<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    }

    body {
      width: 100%;
      background: transparent;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 12px 10px;
      user-select: none;
    }

    /* Controls */
    .controls {
      display: flex;
      gap: 8px;
      margin-bottom: 12px;
      width: 100%;
      max-width: 420px;
      justify-content: center;
    }

    .tab-btn {
      flex: 1;
      padding: 7px 10px;
      font-size: 13px;
      font-weight: 700;
      border: 1px solid #e2e8f0;
      border-radius: 20px;
      background: #ffffff;
      color: #64748b;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      transition: all 0.25s ease;
      box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    }

    .tab-btn.active-snail {
      background: #ecfdf5;
      color: #047857;
      border-color: #10b981;
      box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.2);
    }

    .tab-btn.active-worm {
      background: #fff7ed;
      color: #c2410c;
      border-color: #f97316;
      box-shadow: 0 0 0 2px rgba(249, 115, 22, 0.2);
    }

    /* Tree Diagram Area */
    .tree-container {
      position: relative;
      width: 100%;
      max-width: 440px;
      height: 330px;
    }

    svg.connections {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
      z-index: 1;
    }

    .path-line {
      fill: none;
      stroke: #cbd5e1;
      stroke-width: 3;
      stroke-linecap: round;
      stroke-linejoin: round;
      transition: stroke 0.3s ease, stroke-width 0.3s ease, opacity 0.3s ease;
    }

    .path-line.snail-active {
      stroke: #10b981;
      stroke-width: 4.5;
    }

    .path-line.worm-active {
      stroke: #f97316;
      stroke-width: 4.5;
    }

    .path-line.dimmed {
      opacity: 0.25;
    }

    /* Tree Nodes */
    .node {
      position: absolute;
      z-index: 2;
      transform: translate(-50%, -50%);
      background: #ffffff;
      border: 2px solid #cbd5e1;
      border-radius: 12px;
      padding: 6px 14px;
      font-size: 14px;
      font-weight: 700;
      color: #334155;
      box-shadow: 0 2px 6px rgba(0,0,0,0.06);
      transition: all 0.3s ease;
      white-space: nowrap;
      text-align: center;
    }

    /* Specific Node Positions */
    #node-root {
      top: 10%;
      left: 50%;
      background: #f8fafc;
      border-color: #94a3b8;
    }

    #node-question {
      top: 42%;
      left: 50%;
      background: #ffffff;
      border-color: #94a3b8;
      border-radius: 20px;
      padding: 7px 16px;
    }

    /* Branch Decision Badges */
    .badge {
      position: absolute;
      z-index: 3;
      transform: translate(-50%, -50%);
      padding: 3px 10px;
      border-radius: 10px;
      font-size: 12px;
      font-weight: 800;
      background: #f1f5f9;
      color: #64748b;
      border: 1.5px solid #cbd5e1;
      transition: all 0.3s ease;
    }

    #badge-yes {
      top: 64%;
      left: 24%;
    }

    #badge-no {
      top: 64%;
      left: 76%;
    }

    /* Leaf Cards */
    .leaf-card {
      position: absolute;
      top: 86%;
      z-index: 2;
      transform: translate(-50%, -50%);
      width: 130px;
      padding: 8px 4px;
      background: #ffffff;
      border: 2px solid #cbd5e1;
      border-radius: 14px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 3px;
      box-shadow: 0 4px 10px rgba(0,0,0,0.06);
      transition: all 0.3s ease;
    }

    #leaf-snail {
      left: 24%;
    }

    #leaf-worm {
      left: 76%;
    }

    .organism-icon {
      font-size: 32px;
      line-height: 1;
    }

    .organism-name {
      font-size: 14px;
      font-weight: 800;
      color: #1e2945;
    }

    /* Dynamic Highlighting States */
    .mode-snail #node-root,
    .mode-snail #node-question {
      border-color: #10b981;
      box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
    }

    .mode-snail #badge-yes {
      background: #10b981;
      border-color: #059669;
      color: #ffffff;
      transform: translate(-50%, -50%) scale(1.08);
      box-shadow: 0 2px 8px rgba(16, 185, 129, 0.3);
    }

    .mode-snail #leaf-snail {
      border-color: #10b981;
      background: #ecfdf5;
      transform: translate(-50%, -50%) scale(1.04);
      box-shadow: 0 6px 16px rgba(16, 185, 129, 0.22);
    }

    .mode-worm #node-root,
    .mode-worm #node-question {
      border-color: #f97316;
      box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.15);
    }

    .mode-worm #badge-no {
      background: #f97316;
      border-color: #ea580c;
      color: #ffffff;
      transform: translate(-50%, -50%) scale(1.08);
      box-shadow: 0 2px 8px rgba(249, 115, 22, 0.3);
    }

    .mode-worm #leaf-worm {
      border-color: #f97316;
      background: #fff7ed;
      transform: translate(-50%, -50%) scale(1.04);
      box-shadow: 0 6px 16px rgba(249, 115, 22, 0.22);
    }

    .mode-snail #leaf-worm,
    .mode-snail #badge-no,
    .mode-worm #leaf-snail,
    .mode-worm #badge-yes {
      opacity: 0.35;
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="tab-btn active-snail" id="btn-snail" onclick="setMode('snail')">
      <span>🐌</span> Snail Path
    </button>
    <button class="tab-btn" id="btn-worm" onclick="setMode('worm')">
      <span>🪱</span> Earthworm Path
    </button>
  </div>

  
  <div class="tree-container mode-snail" id="tree">
    <svg class="connections" viewBox="0 0 440 330" preserveAspectRatio="none">
      
      <line id="line-trunk" class="path-line snail-active" x1="220" y1="33" x2="220" y2="138" />

      
      <path id="line-snail" class="path-line snail-active" d="M 220,140 C 220,195 106,190 106,284" />

      
      <path id="line-worm" class="path-line dimmed" d="M 220,140 C 220,195 334,190 334,284" />
    </svg>

    
    <div class="node" id="node-root">No Legs</div>

    
    <div class="node" id="node-question">Has a Shell?</div>

    
    <div class="badge" id="badge-yes">Yes</div>
    <div class="badge" id="badge-no">No</div>

    
    <div class="leaf-card" id="leaf-snail">
      <div class="organism-icon">🐌</div>
      <div class="organism-name">Snail</div>
    </div>

    
    <div class="leaf-card" id="leaf-worm">
      <div class="organism-icon">🪱</div>
      <div class="organism-name">Earthworm</div>
    </div>
  </div>

  <script>
    function setMode(mode) {
      const tree = document.getElementById('tree');
      const btnSnail = document.getElementById('btn-snail');
      const btnWorm = document.getElementById('btn-worm');
      const lineTrunk = document.getElementById('line-trunk');
      const lineSnail = document.getElementById('line-snail');
      const lineWorm = document.getElementById('line-worm');

      if (mode === 'snail') {
        tree.className = 'tree-container mode-snail';
        btnSnail.className = 'tab-btn active-snail';
        btnWorm.className = 'tab-btn';

        lineTrunk.className = 'path-line snail-active';
        lineSnail.className = 'path-line snail-active';
        lineWorm.className = 'path-line dimmed';
      } else {
        tree.className = 'tree-container mode-worm';
        btnSnail.className = 'tab-btn';
        btnWorm.className = 'tab-btn active-worm';

        lineTrunk.className = 'path-line worm-active';
        lineSnail.className = 'path-line dimmed';
        lineWorm.className = 'path-line worm-active';
      }
    }

    // Direct organism tap triggers matching path
    document.getElementById('leaf-snail').onclick = () => setMode('snail');
    document.getElementById('leaf-worm').onclick = () => setMode('worm');
    document.getElementById('badge-yes').onclick = () => setMode('snail');
    document.getElementById('badge-no').onclick = () => setMode('worm');
  </script>
</body>
</html>

Reading and Following a Branching Classification Key

<!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: #f8fafc;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 10px 8px;
      user-select: none;
    }
    .instructions {
      font-size: 13px;
      font-weight: 600;
      color: #64748b;
      margin-bottom: 4px;
      text-align: center;
    }
    .svg-container {
      width: 100%;
      max-width: 580px;
      position: relative;
    }
    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
    }
    .branch-line {
      stroke: #cbd5e1;
      stroke-width: 3;
      stroke-linecap: round;
      fill: none;
      transition: stroke 0.3s ease, stroke-width 0.3s ease;
    }
    .branch-line.active {
      stroke: #22b7ff;
      stroke-width: 4;
    }
    .node-card {
      cursor: pointer;
      transition: transform 0.2s ease, filter 0.2s ease;
    }
    .node-card:active {
      transform: scale(0.98);
    }
    .card-rect {
      fill: #ffffff;
      stroke: #e2e8f0;
      stroke-width: 1.5;
      rx: 14;
      ry: 14;
      filter: drop-shadow(0 3px 6px rgba(30, 41, 69, 0.06));
      transition: stroke 0.3s ease, fill 0.3s ease;
    }
    .node-card.active .card-rect {
      stroke: #22b7ff;
      stroke-width: 2.5;
      fill: #f0f9ff;
    }
    .node-title {
      font-size: 13px;
      font-weight: 700;
      fill: #1e2945;
      text-anchor: middle;
      dominant-baseline: middle;
    }
    .leaf-card .card-rect {
      rx: 16;
      ry: 16;
    }
    .leaf-emoji {
      font-size: 26px;
      text-anchor: middle;
      dominant-baseline: middle;
    }
    .leaf-name {
      font-size: 13px;
      font-weight: 700;
      fill: #1e2945;
      text-anchor: middle;
      dominant-baseline: middle;
    }
    .badge-rect {
      rx: 10;
      ry: 10;
    }
    .badge-no {
      fill: #fee2e2;
    }
    .badge-no-text {
      font-size: 11px;
      font-weight: 800;
      fill: #dc2626;
      text-anchor: middle;
      dominant-baseline: middle;
    }
    .badge-yes {
      fill: #dcfce7;
    }
    .badge-yes-text {
      font-size: 11px;
      font-weight: 800;
      fill: #16a34a;
      text-anchor: middle;
      dominant-baseline: middle;
    }
    .btn-row {
      display: flex;
      flex-wrap: wrap;
      gap: 6px;
      justify-content: center;
      margin-top: 6px;
      width: 100%;
    }
    .filter-btn {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 20px;
      padding: 5px 12px;
      font-size: 12px;
      font-weight: 700;
      color: #1e2945;
      cursor: pointer;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
      transition: all 0.2s ease;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .filter-btn:hover {
      border-color: #22b7ff;
    }
    .filter-btn.active {
      background: #22b7ff;
      border-color: #22b7ff;
      color: #ffffff;
      box-shadow: 0 2px 6px rgba(34, 183, 255, 0.35);
    }
  </style>
</head>
<body>

  <div class="instructions">Tap any animal to trace its path:</div>

  <div class="svg-container">
    <svg viewBox="0 0 540 370">
      <defs>
        <marker id="arrow-default" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1.5 L 8 5 L 0 8.5 z" fill="#cbd5e1" />
        </marker>
        <marker id="arrow-active" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1.5 L 8 5 L 0 8.5 z" fill="#22b7ff" />
        </marker>
      </defs>

      
      
      <path id="line-root-left" class="branch-line" d="M 270 54 L 140 106" marker-end="url(#arrow-default)" />
      
      <path id="line-root-right" class="branch-line" d="M 270 54 L 400 106" marker-end="url(#arrow-default)" />

      
      
      <path id="line-shell-snail" class="branch-line" d="M 140 162 L 72 236" marker-end="url(#arrow-default)" />
      
      <path id="line-shell-worm" class="branch-line" d="M 140 162 L 208 236" marker-end="url(#arrow-default)" />
      
      <path id="line-wings-ladybug" class="branch-line" d="M 400 162 L 332 236" marker-end="url(#arrow-default)" />
      
      <path id="line-wings-spider" class="branch-line" d="M 400 162 L 468 236" marker-end="url(#arrow-default)" />

      
      
      <g transform="translate(182, 64)">
        <rect class="badge-rect badge-no" x="-18" y="-10" width="36" height="20" />
        <text class="badge-no-text" x="0" y="1">No</text>
      </g>
      
      <g transform="translate(358, 64)">
        <rect class="badge-rect badge-yes" x="-19" y="-10" width="38" height="20" />
        <text class="badge-yes-text" x="0" y="1">Yes</text>
      </g>

      
      <g transform="translate(90, 185)">
        <rect class="badge-rect badge-yes" x="-18" y="-9" width="36" height="18" />
        <text class="badge-yes-text" x="0" y="1">Yes</text>
      </g>
      
      <g transform="translate(190, 185)">
        <rect class="badge-rect badge-no" x="-17" y="-9" width="34" height="18" />
        <text class="badge-no-text" x="0" y="1">No</text>
      </g>

      
      <g transform="translate(350, 185)">
        <rect class="badge-rect badge-yes" x="-18" y="-9" width="36" height="18" />
        <text class="badge-yes-text" x="0" y="1">Yes</text>
      </g>
      
      <g transform="translate(450, 185)">
        <rect class="badge-rect badge-no" x="-17" y="-9" width="34" height="18" />
        <text class="badge-no-text" x="0" y="1">No</text>
      </g>

      
      <g id="node-root" class="node-card" transform="translate(270, 32)">
        <rect class="card-rect" x="-95" y="-22" width="190" height="44" />
        <text class="node-title" x="0" y="1">Does it have legs?</text>
      </g>

      
      <g id="node-shell" class="node-card" transform="translate(140, 138)">
        <rect class="card-rect" x="-85" y="-22" width="170" height="44" />
        <text class="node-title" x="0" y="1">Does it have a shell?</text>
      </g>

      
      <g id="node-wings" class="node-card" transform="translate(400, 138)">
        <rect class="card-rect" x="-85" y="-22" width="170" height="44" />
        <text class="node-title" x="0" y="1">Does it have wings?</text>
      </g>

      
      
      <g id="leaf-snail" class="node-card leaf-card" transform="translate(72, 290)" onclick="selectTarget('snail')">
        <rect class="card-rect" x="-58" y="-42" width="116" height="84" />
        <text class="leaf-emoji" x="0" y="-12">🐌</text>
        <text class="leaf-name" x="0" y="24">Snail</text>
      </g>

      
      <g id="leaf-worm" class="node-card leaf-card" transform="translate(208, 290)" onclick="selectTarget('worm')">
        <rect class="card-rect" x="-58" y="-42" width="116" height="84" />
        <text class="leaf-emoji" x="0" y="-12">🪱</text>
        <text class="leaf-name" x="0" y="24">Earthworm</text>
      </g>

      
      <g id="leaf-ladybug" class="node-card leaf-card" transform="translate(332, 290)" onclick="selectTarget('ladybug')">
        <rect class="card-rect" x="-58" y="-42" width="116" height="84" />
        <text class="leaf-emoji" x="0" y="-12">🐞</text>
        <text class="leaf-name" x="0" y="24">Ladybug</text>
      </g>

      
      <g id="leaf-spider" class="node-card leaf-card" transform="translate(468, 290)" onclick="selectTarget('spider')">
        <rect class="card-rect" x="-58" y="-42" width="116" height="84" />
        <text class="leaf-emoji" x="0" y="-12">🕷️</text>
        <text class="leaf-name" x="0" y="24">Spider</text>
      </g>
    </svg>
  </div>

  <div class="btn-row">
    <button class="filter-btn" id="btn-snail" onclick="selectTarget('snail')">🐌 Snail</button>
    <button class="filter-btn" id="btn-worm" onclick="selectTarget('worm')">🪱 Earthworm</button>
    <button class="filter-btn" id="btn-ladybug" onclick="selectTarget('ladybug')">🐞 Ladybug</button>
    <button class="filter-btn" id="btn-spider" onclick="selectTarget('spider')">🕷️ Spider</button>
  </div>

  <script>
    const paths = {
      snail: {
        nodes: ['node-root', 'node-shell', 'leaf-snail'],
        lines: ['line-root-left', 'line-shell-snail']
      },
      worm: {
        nodes: ['node-root', 'node-shell', 'leaf-worm'],
        lines: ['line-root-left', 'line-shell-worm']
      },
      ladybug: {
        nodes: ['node-root', 'node-wings', 'leaf-ladybug'],
        lines: ['line-root-right', 'line-wings-ladybug']
      },
      spider: {
        nodes: ['node-root', 'node-wings', 'leaf-spider'],
        lines: ['line-root-right', 'line-wings-spider']
      }
    };

    let activeKey = null;

    function selectTarget(key) {
      if (activeKey === key) {
        clearSelection();
        return;
      }
      activeKey = key;

      // Clear all
      document.querySelectorAll('.node-card').forEach(el => el.classList.remove('active'));
      document.querySelectorAll('.branch-line').forEach(el => {
        el.classList.remove('active');
        el.setAttribute('marker-end', 'url(#arrow-default)');
      });
      document.querySelectorAll('.filter-btn').forEach(el => el.classList.remove('active'));

      // Activate path
      const p = paths[key];
      p.nodes.forEach(id => {
        const el = document.getElementById(id);
        if (el) el.classList.add('active');
      });
      p.lines.forEach(id => {
        const el = document.getElementById(id);
        if (el) {
          el.classList.add('active');
          el.setAttribute('marker-end', 'url(#arrow-active)');
        }
      });

      const btn = document.getElementById('btn-' + key);
      if (btn) btn.classList.add('active');
    }

    function clearSelection() {
      activeKey = null;
      document.querySelectorAll('.node-card').forEach(el => el.classList.remove('active'));
      document.querySelectorAll('.branch-line').forEach(el => {
        el.classList.remove('active');
        el.setAttribute('marker-end', 'url(#arrow-default)');
      });
      document.querySelectorAll('.filter-btn').forEach(el => el.classList.remove('active'));
    }

    // Default resting highlight to ladybug to instantly show structure
    selectTarget('ladybug');
  </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;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px 8px;
      user-select: none;
    }
    .diagram-wrap {
      width: 100%;
      max-width: 440px;
      position: relative;
    }
    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
    }

    /* Node & Line styling */
    .branch-line {
      fill: none;
      stroke: #cbd5e1;
      stroke-width: 2.5;
      stroke-linecap: round;
      stroke-linejoin: round;
      transition: stroke 0.4s ease, stroke-width 0.4s ease;
    }
    .active-path {
      stroke-dasharray: 200;
      stroke-dashoffset: 200;
      transition: stroke-dashoffset 0.8s ease-in-out, stroke 0.4s ease, stroke-width 0.4s ease;
    }
    .node-box {
      fill: #ffffff;
      stroke: #cbd5e1;
      stroke-width: 1.5;
      rx: 8;
      transition: stroke 0.4s ease, filter 0.4s ease, fill 0.4s ease;
    }
    .node-text {
      font-size: 12px;
      font-weight: 600;
      fill: #334155;
      text-anchor: middle;
      dominant-baseline: central;
      pointer-events: none;
    }
    .node-title {
      font-size: 13px;
      font-weight: 700;
      fill: #1e2945;
    }
    .badge-step {
      font-size: 10px;
      font-weight: 800;
      fill: #ffffff;
      text-anchor: middle;
      dominant-baseline: central;
    }
    .branch-tag {
      font-size: 11px;
      font-weight: 700;
      text-anchor: middle;
      dominant-baseline: central;
    }
    .tag-yes { fill: #16a34a; }
    .tag-no { fill: #94a3b8; }

    /* Highlights */
    .highlight-node {
      stroke: #16a34a;
      stroke-width: 2.5;
      filter: drop-shadow(0 2px 6px rgba(22, 163, 74, 0.25));
    }
    .highlight-line {
      stroke: #16a34a;
      stroke-width: 3.5;
      stroke-dashoffset: 0;
    }
    .celebrate-node {
      stroke: #16a34a;
      stroke-width: 2.5;
      fill: #f0fdf4;
      filter: drop-shadow(0 0 10px rgba(34, 197, 94, 0.45));
    }

    /* Controls bar */
    .controls {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      margin-top: 10px;
      width: 100%;
    }
    .btn {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      color: #334155;
      font-size: 13px;
      font-weight: 600;
      padding: 6px 14px;
      border-radius: 20px;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 5px;
      transition: background 0.2s, border-color 0.2s, color 0.2s;
    }
    .btn:hover {
      background: #e2e8f0;
    }
    .btn.active {
      background: #16a34a;
      border-color: #16a34a;
      color: #ffffff;
    }
    .btn-play {
      padding: 6px 12px;
      font-size: 12px;
    }
  </style>
</head>
<body>

  <div class="diagram-wrap">
    <svg viewBox="0 0 380 270">
      <defs>
        <filter id="glow-badge" x="-20%" y="-20%" width="140%" height="140%">
          <feDropShadow dx="0" dy="1" stdDeviation="2" flood-color="#16a34a" flood-opacity="0.3"/>
        </filter>
      </defs>

      
      <path class="branch-line" d="M 190,44 L 190,68 L 75,68 L 75,100" />
      <path class="branch-line" d="M 285,144 L 285,170 L 215,170 L 215,200" />

      
      <path class="branch-line" d="M 190,44 L 190,68 L 285,68 L 285,100" />
      <path id="path1" class="branch-line active-path" d="M 190,44 L 190,68 L 285,68 L 285,100" />

      
      <path class="branch-line" d="M 285,144 L 285,170 L 325,170 L 325,200" />
      <path id="path2" class="branch-line active-path" d="M 285,144 L 285,170 L 325,170 L 325,200" />

      
      <text class="branch-tag tag-no" x="125" y="62">No</text>
      <text class="branch-tag tag-yes" x="245" y="62">Yes ✓</text>
      <text class="branch-tag tag-no" x="244" y="164">No</text>
      <text class="branch-tag tag-yes" x="312" y="164">Yes ✓</text>

      
      <g id="node-root" transform="translate(130, 8)">
        <rect id="rect-root" class="node-box highlight-node" width="120" height="38" />
        <text class="node-text node-title" x="60" y="19">Has legs?</text>
        <g id="badge1">
          <circle cx="0" cy="0" r="10" fill="#16a34a" filter="url(#glow-badge)"/>
          <text class="badge-step" x="0" y="0">1</text>
        </g>
      </g>

      
      <g transform="translate(25, 100)">
        <rect class="node-box" width="100" height="38" fill="#f8fafc" />
        <text class="node-text" x="50" y="19">Earthworm 🪱</text>
      </g>

      
      <g id="node-wings" transform="translate(225, 100)">
        <rect id="rect-wings" class="node-box" width="120" height="38" />
        <text class="node-text node-title" x="60" y="19">Has wings?</text>
        <g id="badge2" opacity="0.4">
          <circle cx="0" cy="0" r="10" fill="#64748b"/>
          <text class="badge-step" x="0" y="0">2</text>
        </g>
      </g>

      
      <g transform="translate(170, 200)">
        <rect class="node-box" width="90" height="38" fill="#f8fafc" />
        <text class="node-text" x="45" y="19">Ant 🐜</text>
      </g>

      
      <g id="node-ladybug" transform="translate(275, 200)">
        <rect id="rect-ladybug" class="node-box" width="100" height="38" />
        <text class="node-text node-title" x="50" y="19">Ladybug 🐞</text>
      </g>
    </svg>
  </div>

  <div class="controls">
    <button id="btn-step1" class="btn active">Step 1</button>
    <button id="btn-step2" class="btn">Step 2</button>
    <button id="btn-play" class="btn btn-play" title="Toggle Auto-Play">⏸</button>
  </div>

  <script>
    let currentStep = 1;
    let isPlaying = true;
    let timer = null;

    const path1 = document.getElementById('path1');
    const path2 = document.getElementById('path2');
    const rectRoot = document.getElementById('rect-root');
    const rectWings = document.getElementById('rect-wings');
    const rectLadybug = document.getElementById('rect-ladybug');
    const badge2 = document.getElementById('badge2');
    const badge2Circle = badge2.querySelector('circle');
    const btnStep1 = document.getElementById('btn-step1');
    const btnStep2 = document.getElementById('btn-step2');
    const btnPlay = document.getElementById('btn-play');

    function renderState(step) {
      currentStep = step;
      if (step === 1) {
        btnStep1.classList.add('active');
        btnStep2.classList.remove('active');

        rectRoot.classList.add('highlight-node');
        path1.classList.add('highlight-line');

        rectWings.classList.remove('highlight-node');
        path2.classList.remove('highlight-line');
        rectLadybug.classList.remove('celebrate-node');

        badge2.style.opacity = '0.4';
        badge2Circle.setAttribute('fill', '#64748b');
      } else {
        btnStep1.classList.remove('active');
        btnStep2.classList.add('active');

        rectRoot.classList.remove('highlight-node');
        path1.classList.add('highlight-line');

        rectWings.classList.add('highlight-node');
        path2.classList.add('highlight-line');
        rectLadybug.classList.add('celebrate-node');

        badge2.style.opacity = '1';
        badge2Circle.setAttribute('fill', '#16a34a');
      }
    }

    function goTo(step) {
      renderState(step);
    }

    function togglePlay() {
      isPlaying = !isPlaying;
      btnPlay.textContent = isPlaying ? '⏸' : '▶';
      if (isPlaying) startLoop();
      else clearInterval(timer);
    }

    function startLoop() {
      clearInterval(timer);
      timer = setInterval(() => {
        if (!isPlaying) return;
        goTo(currentStep === 1 ? 2 : 1);
      }, 3500);
    }

    btnStep1.addEventListener('click', () => { goTo(1); });
    btnStep2.addEventListener('click', () => { goTo(2); });
    btnPlay.addEventListener('click', togglePlay);

    renderState(1);
    startLoop();
  </script>
</body>
</html>

science.ks2.y2.t1.s2

Aligned learning resources

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