<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      min-height: 100%;
    }
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
      width: 100%;
    }
    @media (max-width: 480px) {
      .cards-grid {
        grid-template-columns: 1fr;
        gap: 8px;
      }
    }
    .beak-card {
      background: #f8fafc;
      border: 2px solid #e2e8f0;
      border-radius: 14px;
      padding: 10px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      transition: border-color 0.25s ease, box-shadow 0.25s ease, background-color 0.25s ease;
      user-select: none;
    }
    .beak-card:hover {
      border-color: #cbd5e1;
    }
    .beak-card.active {
      border-color: #0284c7;
      background: #f0f9ff;
      box-shadow: 0 4px 12px rgba(2, 132, 199, 0.12);
    }
    .beak-card.card-1.active {
      border-color: #d97706;
      background: #fffbeb;
      box-shadow: 0 4px 12px rgba(217, 119, 6, 0.12);
    }
    .beak-card.card-2.active {
      border-color: #db2777;
      background: #fdf2f8;
      box-shadow: 0 4px 12px rgba(219, 39, 119, 0.12);
    }
    .card-title {
      font-size: 14px;
      font-weight: 700;
      color: #334155;
      margin-bottom: 2px;
    }
    .beak-shape {
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      margin-bottom: 6px;
    }
    .svg-stage {
      width: 100%;
      height: 95px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .svg-stage svg {
      width: 100%;
      height: 100%;
      max-height: 95px;
    }
    .food-tag {
      margin-top: 6px;
      font-size: 12px;
      font-weight: 600;
      padding: 3px 8px;
      border-radius: 20px;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      color: #475569;
    }
    .main-banner {
      background: linear-gradient(135deg, #0284c7 0%, #0369a1 100%);
      color: #ffffff;
      border-radius: 12px;
      padding: 10px 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      font-weight: 700;
      font-size: 14px;
      text-align: center;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.2);
    }
    .badge-no-teeth {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      background: #ffffff;
      color: #b91c1c;
      padding: 3px 8px;
      border-radius: 16px;
      font-size: 12px;
      font-weight: 800;
      letter-spacing: 0.3px;
      border: 1px solid #fecaca;
    }
    .strike-icon {
      font-size: 14px;
      line-height: 1;
    }
  </style>
</head>
<body>

  
  <div class="cards-grid">
    
    
    <div class="beak-card card-1 active" onclick="selectCard(0)" id="card-0">
      <div class="card-title">Sparrow</div>
      <div class="beak-shape">Short &amp; Stout</div>
      <div class="svg-stage">
        <svg viewBox="0 0 140 100">
          
          <circle cx="50" cy="52" r="32" fill="#d97706" />
          <circle cx="50" cy="52" r="28" fill="#b45309" />
          <circle cx="54" cy="56" r="22" fill="#fed7aa" />
          
          <circle cx="44" cy="42" r="5" fill="#1e293b" />
          <circle cx="42.5" cy="40.5" r="1.8" fill="#ffffff" />
          
          <polygon points="68,36 100,52 68,52" fill="#f59e0b" stroke="#78350f" stroke-width="1.5" stroke-linejoin="round" />
          <polygon points="68,52 100,52 68,64" fill="#d97706" stroke="#78350f" stroke-width="1.5" stroke-linejoin="round" />
          
          <g transform="translate(94, 46)">
            <ellipse cx="12" cy="6" rx="9" ry="6" fill="#1e293b" stroke="#475569" stroke-width="1" transform="rotate(-15, 12, 6)" />
            
            <path d="M7 6 L12 4 L16 7" fill="none" stroke="#fbbf24" stroke-width="1.5" stroke-linecap="round" />
            
            <ellipse cx="14" cy="3" rx="3" ry="2" fill="#fef08a" />
          </g>
        </svg>
      </div>
      <div class="food-tag">Cracks Seeds 🌻</div>
    </div>

    
    <div class="beak-card card-2" onclick="selectCard(1)" id="card-1">
      <div class="card-title">Hummingbird</div>
      <div class="beak-shape">Long &amp; Slender</div>
      <div class="svg-stage">
        <svg viewBox="0 0 140 100">
          
          <circle cx="34" cy="50" r="24" fill="#059669" />
          <circle cx="36" cy="52" r="18" fill="#10b981" />
          
          <path d="M30 54 Q42 66 48 56 Z" fill="#db2777" />
          
          <circle cx="30" cy="44" r="4.5" fill="#1e293b" />
          <circle cx="28.5" cy="42.5" r="1.5" fill="#ffffff" />
          
          <polygon points="46,47 106,53 46,50" fill="#334155" />
          <polygon points="46,50 106,53 46,53" fill="#1e293b" />
          
          <g transform="translate(100, 36)">
            
            <path d="M12 17 C20 4, 30 10, 24 17 C32 18, 30 30, 22 25 C20 32, 10 30, 12 17 Z" fill="#f43f5e" />
            
            <ellipse cx="10" cy="17" rx="3" ry="6" fill="#fb7185" />
            
            <circle cx="7" cy="17" r="2.5" fill="#38bdf8" />
          </g>
        </svg>
      </div>
      <div class="food-tag">Sips Nectar 🌺</div>
    </div>

    
    <div class="beak-card card-3" onclick="selectCard(2)" id="card-2">
      <div class="card-title">Eagle</div>
      <div class="beak-shape">Sharp &amp; Hooked</div>
      <div class="svg-stage">
        <svg viewBox="0 0 140 100">
          
          <circle cx="48" cy="52" r="32" fill="#ffffff" stroke="#e2e8f0" stroke-width="1.5" />
          
          <circle cx="44" cy="42" r="5.5" fill="#fbbf24" stroke="#78350f" stroke-width="1" />
          <circle cx="44" cy="42" r="3.2" fill="#1e293b" />
          <circle cx="42.5" cy="40.5" r="1.2" fill="#ffffff" />
          
          <path d="M35 37 Q46 36 54 41" fill="none" stroke="#64748b" stroke-width="2" stroke-linecap="round" />
          
          
          <path d="M64 38 L75 42 L72 58 L62 58 Z" fill="#facc15" />
          
          <path d="M74 42 Q94 44 98 56 Q94 68 84 66 Q88 56 72 58 Z" fill="#f59e0b" stroke="#b45309" stroke-width="1" />
          
          <g transform="translate(86, 56) rotate(35)">
            <ellipse cx="14" cy="5" rx="14" ry="5" fill="#38bdf8" stroke="#0284c7" stroke-width="1" />
            
            <polygon points="26,5 34,0 34,10" fill="#0284c7" />
            
            <circle cx="4" cy="4" r="1.5" fill="#1e293b" />
          </g>
        </svg>
      </div>
      <div class="food-tag">Catches Fish 🐟</div>
    </div>

  </div>

  
  <div class="main-banner">
    <span>All Birds Have Beaks</span>
    <span>•</span>
    <div class="badge-no-teeth">
      <span class="strike-icon">🚫🦷</span>
      <span>ZERO TEETH</span>
    </div>
  </div>

  <script>
    function selectCard(index) {
      for (let i = 0; i < 3; i++) {
        const card = document.getElementById('card-' + i);
        if (card) {
          if (i === index) {
            card.classList.add('active');
          } else {
            card.classList.remove('active');
          }
        }
      }
    }
  </script>
</body>
</html>

What Makes an Animal a Bird?

<!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>Bird Checklist</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      -webkit-tap-highlight-color: transparent;
    }
    body {
      width: 100%;
      height: 100%;
      background-color: #f8fafc;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e293b;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      padding: 16px;
    }

    .checklist-grid {
      width: 100%;
      max-width: 520px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
    }

    .check-card {
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 14px;
      padding: 14px 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      user-select: none;
      transition: border-color 0.25s ease, box-shadow 0.25s ease, background-color 0.25s ease;
      position: relative;
    }

    .check-card:hover {
      border-color: #cbd5e1;
      box-shadow: 0 3px 10px rgba(0, 0, 0, 0.04);
    }

    .check-card.active {
      border-color: #10b981;
      background-color: #f0fdf4;
      box-shadow: 0 4px 14px rgba(16, 185, 129, 0.12);
    }

    .icon-row {
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      width: 100%;
      margin-bottom: 8px;
    }

    .main-emoji {
      font-size: 32px;
      line-height: 1;
    }

    .check-badge {
      position: absolute;
      right: 4px;
      top: 0px;
      width: 22px;
      height: 22px;
      border-radius: 50%;
      background: #10b981;
      color: #ffffff;
      font-size: 13px;
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 2px 4px rgba(16, 185, 129, 0.3);
      transition: transform 0.2s ease, opacity 0.2s ease;
    }

    .check-card:not(.active) .check-badge {
      opacity: 0.35;
      background: #94a3b8;
      box-shadow: none;
    }

    .title {
      font-size: 16px;
      font-weight: 700;
      color: #0f172a;
      margin-bottom: 6px;
      line-height: 1.2;
    }

    .tag {
      font-size: 12px;
      font-weight: 600;
      padding: 3px 8px;
      border-radius: 6px;
      background: #e2e8f0;
      color: #475569;
      transition: background-color 0.25s ease, color 0.25s ease;
      white-space: nowrap;
    }

    .check-card.active .tag {
      background: #dcfce7;
      color: #15803d;
    }

    @media (max-width: 380px) {
      body {
        padding: 10px;
      }
      .checklist-grid {
        gap: 8px;
      }
      .check-card {
        padding: 12px 8px;
      }
      .main-emoji {
        font-size: 28px;
      }
      .title {
        font-size: 14px;
      }
      .tag {
        font-size: 11px;
        padding: 2px 6px;
      }
    }
  </style>
</head>
<body>

  <div class="checklist-grid" role="region" aria-label="Bird Trait Checklist">
    <div class="check-card active" tabindex="0" role="button" aria-pressed="true">
      <div class="icon-row">
        <span class="main-emoji">🪶</span>
        <span class="check-badge">✓</span>
      </div>
      <div class="title">Feathers</div>
      <div class="tag">Only birds!</div>
    </div>

    <div class="check-card active" tabindex="0" role="button" aria-pressed="true">
      <div class="icon-row">
        <span class="main-emoji">🦜</span>
        <span class="check-badge">✓</span>
      </div>
      <div class="title">Beak / Bill</div>
      <div class="tag">Toothless</div>
    </div>

    <div class="check-card active" tabindex="0" role="button" aria-pressed="true">
      <div class="icon-row">
        <span class="main-emoji">🪽</span>
        <span class="check-badge">✓</span>
      </div>
      <div class="title">Two Wings</div>
      <div class="tag">Even flightless</div>
    </div>

    <div class="check-card active" tabindex="0" role="button" aria-pressed="true">
      <div class="icon-row">
        <span class="main-emoji">🥚</span>
        <span class="check-badge">✓</span>
      </div>
      <div class="title">Hard Eggs</div>
      <div class="tag">Tough shell</div>
    </div>
  </div>

  <script>
    document.querySelectorAll('.check-card').forEach(card => {
      const toggle = () => {
        const isActive = card.classList.toggle('active');
        card.setAttribute('aria-pressed', isActive ? 'true' : 'false');
      };
      card.addEventListener('click', toggle);
      card.addEventListener('keydown', (e) => {
        if (e.key === 'Enter' || e.key === ' ') {
          e.preventDefault();
          toggle();
        }
      });
    });
  </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;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    }

    body {
      background: transparent;
      padding: 12px;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .scorecard-container {
      width: 100%;
      max-width: 580px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
    }

    .animal-card {
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 16px;
      padding: 14px 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.04);
      transition: border-color 0.2s ease;
    }

    .animal-card.bat {
      border-color: #cbd5e1;
    }

    .animal-card.penguin {
      border-color: #38bdf8;
      background: #f0f9ff;
    }

    .animal-header {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      padding-bottom: 8px;
      border-bottom: 1px dashed #cbd5e1;
    }

    .animal-icon {
      font-size: 28px;
      line-height: 1;
    }

    .animal-title {
      font-size: 18px;
      font-weight: 800;
      letter-spacing: -0.01em;
    }

    .rules-list {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .rule-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: #f8fafc;
      padding: 6px 10px;
      border-radius: 8px;
      font-size: 14px;
      font-weight: 600;
    }

    .rule-name {
      display: flex;
      align-items: center;
      gap: 6px;
      color: #334155;
    }

    .rule-symbol {
      font-size: 15px;
    }

    .rule-status {
      display: flex;
      align-items: center;
      gap: 4px;
      font-size: 13px;
      font-weight: 700;
    }

    .status-pass {
      color: #16a34a;
      background: #dcfce7;
      padding: 2px 8px;
      border-radius: 6px;
    }

    .status-fail {
      color: #dc2626;
      background: #fee2e2;
      padding: 2px 8px;
      border-radius: 6px;
    }

    .detail-tag {
      font-size: 11px;
      font-weight: 500;
      color: #64748b;
    }

    .result-badge {
      margin-top: 4px;
      padding: 10px 8px;
      border-radius: 10px;
      text-align: center;
      font-size: 16px;
      font-weight: 800;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    .badge-mammal {
      background: #f1f5f9;
      color: #475569;
      border: 1px solid #cbd5e1;
    }

    .badge-bird {
      background: #22c55e;
      color: #ffffff;
      box-shadow: 0 3px 10px rgba(34, 197, 94, 0.3);
    }

    @media (max-width: 420px) {
      .scorecard-container {
        gap: 8px;
      }
      .animal-card {
        padding: 10px 8px;
        gap: 8px;
      }
      .animal-title {
        font-size: 16px;
      }
      .rule-row {
        padding: 5px 6px;
        font-size: 13px;
      }
      .result-badge {
        font-size: 14px;
        padding: 8px 6px;
      }
    }
  </style>
</head>
<body>

  <div class="scorecard-container">
    
    
    <div class="animal-card bat">
      <div class="animal-header">
        <span class="animal-icon">🦇</span>
        <span class="animal-title">Bat</span>
      </div>

      <div class="rules-list">
        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">🪶</span> Feathers</span>
          <span class="rule-status status-fail">✕ <span class="detail-tag">(Fur)</span></span>
        </div>

        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">👄</span> Beak</span>
          <span class="rule-status status-fail">✕ <span class="detail-tag">(Teeth)</span></span>
        </div>

        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">🪽</span> Wings</span>
          <span class="rule-status status-pass">✓</span>
        </div>

        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">🥚</span> Eggs</span>
          <span class="rule-status status-fail">✕ <span class="detail-tag">(Live)</span></span>
        </div>
      </div>

      <div class="result-badge badge-mammal">
        <span>🦇 Mammal!</span>
      </div>
    </div>

    
    <div class="animal-card penguin">
      <div class="animal-header">
        <span class="animal-icon">🐧</span>
        <span class="animal-title">Penguin</span>
      </div>

      <div class="rules-list">
        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">🪶</span> Feathers</span>
          <span class="rule-status status-pass">✓</span>
        </div>

        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">👄</span> Beak</span>
          <span class="rule-status status-pass">✓</span>
        </div>

        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">🪽</span> Wings</span>
          <span class="rule-status status-pass">✓</span>
        </div>

        <div class="rule-row">
          <span class="rule-name"><span class="rule-symbol">🥚</span> Eggs</span>
          <span class="rule-status status-pass">✓</span>
        </div>
      </div>

      <div class="result-badge badge-bird">
        <span>🐧 Bird!</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">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      width: 100%;
      min-height: 100%;
      background: #f8fafc;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 16px 12px;
    }

    .diagram-grid {
      width: 100%;
      max-width: 620px;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 12px;
      align-items: stretch;
    }

    .animal-card {
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 16px;
      padding: 18px 10px 16px;
      text-align: center;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      box-shadow: 0 4px 10px rgba(0, 0, 0, 0.04);
      position: relative;
    }

    .animal-card.featured {
      border: 2px solid #22b7ff;
      background: #ffffff;
      box-shadow: 0 0 18px rgba(34, 183, 255, 0.3), 0 4px 12px rgba(34, 183, 255, 0.15);
    }

    .star-tag {
      position: absolute;
      top: -12px;
      background: #38bdf8;
      color: #ffffff;
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.2px;
      padding: 3px 10px;
      border-radius: 20px;
      box-shadow: 0 2px 6px rgba(14, 165, 233, 0.35);
      white-space: nowrap;
    }

    .icon-box {
      font-size: 38px;
      line-height: 1;
      margin: 8px 0 12px;
      filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.08));
    }

    .covering-name {
      font-size: 16px;
      font-weight: 800;
      color: #1e2945;
      margin-bottom: 4px;
      line-height: 1.2;
    }

    .group-name {
      font-size: 13px;
      font-weight: 600;
      color: #64748b;
    }

    .featured .group-name {
      color: #0284c7;
    }

    @media (max-width: 480px) {
      .diagram-grid {
        grid-template-columns: 1fr;
        gap: 16px;
        max-width: 320px;
      }

      .animal-card {
        padding: 16px 12px;
      }

      .icon-box {
        font-size: 32px;
        margin: 6px 0 8px;
      }

      .star-tag {
        top: -10px;
      }
    }
  </style>
</head>
<body>

  <div class="diagram-grid">
    
    <div class="animal-card">
      <div class="icon-box">🐻</div>
      <div>
        <div class="covering-name">Fur / Hair</div>
        <div class="group-name">Mammal</div>
      </div>
    </div>

    
    <div class="animal-card">
      <div class="icon-box">🐍</div>
      <div>
        <div class="covering-name">Scales</div>
        <div class="group-name">Reptile</div>
      </div>
    </div>

    
    <div class="animal-card featured">
      <span class="star-tag">⭐ 100% Unique to Birds!</span>
      <div class="icon-box">🪶</div>
      <div>
        <div class="covering-name">Feathers</div>
        <div class="group-name">Bird</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;
      font-family: system-ui, -apple-system, sans-serif;
    }

    body {
      background: #f8fafc;
      color: #1e293b;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px;
      user-select: none;
    }

    .stepper-nav {
      display: flex;
      gap: 8px;
      width: 100%;
      max-width: 480px;
      margin-bottom: 8px;
    }

    .step-btn {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      padding: 8px 12px;
      font-size: 14px;
      font-weight: 600;
      border-radius: 8px;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #64748b;
      cursor: pointer;
      transition: all 0.25s ease;
    }

    .step-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.25);
    }

    .stage-container {
      position: relative;
      width: 100%;
      max-width: 500px;
      height: 280px;
      background: #ffffff;
      border-radius: 12px;
      border: 1px solid #e2e8f0;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    svg {
      width: 100%;
      height: 100%;
      display: block;
    }

    /* Flow Animations */
    @keyframes flowIn {
      0% { stroke-dashoffset: 60; opacity: 0.2; }
      50% { opacity: 1; }
      100% { stroke-dashoffset: 0; opacity: 0.2; }
    }

    @keyframes pulseOxygen {
      0%, 100% { transform: scale(1); filter: drop-shadow(0 0 2px #38bdf8); }
      50% { transform: scale(1.2); filter: drop-shadow(0 0 6px #0284c7); }
    }

    @keyframes bloodGlow {
      0%, 100% { stroke: #e11d48; stroke-width: 3.5px; }
      50% { stroke: #fb7185; stroke-width: 5px; }
    }

    @keyframes exitFlow {
      0% { stroke-dashoffset: 50; opacity: 0.2; }
      50% { opacity: 0.9; }
      100% { stroke-dashoffset: 0; opacity: 0.2; }
    }

    .stream-line {
      stroke-dasharray: 8 6;
      animation: flowIn 1.4s linear infinite;
    }

    .exit-stream {
      stroke-dasharray: 6 5;
      animation: exitFlow 1.2s linear infinite;
    }

    .oxygen-dot {
      animation: pulseOxygen 1.8s ease-in-out infinite;
      transform-origin: center;
    }

    .gill-filament {
      transition: stroke 0.3s ease;
    }

    .active-blood {
      animation: bloodGlow 1.5s ease-in-out infinite;
    }

    /* Step Visibility Controls */
    .step-1-layer, .step-2-layer {
      transition: opacity 0.35s ease, transform 0.35s ease;
    }

    .hidden {
      opacity: 0;
      pointer-events: none;
      transform: translateY(4px);
    }

    .visible {
      opacity: 1;
      pointer-events: auto;
      transform: translateY(0);
    }

    .controls-footer {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      margin-top: 8px;
      width: 100%;
      max-width: 480px;
    }

    .play-toggle {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      border-radius: 20px;
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 5px;
    }

    .play-toggle:hover {
      background: #e2e8f0;
    }

    .status-badge {
      font-size: 13px;
      font-weight: 700;
      color: #0369a1;
      background: #e0f2fe;
      padding: 4px 10px;
      border-radius: 6px;
    }
  </style>
</head>
<body>

  
  <div class="stepper-nav">
    <button class="step-btn active" id="btnStep1" onclick="setStep(0)">
      <span>1.</span> Water In
    </button>
    <button class="step-btn" id="btnStep2" onclick="setStep(1)">
      <span>2.</span> Gills Trap O₂
    </button>
  </div>

  
  <div class="stage-container">
    <svg viewBox="0 0 460 260">
      <defs>
        
        <linearGradient id="fishGrad" x1="0" y1="0" x2="1" y2="1">
          <stop offset="0%" stop-color="#f8fafc"/>
          <stop offset="60%" stop-color="#e2e8f0"/>
          <stop offset="100%" stop-color="#cbd5e1"/>
        </linearGradient>
        <linearGradient id="finGrad" x1="0" y1="0" x2="1" y2="0">
          <stop offset="0%" stop-color="#93c5fd" stop-opacity="0.8"/>
          <stop offset="100%" stop-color="#3b82f6" stop-opacity="0.4"/>
        </linearGradient>
        <marker id="arrowWater" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1 L 10 5 L 0 9 z" fill="#0284c7" />
        </marker>
        <marker id="arrowExit" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1 L 10 5 L 0 9 z" fill="#0ea5e9" />
        </marker>
        <marker id="arrowBlood" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1 L 10 5 L 0 9 z" fill="#e11d48" />
        </marker>
      </defs>

      
      <rect x="0" y="0" width="460" height="260" fill="#f0f9ff" />

      
      <g transform="translate(10, 0)">
        
        <path d="M 360 130 L 420 75 Q 395 130 420 185 Z" fill="url(#finGrad)" stroke="#38bdf8" stroke-width="2"/>
        
        <path d="M 220 72 Q 260 30 300 68 Z" fill="url(#finGrad)" stroke="#38bdf8" stroke-width="2"/>
        
        <path d="M 240 188 Q 275 225 300 188 Z" fill="url(#finGrad)" stroke="#38bdf8" stroke-width="2"/>

        
        <path d="M 85 130 Q 140 65 260 68 Q 360 70 365 130 Q 360 190 260 192 Q 140 195 85 130 Z" 
              fill="url(#fishGrad)" stroke="#94a3b8" stroke-width="2.5"/>

        
        <path id="bloodVessel" d="M 180 130 Q 250 120 340 130" fill="none" stroke="#f43f5e" stroke-width="3" stroke-linecap="round"/>

        
        <circle cx="120" cy="108" r="11" fill="#ffffff" stroke="#475569" stroke-width="2"/>
        <circle cx="118" cy="108" r="5.5" fill="#0f172a"/>
        <circle cx="116" cy="106" r="2" fill="#ffffff"/>

        
        <g id="gillsGroup">
          <path class="gill-filament" d="M 168 102 Q 182 130 168 158" fill="none" stroke="#e11d48" stroke-width="4.5" stroke-linecap="round"/>
          <path class="gill-filament" d="M 176 100 Q 190 130 176 160" fill="none" stroke="#e11d48" stroke-width="4.5" stroke-linecap="round"/>
          <path class="gill-filament" d="M 184 104 Q 198 130 184 156" fill="none" stroke="#e11d48" stroke-width="4.5" stroke-linecap="round"/>
        </g>

        
        <path id="operculum" d="M 170 92 Q 206 130 172 168" fill="none" stroke="#64748b" stroke-width="2.5" stroke-linecap="round"/>

        
        <text x="178" y="85" font-size="12" font-weight="700" fill="#e11d48" text-anchor="middle">Gills</text>
        <line x1="178" y1="88" x2="178" y2="98" stroke="#e11d48" stroke-width="1.5" stroke-dasharray="2 2"/>
      </g>

      
      <g id="step1Layer" class="step-1-layer visible">
        
        <path d="M 95 116 Q 80 130 95 144" fill="none" stroke="#0284c7" stroke-width="4" stroke-linecap="round"/>

        
        <path class="stream-line" d="M 15 115 C 45 115, 65 125, 95 125" fill="none" stroke="#0284c7" stroke-width="3.5" marker-end="url(#arrowWater)"/>
        <path class="stream-line" d="M 10 130 C 45 130, 65 130, 95 130" fill="none" stroke="#0284c7" stroke-width="4" marker-end="url(#arrowWater)"/>
        <path class="stream-line" d="M 15 145 C 45 145, 65 135, 95 135" fill="none" stroke="#0284c7" stroke-width="3.5" marker-end="url(#arrowWater)"/>

        
        <g class="oxygen-dot">
          <circle cx="35" cy="115" r="7" fill="#38bdf8" stroke="#0284c7" stroke-width="1.5"/>
          <text x="35" y="118.5" font-size="9" font-weight="800" fill="#ffffff" text-anchor="middle">O₂</text>
        </g>
        <g class="oxygen-dot">
          <circle cx="65" cy="138" r="7" fill="#38bdf8" stroke="#0284c7" stroke-width="1.5"/>
          <text x="65" y="141.5" font-size="9" font-weight="800" fill="#ffffff" text-anchor="middle">O₂</text>
        </g>
        <g class="oxygen-dot">
          <circle cx="45" cy="148" r="6" fill="#38bdf8" stroke="#0284c7" stroke-width="1.5"/>
          <text x="45" y="151" font-size="8" font-weight="800" fill="#ffffff" text-anchor="middle">O₂</text>
        </g>

        
        <rect x="25" y="18" width="130" height="28" rx="6" fill="#ffffff" stroke="#bae6fd" stroke-width="1.5"/>
        <text x="90" y="36" font-size="13" font-weight="700" fill="#0369a1" text-anchor="middle">1. Water + O₂ enters</text>
      </g>

      
      <g id="step2Layer" class="step-2-layer hidden">
        
        <path class="exit-stream" d="M 160 120 Q 185 110 205 100 Q 225 90 250 85" fill="none" stroke="#38bdf8" stroke-width="3.5" marker-end="url(#arrowExit)"/>
        <path class="exit-stream" d="M 165 140 Q 195 145 220 160 Q 240 175 260 185" fill="none" stroke="#38bdf8" stroke-width="3.5" marker-end="url(#arrowExit)"/>

        
        <path d="M 195 130 L 225 130" fill="none" stroke="#e11d48" stroke-width="3" stroke-dasharray="4 3" marker-end="url(#arrowBlood)"/>

        
        <g class="oxygen-dot">
          <circle cx="210" cy="122" r="6.5" fill="#f43f5e" stroke="#be123c" stroke-width="1.5"/>
          <text x="210" y="125.5" font-size="8" font-weight="800" fill="#ffffff" text-anchor="middle">O₂</text>
        </g>
        <g class="oxygen-dot">
          <circle cx="270" cy="126" r="6.5" fill="#f43f5e" stroke="#be123c" stroke-width="1.5"/>
          <text x="270" y="129.5" font-size="8" font-weight="800" fill="#ffffff" text-anchor="middle">O₂</text>
        </g>

        
        
        <rect x="235" y="18" width="120" height="26" rx="6" fill="#fff1f2" stroke="#fecdd3" stroke-width="1.5"/>
        <text x="295" y="35" font-size="12" font-weight="700" fill="#e11d48" text-anchor="middle">O₂ into blood →</text>

        
        <rect x="245" y="218" width="110" height="26" rx="6" fill="#f0f9ff" stroke="#bae6fd" stroke-width="1.5"/>
        <text x="300" y="235" font-size="12" font-weight="700" fill="#0284c7" text-anchor="middle">Water exits slit</text>
      </g>
    </svg>
  </div>

  
  <div class="controls-footer">
    <button class="play-toggle" id="autoBtn" onclick="toggleAutoPlay()">
      <span id="playIcon">⏸</span> Auto-play
    </button>
    <div class="status-badge" id="stepBadge">Step 1 of 2</div>
  </div>

  <script>
    let currentStep = 0;
    let autoPlaying = true;
    let autoTimer = null;

    const step1Layer = document.getElementById('step1Layer');
    const step2Layer = document.getElementById('step2Layer');
    const btn1 = document.getElementById('btnStep1');
    const btn2 = document.getElementById('btnStep2');
    const bloodVessel = document.getElementById('bloodVessel');
    const badge = document.getElementById('stepBadge');
    const playIcon = document.getElementById('playIcon');

    function setStep(index) {
      currentStep = index;
      if (currentStep === 0) {
        step1Layer.classList.remove('hidden');
        step1Layer.classList.add('visible');
        step2Layer.classList.remove('visible');
        step2Layer.classList.add('hidden');

        btn1.classList.add('active');
        btn2.classList.remove('active');

        bloodVessel.classList.remove('active-blood');
        badge.textContent = 'Step 1: Gulps Water';
      } else {
        step1Layer.classList.remove('visible');
        step1Layer.classList.add('hidden');
        step2Layer.classList.remove('hidden');
        step2Layer.classList.add('visible');

        btn1.classList.remove('active');
        btn2.classList.add('active');

        bloodVessel.classList.add('active-blood');
        badge.textContent = 'Step 2: Traps Oxygen';
      }
    }

    function nextStep() {
      setStep((currentStep + 1) % 2);
    }

    function startTimer() {
      if (autoTimer) clearInterval(autoTimer);
      autoTimer = setInterval(() => {
        nextStep();
      }, 3500);
    }

    function toggleAutoPlay() {
      autoPlaying = !autoPlaying;
      if (autoPlaying) {
        playIcon.textContent = '⏸';
        startTimer();
      } else {
        playIcon.textContent = '▶';
        clearInterval(autoTimer);
      }
    }

    // Initialize
    setStep(0);
    startTimer();
  </script>
</body>
</html>

What Makes an Animal a Fish?

<!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;
      color: #1e2945;
      background: transparent;
      padding: 8px;
    }
    .grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
      width: 100%;
    }
    .panel {
      background: #f8fafc;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
    }
    .panel-fish {
      border-color: #86efac;
      background: #f0fdf4;
    }
    .panel-dolphin {
      border-color: #fdba74;
      background: #fff7ed;
    }
    .avatar {
      font-size: 38px;
      line-height: 1;
    }
    .animal-name {
      font-size: 16px;
      font-weight: 800;
      letter-spacing: -0.2px;
    }
    .traits {
      width: 100%;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }
    .trait-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: #ffffff;
      padding: 6px 8px;
      border-radius: 8px;
      border: 1px solid rgba(0,0,0,0.06);
      font-size: 13px;
      font-weight: 600;
    }
    .label {
      color: #475569;
      font-size: 12px;
    }
    .status {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      font-size: 12px;
      font-weight: 700;
    }
    .yes {
      color: #15803d;
    }
    .no {
      color: #b91c1c;
    }
    .badge {
      margin-top: 4px;
      width: 100%;
      text-align: center;
      padding: 7px 4px;
      border-radius: 8px;
      font-size: 13px;
      font-weight: 800;
      letter-spacing: 0.2px;
    }
    .badge-fish {
      background: #22c55e;
      color: #ffffff;
    }
    .badge-mammal {
      background: #f97316;
      color: #ffffff;
    }
    .sub {
      display: block;
      font-size: 10px;
      font-weight: 600;
      opacity: 0.95;
    }
  </style>
</head>
<body>
  <div class="grid">
    
    <div class="panel panel-fish">
      <div class="avatar">🐠</div>
      <div class="animal-name">Clownfish</div>
      
      <div class="traits">
        <div class="trait-row">
          <span class="label">Gills?</span>
          <span class="status yes">✓ Yes</span>
        </div>
        <div class="trait-row">
          <span class="label">Fins?</span>
          <span class="status yes">✓ Yes</span>
        </div>
        <div class="trait-row">
          <span class="label">Scales?</span>
          <span class="status yes">✓ Yes</span>
        </div>
        <div class="trait-row">
          <span class="label">In water?</span>
          <span class="status yes">✓ 100%</span>
        </div>
      </div>

      <div class="badge badge-fish">
        REAL FISH
        <span class="sub">All 4 traits match</span>
      </div>
    </div>

    
    <div class="panel panel-dolphin">
      <div class="avatar">🐬</div>
      <div class="animal-name">Dolphin</div>
      
      <div class="traits">
        <div class="trait-row">
          <span class="label">Gills?</span>
          <span class="status no">✗ Lungs</span>
        </div>
        <div class="trait-row">
          <span class="label">Fins?</span>
          <span class="status yes">✓ Flippers</span>
        </div>
        <div class="trait-row">
          <span class="label">Scales?</span>
          <span class="status no">✗ Smooth</span>
        </div>
        <div class="trait-row">
          <span class="label">In water?</span>
          <span class="status yes">✓ 100%</span>
        </div>
      </div>

      <div class="badge badge-mammal">
        NOT A FISH
        <span class="sub">It is a mammal!</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">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      width: 100%;
      min-height: 100vh;
      background: #f0f8ff;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 12px;
      user-select: none;
      overflow-x: hidden;
    }

    .main-container {
      width: 100%;
      max-width: 540px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 10px;
    }

    /* Mode Selector Tabs */
    .header-tabs {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 6px;
      width: 100%;
      z-index: 10;
    }

    @media (max-width: 440px) {
      .header-tabs {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    .tab-btn {
      background: #ffffff;
      border: 2px solid #d0e4ff;
      border-radius: 12px;
      padding: 8px 6px;
      font-size: 13px;
      font-weight: 700;
      color: #1e2945;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      transition: background-color 0.5s ease, border-color 0.5s ease, color 0.5s ease, box-shadow 0.5s ease;
      outline: none;
      white-space: nowrap;
    }

    .tab-btn:hover {
      border-color: #22b7ff;
      background: #f4faff;
    }

    .tab-btn.active {
      background: #008be3;
      border-color: #008be3;
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(0, 139, 227, 0.35);
    }

    /* Interactive Underwater Scene */
    .scene-wrapper {
      position: relative;
      width: 100%;
      height: 270px;
      background: radial-gradient(circle at 50% 30%, #e0f2fe 0%, #bae6fd 60%, #90cdf4 100%);
      border-radius: 16px;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      border: 2px solid #b9ddff;
    }

    /* Ambient animated bubbles */
    .bg-bubble {
      position: absolute;
      background: rgba(255, 255, 255, 0.65);
      border: 1.5px solid rgba(255, 255, 255, 0.9);
      border-radius: 50%;
      pointer-events: none;
      animation: rise 6s infinite ease-in;
    }
    .b1 { width: 14px; height: 14px; left: 12%; bottom: -20px; animation-duration: 5.6s; }
    .b2 { width: 9px; height: 9px; left: 24%; bottom: -20px; animation-duration: 6.8s; animation-delay: 1.5s; }
    .b3 { width: 16px; height: 16px; left: 78%; bottom: -20px; animation-duration: 6.2s; animation-delay: 0.8s; }
    .b4 { width: 10px; height: 10px; left: 88%; bottom: -20px; animation-duration: 5.2s; animation-delay: 2.2s; }

    @keyframes rise {
      0% { transform: translateY(0) translateX(0); opacity: 0; }
      20% { opacity: 0.85; }
      80% { opacity: 0.85; }
      100% { transform: translateY(-290px) translateX(15px); opacity: 0; }
    }

    /* Seaweed bottom decor */
    .seaweed-group {
      position: absolute;
      bottom: 0;
      left: 12px;
      pointer-events: none;
      opacity: 0.75;
      transition: opacity 0.5s ease, filter 0.5s ease;
    }
    .seaweed-group.right {
      left: auto;
      right: 12px;
    }
    .seaweed-active {
      opacity: 1;
      filter: drop-shadow(0 0 8px #2ec4b6);
    }

    /* Fish SVG Container & Animations */
    .fish-container {
      position: relative;
      width: 280px;
      height: 180px;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: transform 0.5s ease;
    }

    .fin-tail {
      transform-origin: 55px 95px;
      animation: tailWiggle 2s ease-in-out infinite alternate;
    }
    .fin-pectoral {
      transform-origin: 150px 115px;
      animation: pectoralWiggle 1.6s ease-in-out infinite alternate;
    }
    .fin-dorsal {
      transform-origin: 145px 50px;
      animation: dorsalWave 2.4s ease-in-out infinite alternate;
    }

    @keyframes tailWiggle {
      0% { transform: rotate(-8deg); }
      100% { transform: rotate(10deg); }
    }
    @keyframes pectoralWiggle {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(16deg); }
    }
    @keyframes dorsalWave {
      0% { transform: skewX(-4deg); }
      100% { transform: skewX(5deg); }
    }

    /* Gill Bubble Stream */
    .gill-stream {
      position: absolute;
      top: 96px;
      left: 172px;
      pointer-events: none;
      display: flex;
      gap: 6px;
    }
    .g-bubble {
      width: 8px;
      height: 8px;
      background: #ffffff;
      border: 1.5px solid #008be3;
      border-radius: 50%;
      opacity: 0;
      animation: gillBreath 2.2s infinite ease-out;
    }
    .g-bubble:nth-child(2) { animation-delay: 0.6s; }
    .g-bubble:nth-child(3) { animation-delay: 1.2s; }

    @keyframes gillBreath {
      0% { transform: translate(0, 0) scale(0.6); opacity: 0; }
      35% { opacity: 0.95; }
      100% { transform: translate(-32px, -26px) scale(1.3); opacity: 0; }
    }

    /* Magnifier for Scales */
    .zoom-circle {
      position: absolute;
      top: 14px;
      right: 14px;
      width: 76px;
      height: 76px;
      border-radius: 50%;
      background: #f0f9ff;
      border: 3px solid #ff9f1c;
      box-shadow: 0 4px 12px rgba(0,0,0,0.12);
      display: flex;
      align-items: center;
      justify-content: center;
      transition: opacity 0.5s ease, filter 0.5s ease, border-color 0.5s ease;
      opacity: 0.45;
    }
    .zoom-circle.highlight {
      opacity: 1;
      border-color: #ff7b00;
      box-shadow: 0 0 16px rgba(255, 123, 0, 0.6);
    }

    /* Active Callout Overlay Pill */
    .callouts-container {
      position: absolute;
      inset: 0;
      pointer-events: none;
    }

    .callout-pill {
      position: absolute;
      background: #ffffff;
      padding: 6px 12px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 800;
      color: #0f2b48;
      box-shadow: 0 4px 14px rgba(0,0,0,0.18);
      border: 2px solid #008be3;
      display: none;
      align-items: center;
      gap: 5px;
      z-index: 5;
      animation: fadeInCallout 0.5s ease forwards;
    }

    .callout-pill.active {
      display: flex;
    }

    /* Pointer arrow tip */
    .callout-pill::after {
      content: '';
      position: absolute;
      width: 0;
      height: 0;
      border: 6px solid transparent;
    }

    /* Individual Callout Placements */
    .callout-gills {
      top: 16px;
      left: 48%;
      transform: translateX(-50%);
    }
    .callout-gills::after {
      top: 100%;
      left: 50%;
      margin-left: -6px;
      border-top-color: #008be3;
    }

    .callout-fins {
      bottom: 14px;
      left: 14px;
    }
    .callout-fins::after {
      bottom: 100%;
      left: 30px;
      border-bottom-color: #008be3;
    }

    .callout-scales {
      top: 96px;
      right: 14px;
    }
    .callout-scales::after {
      bottom: 100%;
      right: 28px;
      border-bottom-color: #008be3;
    }

    .callout-water {
      bottom: 14px;
      right: 14px;
    }
    .callout-water::after {
      bottom: 100%;
      right: 24px;
      border-bottom-color: #008be3;
    }

    @keyframes fadeInCallout {
      from { opacity: 0; transform: translateY(4px); }
      to { opacity: 1; transform: translateY(0); }
    }
    .callout-gills.active {
      animation: fadeInCalloutCenter 0.5s ease forwards;
    }
    @keyframes fadeInCalloutCenter {
      from { opacity: 0; transform: translate(-50%, 4px); }
      to { opacity: 1; transform: translate(-50%, 0); }
    }

    /* Part highlighting pulse */
    .part-highlight {
      transition: filter 0.5s ease;
    }
    .active-glow {
      filter: drop-shadow(0 0 7px #ff0055);
    }
    .active-glow-blue {
      filter: drop-shadow(0 0 7px #008be3);
    }

    /* Educational 1-Line Status Banner */
    .caption-banner {
      width: 100%;
      min-height: 48px;
      font-size: 14px;
      font-weight: 600;
      color: #1e2945;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      background: #ffffff;
      padding: 10px 16px;
      border-radius: 12px;
      border: 1.5px solid #cce3fe;
      box-shadow: 0 2px 6px rgba(0,0,0,0.04);
      text-align: center;
      line-height: 1.35;
    }
    .caption-icon {
      font-size: 18px;
      flex-shrink: 0;
    }
  </style>
</head>
<body>

  <div class="main-container">
    
    <div class="header-tabs" role="tablist">
      <button class="tab-btn active" data-part="gills" role="tab" aria-selected="true">🫁 Gills</button>
      <button class="tab-btn" data-part="fins" role="tab" aria-selected="false">🏊 Fins</button>
      <button class="tab-btn" data-part="scales" role="tab" aria-selected="false">✨ Scales</button>
      <button class="tab-btn" data-part="water" role="tab" aria-selected="false">🌊 Habitat</button>
    </div>

    
    <div class="scene-wrapper" id="scene">
      
      <div class="bg-bubble b1"></div>
      <div class="bg-bubble b2"></div>
      <div class="bg-bubble b3"></div>
      <div class="bg-bubble b4"></div>

      
      <svg class="seaweed-group" id="seaweedLeft" width="45" height="90" viewBox="0 0 45 90">
        <path d="M12 90 Q 2 55 18 35 Q 28 18 16 0" fill="none" stroke="#10b981" stroke-width="7" stroke-linecap="round"/>
        <path d="M30 90 Q 40 60 26 40 Q 15 20 28 8" fill="none" stroke="#059669" stroke-width="5" stroke-linecap="round"/>
      </svg>
      <svg class="seaweed-group right" id="seaweedRight" width="45" height="90" viewBox="0 0 45 90">
        <path d="M32 90 Q 42 55 26 35 Q 16 18 28 0" fill="none" stroke="#10b981" stroke-width="6" stroke-linecap="round"/>
        <path d="M14 90 Q 4 60 18 40 Q 29 20 16 8" fill="none" stroke="#059669" stroke-width="5" stroke-linecap="round"/>
      </svg>

      
      <div class="fish-container">
        <svg width="280" height="180" viewBox="0 0 290 190">
          <defs>
            
            <linearGradient id="bodyGrad" x1="0%" y1="0%" x2="100%" y2="0%">
              <stop offset="0%" stop-color="#ff6b35"/>
              <stop offset="60%" stop-color="#ffa62b"/>
              <stop offset="100%" stop-color="#ffd166"/>
            </linearGradient>
            
            <linearGradient id="finGrad" x1="0%" y1="0%" x2="100%" y2="100%">
              <stop offset="0%" stop-color="#ff477e"/>
              <stop offset="100%" stop-color="#ff85a1"/>
            </linearGradient>
            
            <pattern id="scalePat" width="14" height="14" patternUnits="userSpaceOnUse">
              <path d="M 0 7 A 7 7 0 0 0 14 7 A 7 7 0 0 0 0 7 Z" fill="#ffd166" stroke="#ff9f1c" stroke-width="1.5"/>
              <path d="M 7 14 A 7 7 0 0 0 21 14" fill="#ffd166" stroke="#ff9f1c" stroke-width="1.5"/>
            </pattern>
          </defs>

          
          <g class="fin-tail part-highlight" id="finTailGroup">
            <path d="M 72 95 C 40 45, 10 35, 12 75 C 14 95, 14 95, 12 115 C 10 155, 40 145, 72 95 Z" fill="url(#finGrad)"/>
            <path d="M 60 95 L 20 60 M 60 95 L 18 95 M 60 95 L 20 130" stroke="#ffffff" stroke-width="2" stroke-linecap="round" opacity="0.6"/>
          </g>

          
          <g class="fin-dorsal part-highlight" id="finDorsalGroup">
            <path d="M 125 55 C 140 20, 190 25, 205 63 C 165 52, 140 50, 125 55 Z" fill="url(#finGrad)"/>
            <path d="M 145 52 L 155 32 M 170 54 L 178 33 M 190 58 L 195 40" stroke="#ffffff" stroke-width="1.8" stroke-linecap="round" opacity="0.6"/>
          </g>

          
          <path id="bodyPath" d="M 65 95 C 80 45, 180 40, 240 95 C 180 150, 80 145, 65 95 Z" fill="url(#bodyGrad)" stroke="#e85d04" stroke-width="2.5"/>

          
          <g id="bodyScalesGroup" opacity="0.5">
            <path d="M 120 78 Q 128 85 120 92" stroke="#ffffff" stroke-width="2" fill="none" stroke-linecap="round"/>
            <path d="M 134 70 Q 142 77 134 84" stroke="#ffffff" stroke-width="2" fill="none" stroke-linecap="round"/>
            <path d="M 134 86 Q 142 93 134 100" stroke="#ffffff" stroke-width="2" fill="none" stroke-linecap="round"/>
            <path d="M 148 78 Q 156 85 148 92" stroke="#ffffff" stroke-width="2" fill="none" stroke-linecap="round"/>
            <path d="M 148 94 Q 156 101 148 108" stroke="#ffffff" stroke-width="2" fill="none" stroke-linecap="round"/>
          </g>

          
          <g id="gillsGroup" class="part-highlight">
            <path d="M 188 74 C 180 85, 180 105, 188 116" fill="none" stroke="#d00000" stroke-width="4.5" stroke-linecap="round"/>
            <path d="M 195 77 C 189 87, 189 103, 195 113" fill="none" stroke="#ff477e" stroke-width="3" stroke-linecap="round"/>
          </g>

          
          <circle cx="218" cy="85" r="11" fill="#ffffff"/>
          <circle cx="221" cy="85" r="5.5" fill="#1e2945"/>
          <circle cx="223" cy="83" r="2" fill="#ffffff"/>
          <path d="M 238 98 Q 230 106 222 101" fill="none" stroke="#8a1c00" stroke-width="2.5" stroke-linecap="round"/>

          
          <g class="fin-pectoral part-highlight" id="finPectoralGroup">
            <path d="M 148 98 C 130 102, 120 125, 140 130 C 158 135, 168 115, 148 98 Z" fill="url(#finGrad)" stroke="#e85d04" stroke-width="1.5"/>
            <path d="M 146 105 L 132 120 M 151 110 L 140 126" stroke="#ffffff" stroke-width="1.8" stroke-linecap="round" opacity="0.6"/>
          </g>
        </svg>

        
        <div class="gill-stream" id="gillStream">
          <div class="g-bubble"></div>
          <div class="g-bubble"></div>
          <div class="g-bubble"></div>
        </div>
      </div>

      
      <div class="zoom-circle" id="zoomScales">
        <svg width="58" height="58" viewBox="0 0 60 60">
          <circle cx="30" cy="30" r="28" fill="url(#scalePat)"/>
          <circle cx="30" cy="30" r="28" fill="none" stroke="#ff9f1c" stroke-width="2"/>
          <path d="M 12 18 Q 20 28 32 18" stroke="#ffffff" stroke-width="2" fill="none" opacity="0.75"/>
        </svg>
      </div>

      
      <div class="callouts-container">
        <div class="callout-pill callout-gills active" id="calloutGills">🫁 Gills: Take in Oxygen</div>
        <div class="callout-pill callout-fins" id="calloutFins">🏊 Fins: Steer &amp; Swim</div>
        <div class="callout-pill callout-scales" id="calloutScales">✨ Scales: Shiny Shield</div>
        <div class="callout-pill callout-water" id="calloutWater">🌊 Water: Underwater Home</div>
      </div>
    </div>

    
    <div class="caption-banner" id="captionBanner">
      <span class="caption-icon" id="captionIcon">🫁</span>
      <span id="captionText">Gills absorb dissolved oxygen directly from the water.</span>
    </div>
  </div>

  <script>
    const tabs = document.querySelectorAll('.tab-btn');
    const callouts = {
      gills: document.getElementById('calloutGills'),
      fins: document.getElementById('calloutFins'),
      scales: document.getElementById('calloutScales'),
      water: document.getElementById('calloutWater')
    };

    const finTail = document.getElementById('finTailGroup');
    const finDorsal = document.getElementById('finDorsalGroup');
    const finPectoral = document.getElementById('finPectoralGroup');
    const gillsGroup = document.getElementById('gillsGroup');
    const zoomScales = document.getElementById('zoomScales');
    const gillStream = document.getElementById('gillStream');
    const seaweedLeft = document.getElementById('seaweedLeft');
    const seaweedRight = document.getElementById('seaweedRight');
    const captionIcon = document.getElementById('captionIcon');
    const captionText = document.getElementById('captionText');

    const details = {
      gills: {
        icon: '🫁',
        text: 'Gills absorb dissolved oxygen directly from the water.'
      },
      fins: {
        icon: '🏊',
        text: 'Fins provide balance, steering, and push the fish through water.'
      },
      scales: {
        icon: '✨',
        text: 'Smooth overlapping scales protect skin and reduce water drag.'
      },
      water: {
        icon: '🌊',
        text: 'Fish are adapted to breathe, swim, and lay eggs in water.'
      }
    };

    function setPart(part) {
      // Update buttons & accessibility
      tabs.forEach(btn => {
        const isActive = btn.dataset.part === part;
        btn.classList.toggle('active', isActive);
        btn.setAttribute('aria-selected', isActive ? 'true' : 'false');
      });

      // Update callouts (only active is shown to avoid collisions)
      Object.keys(callouts).forEach(k => {
        callouts[k].classList.toggle('active', k === part);
      });

      // Reset visual states
      gillsGroup.classList.remove('active-glow');
      finTail.classList.remove('active-glow-blue');
      finDorsal.classList.remove('active-glow-blue');
      finPectoral.classList.remove('active-glow-blue');
      zoomScales.classList.remove('highlight');
      seaweedLeft.classList.remove('seaweed-active');
      seaweedRight.classList.remove('seaweed-active');

      // Apply focused state
      if (part === 'gills') {
        gillsGroup.classList.add('active-glow');
        gillStream.style.display = 'flex';
      } else if (part === 'fins') {
        finTail.classList.add('active-glow-blue');
        finDorsal.classList.add('active-glow-blue');
        finPectoral.classList.add('active-glow-blue');
        gillStream.style.display = 'none';
      } else if (part === 'scales') {
        zoomScales.classList.add('highlight');
        gillStream.style.display = 'none';
      } else if (part === 'water') {
        seaweedLeft.classList.add('seaweed-active');
        seaweedRight.classList.add('seaweed-active');
        gillStream.style.display = 'flex';
      }

      // Update educational text
      captionIcon.textContent = details[part].icon;
      captionText.textContent = details[part].text;
    }

    tabs.forEach(btn => {
      btn.addEventListener('click', () => {
        setPart(btn.dataset.part);
      });
    });

    // Initialize default view
    setPart('gills');
  </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: center;
      padding: 12px;
      min-height: 100%;
      user-select: none;
    }

    .legend-nav {
      display: flex;
      gap: 6px;
      margin-bottom: 12px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .nav-btn {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      border-radius: 20px;
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .nav-btn .dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      display: inline-block;
    }

    .nav-btn.active {
      background: #ffffff;
      border-color: #1e2945;
      color: #0f172a;
      box-shadow: 0 2px 5px rgba(0,0,0,0.12);
    }

    .dot-head { background: #eab308; }
    .dot-body { background: #2563eb; }
    .dot-tail { background: #16a34a; }

    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
      max-width: 620px;
    }

    .stage-card {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 8px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      position: relative;
    }

    .stage-title {
      font-size: 14px;
      font-weight: 700;
      color: #334155;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      margin-bottom: 4px;
    }

    .svg-container {
      width: 100%;
      height: auto;
      max-height: 240px;
    }

    /* Part highlighting styles */
    .part {
      transition: opacity 0.3s ease, stroke-width 0.3s ease;
      cursor: pointer;
    }

    .part-head { fill: #fef08a; stroke: #ca8a04; }
    .part-body { fill: #bfdbfe; stroke: #2563eb; }
    .part-tail { fill: #bbf7d0; stroke: #16a34a; }

    .dimmed {
      opacity: 0.2;
    }

    .highlighted {
      stroke-width: 3.5px !important;
      filter: drop-shadow(0 0 4px rgba(0,0,0,0.15));
    }

    .label-text {
      font-size: 11px;
      font-weight: 700;
      fill: #1e2945;
      text-anchor: middle;
      font-family: inherit;
    }

    .sub-label {
      font-size: 9.5px;
      font-weight: 600;
      fill: #64748b;
      text-anchor: middle;
      font-family: inherit;
    }

    .pointer-line {
      stroke: #64748b;
      stroke-width: 1.2;
      stroke-dasharray: 2, 2;
    }

    @media (max-width: 400px) {
      .stage-title { font-size: 12px; }
      .nav-btn { font-size: 11px; padding: 4px 10px; }
    }
  </style>
</head>
<body>

  <div class="legend-nav" role="tablist">
    <button class="nav-btn active" data-filter="all">All Parts</button>
    <button class="nav-btn" data-filter="head"><span class="dot dot-head"></span>Head</button>
    <button class="nav-btn" data-filter="body"><span class="dot dot-body"></span>Body</button>
    <button class="nav-btn" data-filter="tail"><span class="dot dot-tail"></span>Tail</button>
  </div>

  <div class="comparison-grid">
    
    <div class="stage-card">
      <div class="stage-title">Tadpole</div>
      <svg class="svg-container" viewBox="0 0 200 170">
        
        <line class="pointer-line" x1="42" y1="28" x2="42" y2="48" />
        <line class="pointer-line" x1="90" y1="28" x2="90" y2="52" />
        <line class="pointer-line" x1="145" y1="28" x2="145" y2="70" />

        
        <text class="label-text" x="42" y="22">Head</text>
        <text class="label-text" x="90" y="22">Body</text>
        <text class="label-text" x="145" y="22">Tail</text>

        
        <g class="part part-tail" data-part="tail">
          
          <path d="M 100,75 C 130,50 180,68 192,80 C 180,92 130,110 100,85 Z" stroke-width="2" stroke-linejoin="round" />
          
          <path d="M 102,80 C 135,76 165,79 188,80" stroke="#16a34a" stroke-width="1.8" fill="none" />
        </g>

        
        <g class="part part-body" data-part="body">
          <ellipse cx="85" cy="80" rx="26" ry="22" stroke-width="2" />
          <path d="M 72,92 Q 85,96 98,92" stroke="#2563eb" stroke-width="1.5" fill="none" opacity="0.6" />
        </g>

        
        <g class="part part-head" data-part="head">
          <ellipse cx="44" cy="80" rx="24" ry="20" stroke-width="2" />
          
          <circle cx="40" cy="71" r="4.5" fill="#ffffff" stroke="#ca8a04" stroke-width="1.5" />
          <circle cx="39" cy="71" r="2.2" fill="#1e2945" />
          
          <path d="M 23,82 Q 28,87 34,84" stroke="#ca8a04" stroke-width="1.8" fill="none" stroke-linecap="round" />
        </g>
      </svg>
    </div>

    
    <div class="stage-card">
      <div class="stage-title">Adult Frog</div>
      <svg class="svg-container" viewBox="0 0 200 170">
        
        <line class="pointer-line" x1="45" y1="28" x2="45" y2="48" />
        <line class="pointer-line" x1="110" y1="28" x2="110" y2="58" />

        
        <line class="pointer-line" x1="150" y1="138" x2="135" y2="108" />

        
        <text class="label-text" x="45" y="22">Head</text>
        <text class="label-text" x="110" y="22">Body</text>

        
        <text class="label-text" x="150" y="148" fill="#16a34a">No Tail</text>
        <text class="sub-label" x="150" y="160">(absorbed)</text>

        
        <g class="part part-body" data-part="body">
          
          <path d="M 95,95 C 115,70 145,75 140,105 C 136,118 115,115 100,108" stroke-width="2" />
          <ellipse cx="120" cy="115" rx="14" ry="5" transform="rotate(10 120 115)" stroke-width="1.5" />

          
          <ellipse cx="92" cy="85" rx="27" ry="23" stroke-width="2" />

          
          <path d="M 68,96 L 64,116 L 55,118" stroke="#2563eb" stroke-width="3" stroke-linecap="round" stroke-linejoin="round" fill="none" />
        </g>

        
        <g class="part part-tail" data-part="tail">
          <circle cx="128" cy="98" r="6" stroke-dasharray="2,2" stroke-width="2" />
          <circle cx="128" cy="98" r="2.5" fill="#16a34a" />
        </g>

        
        <g class="part part-head" data-part="head">
          <path d="M 40,96 C 25,90 28,75 42,66 C 58,58 76,70 76,86 C 76,96 55,102 40,96 Z" stroke-width="2" />
          
          <circle cx="50" cy="62" r="6.5" fill="#fef08a" stroke="#ca8a04" stroke-width="2" />
          <circle cx="50" cy="62" r="5" fill="#ffffff" />
          <circle cx="49" cy="62" r="2.8" fill="#1e2945" />
          
          <path d="M 28,84 Q 45,92 62,84" stroke="#ca8a04" stroke-width="1.8" fill="none" stroke-linecap="round" />
        </g>
      </svg>
    </div>
  </div>

  <script>
    const buttons = document.querySelectorAll('.nav-btn');
    const parts = document.querySelectorAll('.part');

    function filterParts(selected) {
      buttons.forEach(btn => {
        btn.classList.toggle('active', btn.dataset.filter === selected);
      });

      parts.forEach(part => {
        const type = part.dataset.part;
        if (selected === 'all') {
          part.classList.remove('dimmed', 'highlighted');
        } else if (type === selected) {
          part.classList.remove('dimmed');
          part.classList.add('highlighted');
        } else {
          part.classList.add('dimmed');
          part.classList.remove('highlighted');
        }
      });
    }

    buttons.forEach(btn => {
      btn.addEventListener('click', () => {
        filterParts(btn.dataset.filter);
      });
    });

    parts.forEach(part => {
      part.addEventListener('click', () => {
        const type = part.dataset.part;
        const currentActive = document.querySelector('.nav-btn.active').dataset.filter;
        filterParts(currentActive === type ? 'all' : type);
      });
    });
  </script>
</body>
</html>

Main Animal Body Parts: Head, Body, and Tail

<!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>Main Animal Body Parts</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      user-select: none;
      -webkit-user-select: none;
    }
    body {
      width: 100%;
      min-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 10px;
    }

    /* Tabs / Filter Buttons */
    .controls {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 6px;
      width: 100%;
      max-width: 500px;
      margin-bottom: 6px;
    }
    .part-btn {
      padding: 6px 12px;
      font-size: 13px;
      font-weight: 700;
      border: 2px solid transparent;
      border-radius: 20px;
      cursor: pointer;
      background: #f1f5f9;
      color: #475569;
      transition: all 0.25s ease;
      display: flex;
      align-items: center;
      gap: 5px;
    }
    .part-btn:active {
      transform: scale(0.98);
    }
    .part-btn.active {
      color: #0f172a;
      box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    }
    .part-btn[data-part="all"].active {
      background: #e2e8f0;
      border-color: #94a3b8;
    }
    .part-btn[data-part="head"].active {
      background: #fef08a;
      border-color: #eab308;
      color: #854d0e;
    }
    .part-btn[data-part="body"].active {
      background: #bae6fd;
      border-color: #0284c7;
      color: #0369a1;
    }
    .part-btn[data-part="tail"].active {
      background: #bbf7d0;
      border-color: #16a34a;
      color: #15803d;
    }
    .dot-badge {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      display: inline-block;
    }

    /* Graphic Area */
    .stage {
      position: relative;
      width: 100%;
      max-width: 520px;
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    svg {
      width: 100%;
      height: auto;
      max-height: 280px;
      overflow: visible;
    }

    /* Part Regions */
    .part-region {
      transition: opacity 0.3s ease, filter 0.3s ease;
      cursor: pointer;
    }
    .part-region.dimmed {
      opacity: 0.18;
      filter: grayscale(80%);
    }

    /* Labels */
    .legend-row {
      display: flex;
      justify-content: space-around;
      width: 100%;
      max-width: 480px;
      margin-top: 4px;
      padding-top: 6px;
      border-top: 1px dashed #e2e8f0;
    }
    .legend-tag {
      font-size: 12px;
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .tag-head { color: #b45309; }
    .tag-body { color: #0284c7; }
    .tag-tail { color: #16a34a; }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="part-btn active" data-part="all">Show All</button>
    <button class="part-btn" data-part="head"><span class="dot-badge" style="background:#eab308;"></span>Head</button>
    <button class="part-btn" data-part="body"><span class="dot-badge" style="background:#0284c7;"></span>Body</button>
    <button class="part-btn" data-part="tail"><span class="dot-badge" style="background:#16a34a;"></span>Tail</button>
  </div>

  
  <div class="stage">
    <svg viewBox="0 0 540 260">
      <defs>
        
        <filter id="softGlow" x="-10%" y="-10%" width="120%" height="120%">
          <feDropShadow dx="0" dy="2" stdDeviation="2" flood-opacity="0.1" />
        </filter>
      </defs>

      
      <g id="bg-zones">
        
        <rect class="part-region zone-head" x="20" y="25" width="80" height="150" rx="16" fill="#fef9c3" stroke="#facc15" stroke-width="2" stroke-dasharray="4 4" opacity="0.6"/>
        <rect class="part-region zone-body" x="95" y="45" width="105" height="175" rx="16" fill="#e0f2fe" stroke="#38bdf8" stroke-width="2" stroke-dasharray="4 4" opacity="0.6"/>
        <rect class="part-region zone-tail" x="195" y="70" width="55" height="90" rx="16" fill="#dcfce7" stroke="#4ade80" stroke-width="2" stroke-dasharray="4 4" opacity="0.6"/>

        
        <rect class="part-region zone-head" x="290" y="25" width="80" height="150" rx="16" fill="#fef9c3" stroke="#facc15" stroke-width="2" stroke-dasharray="4 4" opacity="0.6"/>
        <rect class="part-region zone-body" x="365" y="45" width="105" height="175" rx="16" fill="#e0f2fe" stroke="#38bdf8" stroke-width="2" stroke-dasharray="4 4" opacity="0.6"/>
        <rect class="part-region zone-tail" x="465" y="55" width="65" height="110" rx="16" fill="#dcfce7" stroke="#4ade80" stroke-width="2" stroke-dasharray="4 4" opacity="0.6"/>
      </g>

      
      <g id="dog-group" filter="url(#softGlow)">
        
        <g class="part-region zone-tail">
          
          <path d="M 185 105 C 215 100, 235 75, 230 65 C 225 58, 205 80, 180 95 Z" fill="#b45309"/>
          <path d="M 230 65 C 235 60, 238 68, 230 75 Z" fill="#fbbf24"/>
        </g>

        
        <g class="part-region zone-body">
          
          <rect x="165" y="125" width="22" height="75" rx="11" fill="#9a3412"/>
          <ellipse cx="178" cy="198" rx="14" ry="7" fill="#7c2d12"/>
          
          
          <ellipse cx="145" cy="115" rx="45" ry="32" fill="#b45309"/>
          
          <ellipse cx="142" cy="122" rx="28" ry="18" fill="#fde68a"/>
          
          
          <rect x="110" y="120" width="20" height="80" rx="10" fill="#b45309"/>
          <ellipse cx="118" cy="198" rx="13" ry="7" fill="#9a3412"/>
          
          <rect x="86" y="90" width="16" height="8" rx="3" fill="#ef4444" transform="rotate(35 90 90)"/>
        </g>

        
        <g class="part-region zone-head">
          
          <ellipse cx="50" cy="85" rx="11" ry="24" fill="#7c2d12" transform="rotate(20 50 85)"/>
          
          <circle cx="68" cy="80" r="26" fill="#b45309"/>
          
          <ellipse cx="48" cy="90" rx="16" ry="12" fill="#fde68a"/>
          
          <ellipse cx="38" cy="86" rx="6" ry="5" fill="#1e293b"/>
          
          <circle cx="62" cy="74" r="5" fill="#1e293b"/>
          <circle cx="64" cy="72" r="2" fill="#ffffff"/>
          
          <path d="M 44 94 Q 50 99 56 94" fill="none" stroke="#1e293b" stroke-width="2" stroke-linecap="round"/>
        </g>
        <text x="135" y="240" font-size="14" font-weight="700" fill="#475569" text-anchor="middle">Dog (Mammal)</text>
      </g>

      
      <g id="lizard-group" filter="url(#softGlow)">
        
        <g class="part-region zone-tail">
          <path d="M 445 110 Q 485 115 505 85 Q 520 60 515 55 Q 500 70 475 98 Q 450 106 435 112 Z" fill="#15803d"/>
          
          <circle cx="475" cy="98" r="3" fill="#86efac"/>
          <circle cx="495" cy="82" r="2.5" fill="#86efac"/>
        </g>

        
        <g class="part-region zone-body">
          
          <path d="M 425 115 Q 450 135 440 160 Q 430 165 425 158" fill="none" stroke="#166534" stroke-width="9" stroke-linecap="round"/>
          <path d="M 435 160 L 448 165 M 438 163 L 445 171" stroke="#166534" stroke-width="3" stroke-linecap="round"/>
          
          
          <ellipse cx="410" cy="115" rx="42" ry="20" fill="#16a34a"/>
          <ellipse cx="410" cy="118" rx="30" ry="12" fill="#4ade80"/>
          
          
          <circle cx="395" cy="108" r="3" fill="#15803d"/>
          <circle cx="415" cy="106" r="3" fill="#15803d"/>
          <circle cx="428" cy="112" r="3" fill="#15803d"/>

          
          <path d="M 375 115 Q 355 135 365 160" fill="none" stroke="#166534" stroke-width="9" stroke-linecap="round"/>
          <path d="M 365 160 L 355 165 M 363 163 L 358 171" stroke="#166534" stroke-width="3" stroke-linecap="round"/>
        </g>

        
        <g class="part-region zone-head">
          
          <path d="M 380 115 Q 365 85 330 85 Q 315 95 315 105 Q 320 120 375 120 Z" fill="#16a34a"/>
          
          <path d="M 318 108 Q 345 120 375 120" fill="none" stroke="#4ade80" stroke-width="4"/>
          
          <circle cx="342" cy="88" r="7" fill="#facc15"/>
          <circle cx="342" cy="88" r="4" fill="#0f172a"/>
          <circle cx="344" cy="86" r="1.5" fill="#ffffff"/>
          
          <circle cx="323" cy="98" r="1.5" fill="#14532d"/>
        </g>
        <text x="410" y="240" font-size="14" font-weight="700" fill="#475569" text-anchor="middle">Lizard (Reptile)</text>
      </g>

      
      <line x1="270" y1="30" x2="270" y2="215" stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="5 5"/>

      
      <g id="floating-labels" font-weight="800" font-size="12" text-anchor="middle">
        
        <g class="part-region zone-head" transform="translate(60, 20)">
          <rect x="-30" y="-12" width="60" height="20" rx="10" fill="#fef08a" stroke="#ca8a04" stroke-width="1.5"/>
          <text y="2" fill="#854d0e" font-size="11">HEAD</text>
        </g>
        
        <g class="part-region zone-body" transform="translate(145, 20)">
          <rect x="-42" y="-12" width="84" height="20" rx="10" fill="#bae6fd" stroke="#0284c7" stroke-width="1.5"/>
          <text y="2" fill="#0369a1" font-size="11">BODY</text>
        </g>
        
        <g class="part-region zone-tail" transform="translate(225, 20)">
          <rect x="-26" y="-12" width="52" height="20" rx="10" fill="#bbf7d0" stroke="#16a34a" stroke-width="1.5"/>
          <text y="2" fill="#15803d" font-size="11">TAIL</text>
        </g>

        
        <g class="part-region zone-head" transform="translate(330, 20)">
          <rect x="-30" y="-12" width="60" height="20" rx="10" fill="#fef08a" stroke="#ca8a04" stroke-width="1.5"/>
          <text y="2" fill="#854d0e" font-size="11">HEAD</text>
        </g>
        <g class="part-region zone-body" transform="translate(415, 20)">
          <rect x="-42" y="-12" width="84" height="20" rx="10" fill="#bae6fd" stroke="#0284c7" stroke-width="1.5"/>
          <text y="2" fill="#0369a1" font-size="11">BODY</text>
        </g>
        <g class="part-region zone-tail" transform="translate(495, 20)">
          <rect x="-26" y="-12" width="52" height="20" rx="10" fill="#bbf7d0" stroke="#16a34a" stroke-width="1.5"/>
          <text y="2" fill="#15803d" font-size="11">TAIL</text>
        </g>
      </g>
    </svg>
  </div>

  
  <div class="legend-row">
    <div class="legend-tag tag-head">
      <span class="dot-badge" style="background:#eab308;"></span>
      <span>1. Head</span>
    </div>
    <div class="legend-tag tag-body">
      <span class="dot-badge" style="background:#0284c7;"></span>
      <span>2. Body (Trunk + Limbs)</span>
    </div>
    <div class="legend-tag tag-tail">
      <span class="dot-badge" style="background:#16a34a;"></span>
      <span>3. Tail</span>
    </div>
  </div>

  <script>
    const buttons = document.querySelectorAll('.part-btn');
    const allRegions = document.querySelectorAll('.part-region');

    function filterPart(part) {
      // Update buttons
      buttons.forEach(btn => {
        if (btn.dataset.part === part) {
          btn.classList.add('active');
        } else {
          btn.classList.remove('active');
        }
      });

      // Update graphic elements
      allRegions.forEach(el => {
        if (part === 'all') {
          el.classList.remove('dimmed');
        } else {
          if (el.classList.contains('zone-' + part)) {
            el.classList.remove('dimmed');
          } else {
            el.classList.add('dimmed');
          }
        }
      });
    }

    buttons.forEach(btn => {
      btn.addEventListener('click', () => {
        filterPart(btn.dataset.part);
      });
    });

    // Also let users tap directly on parts in the SVG
    document.querySelectorAll('.zone-head').forEach(el => {
      el.addEventListener('click', () => filterPart('head'));
    });
    document.querySelectorAll('.zone-body').forEach(el => {
      el.addEventListener('click', () => filterPart('body'));
    });
    document.querySelectorAll('.zone-tail').forEach(el => {
      el.addEventListener('click', () => filterPart('tail'));
    });
  </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>Vertebrate Body Regions</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    }

    body {
      background: #ffffff;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
    }

    /* Tabs */
    .tabs {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 6px;
      width: 100%;
      max-width: 480px;
      margin-bottom: 8px;
    }

    .tab-btn {
      appearance: none;
      background: #f1f5f9;
      border: 2px solid transparent;
      border-radius: 8px;
      padding: 6px 4px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      transition: background 0.2s, border-color 0.2s, color 0.2s;
    }

    .tab-btn.active {
      background: #e0f2fe;
      border-color: #0284c7;
      color: #0369a1;
    }

    /* Region Legend / Header */
    .region-legend {
      display: flex;
      justify-content: center;
      gap: 8px;
      width: 100%;
      max-width: 480px;
      margin-bottom: 8px;
    }

    .legend-tag {
      flex: 1;
      text-align: center;
      padding: 4px 6px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .tag-head {
      background: #fef08a;
      border: 1.5px solid #ca8a04;
      color: #854d0e;
    }

    .tag-body {
      background: #bfdbfe;
      border: 1.5px solid #2563eb;
      color: #1e40af;
    }

    .tag-tail {
      background: #bbf7d0;
      border: 1.5px solid #16a34a;
      color: #166534;
    }

    /* Display Area */
    .display-stage {
      position: relative;
      width: 100%;
      max-width: 480px;
      height: 190px;
      background: #f8fafc;
      border-radius: 12px;
      overflow: hidden;
    }

    .animal-panel {
      position: absolute;
      inset: 0;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.25s ease;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 8px;
    }

    .animal-panel.active {
      opacity: 1;
      pointer-events: auto;
    }

    svg {
      width: 100%;
      height: 100%;
      display: block;
    }

    /* Region highlight boxes in SVG */
    .box-head {
      fill: #fef9c3;
      fill-opacity: 0.45;
      stroke: #eab308;
      stroke-width: 2;
      stroke-dasharray: 4 3;
      rx: 8;
    }

    .box-body {
      fill: #dbeafe;
      fill-opacity: 0.45;
      stroke: #3b82f6;
      stroke-width: 2;
      stroke-dasharray: 4 3;
      rx: 8;
    }

    .box-tail {
      fill: #dcfce7;
      fill-opacity: 0.45;
      stroke: #22c55e;
      stroke-width: 2;
      stroke-dasharray: 4 3;
      rx: 8;
    }

    /* Caption Box */
    .caption-box {
      width: 100%;
      max-width: 480px;
      margin-top: 8px;
      padding: 8px 12px;
      background: #f1f5f9;
      border-radius: 8px;
      text-align: center;
      font-size: 13px;
      font-weight: 600;
      color: #334155;
      min-height: 38px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    @media (max-width: 380px) {
      .tab-btn {
        font-size: 11px;
        padding: 5px 2px;
      }
      .legend-tag {
        font-size: 11px;
        padding: 3px 4px;
      }
      .caption-box {
        font-size: 12px;
      }
    }
  </style>
</head>
<body>

  
  <div class="tabs" role="tablist">
    <button class="tab-btn active" id="tab-0" onclick="showAnimal(0)" role="tab" aria-selected="true">🐟 Fish</button>
    <button class="tab-btn" id="tab-1" onclick="showAnimal(1)" role="tab" aria-selected="false">🐦 Bird</button>
    <button class="tab-btn" id="tab-2" onclick="showAnimal(2)" role="tab" aria-selected="false">🐱 Cat</button>
    <button class="tab-btn" id="tab-3" onclick="showAnimal(3)" role="tab" aria-selected="false">🐊 Reptile</button>
  </div>

  
  <div class="region-legend">
    <div class="legend-tag tag-head">1. Head</div>
    <div class="legend-tag tag-body">2. Body & Limbs</div>
    <div class="legend-tag tag-tail">3. Tail</div>
  </div>

  
  <div class="display-stage">
    
    <div class="animal-panel active" id="panel-0">
      <svg viewBox="0 0 360 140">
        
        <rect class="box-head" x="20" y="20" width="85" height="100" />
        <rect class="box-body" x="115" y="20" width="130" height="100" />
        <rect class="box-tail" x="255" y="20" width="85" height="100" />

        
        
        <path d="M75,70 C100,35 210,40 260,70 C210,100 100,105 75,70 Z" fill="#38bdf8" stroke="#0284c7" stroke-width="3" />
        
        <path d="M75,70 C75,45 50,55 35,70 C50,85 75,95 75,70 Z" fill="#7dd3fc" stroke="#0284c7" stroke-width="3" />
        <circle cx="52" cy="65" r="4.5" fill="#0f172a" />
        <circle cx="50" cy="63" r="1.5" fill="#ffffff" />
        <path d="M75,50 C80,60 80,80 75,90" fill="none" stroke="#0284c7" stroke-width="2" stroke-dasharray="2 2" />

        
        <polygon points="140,43 170,22 190,45" fill="#0284c7" opacity="0.85" />
        <polygon points="145,95 170,116 185,97" fill="#0284c7" opacity="0.85" />
        <path d="M125,75 Q145,70 150,85 Q135,90 125,75" fill="#0284c7" opacity="0.9" />

        
        <polygon points="255,70 325,32 305,70 325,108" fill="#0ea5e9" stroke="#0284c7" stroke-width="3" stroke-linejoin="round" />
      </svg>
    </div>

    
    <div class="animal-panel" id="panel-1">
      <svg viewBox="0 0 360 140">
        
        <rect class="box-head" x="20" y="20" width="85" height="100" />
        <rect class="box-body" x="115" y="20" width="130" height="100" />
        <rect class="box-tail" x="255" y="20" width="85" height="100" />

        
        
        <polygon points="235,75 320,55 328,70 322,85" fill="#ea580c" stroke="#c2410c" stroke-width="2.5" stroke-linejoin="round" />

        
        <ellipse cx="170" cy="74" rx="55" ry="32" fill="#fb923c" stroke="#ea580c" stroke-width="3" />
        
        <path d="M140,65 C170,45 215,65 210,85 C180,95 150,85 140,65 Z" fill="#c2410c" />
        
        <line x1="165" y1="104" x2="160" y2="120" stroke="#78350f" stroke-width="3" stroke-linecap="round" />
        <line x1="180" y1="104" x2="178" y2="120" stroke="#78350f" stroke-width="3" stroke-linecap="round" />
        <line x1="155" y1="120" x2="166" y2="120" stroke="#78350f" stroke-width="2.5" stroke-linecap="round" />
        <line x1="173" y1="120" x2="184" y2="120" stroke="#78350f" stroke-width="2.5" stroke-linecap="round" />

        
        <circle cx="85" cy="58" r="24" fill="#fdba74" stroke="#ea580c" stroke-width="3" />
        <polygon points="63,56 34,63 63,68" fill="#eab308" stroke="#ca8a04" stroke-width="2" />
        <circle cx="75" cy="53" r="3.5" fill="#0f172a" />
      </svg>
    </div>

    
    <div class="animal-panel" id="panel-2">
      <svg viewBox="0 0 360 140">
        
        <rect class="box-head" x="20" y="20" width="85" height="100" />
        <rect class="box-body" x="115" y="20" width="130" height="100" />
        <rect class="box-tail" x="255" y="20" width="85" height="100" />

        
        <path d="M235,70 C270,70 300,50 310,32 C318,32 312,48 290,75 C265,95 240,82 235,75" fill="#94a3b8" stroke="#64748b" stroke-width="2.5" />

        
        
        <path d="M210,70 C225,80 225,105 218,120 L206,120 C206,105 200,90 195,78" fill="#cbd5e1" stroke="#64748b" stroke-width="2.5" />
        
        <ellipse cx="175" cy="72" rx="52" ry="26" fill="#94a3b8" stroke="#64748b" stroke-width="3" />
        
        <path d="M145,72 L140,120 L128,120 L132,72" fill="#cbd5e1" stroke="#64748b" stroke-width="2.5" />

        
        <polygon points="65,30 78,52 56,48" fill="#64748b" />
        <polygon points="90,32 98,54 80,48" fill="#64748b" />
        <ellipse cx="75" cy="62" rx="22" ry="20" fill="#cbd5e1" stroke="#64748b" stroke-width="3" />
        <circle cx="67" cy="58" r="3" fill="#0f172a" />
        <polygon points="56,66 52,69 56,71" fill="#f43f5e" />
        
        <line x1="50" y1="67" x2="32" y2="64" stroke="#64748b" stroke-width="1.5" />
        <line x1="50" y1="71" x2="33" y2="75" stroke="#64748b" stroke-width="1.5" />
      </svg>
    </div>

    
    <div class="animal-panel" id="panel-3">
      <svg viewBox="0 0 360 140">
        
        <rect class="box-head" x="20" y="20" width="85" height="100" />
        <rect class="box-body" x="115" y="20" width="130" height="100" />
        <rect class="box-tail" x="255" y="20" width="85" height="100" />

        
        
        <path d="M230,72 Q280,72 328,66 Q280,84 230,80 Z" fill="#15803d" stroke="#166534" stroke-width="2.5" />
        <polygon points="250,68 256,60 262,68" fill="#166534" />
        <polygon points="270,67 276,59 282,67" fill="#166534" />
        <polygon points="290,66 295,60 300,66" fill="#166534" />

        
        <ellipse cx="175" cy="76" rx="55" ry="18" fill="#22c55e" stroke="#166534" stroke-width="3" />
        
        <path d="M210,80 Q225,95 215,108 L203,108 Q208,94 198,84" fill="#15803d" stroke="#166534" stroke-width="2" />
        
        <path d="M145,80 Q155,95 145,108 L133,108 Q138,94 135,84" fill="#15803d" stroke="#166534" stroke-width="2" />

        
        <path d="M125,70 L40,64 C32,68 32,74 40,78 L125,82 Z" fill="#4ade80" stroke="#166534" stroke-width="3" />
        <circle cx="102" cy="65" r="4" fill="#0f172a" />
        <circle cx="101" cy="64" r="1.5" fill="#ffffff" />
        <line x1="40" y1="71" x2="80" y2="72" stroke="#166534" stroke-width="2" />
      </svg>
    </div>
  </div>

  
  <div class="caption-box" id="caption">
    Fins attach to trunk for balance; tail pushes through water.
  </div>

  <script>
    const captions = [
      "Fins attach to trunk for balance; tail pushes through water.",
      "Wings attach to trunk for lift; tail feathers steer flight.",
      "4 legs attach to trunk for running; tail aids balance.",
      "4 legs attach to trunk for crawling; muscular tail swims."
    ];

    function showAnimal(index) {
      for (let i = 0; i < 4; i++) {
        const btn = document.getElementById('tab-' + i);
        const panel = document.getElementById('panel-' + i);
        if (i === index) {
          btn.classList.add('active');
          btn.setAttribute('aria-selected', 'true');
          panel.classList.add('active');
        } else {
          btn.classList.remove('active');
          btn.setAttribute('aria-selected', 'false');
          panel.classList.remove('active');
        }
      }
      document.getElementById('caption').textContent = captions[index];
    }
  </script>
</body>
</html>

science.ks1.y1.t2.s3

Aligned learning resources

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