<!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;
    }
    html, body {
      width: 100%;
      height: 100%;
      background: #ffffff;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      padding: 12px;
      user-select: none;
    }
    .diagram-wrap {
      width: 100%;
      max-width: 580px;
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
    }
    .btn-group {
      display: flex;
      gap: 8px;
      margin-top: 4px;
      flex-wrap: wrap;
      justify-content: center;
    }
    .filter-btn {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      border-radius: 20px;
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .filter-btn:hover {
      background: #e2e8f0;
      color: #1e2945;
    }
    .filter-btn.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #2563eb;
      box-shadow: 0 2px 6px rgba(37, 99, 235, 0.3);
    }
    .region {
      transition: opacity 0.3s ease;
    }
    .dimmed {
      opacity: 0.25;
    }
  </style>
</head>
<body>

  <div class="diagram-wrap">
    <svg viewBox="0 0 600 320" aria-label="Box plot showing center at median 10 with equal 50% halves">
      
      <g id="leftHalf" class="region">
        <rect x="100" y="70" width="200" height="130" rx="8" fill="#e0f2fe" stroke="#38bdf8" stroke-width="1.5" stroke-dasharray="4 4" />
        <text x="200" y="92" text-anchor="middle" font-size="13" font-weight="700" fill="#0284c7">50% of data</text>
      </g>

      <g id="rightHalf" class="region">
        <rect x="300" y="70" width="200" height="130" rx="8" fill="#ede9fe" stroke="#a78bfa" stroke-width="1.5" stroke-dasharray="4 4" />
        <text x="400" y="92" text-anchor="middle" font-size="13" font-weight="700" fill="#7c3aed">50% of data</text>
      </g>

      
      
      <line x1="100" y1="145" x2="200" y2="145" stroke="#334155" stroke-width="3" stroke-linecap="round" />
      <line x1="100" y1="125" x2="100" y2="165" stroke="#334155" stroke-width="3" stroke-linecap="round" />

      
      <line x1="400" y1="145" x2="500" y2="145" stroke="#334155" stroke-width="3" stroke-linecap="round" />
      <line x1="500" y1="125" x2="500" y2="165" stroke="#334155" stroke-width="3" stroke-linecap="round" />

      
      <rect x="200" y="115" width="200" height="60" fill="#ffffff" stroke="#1e2945" stroke-width="3" rx="4" />

      
      <line x1="300" y1="115" x2="300" y2="175" stroke="#2563eb" stroke-width="4" stroke-linecap="round" />

      
      <text x="100" y="185" text-anchor="middle" font-size="11" font-weight="600" fill="#64748b">Min (2)</text>
      <text x="200" y="195" text-anchor="middle" font-size="11" font-weight="600" fill="#64748b">Q1 (6)</text>
      <text x="400" y="195" text-anchor="middle" font-size="11" font-weight="600" fill="#64748b">Q3 (14)</text>
      <text x="500" y="185" text-anchor="middle" font-size="11" font-weight="600" fill="#64748b">Max (18)</text>

      
      <g id="medianCallout">
        <rect x="210" y="18" width="180" height="32" rx="6" fill="#1e2945" />
        <text x="300" y="39" text-anchor="middle" font-size="13" font-weight="700" fill="#ffffff">Center (Median) = 10</text>
        <path d="M 300 50 L 300 106" stroke="#2563eb" stroke-width="2.5" />
        <polygon points="295,104 300,113 305,104" fill="#2563eb" />
      </g>

      
      
      <line x1="40" y1="245" x2="560" y2="245" stroke="#94a3b8" stroke-width="2" stroke-linecap="round" />

      
      <polygon points="40,241 32,245 40,249" fill="#94a3b8" />
      <polygon points="560,241 568,245 560,249" fill="#94a3b8" />

      
      
      <line x1="50" y1="240" x2="50" y2="250" stroke="#64748b" stroke-width="1.5" />
      <text x="50" y="268" text-anchor="middle" font-size="12" fill="#475569">0</text>

      
      <line x1="100" y1="238" x2="100" y2="252" stroke="#334155" stroke-width="2" />
      <text x="100" y="268" text-anchor="middle" font-size="13" font-weight="700" fill="#1e2945">2</text>

      
      <line x1="150" y1="242" x2="150" y2="248" stroke="#94a3b8" stroke-width="1" />
      <text x="150" y="268" text-anchor="middle" font-size="12" fill="#64748b">4</text>

      
      <line x1="200" y1="238" x2="200" y2="252" stroke="#334155" stroke-width="2" />
      <text x="200" y="268" text-anchor="middle" font-size="13" font-weight="700" fill="#1e2945">6</text>

      
      <line x1="250" y1="242" x2="250" y2="248" stroke="#94a3b8" stroke-width="1" />
      <text x="250" y="268" text-anchor="middle" font-size="12" fill="#64748b">8</text>

      
      <line x1="300" y1="236" x2="300" y2="254" stroke="#2563eb" stroke-width="2.5" />
      <text x="300" y="268" text-anchor="middle" font-size="14" font-weight="800" fill="#2563eb">10</text>

      
      <line x1="350" y1="242" x2="350" y2="248" stroke="#94a3b8" stroke-width="1" />
      <text x="350" y="268" text-anchor="middle" font-size="12" fill="#64748b">12</text>

      
      <line x1="400" y1="238" x2="400" y2="252" stroke="#334155" stroke-width="2" />
      <text x="400" y="268" text-anchor="middle" font-size="13" font-weight="700" fill="#1e2945">14</text>

      
      <line x1="450" y1="242" x2="450" y2="248" stroke="#94a3b8" stroke-width="1" />
      <text x="450" y="268" text-anchor="middle" font-size="12" fill="#64748b">16</text>

      
      <line x1="500" y1="238" x2="500" y2="252" stroke="#334155" stroke-width="2" />
      <text x="500" y="268" text-anchor="middle" font-size="13" font-weight="700" fill="#1e2945">18</text>

      
      <line x1="550" y1="240" x2="550" y2="250" stroke="#64748b" stroke-width="1.5" />
      <text x="550" y="268" text-anchor="middle" font-size="12" fill="#475569">20</text>
    </svg>
  </div>

  
  <div class="btn-group">
    <button class="filter-btn active" onclick="setMode('all', this)">Show All</button>
    <button class="filter-btn" onclick="setMode('left', this)">Lower 50%</button>
    <button class="filter-btn" onclick="setMode('right', this)">Upper 50%</button>
  </div>

  <script>
    function setMode(mode, btn) {
      document.querySelectorAll('.filter-btn').forEach(b => b.classList.remove('active'));
      btn.classList.add('active');

      const left = document.getElementById('leftHalf');
      const right = document.getElementById('rightHalf');

      if (mode === 'all') {
        left.classList.remove('dimmed');
        right.classList.remove('dimmed');
      } else if (mode === 'left') {
        left.classList.remove('dimmed');
        right.classList.add('dimmed');
      } else if (mode === 'right') {
        left.classList.add('dimmed');
        right.classList.remove('dimmed');
      }
    }
  </script>
</body>
</html>

Describing the Center of Data from Graphs

<!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: transparent;
      color: #1e293b;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100vh;
    }
    .diagram-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      width: 100%;
      max-width: 640px;
    }
    @media (max-width: 480px) {
      .diagram-grid {
        grid-template-columns: 1fr;
        gap: 16px;
      }
    }
    .chart-panel {
      display: flex;
      flex-direction: column;
      align-items: center;
      width: 100%;
    }
    .chart-title {
      font-size: 15px;
      font-weight: 700;
      margin-bottom: 6px;
      color: #0f172a;
      text-align: center;
    }
    svg {
      width: 100%;
      height: auto;
      max-width: 280px;
      overflow: visible;
    }
    .bar {
      fill: #bae6fd;
      stroke: #38bdf8;
      stroke-width: 1.5;
      rx: 2;
    }
    .bar-peak {
      fill: #7dd3fc;
    }
    .axis-line {
      stroke: #64748b;
      stroke-width: 1.5;
      stroke-linecap: round;
    }
    .axis-label {
      font-size: 11px;
      fill: #64748b;
      text-anchor: middle;
      font-weight: 600;
    }
    .line-sym {
      stroke: #2563eb;
      stroke-width: 2.5;
      stroke-dasharray: 4 3;
    }
    .line-median {
      stroke: #16a34a;
      stroke-width: 2.5;
      stroke-dasharray: 4 3;
    }
    .line-mean {
      stroke: #dc2626;
      stroke-width: 2.5;
      stroke-dasharray: 4 3;
    }
    .badge {
      font-size: 11px;
      font-weight: 700;
      padding: 3px 7px;
      border-radius: 4px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .badge-sym { background: #dbeafe; color: #1d4ed8; }
    .badge-median { background: #dcfce7; color: #15803d; }
    .badge-mean { background: #fee2e2; color: #b91c1c; }
    .legend {
      display: flex;
      flex-wrap: wrap;
      gap: 6px;
      justify-content: center;
      margin-top: 8px;
    }
    .arrow-tail {
      stroke: #ea580c;
      stroke-width: 1.5;
      fill: none;
      marker-end: url(#arrowhead);
    }
  </style>
</head>
<body>

  <div class="diagram-grid">
    
    <div class="chart-panel">
      <div class="chart-title">Symmetric Distribution</div>
      <svg viewBox="0 0 260 170" aria-label="Symmetric bell-shaped histogram">
        
        <rect class="bar" x="35"  y="125" width="20" height="15" />
        <rect class="bar" x="58"  y="100" width="20" height="40" />
        <rect class="bar" x="81"  y="65"  width="20" height="75" />
        <rect class="bar bar-peak" x="104" y="35"  width="20" height="105" />
        <rect class="bar bar-peak" x="127" y="35"  width="20" height="105" />
        <rect class="bar" x="150" y="65"  width="20" height="75" />
        <rect class="bar" x="173" y="100" width="20" height="40" />
        <rect class="bar" x="196" y="125" width="20" height="15" />

        
        <line class="axis-line" x1="25" y1="140" x2="235" y2="140" />
        <text class="axis-label" x="35" y="155">0</text>
        <text class="axis-label" x="125" y="155">50</text>
        <text class="axis-label" x="215" y="155">100</text>

        
        <line class="line-sym" x1="125" y1="20" x2="125" y2="140" />
      </svg>
      <div class="legend">
        <span class="badge badge-sym">Mean = Median = 50</span>
      </div>
    </div>

    
    <div class="chart-panel">
      <div class="chart-title">Right-Skewed Distribution</div>
      <svg viewBox="0 0 260 170" aria-label="Right-skewed histogram with tail stretching right">
        <defs>
          <marker id="arrowhead" markerWidth="6" markerHeight="6" refX="5" refY="3" orient="auto">
            <polygon points="0 0, 6 3, 0 6" fill="#ea580c" />
          </marker>
        </defs>

        
        <rect class="bar" x="35"  y="75"  width="18" height="65" />
        <rect class="bar bar-peak" x="55"  y="35"  width="18" height="105" />
        <rect class="bar" x="75"  y="60"  width="18" height="80" />
        <rect class="bar" x="95"  y="90"  width="18" height="50" />
        <rect class="bar" x="115" y="110" width="18" height="30" />
        <rect class="bar" x="135" y="122" width="18" height="18" />
        <rect class="bar" x="155" y="128" width="18" height="12" />
        <rect class="bar" x="175" y="132" width="18" height="8" />
        <rect class="bar" x="195" y="135" width="18" height="5" />

        
        <path class="arrow-tail" d="M 130 100 Q 170 95 205 115" />

        
        <line class="axis-line" x1="25" y1="140" x2="235" y2="140" />
        <text class="axis-label" x="35" y="155">0</text>
        <text class="axis-label" x="64" y="155">20</text>
        <text class="axis-label" x="215" y="155">100</text>

        
        <line class="line-median" x1="84" y1="20" x2="84" y2="140" />

        
        <line class="line-mean" x1="112" y1="20" x2="112" y2="140" />
      </svg>
      <div class="legend">
        <span class="badge badge-median">Median (Center of Data) = 30</span>
        <span class="badge badge-mean">Mean (Pulled by Tail) = 45</span>
      </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">
  <title>Balance Point Number Line</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      width: 100%;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      padding: 16px;
    }

    .controls {
      display: flex;
      gap: 8px;
      margin-bottom: 12px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .btn {
      padding: 8px 16px;
      font-size: 14px;
      font-weight: 600;
      border-radius: 8px;
      border: 1px solid #cbd5e1;
      background: #f8fafc;
      color: #475569;
      cursor: pointer;
      transition: background 0.2s, color 0.2s, border-color 0.2s;
    }

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

    .btn.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #2563eb;
    }

    .svg-container {
      width: 100%;
      max-width: 580px;
      height: auto;
    }

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

    .beam-group {
      transition: transform 0.45s cubic-bezier(0.34, 1.3, 0.64, 1);
    }

    .fulcrum-group {
      transition: transform 0.45s cubic-bezier(0.34, 1.3, 0.64, 1);
    }

    .status-badge {
      transition: fill 0.3s, stroke 0.3s;
    }
  </style>
</head>
<body>

  <div class="controls">
    <button class="btn" onclick="setFulcrum(5)">Fulcrum at 5</button>
    <button class="btn active" onclick="setFulcrum(6)">Fulcrum at 6</button>
    <button class="btn" onclick="setFulcrum(7)">Fulcrum at 7</button>
  </div>

  <div class="svg-container">
    <svg viewBox="0 0 600 320" aria-label="Balanced number line seesaw">
      
      <line x1="30" y1="240" x2="570" y2="240" stroke="#cbd5e1" stroke-width="3" stroke-linecap="round" />

      
      <g id="beamGroup" class="beam-group" transform="rotate(0, 325, 170)">
        
        <rect x="50" y="162" width="500" height="14" rx="5" fill="#334155" />

        
        
        <g fill="#64748b" font-size="14" font-weight="700" text-anchor="middle">
          
          <line x1="75" y1="162" x2="75" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="75" y="196">1</text>
          
          <line x1="125" y1="162" x2="125" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="125" y="196">2</text>
          
          <line x1="175" y1="162" x2="175" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="175" y="196">3</text>
          
          <line x1="225" y1="162" x2="225" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="225" y="196">4</text>
          
          <line x1="275" y1="162" x2="275" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="275" y="196">5</text>
          
          <line x1="325" y1="162" x2="325" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="325" y="196">6</text>
          
          <line x1="375" y1="162" x2="375" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="375" y="196">7</text>
          
          <line x1="425" y1="162" x2="425" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="425" y="196">8</text>
          
          <line x1="475" y1="162" x2="475" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="475" y="196">9</text>
          
          <line x1="525" y1="162" x2="525" y2="176" stroke="#94a3b8" stroke-width="2" />
          <text x="525" y="196">10</text>
        </g>

        
        
        <circle cx="225" cy="148" r="13" fill="#0ea5e9" stroke="#0284c7" stroke-width="2" />
        <circle cx="225" cy="120" r="13" fill="#0ea5e9" stroke="#0284c7" stroke-width="2" />

        
        <circle cx="325" cy="148" r="13" fill="#0ea5e9" stroke="#0284c7" stroke-width="2" />
        <circle cx="325" cy="120" r="13" fill="#0ea5e9" stroke="#0284c7" stroke-width="2" />
        <circle cx="325" cy="92" r="13" fill="#0ea5e9" stroke="#0284c7" stroke-width="2" />

        
        <circle cx="425" cy="148" r="13" fill="#0ea5e9" stroke="#0284c7" stroke-width="2" />
        <circle cx="425" cy="120" r="13" fill="#0ea5e9" stroke="#0284c7" stroke-width="2" />
      </g>

      
      <g id="fulcrumGroup" class="fulcrum-group" transform="translate(325, 0)">
        
        <polygon points="0,176 -28,240 28,240" fill="#f59e0b" stroke="#d97706" stroke-width="2" stroke-linejoin="round" />
        <circle cx="0" cy="176" r="3.5" fill="#b45309" />
      </g>

      
      <g id="statusGroup" transform="translate(300, 285)">
        <rect id="statusBg" x="-115" y="-18" width="230" height="34" rx="17" fill="#ecfdf5" stroke="#10b981" stroke-width="1.5" />
        <text id="statusText" x="0" y="4" font-size="14" font-weight="700" fill="#047857" text-anchor="middle">Balance Point = 6</text>
      </g>
    </svg>
  </div>

  <script>
    const configs = {
      5: {
        x: 275,
        rot: 6,
        text: 'Tilts Right (Center > 5)',
        textColor: '#b45309',
        bgColor: '#fffbeb',
        borderColor: '#f59e0b'
      },
      6: {
        x: 325,
        rot: 0,
        text: 'Balance Point = 6',
        textColor: '#047857',
        bgColor: '#ecfdf5',
        borderColor: '#10b981'
      },
      7: {
        x: 375,
        rot: -6,
        text: 'Tilts Left (Center < 7)',
        textColor: '#b45309',
        bgColor: '#fffbeb',
        borderColor: '#f59e0b'
      }
    };

    function setFulcrum(pos) {
      const cfg = configs[pos];
      if (!cfg) return;

      // Update buttons
      document.querySelectorAll('.btn').forEach(btn => {
        btn.classList.toggle('active', btn.textContent.includes(pos.toString()));
      });

      // Update beam rotation around current fulcrum point
      const beam = document.getElementById('beamGroup');
      beam.setAttribute('transform', `rotate(${cfg.rot}, ${cfg.x}, 176)`);

      // Update fulcrum position
      const fulcrum = document.getElementById('fulcrumGroup');
      fulcrum.setAttribute('transform', `translate(${cfg.x}, 0)`);

      // Update label
      const statusText = document.getElementById('statusText');
      const statusBg = document.getElementById('statusBg');
      statusText.textContent = cfg.text;
      statusText.setAttribute('fill', cfg.textColor);
      statusBg.setAttribute('fill', cfg.bgColor);
      statusBg.setAttribute('stroke', cfg.borderColor);
    }
  </script>
</body>
</html>

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

    .header-pill {
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 0.5px;
      text-transform: uppercase;
      color: #475569;
      background: #f1f5f9;
      padding: 4px 12px;
      border-radius: 999px;
      text-align: center;
    }

    .plot-container {
      width: 100%;
      max-width: 480px;
      position: relative;
      margin: 0 auto;
    }

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

    .axis-line {
      stroke: #94a3b8;
      stroke-width: 2.5;
      stroke-linecap: round;
    }

    .tick-line {
      stroke: #cbd5e1;
      stroke-width: 1.5;
    }

    .tick-label {
      font-size: 15px;
      font-weight: 700;
      fill: #475569;
      text-anchor: middle;
      dominant-baseline: hanging;
    }

    .dot {
      transition: fill 0.3s ease, stroke 0.3s ease, opacity 0.3s ease, filter 0.3s ease;
      cursor: pointer;
    }

    .dot.active {
      fill: #38bdf8;
      stroke: #0284c7;
      stroke-width: 2;
      opacity: 1;
    }

    .dot.crossed {
      fill: #e2e8f0;
      stroke: #94a3b8;
      stroke-width: 1.5;
      opacity: 0.4;
    }

    .dot.median {
      fill: #0284c7;
      stroke: #0369a1;
      stroke-width: 3;
      opacity: 1;
      filter: drop-shadow(0 0 6px rgba(2, 132, 199, 0.8));
    }

    .cross-line {
      stroke: #64748b;
      stroke-width: 2;
      stroke-linecap: round;
      opacity: 0;
      transition: opacity 0.3s ease;
      pointer-events: none;
    }

    .cross-line.visible {
      opacity: 0.8;
    }

    .median-badge {
      position: absolute;
      top: 6px;
      left: 57.2%;
      transform: translateX(-50%) translateY(4px);
      background: #0284c7;
      color: #ffffff;
      font-size: 13px;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 16px;
      box-shadow: 0 3px 10px rgba(2, 132, 199, 0.4);
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.3s ease, transform 0.3s ease;
      display: flex;
      align-items: center;
      gap: 4px;
      white-space: nowrap;
      z-index: 10;
    }

    .median-badge.visible {
      opacity: 1;
      transform: translateX(-50%) translateY(0);
    }

    .median-badge::after {
      content: '';
      position: absolute;
      bottom: -5px;
      left: 50%;
      transform: translateX(-50%);
      border-width: 5px 5px 0;
      border-style: solid;
      border-color: #0284c7 transparent transparent;
    }

    /* Stepper Controls */
    .controls {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      justify-content: center;
      gap: 5px;
      width: 100%;
      max-width: 480px;
    }

    .step-pills {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 4px;
    }

    .btn {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      color: #334155;
      font-size: 12px;
      font-weight: 600;
      padding: 4px 8px;
      border-radius: 6px;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-width: 28px;
      height: 30px;
      box-shadow: 0 1px 2px rgba(0,0,0,0.05);
      transition: background-color 0.15s, border-color 0.15s, color 0.15s;
    }

    .btn:active {
      background: #e2e8f0;
    }

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

    .btn-nav {
      font-size: 13px;
      padding: 4px 7px;
    }

    @media (max-width: 360px) {
      body {
        padding: 6px 8px;
        gap: 6px;
      }
      .btn {
        padding: 3px 6px;
        font-size: 11px;
        min-width: 26px;
        height: 28px;
      }
      .header-pill {
        font-size: 11px;
        padding: 3px 10px;
      }
    }
  </style>
</head>
<body>

  <div class="header-pill" id="stepLabel">9 Quiz Scores</div>

  <div class="plot-container">
    <div class="median-badge" id="medianBadge">✦ Median = 7</div>
    <svg viewBox="0 0 500 190" id="plotSvg" aria-label="Dot plot of quiz scores">
      
      <line x1="30" y1="150" x2="470" y2="150" class="axis-line" />
      
      
      
      <g>
        <line x1="70" y1="150" x2="70" y2="158" class="tick-line" />
        <text x="70" y="164" class="tick-label">4</text>

        <line x1="142" y1="150" x2="142" y2="158" class="tick-line" />
        <text x="142" y="164" class="tick-label">5</text>

        <line x1="214" y1="150" x2="214" y2="158" class="tick-line" />
        <text x="214" y="164" class="tick-label">6</text>

        <line x1="286" y1="150" x2="286" y2="158" class="tick-line" />
        <text x="286" y="164" class="tick-label">7</text>

        <line x1="358" y1="150" x2="358" y2="158" class="tick-line" />
        <text x="358" y="164" class="tick-label">8</text>

        <line x1="430" y1="150" x2="430" y2="158" class="tick-line" />
        <text x="430" y="164" class="tick-label">9</text>
      </g>

      
      
      
      
      <g id="dotGroup0">
        <circle id="dot0" cx="70" cy="130" r="11" class="dot active" />
        <line id="cross0a" x1="62" y1="122" x2="78" y2="138" class="cross-line" />
        <line id="cross0b" x1="78" y1="122" x2="62" y2="138" class="cross-line" />
      </g>

      
      <g id="dotGroup1">
        <circle id="dot1" cx="142" cy="130" r="11" class="dot active" />
        <line id="cross1a" x1="134" y1="122" x2="150" y2="138" class="cross-line" />
        <line id="cross1b" x1="150" y1="122" x2="134" y2="138" class="cross-line" />
      </g>

      
      <g id="dotGroup2">
        <circle id="dot2" cx="142" cy="104" r="11" class="dot active" />
        <line id="cross2a" x1="134" y1="96" x2="150" y2="112" class="cross-line" />
        <line id="cross2b" x1="150" y1="96" x2="134" y2="112" class="cross-line" />
      </g>

      
      <g id="dotGroup3">
        <circle id="dot3" cx="214" cy="130" r="11" class="dot active" />
        <line id="cross3a" x1="206" y1="122" x2="222" y2="138" class="cross-line" />
        <line id="cross3b" x1="222" y1="122" x2="206" y2="138" class="cross-line" />
      </g>

      
      <g id="dotGroup4">
        <circle id="dot4" cx="286" cy="130" r="11" class="dot active" />
      </g>

      
      <g id="dotGroup5">
        <circle id="dot5" cx="286" cy="104" r="11" class="dot active" />
        <line id="cross5a" x1="278" y1="96" x2="294" y2="112" class="cross-line" />
        <line id="cross5b" x1="294" y1="96" x2="278" y2="112" class="cross-line" />
      </g>

      
      <g id="dotGroup6">
        <circle id="dot6" cx="358" cy="104" r="11" class="dot active" />
        <line id="cross6a" x1="350" y1="96" x2="366" y2="112" class="cross-line" />
        <line id="cross6b" x1="366" y1="96" x2="350" y2="112" class="cross-line" />
      </g>

      
      <g id="dotGroup7">
        <circle id="dot7" cx="358" cy="130" r="11" class="dot active" />
        <line id="cross7a" x1="350" y1="122" x2="366" y2="138" class="cross-line" />
        <line id="cross7b" x1="366" y1="122" x2="350" y2="138" class="cross-line" />
      </g>

      
      <g id="dotGroup8">
        <circle id="dot8" cx="430" cy="130" r="11" class="dot active" />
        <line id="cross8a" x1="422" y1="122" x2="438" y2="138" class="cross-line" />
        <line id="cross8b" x1="438" y1="122" x2="422" y2="138" class="cross-line" />
      </g>
    </svg>
  </div>

  
  <div class="controls">
    <button class="btn btn-nav" id="prevBtn" title="Previous Step" aria-label="Previous Step">‹</button>
    <div class="step-pills" id="pillsContainer">
      <button class="btn active-step" data-step="0">Start</button>
      <button class="btn" data-step="1">Pair 1</button>
      <button class="btn" data-step="2">Pair 2</button>
      <button class="btn" data-step="3">Pair 3</button>
      <button class="btn" data-step="4">Center</button>
    </div>
    <button class="btn btn-nav" id="nextBtn" title="Next Step" aria-label="Next Step">›</button>
    <button class="btn btn-nav" id="playBtn" title="Auto Play" aria-label="Auto Play">▶</button>
  </div>

  <script>
    const stepsData = [
      { crossed: [], median: false, label: "9 Quiz Scores" },
      { crossed: [0, 8], median: false, label: "Cross ends: 4 & 9" },
      { crossed: [0, 8, 1, 7], median: false, label: "Cross next: 5 & 8" },
      { crossed: [0, 8, 1, 7, 2, 6], median: false, label: "Cross next: 5 & 8" },
      { crossed: [0, 8, 1, 7, 2, 6, 3, 5], median: true, label: "Center Score = Median (7)" }
    ];

    let currentStep = 0;
    let timer = null;

    const medianBadge = document.getElementById('medianBadge');
    const stepLabel = document.getElementById('stepLabel');
    const playBtn = document.getElementById('playBtn');
    const pillButtons = document.querySelectorAll('.step-pills .btn');

    function renderStep(idx) {
      currentStep = idx;
      const data = stepsData[idx];

      stepLabel.textContent = data.label;

      // Update dots and cross lines
      for (let i = 0; i <= 8; i++) {
        const dot = document.getElementById(`dot${i}`);
        const crossA = document.getElementById(`cross${i}a`);
        const crossB = document.getElementById(`cross${i}b`);

        const isCrossed = data.crossed.includes(i);
        const isMedian = (i === 4 && data.median);

        if (dot) {
          dot.setAttribute('class', 'dot ' + (isMedian ? 'median' : (isCrossed ? 'crossed' : 'active')));
        }
        if (crossA && crossB) {
          const crossClass = 'cross-line ' + (isCrossed ? 'visible' : '');
          crossA.setAttribute('class', crossClass);
          crossB.setAttribute('class', crossClass);
        }
      }

      // Median badge
      if (data.median) {
        medianBadge.classList.add('visible');
      } else {
        medianBadge.classList.remove('visible');
      }

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

    function setStep(idx) {
      renderStep(idx);
    }

    function next() {
      setStep((currentStep + 1) % stepsData.length);
    }

    function prev() {
      setStep((currentStep - 1 + stepsData.length) % stepsData.length);
    }

    function togglePlay() {
      if (timer) {
        clearInterval(timer);
        timer = null;
        playBtn.textContent = '▶';
        playBtn.title = 'Auto Play';
      } else {
        playBtn.textContent = '⏸';
        playBtn.title = 'Pause';
        timer = setInterval(() => {
          next();
        }, 2500);
      }
    }

    // Attach events
    document.getElementById('nextBtn').addEventListener('click', () => {
      if (timer) togglePlay();
      next();
    });

    document.getElementById('prevBtn').addEventListener('click', () => {
      if (timer) togglePlay();
      prev();
    });

    playBtn.addEventListener('click', togglePlay);

    pillButtons.forEach(btn => {
      btn.addEventListener('click', (e) => {
        if (timer) togglePlay();
        const stepNum = parseInt(e.currentTarget.getAttribute('data-step'), 10);
        setStep(stepNum);
      });
    });

    // Start in initial state
    renderStep(0);
  </script>
</body>
</html>

111.26(b)(12)(B)

Aligned learning resources

Related diagrams