');
          circle.classList.remove('highlighted');
        }
      });

      composites.forEach(c => {
        c.classList.toggle('dimmed', type !== 'all');
      });

      lines.forEach(l => {
        l.classList.toggle('dimmed', type !== 'all');
      });
    }

    // Node click interactions
    document.querySelectorAll('.prime').forEach(p => {
      p.addEventListener('click', () => {
        const val = p.getAttribute('data-prime');
        setFilter(val);
      });
    });
  </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;
      user-select: none;
      -webkit-user-select: none;
    }

    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;
      justify-content: space-between;
      min-height: 100%;
      padding: 16px;
      gap: 12px;
    }

    /* Badge */
    .badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: #ecfdf5;
      color: #065f46;
      border: 1.5px solid #a7f3d0;
      border-radius: 9999px;
      padding: 6px 16px;
      font-size: 15px;
      font-weight: 800;
      letter-spacing: -0.01em;
      box-shadow: 0 2px 6px rgba(16, 185, 129, 0.12);
    }

    .badge-icon {
      color: #059669;
      font-size: 14px;
    }

    /* Grid layout */
    .grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 12px;
      width: 100%;
      max-width: 600px;
      margin: auto 0;
    }

    @media (max-width: 480px) {
      .grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
      }
    }

    /* Prime Card */
    .prime-card {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 16px;
      padding: 14px 8px 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
      cursor: pointer;
      box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
      transition: border-color 0.25s ease, box-shadow 0.25s ease, background-color 0.25s ease;
    }

    .prime-card:hover {
      border-color: #6ee7b7;
      box-shadow: 0 4px 12px rgba(16, 185, 129, 0.15);
    }

    .prime-card.active {
      border-color: #10b981;
      background: #f0fdf4;
      box-shadow: 0 0 0 2px #10b981, 0 6px 16px rgba(16, 185, 129, 0.2);
    }

    /* Prime Bubble */
    .prime-bubble {
      width: 48px;
      height: 48px;
      background: linear-gradient(135deg, #10b981, #059669);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 22px;
      font-weight: 800;
      box-shadow: 0 4px 10px rgba(5, 150, 105, 0.3);
      transition: transform 0.2s ease;
    }

    .prime-card.active .prime-bubble {
      transform: scale(1.06);
    }

    /* Arrow SVG */
    .split-svg {
      width: 68px;
      height: 28px;
      display: block;
    }

    .split-svg path {
      stroke: #94a3b8;
      stroke-width: 2;
      fill: none;
      stroke-linecap: round;
      transition: stroke 0.25s ease;
    }

    .split-svg polygon {
      fill: #94a3b8;
      transition: fill 0.25s ease;
    }

    .prime-card.active .split-svg path {
      stroke: #059669;
    }

    .prime-card.active .split-svg polygon {
      fill: #059669;
    }

    /* Factors Row */
    .factors-row {
      display: flex;
      justify-content: center;
      gap: 12px;
      width: 100%;
    }

    .factor-pill {
      min-width: 32px;
      height: 32px;
      padding: 0 8px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 15px;
      font-weight: 700;
      border: 1.5px solid;
      transition: transform 0.2s ease;
    }

    .factor-pill.one {
      background: #f1f5f9;
      color: #334155;
      border-color: #cbd5e1;
    }

    .factor-pill.prime-factor {
      background: #dcfce7;
      color: #166534;
      border-color: #86efac;
    }

    .prime-card.active .factor-pill {
      transform: scale(1.05);
    }

    /* Equation Display */
    .equation-bar {
      display: flex;
      align-items: center;
      justify-content: center;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 8px 18px;
      font-size: 16px;
      font-weight: 700;
      color: #0f172a;
      gap: 8px;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
      min-height: 40px;
    }

    .eq-num {
      color: #059669;
      font-weight: 800;
    }

    .eq-muted {
      color: #64748b;
    }
  </style>
</head>
<body>

  
  <div class="badge">
    <span class="badge-icon">✦</span>
    <span>Exactly 2 Factors = Prime</span>
  </div>

  
  <div class="grid">
    
    <div class="prime-card active" data-prime="2">
      <div class="prime-bubble">2</div>
      <svg class="split-svg" viewBox="0 0 68 28">
        <path d="M 34 2 L 17 20" />
        <path d="M 34 2 L 51 20" />
        <polygon points="17,25 12,18 20,18" />
        <polygon points="51,25 48,18 56,18" />
      </svg>
      <div class="factors-row">
        <div class="factor-pill one">1</div>
        <div class="factor-pill prime-factor">2</div>
      </div>
    </div>

    
    <div class="prime-card" data-prime="3">
      <div class="prime-bubble">3</div>
      <svg class="split-svg" viewBox="0 0 68 28">
        <path d="M 34 2 L 17 20" />
        <path d="M 34 2 L 51 20" />
        <polygon points="17,25 12,18 20,18" />
        <polygon points="51,25 48,18 56,18" />
      </svg>
      <div class="factors-row">
        <div class="factor-pill one">1</div>
        <div class="factor-pill prime-factor">3</div>
      </div>
    </div>

    
    <div class="prime-card" data-prime="5">
      <div class="prime-bubble">5</div>
      <svg class="split-svg" viewBox="0 0 68 28">
        <path d="M 34 2 L 17 20" />
        <path d="M 34 2 L 51 20" />
        <polygon points="17,25 12,18 20,18" />
        <polygon points="51,25 48,18 56,18" />
      </svg>
      <div class="factors-row">
        <div class="factor-pill one">1</div>
        <div class="factor-pill prime-factor">5</div>
      </div>
    </div>

    
    <div class="prime-card" data-prime="7">
      <div class="prime-bubble">7</div>
      <svg class="split-svg" viewBox="0 0 68 28">
        <path d="M 34 2 L 17 20" />
        <path d="M 34 2 L 51 20" />
        <polygon points="17,25 12,18 20,18" />
        <polygon points="51,25 48,18 56,18" />
      </svg>
      <div class="factors-row">
        <div class="factor-pill one">1</div>
        <div class="factor-pill prime-factor">7</div>
      </div>
    </div>
  </div>

  
  <div class="equation-bar" id="eqBar">
    <span class="eq-muted">1</span>
    <span>×</span>
    <span class="eq-num" id="eqSelf">2</span>
    <span>=</span>
    <span class="eq-num" id="eqResult">2</span>
  </div>

  <script>
    const cards = document.querySelectorAll('.prime-card');
    const eqSelf = document.getElementById('eqSelf');
    const eqResult = document.getElementById('eqResult');

    function selectPrime(card) {
      cards.forEach(c => c.classList.remove('active'));
      card.classList.add('active');
      const val = card.getAttribute('data-prime');
      eqSelf.textContent = val;
      eqResult.textContent = val;
    }

    cards.forEach(card => {
      card.addEventListener('click', () => selectPrime(card));
    });

    // Auto-cycle through primes gently
    let currentIndex = 0;
    let autoTimer = setInterval(() => {
      currentIndex = (currentIndex + 1) % cards.length;
      selectPrime(cards[currentIndex]);
    }, 3200);

    // Pause auto-cycle on user interaction
    cards.forEach(card => {
      card.addEventListener('pointerdown', () => {
        clearInterval(autoTimer);
      });
    });
  </script>
</body>
</html>

Classifying Prime and Composite Numbers

<!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;
      -webkit-tap-highlight-color: transparent;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .grid {
      display: grid;
      grid-template-columns: 1fr 1.35fr;
      gap: 12px;
      width: 100%;
      max-width: 600px;
    }

    @media (max-width: 480px) {
      .grid {
        grid-template-columns: 1fr;
        gap: 10px;
      }
    }

    .card-inner {
      background: #ffffff;
      border-radius: 12px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 200px;
      user-select: none;
    }

    .card-prime {
      border: 2px solid #16a34a;
      background: #f0fdf4;
    }

    .card-composite {
      border: 2px solid #9333ea;
      background: #faf5ff;
    }

    .header-badge {
      font-weight: 700;
      font-size: 15px;
      padding: 4px 10px;
      border-radius: 20px;
      letter-spacing: -0.2px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    .badge-prime {
      background: #dcfce7;
      color: #15803d;
    }

    .badge-composite {
      background: #f3e8ff;
      color: #7e22ce;
    }

    .svg-container {
      width: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
      margin: 4px 0;
    }

    svg {
      width: 100%;
      height: auto;
      max-height: 110px;
      overflow: visible;
    }

    .arc {
      fill: none;
      stroke-width: 2.5;
      stroke-linecap: round;
      cursor: pointer;
      transition: stroke-width 0.2s ease, opacity 0.2s ease;
    }

    .arc:hover, .arc.active {
      stroke-width: 4.5;
    }

    .num-node {
      font-size: 15px;
      font-weight: 800;
      text-anchor: middle;
      dominant-baseline: central;
      cursor: pointer;
      transition: transform 0.2s ease, fill 0.2s ease;
    }

    .footer-count {
      font-size: 13px;
      font-weight: 600;
      padding: 3px 8px;
      border-radius: 6px;
      background: rgba(255, 255, 255, 0.85);
      border: 1px solid rgba(0, 0, 0, 0.06);
    }

    .count-prime {
      color: #15803d;
    }

    .count-composite {
      color: #7e22ce;
    }

    .formula-tag {
      font-size: 12px;
      font-weight: 700;
      min-height: 18px;
      margin-top: 2px;
      color: #4b5563;
    }
  </style>
</head>
<body>

  <div class="grid">
    
    <div class="card-inner card-prime" id="cardPrime" onclick="highlightPrime()">
      <div class="header-badge badge-prime">
        <span>Prime: 11</span>
      </div>

      <div class="svg-container">
        <svg viewBox="0 0 160 85">
          
          <path id="arc-p1" class="arc active" d="M 35 60 A 45 32 0 0 1 125 60" stroke="#16a34a" />
          
          
          <circle cx="35" cy="60" r="14" fill="#dcfce7" stroke="#16a34a" stroke-width="2" />
          <circle cx="125" cy="60" r="14" fill="#dcfce7" stroke="#16a34a" stroke-width="2" />
          
          
          <text x="35" y="60" class="num-node" fill="#15803d">1</text>
          <text x="125" y="60" class="num-node" fill="#15803d">11</text>
        </svg>
      </div>

      <div class="formula-tag" id="formulaPrime">1 × 11 = 11</div>
      <div class="footer-count count-prime">2 Factors</div>
    </div>

    
    <div class="card-inner card-composite">
      <div class="header-badge badge-composite">
        <span>Composite: 12</span>
      </div>

      <div class="svg-container">
        <svg viewBox="0 0 250 85">
          
          <path id="arc-c1" class="arc" d="M 25 60 A 100 44 0 0 1 225 60" stroke="#3b82f6" onclick="selectPair(1)" />
          <path id="arc-c2" class="arc" d="M 65 60 A 60 30 0 0 1 185 60" stroke="#ec4899" onclick="selectPair(2)" />
          <path id="arc-c3" class="arc" d="M 105 60 A 20 16 0 0 1 145 60" stroke="#f59e0b" onclick="selectPair(3)" />

          
          <g onclick="selectPair(1)">
            <circle id="node-1" cx="25" cy="60" r="12" fill="#dbeafe" stroke="#3b82f6" stroke-width="1.5" />
            <text x="25" y="60" class="num-node" fill="#1d4ed8">1</text>
            <circle id="node-12" cx="225" cy="60" r="12" fill="#dbeafe" stroke="#3b82f6" stroke-width="1.5" />
            <text x="225" y="60" class="num-node" fill="#1d4ed8">12</text>
          </g>

          <g onclick="selectPair(2)">
            <circle id="node-2" cx="65" cy="60" r="12" fill="#fce7f3" stroke="#ec4899" stroke-width="1.5" />
            <text x="65" y="60" class="num-node" fill="#be185d">2</text>
            <circle id="node-6" cx="185" cy="60" r="12" fill="#fce7f3" stroke="#ec4899" stroke-width="1.5" />
            <text x="185" y="60" class="num-node" fill="#be185d">6</text>
          </g>

          <g onclick="selectPair(3)">
            <circle id="node-3" cx="105" cy="60" r="12" fill="#fef3c7" stroke="#f59e0b" stroke-width="1.5" />
            <text x="105" y="60" class="num-node" fill="#b45309">3</text>
            <circle id="node-4" cx="145" cy="60" r="12" fill="#fef3c7" stroke="#f59e0b" stroke-width="1.5" />
            <text x="145" y="60" class="num-node" fill="#b45309">4</text>
          </g>
        </svg>
      </div>

      <div class="formula-tag" id="formulaComposite">Tap pairs to link</div>
      <div class="footer-count count-composite">6 Factors</div>
    </div>
  </div>

  <script>
    const pairs = {
      1: { text: "1 × 12 = 12", color: "#2563eb" },
      2: { text: "2 × 6 = 12", color: "#db2777" },
      3: { text: "3 × 4 = 12", color: "#d97706" }
    };

    let activePair = null;

    function selectPair(idx) {
      const formulaEl = document.getElementById('formulaComposite');
      const arcs = [1, 2, 3];

      if (activePair === idx) {
        // Reset to show all
        activePair = null;
        arcs.forEach(i => {
          const a = document.getElementById('arc-c' + i);
          a.style.opacity = '1';
          a.style.strokeWidth = '2.5';
        });
        formulaEl.textContent = "Tap pairs to link";
        formulaEl.style.color = "#4b5563";
        return;
      }

      activePair = idx;
      arcs.forEach(i => {
        const a = document.getElementById('arc-c' + i);
        if (i === idx) {
          a.style.opacity = '1';
          a.style.strokeWidth = '4.5';
        } else {
          a.style.opacity = '0.25';
          a.style.strokeWidth = '2';
        }
      });

      formulaEl.textContent = pairs[idx].text;
      formulaEl.style.color = pairs[idx].color;
    }

    function highlightPrime() {
      const el = document.getElementById('formulaPrime');
      el.style.transform = 'scale(1.1)';
      el.style.transition = 'transform 0.15s ease';
      setTimeout(() => {
        el.style.transform = 'scale(1)';
      }, 150);
    }
  </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>Factors of 18 T-Chart</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: center;
      min-height: 100%;
      padding: 16px;
      user-select: none;
    }

    .main-layout {
      width: 100%;
      max-width: 440px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 12px;
    }

    /* Target number badge */
    .title-badge {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 16px;
      font-weight: 700;
      color: #1e2945;
    }

    .num-pill {
      background: #e0f2fe;
      color: #0284c7;
      padding: 2px 10px;
      border-radius: 6px;
      font-size: 18px;
    }

    /* T-Chart Structure */
    .t-chart {
      width: 240px;
      background: #ffffff;
      border-radius: 8px;
      border: 1px solid #e2e8f0;
      overflow: hidden;
    }

    .t-header {
      display: grid;
      grid-template-columns: 1fr 1fr;
      background: #f1f5f9;
      border-bottom: 2px solid #cbd5e1;
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #64748b;
      text-align: center;
      padding: 6px 0;
    }

    .t-header div:first-child {
      border-right: 2px solid #cbd5e1;
    }

    .t-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      text-align: center;
      font-size: 16px;
      font-weight: 700;
      color: #1e2945;
      border-bottom: 1px solid #f1f5f9;
      opacity: 0.25;
      transition: all 0.3s ease;
    }

    .t-row:last-child {
      border-bottom: none;
    }

    .t-row.active {
      opacity: 1;
      background: #f8fafc;
    }

    .t-row.highlight {
      background: #eff6ff;
    }

    .t-cell {
      padding: 8px 0;
    }

    .t-cell:first-child {
      border-right: 2px solid #cbd5e1;
    }

    /* Arrow */
    .flow-arrow {
      font-size: 18px;
      color: #94a3b8;
      line-height: 1;
      opacity: 0.4;
      transition: opacity 0.3s ease;
    }

    .flow-arrow.active {
      opacity: 1;
      color: #0284c7;
    }

    /* Factor list */
    .factor-set-box {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 8px 12px;
      font-size: 15px;
      font-weight: 700;
      color: #64748b;
      transition: all 0.3s ease;
      min-height: 42px;
      flex-wrap: wrap;
    }

    .factor-set-box.active {
      border-color: #38bdf8;
      background: #f0f9ff;
    }

    .factor-item {
      display: inline-block;
      padding: 2px 6px;
      border-radius: 4px;
      color: #94a3b8;
      transition: all 0.3s ease;
    }

    .factor-item.active {
      color: #0284c7;
      background: #e0f2fe;
    }

    /* Result Callout */
    .callout {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      opacity: 0.2;
      transition: all 0.3s ease;
      font-size: 14px;
      font-weight: 600;
    }

    .callout.active {
      opacity: 1;
    }

    .count-tag {
      color: #475569;
    }

    .composite-badge {
      background: #fef3c7;
      color: #d97706;
      border: 1px solid #fde68a;
      padding: 3px 10px;
      border-radius: 6px;
      font-size: 13px;
      font-weight: 800;
      letter-spacing: 0.5px;
    }

    /* Stepper Controls */
    .controls {
      display: flex;
      align-items: center;
      gap: 6px;
      margin-top: 4px;
    }

    .step-btn {
      padding: 5px 12px;
      font-size: 12px;
      font-weight: 600;
      border-radius: 6px;
      border: 1px solid #e2e8f0;
      background: #ffffff;
      color: #64748b;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .step-btn:hover {
      background: #f8fafc;
      color: #1e2945;
    }

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

    .play-btn {
      width: 28px;
      height: 28px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 6px;
      border: 1px solid #e2e8f0;
      background: #ffffff;
      color: #64748b;
      cursor: pointer;
      font-size: 11px;
    }

    .play-btn:hover {
      background: #f8fafc;
      color: #1e2945;
    }
  </style>
</head>
<body>

  <div class="main-layout">
    
    <div class="title-badge">
      <span>Factors of</span>
      <span class="num-pill">18</span>
    </div>

    
    <div class="t-chart">
      <div class="t-header">
        <div>Factor 1</div>
        <div>Factor 2</div>
      </div>
      <div class="t-row" id="row-0">
        <div class="t-cell">1</div>
        <div class="t-cell">18</div>
      </div>
      <div class="t-row" id="row-1">
        <div class="t-cell">2</div>
        <div class="t-cell">9</div>
      </div>
      <div class="t-row" id="row-2">
        <div class="t-cell">3</div>
        <div class="t-cell">6</div>
      </div>
    </div>

    
    <div class="flow-arrow" id="flowArrow">↓</div>

    
    <div class="factor-set-box" id="factorSet">
      <span>{</span>
      <span class="factor-item" id="f-1">1</span>,
      <span class="factor-item" id="f-2">2</span>,
      <span class="factor-item" id="f-3">3</span>,
      <span class="factor-item" id="f-6">6</span>,
      <span class="factor-item" id="f-9">9</span>,
      <span class="factor-item" id="f-18">18</span>
      <span>}</span>
    </div>

    
    <div class="callout" id="calloutBox">
      <span class="count-tag">6 factors</span>
      <span>→</span>
      <span class="composite-badge">COMPOSITE</span>
    </div>

    
    <div class="controls">
      <button class="step-btn active" onclick="setStep(0)">1 × 18</button>
      <button class="step-btn" onclick="setStep(1)">2 × 9</button>
      <button class="step-btn" onclick="setStep(2)">3 × 6</button>
      <button class="step-btn" onclick="setStep(3)">All</button>
      <button class="play-btn" id="playBtn" onclick="toggleAuto()" title="Auto play">▶</button>
    </div>
  </div>

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

    const rows = [
      document.getElementById('row-0'),
      document.getElementById('row-1'),
      document.getElementById('row-2')
    ];

    const factorEls = {
      1: document.getElementById('f-1'),
      2: document.getElementById('f-2'),
      3: document.getElementById('f-3'),
      6: document.getElementById('f-6'),
      9: document.getElementById('f-9'),
      18: document.getElementById('f-18')
    };

    const flowArrow = document.getElementById('flowArrow');
    const factorSet = document.getElementById('factorSet');
    const calloutBox = document.getElementById('calloutBox');
    const buttons = document.querySelectorAll('.step-btn');
    const playBtn = document.getElementById('playBtn');

    function setStep(step) {
      currentStep = step;

      // Update button styles
      buttons.forEach((btn, idx) => {
        btn.classList.toggle('active', idx === step);
      });

      // Update rows
      rows.forEach((row, idx) => {
        row.classList.remove('active', 'highlight');
        if (step === 3) {
          row.classList.add('active');
        } else if (idx <= step) {
          row.classList.add('active');
          if (idx === step) row.classList.add('highlight');
        }
      });

      // Update factor highlights
      Object.values(factorEls).forEach(el => el.classList.remove('active'));

      if (step === 0) {
        factorEls[1].classList.add('active');
        factorEls[18].classList.add('active');
      } else if (step === 1) {
        factorEls[1].classList.add('active');
        factorEls[2].classList.add('active');
        factorEls[9].classList.add('active');
        factorEls[18].classList.add('active');
      } else {
        Object.values(factorEls).forEach(el => el.classList.add('active'));
      }

      // Final step reveals
      const isComplete = step === 3;
      flowArrow.classList.toggle('active', isComplete);
      factorSet.classList.toggle('active', isComplete);
      calloutBox.classList.toggle('active', isComplete);
    }

    function toggleAuto() {
      if (autoInterval) {
        clearInterval(autoInterval);
        autoInterval = null;
        playBtn.textContent = '▶';
      } else {
        playBtn.textContent = '⏸';
        autoInterval = setInterval(() => {
          setStep((currentStep + 1) % 4);
        }, 2200);
      }
    }

    // Initialize
    setStep(0);
  </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: #1e293b;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .grid-container {
      display: flex;
      flex-direction: row;
      gap: 12px;
      width: 100%;
      max-width: 600px;
    }

    .column {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 10px;
      padding: 12px;
      border-radius: 10px;
    }

    .col-blue {
      background: #f0f7ff;
      border: 1px solid #bfdbfe;
    }

    .col-green {
      background: #f0fdf4;
      border: 1px solid #bbf7d0;
    }

    .header-row {
      display: flex;
      align-items: baseline;
      justify-content: space-between;
      border-bottom: 1px solid rgba(0, 0, 0, 0.08);
      padding-bottom: 6px;
    }

    .title {
      font-size: 15px;
      font-weight: 700;
    }

    .col-blue .title { color: #1d4ed8; }
    .col-green .title { color: #047857; }

    .tag {
      font-size: 11px;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      padding: 2px 6px;
      border-radius: 4px;
    }

    .col-blue .tag {
      background: #dbeafe;
      color: #1e40af;
    }

    .col-green .tag {
      background: #dcfce7;
      color: #166534;
    }

    .sub-label {
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      margin-top: -4px;
    }

    .arrangement {
      display: flex;
      flex-direction: column;
      gap: 4px;
      background: #ffffff;
      padding: 8px 10px;
      border-radius: 8px;
      border: 1px solid rgba(0, 0, 0, 0.05);
    }

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

    .dim-label .status {
      font-size: 11px;
      font-weight: 600;
    }

    .status-ok { color: #10b981; }
    .status-no { color: #ef4444; }

    .tile-grid {
      display: grid;
      gap: 2px;
      width: fit-content;
    }

    .tile {
      width: 13px;
      height: 13px;
      border-radius: 2px;
    }

    .tile-blue {
      background: #3b82f6;
    }

    .tile-green {
      background: #10b981;
    }

    .tile-empty {
      background: #fee2e2;
      border: 1px dashed #ef4444;
      width: 11px;
      height: 11px;
    }

    /* Grid Layouts */
    .grid-1x12 { grid-template-columns: repeat(12, 13px); }
    .grid-2x6  { grid-template-columns: repeat(6, 13px); }
    .grid-3x4  { grid-template-columns: repeat(4, 13px); }
    .grid-1x7  { grid-template-columns: repeat(7, 13px); }
    .grid-2x4-incomplete { grid-template-columns: repeat(4, 13px); }

    @media (max-width: 420px) {
      .grid-container {
        flex-direction: column;
      }
      .tile {
        width: 14px;
        height: 14px;
      }
      .grid-1x12 { grid-template-columns: repeat(12, 14px); }
      .grid-2x6  { grid-template-columns: repeat(6, 14px); }
      .grid-3x4  { grid-template-columns: repeat(4, 14px); }
      .grid-1x7  { grid-template-columns: repeat(7, 14px); }
      .grid-2x4-incomplete { grid-template-columns: repeat(4, 14px); }
      .tile-empty {
        width: 12px;
        height: 12px;
      }
    }
  </style>
</head>
<body>

  <div class="grid-container">
    
    <div class="column col-blue">
      <div class="header-row">
        <span class="title">12 Tiles</span>
        <span class="tag">Composite</span>
      </div>
      <span class="sub-label">Multiple ways to build</span>

      
      <div class="arrangement">
        <div class="dim-label">
          <span>1 × 12</span>
          <span class="status status-ok">✓</span>
        </div>
        <div class="tile-grid grid-1x12">
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
        </div>
      </div>

      
      <div class="arrangement">
        <div class="dim-label">
          <span>2 × 6</span>
          <span class="status status-ok">✓</span>
        </div>
        <div class="tile-grid grid-2x6">
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
        </div>
      </div>

      
      <div class="arrangement">
        <div class="dim-label">
          <span>3 × 4</span>
          <span class="status status-ok">✓</span>
        </div>
        <div class="tile-grid grid-3x4">
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
          <div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div><div class="tile tile-blue"></div>
        </div>
      </div>
    </div>

    
    <div class="column col-green">
      <div class="header-row">
        <span class="title">7 Tiles</span>
        <span class="tag">Prime</span>
      </div>
      <span class="sub-label">Only 1 way to build</span>

      
      <div class="arrangement">
        <div class="dim-label">
          <span>1 × 7</span>
          <span class="status status-ok">✓</span>
        </div>
        <div class="tile-grid grid-1x7">
          <div class="tile tile-green"></div><div class="tile tile-green"></div><div class="tile tile-green"></div><div class="tile tile-green"></div>
          <div class="tile tile-green"></div><div class="tile tile-green"></div><div class="tile tile-green"></div>
        </div>
      </div>

      
      <div class="arrangement">
        <div class="dim-label">
          <span>2 × 3 + 1 gap</span>
          <span class="status status-no">✕ Not solid</span>
        </div>
        <div class="tile-grid grid-2x4-incomplete">
          <div class="tile tile-green"></div><div class="tile tile-green"></div><div class="tile tile-green"></div><div class="tile tile-green"></div>
          <div class="tile tile-green"></div><div class="tile tile-green"></div><div class="tile tile-green"></div><div class="tile-empty"></div>
        </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">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      -webkit-tap-highlight-color: transparent;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      user-select: none;
    }

    /* Track Container */
    .line-container {
      position: relative;
      margin: 36px 16px 16px 16px;
      height: 48px;
    }

    .number-line {
      position: absolute;
      top: 22px;
      left: 0;
      right: 0;
      height: 6px;
      background: #e2e8f0;
      border-radius: 3px;
    }

    .line-fill {
      position: absolute;
      left: 25%;
      width: 75%;
      height: 100%;
      background: linear-gradient(90deg, #bae6fd, #fed7aa, #c7d2fe);
      border-radius: 3px;
    }

    /* Interactive Marker */
    .marker {
      position: absolute;
      top: 5px;
      left: 36%;
      transform: translateX(-50%);
      transition: left 0.35s cubic-bezier(0.4, 0, 0.2, 1);
      display: flex;
      flex-direction: column;
      align-items: center;
      pointer-events: none;
      z-index: 10;
    }

    .marker-bubble {
      background: #1e2945;
      color: #ffffff;
      font-size: 13px;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 6px;
      white-space: nowrap;
      box-shadow: 0 4px 10px rgba(30, 41, 69, 0.25);
    }

    .marker-pin {
      width: 0;
      height: 0;
      border-left: 5px solid transparent;
      border-right: 5px solid transparent;
      border-top: 6px solid #1e2945;
    }

    /* Anchor Badges */
    .anchor-badge {
      position: absolute;
      transform: translateX(-50%);
      cursor: pointer;
      display: flex;
      flex-direction: column;
      align-items: center;
      z-index: 5;
    }

    .anchor-tick {
      width: 2px;
      height: 12px;
      background: #0284c7;
      margin-top: 17px;
    }

    .anchor-pill {
      margin-top: 4px;
      background: #e0f2fe;
      border: 1.5px solid #38bdf8;
      color: #0369a1;
      font-size: 13px;
      font-weight: 700;
      padding: 4px 8px;
      border-radius: 12px;
      box-shadow: 0 0 10px rgba(56, 189, 248, 0.45);
      transition: background 0.2s, transform 0.2s;
      white-space: nowrap;
    }

    .anchor-pill span {
      font-size: 11px;
      opacity: 0.85;
      font-weight: 600;
    }

    /* Zone Containers */
    .zones-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
    }

    .zone {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 8px;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .zone-title {
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #64748b;
      text-align: center;
    }

    .cards-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 6px;
    }

    .sq-card {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 8px;
      padding: 6px 4px;
      text-align: center;
      cursor: pointer;
      transition: background-color 0.2s, border-color 0.2s, box-shadow 0.2s;
    }

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

    .sq-card .val {
      font-size: 14px;
      font-weight: 700;
      color: #1e2945;
    }

    /* Pastel themes */
    .zone-left .sq-card {
      background: #fffbeb;
      border-color: #fef08a;
    }
    .zone-right .sq-card {
      background: #f5f3ff;
      border-color: #ddd6fe;
    }

    .sq-card.active {
      border-color: #0284c7;
      background: #e0f2fe;
      box-shadow: 0 0 0 2px #38bdf8;
    }

    .sq-card.active .exp,
    .sq-card.active .val {
      color: #0369a1;
    }

    /* Detail Bar */
    .detail-bar {
      background: #f1f5f9;
      border-radius: 8px;
      padding: 8px 12px;
      display: flex;
      align-items: center;
      justify-content: space-around;
      font-size: 15px;
      font-weight: 600;
    }

    .detail-bar span strong {
      color: #0284c7;
    }
  </style>
</head>
<body>

  
  <div class="line-container">
    <div class="number-line">
      <div class="line-fill"></div>
    </div>

    
    <div id="marker" class="marker">
      <div id="markerBubble" class="marker-bubble">√144 = 12</div>
      <div class="marker-pin"></div>
    </div>

    
    <div class="anchor-badge" style="left: 25%;" data-n="10" data-sq="100" data-pct="25">
      <div class="anchor-tick"></div>
      <div class="anchor-pill">10² <span>= 100</span></div>
    </div>

    
    <div class="anchor-badge" style="left: 56.25%;" data-n="15" data-sq="225" data-pct="56.25">
      <div class="anchor-tick"></div>
      <div class="anchor-pill">15² <span>= 225</span></div>
    </div>

    
    <div class="anchor-badge" style="left: 100%;" data-n="20" data-sq="400" data-pct="100">
      <div class="anchor-tick"></div>
      <div class="anchor-pill">20² <span>= 400</span></div>
    </div>
  </div>

  
  <div class="zones-grid">
    
    <div class="zone zone-left">
      <div class="zone-title">10² to 15²</div>
      <div class="cards-grid">
        <div class="sq-card" data-n="11" data-sq="121" data-pct="30.25">
          <div class="exp">11²</div>
          <div class="val">121</div>
        </div>
        <div class="sq-card active" data-n="12" data-sq="144" data-pct="36">
          <div class="exp">12²</div>
          <div class="val">144</div>
        </div>
        <div class="sq-card" data-n="13" data-sq="169" data-pct="42.25">
          <div class="exp">13²</div>
          <div class="val">169</div>
        </div>
        <div class="sq-card" data-n="14" data-sq="196" data-pct="49">
          <div class="exp">14²</div>
          <div class="val">196</div>
        </div>
      </div>
    </div>

    
    <div class="zone zone-right">
      <div class="zone-title">15² to 20²</div>
      <div class="cards-grid">
        <div class="sq-card" data-n="16" data-sq="256" data-pct="64">
          <div class="exp">16²</div>
          <div class="val">256</div>
        </div>
        <div class="sq-card" data-n="17" data-sq="289" data-pct="72.25">
          <div class="exp">17²</div>
          <div class="val">289</div>
        </div>
        <div class="sq-card" data-n="18" data-sq="324" data-pct="81">
          <div class="exp">18²</div>
          <div class="val">324</div>
        </div>
        <div class="sq-card" data-n="19" data-sq="361" data-pct="90.25">
          <div class="exp">19²</div>
          <div class="val">361</div>
        </div>
      </div>
    </div>
  </div>

  
  <div class="detail-bar">
    <span id="readoutRoot">Edge: <strong>12</strong></span>
    <span>↔</span>
    <span id="readoutSq">Area: <strong>144 tiles</strong></span>
  </div>

  <script>
    const marker = document.getElementById('marker');
    const bubble = document.getElementById('markerBubble');
    const rootOut = document.getElementById('readoutRoot');
    const sqOut = document.getElementById('readoutSq');
    const allSelectables = document.querySelectorAll('.sq-card, .anchor-badge');

    function selectSquare(el) {
      const n = el.getAttribute('data-n');
      const sq = el.getAttribute('data-sq');
      const pct = el.getAttribute('data-pct');

      // Update active cards
      document.querySelectorAll('.sq-card').forEach(c => c.classList.remove('active'));
      if (el.classList.contains('sq-card')) {
        el.classList.add('active');
      }

      // Position Marker
      marker.style.left = pct + '%';
      bubble.textContent = `√${sq} = ${n}`;

      // Update bottom readout
      rootOut.innerHTML = `Edge: <strong>${n}</strong>`;
      sqOut.innerHTML = `Area: <strong>${sq} tiles</strong>`;
    }

    allSelectables.forEach(item => {
      item.addEventListener('click', () => selectSquare(item));
    });
  </script>
</body>
</html>

OGM.7.NS.7

Aligned learning resources

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