<!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>Preservation Without Decay</title>
  <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;
      user-select: none;
    }

    .header-tag {
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.08em;
      text-transform: uppercase;
      color: #6b7280;
      text-align: center;
    }

    .grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
      width: 100%;
    }

    @media (max-width: 520px) {
      .grid {
        grid-template-columns: 1fr;
      }
    }

    .specimen-card {
      background: #ffffff;
      border: 1.5px solid #e5e7eb;
      border-radius: 12px;
      padding: 14px 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      gap: 10px;
      cursor: pointer;
      transition: border-color 0.25s ease, box-shadow 0.25s ease;
    }

    .specimen-card.active {
      border-color: #22b7ff;
      box-shadow: 0 0 0 3px rgba(34, 183, 255, 0.2);
    }

    .badge {
      background: #e0f4ff;
      color: #0077b6;
      border: 1px solid #bae6fd;
      font-size: 11px;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 999px;
      letter-spacing: 0.02em;
    }

    .view-portal {
      width: 84px;
      height: 84px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      font-size: 38px;
      border: 3px solid rgba(255, 255, 255, 0.8);
      box-shadow: inset 0 2px 6px rgba(0,0,0,0.1), 0 4px 10px rgba(0,0,0,0.06);
    }

    .amber-bg {
      background: radial-gradient(circle at 35% 35%, #ffd166 0%, #f48c06 70%, #d97706 100%);
    }

    .ice-bg {
      background: radial-gradient(circle at 35% 35%, #e0f2fe 0%, #7dd3fc 60%, #0284c7 100%);
    }

    .bog-bg {
      background: radial-gradient(circle at 35% 35%, #a78bfa 0%, #5b21b6 70%, #311042 100%);
    }

    .specimen-title {
      font-size: 14px;
      font-weight: 800;
      color: #0f172a;
    }

    .barrier-pill {
      background: #fef2f2;
      border: 1px solid #fecaca;
      color: #dc2626;
      font-size: 11px;
      font-weight: 700;
      padding: 4px 8px;
      border-radius: 6px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    .status-banner {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 8px 12px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 12px;
      font-weight: 600;
      color: #334155;
    }

    .decay-tag {
      background: #dcfce7;
      color: #15803d;
      border: 1px solid #bbf7d0;
      padding: 2px 6px;
      border-radius: 4px;
      font-size: 11px;
      font-weight: 700;
    }
  </style>
</head>
<body>

  <div class="header-tag">Conditions for Zero Decay</div>

  <div class="grid">
    
    <div class="specimen-card active" id="card-0" onclick="selectCard(0)">
      <span class="badge">Tree Resin</span>
      <div class="view-portal amber-bg">
        <span>🐜</span>
      </div>
      <div class="specimen-title">Amber</div>
      <div class="barrier-pill">🚫 No O₂ / Moisture</div>
    </div>

    
    <div class="specimen-card" id="card-1" onclick="selectCard(1)">
      <span class="badge">Permafrost</span>
      <div class="view-portal ice-bg">
        <span>🦣</span>
      </div>
      <div class="specimen-title">Glacial Ice</div>
      <div class="barrier-pill">🚫 No Heat (Enzymes Stop)</div>
    </div>

    
    <div class="specimen-card" id="card-2" onclick="selectCard(2)">
      <span class="badge">Acidic Peat</span>
      <div class="view-portal bog-bg">
        <span>👤</span>
      </div>
      <div class="specimen-title">Peat Bog</div>
      <div class="barrier-pill">🚫 Acid Kills Bacteria</div>
    </div>
  </div>

  <div class="status-banner">
    <span id="detail-text">Resin seals out air &amp; water — body intact</span>
    <span class="decay-tag">✓ 0% DECAY</span>
  </div>

  <script>
    const descriptions = [
      "Resin seals out air & water — body intact",
      "Sub-zero cold freezes microbes & enzymes",
      "High acid & zero oxygen destroy decomposers"
    ];

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

Evidence for Evolution: The Fossil Record

<!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="1:1">
  <title>Fossil Types</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #ffffff;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      width: 100%;
      min-height: 100%;
      justify-content: center;
    }

    .fossil-grid {
      display: flex;
      flex-direction: column;
      gap: 10px;
      width: 100%;
      max-width: 600px;
      margin: 0 auto;
    }

    .fossil-panel {
      display: grid;
      grid-template-columns: 140px 1fr;
      align-items: center;
      gap: 12px;
      padding: 10px 14px;
      border-radius: 12px;
      border: 1px solid rgba(0, 0, 0, 0.06);
      transition: box-shadow 0.2s ease, transform 0.2s ease;
      cursor: pointer;
      user-select: none;
    }

    .fossil-panel:active {
      transform: scale(0.99);
    }

    .panel-impression {
      background: #fffbeb;
      border-color: #fde68a;
    }
    .panel-impression.active {
      box-shadow: 0 0 0 2px #d97706;
    }

    .panel-mould {
      background: #eff6ff;
      border-color: #bfdbfe;
    }
    .panel-mould.active {
      box-shadow: 0 0 0 2px #2563eb;
    }

    .panel-cast {
      background: #f0fdf4;
      border-color: #bbf7d0;
    }
    .panel-cast.active {
      box-shadow: 0 0 0 2px #16a34a;
    }

    .svg-wrap {
      width: 100%;
      height: 90px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .svg-wrap svg {
      width: 100%;
      height: 100%;
      max-height: 90px;
    }

    .info {
      display: flex;
      flex-direction: column;
      gap: 2px;
    }

    .title {
      font-size: 16px;
      font-weight: 700;
      line-height: 1.2;
    }

    .sub {
      font-size: 13px;
      font-weight: 500;
      color: #64748b;
    }

    .badge {
      display: inline-block;
      align-self: flex-start;
      margin-top: 4px;
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      padding: 2px 8px;
      border-radius: 6px;
    }

    .panel-impression .badge {
      background: #fef3c7;
      color: #92400e;
    }

    .panel-mould .badge {
      background: #dbeafe;
      color: #1e40af;
    }

    .panel-cast .badge {
      background: #dcfce7;
      color: #166534;
    }

    @media (max-width: 420px) {
      .fossil-panel {
        grid-template-columns: 110px 1fr;
        padding: 8px 10px;
        gap: 10px;
      }
      .svg-wrap {
        height: 75px;
      }
      .title {
        font-size: 14px;
      }
      .sub {
        font-size: 12px;
      }
    }
  </style>
</head>
<body>

  <div class="fossil-grid">

    
    <div class="fossil-panel panel-impression active" onclick="selectPanel(this)">
      <div class="svg-wrap">
        <svg viewBox="0 0 160 100" fill="none" xmlns="http://www.w3.org/2000/svg">
          
          <polygon points="15,45 125,25 145,55 35,80" fill="#fde68a" stroke="#d97706" stroke-width="1.5" stroke-linejoin="round"/>
          <polygon points="35,80 145,55 145,70 35,95" fill="#f59e0b" stroke="#d97706" stroke-width="1.5" stroke-linejoin="round"/>
          <polygon points="15,45 35,80 35,95 15,60" fill="#d97706" stroke="#b45309" stroke-width="1.5" stroke-linejoin="round"/>

          
          
          <path d="M 75,45 C 70,36 68,34 67,37 C 69,45 74,49 76,57 
                   C 72,52 64,44 61,46 C 60,50 68,58 77,61 
                   C 80,64 85,67 87,63 C 88,59 84,54 83,50 
                   C 89,45 96,38 94,36 C 91,35 84,43 80,48 Z" 
                fill="#b45309" opacity="0.85"/>
          
          <path d="M 76,47 C 72,39 70,37 69,39 C 71,46 75,50 77,57 
                   C 74,53 67,46 64,48 C 63,51 70,58 78,61 
                   C 81,63 84,65 86,62 C 87,58 83,54 82,51 
                   C 87,47 93,41 91,39 C 89,38 83,45 79,49 Z" 
                fill="#78350f"/>
        </svg>
      </div>
      <div class="info">
        <div class="title">Impression</div>
        <div class="sub">Surface Trace</div>
        <div class="badge">2D Print</div>
      </div>
    </div>

    
    <div class="fossil-panel panel-mould" onclick="selectPanel(this)">
      <div class="svg-wrap">
        <svg viewBox="0 0 160 100" fill="none" xmlns="http://www.w3.org/2000/svg">
          
          <rect x="15" y="15" width="130" height="70" rx="8" fill="#cbd5e1" stroke="#64748b" stroke-width="1.5"/>
          
          <line x1="15" y1="38" x2="145" y2="38" stroke="#94a3b8" stroke-width="1" stroke-dasharray="4 2"/>
          <line x1="15" y1="62" x2="145" y2="62" stroke="#94a3b8" stroke-width="1" stroke-dasharray="4 2"/>

          
          
          <circle cx="80" cy="50" r="26" fill="#1e293b"/>
          
          <path d="M 80,50 
                   A 4 4 0 0 1 84,50 
                   A 8 8 0 0 1 76,53 
                   A 13 13 0 0 1 89,56 
                   A 18 18 0 0 1 70,61 
                   A 24 24 0 0 1 98,63" 
                stroke="#475569" stroke-width="2.5" fill="none" stroke-linecap="round"/>
          
          <line x1="72" y1="32" x2="77" y2="40" stroke="#334155" stroke-width="1.5"/>
          <line x1="88" y1="28" x2="86" y2="38" stroke="#334155" stroke-width="1.5"/>
          <line x1="102" y1="42" x2="93" y2="46" stroke="#334155" stroke-width="1.5"/>
          <line x1="104" y1="58" x2="93" y2="56" stroke="#334155" stroke-width="1.5"/>
          <line x1="60" y1="58" x2="70" y2="55" stroke="#334155" stroke-width="1.5"/>

          
          <circle cx="80" cy="50" r="26" stroke="#3b82f6" stroke-width="1.5" stroke-dasharray="3 3" fill="none"/>
        </svg>
      </div>
      <div class="info">
        <div class="title">Mould</div>
        <div class="sub">Empty Cavity</div>
        <div class="badge">Hollow Void</div>
      </div>
    </div>

    
    <div class="fossil-panel panel-cast" onclick="selectPanel(this)">
      <div class="svg-wrap">
        <svg viewBox="0 0 160 100" fill="none" xmlns="http://www.w3.org/2000/svg">
          
          <rect x="15" y="15" width="130" height="70" rx="8" fill="#cbd5e1" stroke="#64748b" stroke-width="1.5"/>
          <line x1="15" y1="38" x2="145" y2="38" stroke="#94a3b8" stroke-width="1" stroke-dasharray="4 2"/>
          <line x1="15" y1="62" x2="145" y2="62" stroke="#94a3b8" stroke-width="1" stroke-dasharray="4 2"/>

          
          <circle cx="80" cy="50" r="26" fill="#10b981" stroke="#059669" stroke-width="1.5"/>
          
          
          <path d="M 80,50 
                   A 4 4 0 0 1 84,50 
                   A 8 8 0 0 1 76,53 
                   A 13 13 0 0 1 89,56 
                   A 18 18 0 0 1 70,61 
                   A 24 24 0 0 1 98,63" 
                stroke="#ecfdf5" stroke-width="3" fill="none" stroke-linecap="round"/>
          
          
          <line x1="72" y1="30" x2="77" y2="40" stroke="#a7f3d0" stroke-width="2.5" stroke-linecap="round"/>
          <line x1="88" y1="26" x2="86" y2="38" stroke="#a7f3d0" stroke-width="2.5" stroke-linecap="round"/>
          <line x1="103" y1="42" x2="93" y2="46" stroke="#a7f3d0" stroke-width="2.5" stroke-linecap="round"/>
          <line x1="104" y1="58" x2="93" y2="56" stroke="#a7f3d0" stroke-width="2.5" stroke-linecap="round"/>
          <line x1="60" y1="58" x2="70" y2="55" stroke="#a7f3d0" stroke-width="2.5" stroke-linecap="round"/>

          
          <polygon points="62,38 64,41 67,41 65,43 66,46 63,44 60,46 61,43 59,41 62,41" fill="#ffffff"/>
          <polygon points="94,32 95,34 98,34 96,36 97,38 95,37 93,38 94,36 92,34 94,34" fill="#ffffff"/>
        </svg>
      </div>
      <div class="info">
        <div class="title">Cast</div>
        <div class="sub">Mineral Replica</div>
        <div class="badge">Solid 3D</div>
      </div>
    </div>

  </div>

  <script>
    function selectPanel(panel) {
      document.querySelectorAll('.fossil-panel').forEach(p => p.classList.remove('active'));
      panel.classList.add('active');
    }
  </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="1:1">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      width: 100%;
      min-height: 100%;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: transparent;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 12px;
    }

    .header-bar {
      text-align: center;
      margin-bottom: 12px;
      width: 100%;
      max-width: 540px;
    }
    .header-title {
      font-size: 15px;
      font-weight: 800;
      letter-spacing: 0.5px;
      text-transform: uppercase;
      color: #475569;
    }

    .grid-container {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 10px;
      width: 100%;
      max-width: 540px;
    }

    .reason-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      position: relative;
      overflow: hidden;
      transition: box-shadow 0.25s ease, background-color 0.25s ease;
      user-select: none;
    }

    .reason-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 4px;
      background: var(--accent);
    }

    .reason-card:active {
      background: #f8fafc;
    }

    .reason-card.active {
      box-shadow: 0 0 0 2px var(--accent), 0 4px 12px rgba(0,0,0,0.06);
      background: #ffffff;
    }

    .card-num {
      position: absolute;
      top: 8px;
      left: 10px;
      font-size: 11px;
      font-weight: 800;
      color: var(--accent);
      opacity: 0.85;
    }

    .visual-stage {
      width: 100%;
      height: 62px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      margin: 4px 0 6px 0;
    }

    .symbol-box {
      font-size: 26px;
      line-height: 1;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .arrow-flow {
      font-size: 14px;
      color: #94a3b8;
      font-weight: bold;
    }

    .badge-fade {
      font-size: 20px;
      opacity: 0.35;
      filter: grayscale(1);
    }

    .card-title {
      font-size: 13px;
      font-weight: 700;
      color: #0f172a;
      margin-bottom: 3px;
    }

    .card-desc {
      font-size: 11.5px;
      line-height: 1.35;
      color: #64748b;
      max-width: 95%;
    }

    /* Color Themes */
    .theme-soft { --accent: #f59e0b; }
    .theme-rare { --accent: #ef4444; }
    .theme-geo  { --accent: #3b82f6; }
    .theme-deep { --accent: #10b981; }

    /* Interactive Strata Mini Diagram for Card 3 & 4 */
    .strata-mini {
      width: 44px;
      height: 36px;
      border-radius: 4px;
      display: flex;
      flex-direction: column;
      overflow: hidden;
      border: 1px solid #cbd5e1;
    }
    .strata-layer {
      flex: 1;
      width: 100%;
    }

    .status-pill {
      margin-top: 10px;
      font-size: 11px;
      font-weight: 600;
      color: #64748b;
      background: #f1f5f9;
      padding: 4px 10px;
      border-radius: 20px;
      display: inline-flex;
      align-items: center;
      gap: 5px;
    }

    @media (max-width: 380px) {
      .grid-container {
        gap: 8px;
      }
      .reason-card {
        padding: 10px 8px;
      }
      .visual-stage {
        height: 52px;
      }
      .symbol-box {
        font-size: 22px;
      }
      .card-title {
        font-size: 12px;
      }
      .card-desc {
        font-size: 10.5px;
      }
    }
  </style>
</head>
<body>

  <div class="header-bar">
    <div class="header-title">Why the Fossil Record Has Gaps</div>
  </div>

  <div class="grid-container">
    
    <div class="reason-card theme-soft active" onclick="selectCard(this)">
      <span class="card-num">01</span>
      <div class="visual-stage">
        <div class="symbol-box">🪼</div>
        <div class="arrow-flow">→</div>
        <div class="symbol-box badge-fade">💨</div>
      </div>
      <div class="card-title">Soft-Bodied Life</div>
      <div class="card-desc">No bones or shells to mineralise; decay completely</div>
    </div>

    
    <div class="reason-card theme-rare" onclick="selectCard(this)">
      <span class="card-num">02</span>
      <div class="visual-stage">
        <div class="symbol-box">🐟</div>
        <div class="arrow-flow">→</div>
        <div class="symbol-box">🦀</div>
      </div>
      <div class="card-title">Rare Conditions</div>
      <div class="card-desc">Eaten by scavengers or rot before sediment buries them</div>
    </div>

    
    <div class="reason-card theme-geo" onclick="selectCard(this)">
      <span class="card-num">03</span>
      <div class="visual-stage">
        <div class="symbol-box">🌋</div>
        <div class="strata-mini">
          <div class="strata-layer" style="background:#94a3b8;"></div>
          <div class="strata-layer" style="background:#ef4444;"></div>
          <div class="strata-layer" style="background:#475569;"></div>
        </div>
      </div>
      <div class="card-title">Rock Destruction</div>
      <div class="card-desc">Tectonic heat, pressure, and melting destroy strata</div>
    </div>

    
    <div class="reason-card theme-deep" onclick="selectCard(this)">
      <span class="card-num">04</span>
      <div class="visual-stage">
        <div class="symbol-box">🌊</div>
        <div class="arrow-flow">⬇</div>
        <div class="symbol-box">⛏️</div>
      </div>
      <div class="card-title">Still Undiscovered</div>
      <div class="card-desc">Buried deep under mountain rock or ocean floors</div>
    </div>
  </div>

  <div class="status-pill">
    <span>✦</span> Tap a reason to focus
  </div>

  <script>
    function selectCard(el) {
      document.querySelectorAll('.reason-card').forEach(c => c.classList.remove('active'));
      el.classList.add('active');
    }
  </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">
  <script src="{{VENDOR_CDN}}/classace-diagram.js"></script>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: system-ui, -apple-system, sans-serif;
    }

    body {
      background: transparent;
      color: #1e2945;
      padding: 12px 8px;
    }

    .diagram-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 10px;
      width: 100%;
      max-width: 720px;
      margin: 0 auto;
    }

    @media (max-width: 540px) {
      .diagram-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
      }
    }

    .step-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      cursor: pointer;
      transition: box-shadow 0.25s ease, border-color 0.25s ease;
      position: relative;
    }

    .step-card.active {
      border-color: #22b7ff;
      box-shadow: 0 0 0 2px #22b7ff, 0 4px 12px rgba(34, 183, 255, 0.15);
    }

    .step-header {
      padding: 8px 10px 4px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .badge {
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.3px;
      padding: 2px 8px;
      border-radius: 12px;
      background: #f1f5f9;
      color: #475569;
    }

    .step-card.active .badge {
      background: #22b7ff;
      color: #ffffff;
    }

    .step-title {
      font-size: 13px;
      font-weight: 700;
      color: #0f172a;
      padding: 0 10px 4px;
    }

    .stage-view {
      width: 100%;
      height: 140px;
      position: relative;
      background: #f8fafc;
    }

    .stage-svg {
      width: 100%;
      height: 100%;
      display: block;
    }

    .step-desc {
      font-size: 12px;
      line-height: 1.35;
      color: #475569;
      padding: 6px 10px 10px;
      min-height: 42px;
      background: #ffffff;
    }

    .controls {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      margin-top: 12px;
    }

    .btn-ctrl {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      color: #334155;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      cursor: pointer;
    }

    .btn-ctrl:active {
      background: #f1f5f9;
    }

    .dots-nav {
      display: flex;
      gap: 6px;
      align-items: center;
    }

    .dot-btn {
      width: 9px;
      height: 9px;
      border-radius: 50%;
      background: #cbd5e1;
      border: none;
      padding: 0;
      cursor: pointer;
    }

    .dot-btn.active {
      background: #22b7ff;
      width: 18px;
      border-radius: 6px;
    }
  </style>
</head>
<body>

  <div class="diagram-grid">
    
    <div class="step-card active" id="card-0">
      <div class="step-header">
        <span class="badge">STEP 1</span>
      </div>
      <div class="step-title">Burial</div>
      <div class="stage-view">
        <svg class="stage-svg" viewBox="0 0 160 140">
          
          <rect x="0" y="0" width="160" height="70" fill="#bae6fd" />
          <path d="M0 10 Q 40 5, 80 10 T 160 10 L 160 0 L 0 0 Z" fill="#7dd3fc" opacity="0.6"/>
          
          
          <rect x="0" y="70" width="160" height="70" fill="#d6c7a1" />
          
          
          <g fill="#bfae80" opacity="0.8">
            <circle cx="35" cy="50" r="2.5"/>
            <circle cx="65" cy="40" r="3"/>
            <circle cx="100" cy="45" r="2"/>
            <circle cx="130" cy="55" r="3.5"/>
            <circle cx="80" cy="62" r="2.5"/>
          </g>

          
          <g transform="translate(45, 75)">
            
            <ellipse cx="35" cy="18" rx="34" ry="14" fill="#fb923c" opacity="0.85"/>
            <polygon points="65,18 80,8 76,28" fill="#fb923c" opacity="0.85"/>
            
            <circle cx="15" cy="14" r="2.5" fill="#ffffff"/>
            <circle cx="14" cy="14" r="1.2" fill="#0f172a"/>
            
            <path d="M18 18 Q 40 18 64 18" stroke="#ffffff" stroke-width="2.5" stroke-linecap="round" fill="none"/>
            <path d="M28 12 L 28 24 M38 10 L 38 26 M48 11 L 48 25 M58 13 L 58 23" stroke="#ffffff" stroke-width="1.8" stroke-linecap="round"/>
          </g>
          
          
          <path d="M 0 95 Q 80 82 160 95 L 160 140 L 0 140 Z" fill="#c2b078" opacity="0.75"/>
        </svg>
      </div>
      <div class="step-desc">Sediment quickly buries dead organism</div>
    </div>

    
    <div class="step-card" id="card-1">
      <div class="step-header">
        <span class="badge">STEP 2</span>
      </div>
      <div class="step-title">Decay</div>
      <div class="stage-view">
        <svg class="stage-svg" viewBox="0 0 160 140">
          
          <rect x="0" y="0" width="160" height="30" fill="#93c5fd" />
          <rect x="0" y="30" width="160" height="35" fill="#e2d9c2" />
          
          
          <rect x="0" y="65" width="160" height="75" fill="#bfae80" />
          
          
          <line x1="0" y1="65" x2="160" y2="65" stroke="#998650" stroke-dasharray="3 3" stroke-width="1.5"/>

          
          <g transform="translate(45, 82)">
            
            <path d="M12 18 C12 12, 22 10, 24 18 C22 22, 14 22, 12 18 Z" fill="#ffffff" stroke="#cbd5e1" stroke-width="1"/>
            <circle cx="16" cy="16" r="1.5" fill="#475569"/>
            
            <path d="M24 18 Q 45 18 66 18" stroke="#ffffff" stroke-width="2.5" stroke-linecap="round" fill="none"/>
            <path d="M30 11 L 30 25 M38 10 L 38 26 M46 10 L 46 26 M54 11 L 54 25 M62 13 L 62 23" stroke="#ffffff" stroke-width="2" stroke-linecap="round"/>
            <polygon points="66,18 76,10 73,26" fill="#ffffff"/>
          </g>

          
          <g stroke="#64748b" stroke-width="1.5" opacity="0.6" fill="none">
            <path d="M35 15 L35 25 M35 25 L32 22 M35 25 L38 22"/>
            <path d="M80 15 L80 25 M80 25 L77 22 M80 25 L83 22"/>
            <path d="M125 15 L125 25 M125 25 L122 22 M125 25 L128 22"/>
          </g>
        </svg>
      </div>
      <div class="step-desc">Soft tissues rot; bones remain buried</div>
    </div>

    
    <div class="step-card" id="card-2">
      <div class="step-header">
        <span class="badge">STEP 3</span>
      </div>
      <div class="step-title">Mineralisation</div>
      <div class="stage-view">
        <svg class="stage-svg" viewBox="0 0 160 140">
          
          <rect x="0" y="0" width="160" height="35" fill="#b09b70" />
          <rect x="0" y="35" width="160" height="40" fill="#917f5a" />
          <rect x="0" y="75" width="160" height="65" fill="#756544" />
          
          <line x1="0" y1="35" x2="160" y2="35" stroke="#5a4e33" stroke-width="1.5"/>
          <line x1="0" y1="75" x2="160" y2="75" stroke="#5a4e33" stroke-width="1.5"/>

          
          <g stroke="#38bdf8" stroke-width="1.5" stroke-dasharray="2 3" opacity="0.85">
            <line x1="30" y1="40" x2="30" y2="85" />
            <line x1="80" y1="40" x2="80" y2="85" />
            <line x1="130" y1="40" x2="130" y2="85" />
          </g>

          
          <g transform="translate(45, 88)">
            
            <path d="M12 18 C12 12, 22 10, 24 18 C22 22, 14 22, 12 18 Z" fill="#64748b" stroke="#38bdf8" stroke-width="1.2"/>
            <circle cx="16" cy="16" r="1.5" fill="#0f172a"/>
            
            <path d="M24 18 Q 45 18 66 18" stroke="#64748b" stroke-width="3" stroke-linecap="round" fill="none"/>
            <path d="M30 11 L 30 25 M38 10 L 38 26 M46 10 L 46 26 M54 11 L 54 25 M62 13 L 62 23" stroke="#64748b" stroke-width="2.5" stroke-linecap="round"/>
            <polygon points="66,18 76,10 73,26" fill="#64748b" stroke="#38bdf8" stroke-width="1"/>

            
            <polygon points="30,8 32,11 30,14 28,11" fill="#38bdf8"/>
            <polygon points="46,7 48,10 46,13 44,10" fill="#38bdf8"/>
            <polygon points="62,10 64,13 62,16 60,13" fill="#38bdf8"/>
            <polygon points="50,22 52,25 50,28 48,25" fill="#38bdf8"/>
          </g>
        </svg>
      </div>
      <div class="step-desc">Minerals seep in and replace bone with rock</div>
    </div>

    
    <div class="step-card" id="card-3">
      <div class="step-header">
        <span class="badge">STEP 4</span>
      </div>
      <div class="step-title">Exposure</div>
      <div class="stage-view">
        <svg class="stage-svg" viewBox="0 0 160 140">
          
          <rect x="0" y="0" width="160" height="140" fill="#fef08a" opacity="0.3"/>
          <circle cx="140" cy="20" r="12" fill="#facc15" opacity="0.8"/>

          
          <path d="M 0 35 Q 60 50 100 85 L 160 100 L 160 140 L 0 140 Z" fill="#a89260"/>
          <path d="M 0 65 Q 50 78 95 105 L 160 115 L 160 140 L 0 140 Z" fill="#8a7548"/>
          <path d="M 0 95 Q 40 105 85 125 L 160 130 L 160 140 L 0 140 Z" fill="#6d5a32"/>

          
          <path d="M 110 35 Q 130 30 150 36" stroke="#94a3b8" stroke-width="1.5" stroke-linecap="round" fill="none" opacity="0.8"/>
          <path d="M 120 45 Q 140 40 158 47" stroke="#94a3b8" stroke-width="1.5" stroke-linecap="round" fill="none" opacity="0.8"/>

          
          <g transform="translate(42, 60) rotate(14)">
            
            <path d="M12 18 C12 12, 22 10, 24 18 C22 22, 14 22, 12 18 Z" fill="#475569" stroke="#1e293b" stroke-width="1"/>
            <circle cx="16" cy="16" r="1.5" fill="#0f172a"/>
            
            <path d="M24 18 Q 45 18 66 18" stroke="#475569" stroke-width="3" stroke-linecap="round" fill="none"/>
            <path d="M30 11 L 30 25 M38 10 L 38 26 M46 10 L 46 26 M54 11 L 54 25 M62 13 L 62 23" stroke="#475569" stroke-width="2.5" stroke-linecap="round"/>
            <polygon points="66,18 76,10 73,26" fill="#475569" stroke="#1e293b" stroke-width="1"/>
          </g>

          
          <circle cx="82" cy="80" r="18" fill="none" stroke="#22b7ff" stroke-width="2" stroke-dasharray="3 2"/>
        </svg>
      </div>
      <div class="step-desc">Uplift & erosion expose fossil at surface</div>
    </div>
  </div>

  
  <div class="controls">
    <button class="btn-ctrl" id="playToggle">
      <span id="playIcon">⏸</span>
      <span id="playText">Pause</span>
    </button>
    <div class="dots-nav">
      <button class="dot-btn active" data-idx="0" aria-label="Step 1"></button>
      <button class="dot-btn" data-idx="1" aria-label="Step 2"></button>
      <button class="dot-btn" data-idx="2" aria-label="Step 3"></button>
      <button class="dot-btn" data-idx="3" aria-label="Step 4"></button>
    </div>
  </div>

  <script>
    const cards = [$('#card-0'), $('#card-1'), $('#card-2'), $('#card-3')];
    const dots = $$('.dot-btn');
    const playBtn = $('#playToggle');
    const playIcon = $('#playIcon');
    const playText = $('#playText');

    let currentIndex = 0;
    let timer = null;
    let isPlaying = true;

    function setStep(idx) {
      currentIndex = idx;
      cards.forEach((card, i) => {
        if (card) card.classList.toggle('active', i === idx);
      });
      dots.forEach((dot, i) => {
        if (dot) dot.classList.toggle('active', i === idx);
      });
    }

    function nextStep() {
      setStep((currentIndex + 1) % 4);
    }

    function startAuto() {
      stopAuto();
      isPlaying = true;
      playIcon.textContent = '⏸';
      playText.textContent = 'Pause';
      timer = setInterval(nextStep, 3200);
    }

    function stopAuto() {
      isPlaying = false;
      playIcon.textContent = '▶';
      playText.textContent = 'Play';
      if (timer) {
        clearInterval(timer);
        timer = null;
      }
    }

    // Bind cards
    cards.forEach((card, i) => {
      if (card) {
        onTap(card, () => {
          setStep(i);
          stopAuto();
        });
      }
    });

    // Bind dots
    dots.forEach((dot, i) => {
      onTap(dot, () => {
        setStep(i);
        stopAuto();
      });
    });

    // Bind Play/Pause
    onTap(playBtn, () => {
      if (isPlaying) {
        stopAuto();
      } else {
        startAuto();
      }
    });

    // Start auto loop
    startAuto();
  </script>
</body>
</html>

UK-GCSE-SCIENCE-BIO-IVE-03-05

Aligned learning resources

Related diagrams