<!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;
      user-select: none;
      -webkit-user-select: none;
    }

    body {
      width: 100%;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: transparent;
      color: #1e2945;
      padding: 10px;
    }

    .grid-container {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 10px;
      width: 100%;
      max-width: 500px;
      margin: 0 auto;
    }

    .tissue-card {
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      transition: border-color 0.25s ease, box-shadow 0.25s ease, transform 0.2s ease;
      outline: none;
    }

    .tissue-card:active {
      transform: scale(0.98);
    }

    .tissue-card.active {
      border-color: #22b7ff;
      box-shadow: 0 0 0 3px rgba(34, 183, 255, 0.25), 0 4px 12px rgba(34, 183, 255, 0.15);
      animation: pulse 1.6s infinite ease-in-out;
    }

    @keyframes pulse {
      0%, 100% { box-shadow: 0 0 0 3px rgba(34, 183, 255, 0.3), 0 2px 8px rgba(34, 183, 255, 0.1); }
      50% { box-shadow: 0 0 0 5px rgba(34, 183, 255, 0.45), 0 4px 14px rgba(34, 183, 255, 0.2); }
    }

    .icon-box {
      width: 100%;
      height: 90px;
      margin-bottom: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      background: #f8fafc;
      border-radius: 8px;
      overflow: hidden;
    }

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

    .title {
      font-size: 15px;
      font-weight: 700;
      color: #0f172a;
      margin-bottom: 4px;
      line-height: 1.2;
    }

    .summary {
      font-size: 12px;
      font-weight: 500;
      color: #64748b;
      line-height: 1.3;
    }

    .tissue-card.active .title {
      color: #0284c7;
    }

    .tissue-card.active .summary {
      color: #334155;
    }
  </style>
</head>
<body>

  <div class="grid-container" id="grid">
    
    <div class="tissue-card active" data-index="0" tabindex="0">
      <div class="icon-box">
        <svg viewBox="0 0 160 80" aria-hidden="true">
          
          <g fill="#f43f5e" opacity="0.85">
            <rect x="15" y="12" width="130" height="14" rx="4" />
            <rect x="15" y="33" width="130" height="14" rx="4" />
            <rect x="15" y="54" width="130" height="14" rx="4" />
          </g>
          
          <g stroke="#ffffff" stroke-width="2" opacity="0.75">
            <path d="M 30,12 v14 M 45,12 v14 M 60,12 v14 M 75,12 v14 M 90,12 v14 M 105,12 v14 M 120,12 v14 M 135,12 v14" />
            <path d="M 25,33 v14 M 40,33 v14 M 55,33 v14 M 70,33 v14 M 85,33 v14 M 100,33 v14 M 115,33 v14 M 130,33 v14" />
            <path d="M 30,54 v14 M 45,54 v14 M 60,54 v14 M 75,54 v14 M 90,54 v14 M 105,54 v14 M 120,54 v14 M 135,54 v14" />
          </g>
          
          <ellipse cx="65" cy="19" rx="5" ry="2.5" fill="#881337" />
          <ellipse cx="105" cy="40" rx="5" ry="2.5" fill="#881337" />
          <ellipse cx="45" cy="61" rx="5" ry="2.5" fill="#881337" />
        </svg>
      </div>
      <div class="title">Muscle</div>
      <div class="summary">Contracts for body movement</div>
    </div>

    
    <div class="tissue-card" data-index="1" tabindex="0">
      <div class="icon-box">
        <svg viewBox="0 0 160 80" aria-hidden="true">
          
          <g stroke="#0284c7" stroke-width="2.5" stroke-linecap="round" fill="none">
            <line x1="45" y1="40" x2="115" y2="40" />
            
            <line x1="45" y1="40" x2="25" y2="25" />
            <line x1="45" y1="40" x2="20" y2="42" />
            <line x1="45" y1="40" x2="26" y2="58" />
            
            <line x1="115" y1="40" x2="135" y2="28" />
            <line x1="115" y1="40" x2="140" y2="42" />
            <line x1="115" y1="40" x2="134" y2="56" />
          </g>
          
          <circle cx="137" cy="28" r="3" fill="#0284c7" />
          <circle cx="142" cy="42" r="3" fill="#0284c7" />
          <circle cx="136" cy="56" r="3" fill="#0284c7" />
          
          <rect x="58" y="34" width="14" height="12" rx="3" fill="#38bdf8" />
          <rect x="78" y="34" width="14" height="12" rx="3" fill="#38bdf8" />
          <rect x="98" y="34" width="14" height="12" rx="3" fill="#38bdf8" />
          
          <circle cx="45" cy="40" r="12" fill="#0284c7" />
          <circle cx="45" cy="40" r="5" fill="#f8fafc" />
          
          <circle cx="85" cy="40" r="2.5" fill="#ffffff" />
        </svg>
      </div>
      <div class="title">Nervous</div>
      <div class="summary">Transmits electrical impulses</div>
    </div>

    
    <div class="tissue-card" data-index="2" tabindex="0">
      <div class="icon-box">
        <svg viewBox="0 0 160 80" aria-hidden="true">
          
          <line x1="15" y1="62" x2="145" y2="62" stroke="#94a3b8" stroke-width="3" stroke-dasharray="4,2" />
          
          <g fill="#10b981" stroke="#059669" stroke-width="1.5" opacity="0.9">
            <rect x="20" y="20" width="22" height="40" rx="3" />
            <rect x="44" y="20" width="22" height="40" rx="3" />
            <rect x="68" y="20" width="22" height="40" rx="3" />
            <rect x="92" y="20" width="22" height="40" rx="3" />
            <rect x="116" y="20" width="22" height="40" rx="3" />
          </g>
          
          <g fill="#064e3b">
            <ellipse cx="31" cy="44" rx="4" ry="5" />
            <ellipse cx="55" cy="44" rx="4" ry="5" />
            <ellipse cx="79" cy="44" rx="4" ry="5" />
            <ellipse cx="103" cy="44" rx="4" ry="5" />
            <ellipse cx="127" cy="44" rx="4" ry="5" />
          </g>
        </svg>
      </div>
      <div class="title">Epithelial</div>
      <div class="summary">Covers surfaces and protects</div>
    </div>

    
    <div class="tissue-card" data-index="3" tabindex="0">
      <div class="icon-box">
        <svg viewBox="0 0 160 80" aria-hidden="true">
          
          <g stroke="#fb923c" stroke-width="2" fill="none" opacity="0.6" stroke-linecap="round">
            <path d="M 15,20 C 45,35 70,10 110,25 C 130,30 140,20 148,22" />
            <path d="M 18,65 C 50,45 80,68 120,52 C 135,46 142,55 146,58" />
            <path d="M 35,10 C 40,40 55,50 65,72" />
            <path d="M 100,12 C 95,35 112,50 118,70" />
          </g>
          
          <g fill="#ea580c">
            <circle cx="42" cy="48" r="7" />
            <circle cx="85" cy="30" r="8" />
            <circle cx="128" cy="42" r="6.5" />
          </g>
          
          <g fill="#7c2d12">
            <circle cx="42" cy="48" r="3" />
            <circle cx="85" cy="30" r="3.5" />
            <circle cx="128" cy="42" r="2.8" />
          </g>
        </svg>
      </div>
      <div class="title">Connective</div>
      <div class="summary">Binds and supports organs</div>
    </div>
  </div>

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</body>
</html>

Levels of Biological Organization

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      color: #1e2945;
      background: #ffffff;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      gap: 10px;
      width: 100%;
      padding: 10px 10px 12px;
      user-select: none;
    }

    .nav-bar {
      display: flex;
      flex-wrap: wrap;
      gap: 5px;
      justify-content: center;
      width: 100%;
      max-width: 520px;
      z-index: 10;
    }

    .tab-btn {
      appearance: none;
      border: 1px solid #e2e8f0;
      background: #f8fafc;
      color: #64748b;
      padding: 5px 9px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 5px;
      transition: all 0.2s ease;
      box-shadow: 0 1px 2px rgba(0,0,0,0.04);
    }

    .tab-btn .dot {
      width: 7px;
      height: 7px;
      border-radius: 50%;
      background: currentColor;
    }

    .tab-btn.active {
      color: #1e2945;
      background: #ffffff;
      border-color: currentColor;
      box-shadow: 0 2px 6px rgba(0,0,0,0.08);
    }

    .tab-btn[data-layer="all"].active { color: #475569; border-color: #94a3b8; }
    .tab-btn[data-layer="connective"].active { color: #0284c7; border-color: #22b7ff; }
    .tab-btn[data-layer="muscle"].active { color: #059669; border-color: #34d399; }
    .tab-btn[data-layer="nerve"].active { color: #db2777; border-color: #ec4899; }
    .tab-btn[data-layer="epithelial"].active { color: #d97706; border-color: #f59e0b; }

    .diagram-area {
      position: relative;
      width: 100%;
      max-width: 520px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

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

    .layer-group {
      cursor: pointer;
      transition: transform 0.35s cubic-bezier(0.2, 0.9, 0.3, 1), opacity 0.25s ease;
    }

    .layer-shape {
      transition: stroke-width 0.25s, filter 0.25s;
    }

    .dimmed {
      opacity: 0.25;
    }

    .highlighted .layer-shape {
      filter: drop-shadow(0 3px 6px rgba(0,0,0,0.22));
    }

    .nerve-path {
      fill: none;
      stroke: #ec4899;
      stroke-width: 2.5;
      stroke-linecap: round;
      stroke-linejoin: round;
      stroke-dasharray: 4, 3;
      animation: pulseNerve 2s ease-in-out infinite;
    }

    @keyframes pulseNerve {
      0%, 100% { stroke-opacity: 0.7; }
      50% { stroke-opacity: 1; }
    }

    .label-box {
      font-size: 11px;
      font-weight: 700;
      pointer-events: none;
      transition: opacity 0.3s ease;
    }

    .tag-bubble {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      padding: 5px 12px;
      border-radius: 999px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      font-size: 12px;
      font-weight: 700;
      color: #334155;
      margin-top: 2px;
    }
  </style>
</head>
<body>

  
  <div class="nav-bar">
    <button class="tab-btn active" data-layer="all">
      <span class="dot" style="background:#64748b"></span>All Tissues
    </button>
    <button class="tab-btn" data-layer="connective">
      <span class="dot" style="background:#22b7ff"></span>Connective
    </button>
    <button class="tab-btn" data-layer="muscle">
      <span class="dot" style="background:#34d399"></span>Muscle
    </button>
    <button class="tab-btn" data-layer="nerve">
      <span class="dot" style="background:#ec4899"></span>Nerve
    </button>
    <button class="tab-btn" data-layer="epithelial">
      <span class="dot" style="background:#f59e0b"></span>Epithelial
    </button>
  </div>

  
  <div class="diagram-area">
    <svg viewBox="0 0 560 265">
      <defs>
        
        <linearGradient id="grad-connective" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#38bdf8" />
          <stop offset="100%" stop-color="#0284c7" />
        </linearGradient>

        <linearGradient id="grad-muscle" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#4ade80" />
          <stop offset="100%" stop-color="#059669" />
        </linearGradient>

        <linearGradient id="grad-epithelial" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#fbbf24" />
          <stop offset="100%" stop-color="#d97706" />
        </linearGradient>

        <filter id="shadow" x="-8%" y="-8%" width="120%" height="130%">
          <feDropShadow dx="0" dy="3" stdDeviation="3" flood-opacity="0.12" />
        </filter>
      </defs>

      
      <g transform="translate(14, 25)">
        <path d="M42,18 C56,18 66,32 61,50 C56,72 42,88 24,88 C12,88 8,78 10,69 C12,55 24,51 24,37 C24,23 33,18 42,18 Z" 
              fill="#f1f5f9" stroke="#cbd5e1" stroke-width="2.5" />
        <rect x="25" y="44" width="20" height="20" rx="3" fill="none" stroke="#64748b" stroke-width="1.5" stroke-dasharray="2 2" />
        <text x="35" y="104" font-size="10.5" font-weight="700" fill="#64748b" text-anchor="middle">Stomach</text>
      </g>

      
      <g id="layer-connective" class="layer-group" transform="translate(0, 0)">
        
        <path class="layer-shape" d="M110,40 L195,30 L238,155 L153,180 Z" 
              fill="url(#grad-connective)" filter="url(#shadow)" />
        <path d="M110,40 L153,180 L148,194 L105,54 Z" fill="#0369a1" opacity="0.6" />
        <path d="M153,180 L238,155 L233,169 L148,194 Z" fill="#0284c7" opacity="0.8" />
        
        <g class="label-box">
          <line x1="150" y1="35" x2="128" y2="18" stroke="#0284c7" stroke-width="1.5" />
          <circle cx="150" cy="35" r="3" fill="#0284c7" />
          <rect x="62" y="3" width="118" height="22" rx="6" fill="#f0f9ff" stroke="#22b7ff" stroke-width="1.5" />
          <text x="121" y="18" text-anchor="middle" fill="#0369a1" font-size="10.5" font-weight="700">Connective · Protection</text>
        </g>
      </g>

      
      <g id="layer-muscle" class="layer-group" transform="translate(50, 15)">
        <path class="layer-shape" d="M150,48 L235,38 L278,163 L193,188 Z" 
              fill="url(#grad-muscle)" filter="url(#shadow)" />
        <path d="M150,48 L193,188 L188,202 L145,62 Z" fill="#047857" opacity="0.6" />
        <path d="M193,188 L278,163 L273,177 L188,202 Z" fill="#059669" opacity="0.8" />
        
        <line x1="168" y1="72" x2="250" y2="62" stroke="#ffffff" stroke-width="1.5" opacity="0.4" />
        <line x1="178" y1="105" x2="260" y2="95" stroke="#ffffff" stroke-width="1.5" opacity="0.4" />
        <line x1="188" y1="138" x2="270" y2="128" stroke="#ffffff" stroke-width="1.5" opacity="0.4" />
        
        <g class="label-box">
          <line x1="248" y1="44" x2="280" y2="20" stroke="#059669" stroke-width="1.5" />
          <circle cx="248" cy="44" r="3" fill="#059669" />
          <rect x="228" y="5" width="104" height="22" rx="6" fill="#ecfdf5" stroke="#34d399" stroke-width="1.5" />
          <text x="280" y="20" text-anchor="middle" fill="#047857" font-size="10.5" font-weight="700">Muscle · Churning</text>
        </g>
      </g>

      
      <g id="layer-nerve" class="layer-group" transform="translate(50, 15)">
        
        <path class="nerve-path" d="M175,76 Q205,91 228,81 T266,114 M205,91 Q223,124 242,138 M223,124 Q256,134 270,152" />
        <circle cx="175" cy="76" r="3" fill="#ec4899" />
        <circle cx="266" cy="114" r="3" fill="#ec4899" />
        <circle cx="242" cy="138" r="3" fill="#ec4899" />
        <circle cx="270" cy="152" r="3" fill="#ec4899" />
        
        <g class="label-box">
          <line x1="228" y1="120" x2="252" y2="230" stroke="#db2777" stroke-width="1.5" />
          <circle cx="228" cy="120" r="3" fill="#ec4899" />
          <rect x="200" y="220" width="104" height="22" rx="6" fill="#fdf2f8" stroke="#ec4899" stroke-width="1.5" />
          <text x="252" y="235" text-anchor="middle" fill="#be185d" font-size="10.5" font-weight="700">Nerves · Signaling</text>
        </g>
      </g>

      
      <g id="layer-epithelial" class="layer-group" transform="translate(100, 28)">
        <path class="layer-shape" d="M190,56 L275,46 L318,171 L233,196 Z" 
              fill="url(#grad-epithelial)" filter="url(#shadow)" />
        <path d="M190,56 L233,196 L228,210 L185,70 Z" fill="#b45309" opacity="0.6" />
        <path d="M233,196 L318,171 L313,185 L228,210 Z" fill="#d97706" opacity="0.8" />
        
        <path d="M210,84 Q215,79 220,84 Q225,89 230,84 M238,112 Q243,107 248,112 Q253,117 258,112" 
              stroke="#78350f" stroke-width="1.5" fill="none" opacity="0.4" />
        
        <g class="label-box">
          <line x1="300" y1="130" x2="330" y2="138" stroke="#d97706" stroke-width="1.5" />
          <circle cx="300" cy="130" r="3" fill="#d97706" />
          <rect x="330" y="126" width="116" height="22" rx="6" fill="#fffbeb" stroke="#f59e0b" stroke-width="1.5" />
          <text x="388" y="141" text-anchor="middle" fill="#b45309" font-size="10.5" font-weight="700">Epithelial · Secretion</text>
        </g>
      </g>
    </svg>
  </div>

  
  <div class="tag-bubble">
    <span>Organ = Tissues working together</span>
  </div>

  <script>
    const buttons = document.querySelectorAll('.tab-btn');
    const layers = {
      connective: document.getElementById('layer-connective'),
      muscle: document.getElementById('layer-muscle'),
      nerve: document.getElementById('layer-nerve'),
      epithelial: document.getElementById('layer-epithelial')
    };

    function setActiveLayer(target) {
      buttons.forEach(btn => {
        btn.classList.toggle('active', btn.dataset.layer === target);
      });

      Object.entries(layers).forEach(([name, el]) => {
        if (target === 'all') {
          el.classList.remove('dimmed', 'highlighted');
          if (name === 'connective') el.style.transform = 'translate(0px, 0px)';
          if (name === 'muscle' || name === 'nerve') el.style.transform = 'translate(50px, 15px)';
          if (name === 'epithelial') el.style.transform = 'translate(100px, 28px)';
        } else if (name === target) {
          el.classList.remove('dimmed');
          el.classList.add('highlighted');
          if (name === 'connective') el.style.transform = 'translate(-6px, -4px)';
          if (name === 'muscle' || name === 'nerve') el.style.transform = 'translate(50px, 10px)';
          if (name === 'epithelial') el.style.transform = 'translate(105px, 26px)';
        } else {
          el.classList.add('dimmed');
          el.classList.remove('highlighted');
          if (name === 'connective') el.style.transform = 'translate(0px, 0px)';
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    }

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

    Object.entries(layers).forEach(([name, el]) => {
      el.addEventListener('click', () => setActiveLayer(name));
    });
  </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;
      color: #1e2945;
      background: #ffffff;
      padding: 16px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
    }

    .main-stage {
      position: relative;
      width: 100%;
      max-width: 440px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    /* Vertical track line */
    .track-line {
      position: absolute;
      top: 24px;
      bottom: 24px;
      left: 28px;
      width: 4px;
      background: #e2e8f0;
      border-radius: 2px;
      z-index: 1;
    }

    /* Glowing Food Particle */
    .particle {
      position: absolute;
      left: 22px;
      top: 20px;
      width: 16px;
      height: 16px;
      background: #f59e0b;
      border: 2px solid #ffffff;
      border-radius: 50%;
      box-shadow: 0 0 10px #f59e0b, 0 0 18px rgba(245, 158, 11, 0.6);
      z-index: 5;
      transition: top 0.6s cubic-bezier(0.4, 0, 0.2, 1), transform 0.3s ease;
      pointer-events: none;
    }

    .step-row {
      position: relative;
      display: flex;
      align-items: center;
      gap: 14px;
      z-index: 2;
      cursor: pointer;
    }

    .node-icon {
      width: 56px;
      height: 56px;
      flex-shrink: 0;
      border-radius: 50%;
      background: #f8fafc;
      border: 2px solid #e2e8f0;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 24px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.05);
      transition: border-color 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
    }

    .info-card {
      flex: 1;
      padding: 10px 14px;
      background: #f8fafc;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      display: flex;
      flex-direction: column;
      justify-content: center;
      min-height: 56px;
      transition: border-color 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
    }

    .organ-title {
      font-size: 14px;
      font-weight: 700;
      color: #334155;
      margin-bottom: 2px;
    }

    .organ-badge {
      font-size: 12px;
      font-weight: 500;
      color: #64748b;
    }

    /* Active Step Styling */
    .step-row.active .node-icon {
      border-color: #22b7ff;
      background: #eff9ff;
      box-shadow: 0 0 0 3px rgba(34, 183, 255, 0.2);
    }

    .step-row.active .info-card {
      border-color: #22b7ff;
      background: #eff9ff;
      box-shadow: 0 2px 8px rgba(34, 183, 255, 0.15);
    }

    .step-row.active .organ-title {
      color: #0284c7;
    }

    .step-row.active .organ-badge {
      color: #0369a1;
      font-weight: 600;
    }

    /* Controls Bar */
    .controls {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      margin-top: 14px;
      width: 100%;
    }

    .btn {
      appearance: none;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #1e2945;
      padding: 8px 16px;
      border-radius: 8px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      user-select: none;
    }

    .btn:active {
      background: #f1f5f9;
    }

    .btn-primary {
      background: #22b7ff;
      border-color: #22b7ff;
      color: #ffffff;
    }

    .btn-primary:active {
      background: #0ea5e9;
    }

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

    .dot {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: #cbd5e1;
      cursor: pointer;
      border: none;
      padding: 0;
      transition: background 0.3s ease, transform 0.2s ease;
    }

    .dot.active {
      background: #22b7ff;
      transform: scale(1.25);
    }
  </style>
</head>
<body>

  <div class="main-stage">
    <div class="track-line"></div>
    <div class="particle" id="particle"></div>

    <div class="step-row active" data-index="0">
      <div class="node-icon">👄</div>
      <div class="info-card">
        <div class="organ-title">Mouth &amp; Esophagus</div>
        <div class="organ-badge">Chews &amp; transports food</div>
      </div>
    </div>

    <div class="step-row" data-index="1">
      <div class="node-icon">🫁</div>
      <div class="info-card">
        <div class="organ-title">Stomach</div>
        <div class="organ-badge">Breaks down proteins</div>
      </div>
    </div>

    <div class="step-row" data-index="2">
      <div class="node-icon">🌀</div>
      <div class="info-card">
        <div class="organ-title">Small Intestine</div>
        <div class="organ-badge">Absorbs nutrients</div>
      </div>
    </div>

    <div class="step-row" data-index="3">
      <div class="node-icon">🔄</div>
      <div class="info-card">
        <div class="organ-title">Large Intestine</div>
        <div class="organ-badge">Absorbs water</div>
      </div>
    </div>
  </div>

  <div class="controls">
    <button class="btn" id="playBtn">⏸ Pause</button>
    <button class="btn btn-primary" id="nextBtn">Next →</button>
    <div class="dots-nav">
      <button class="dot active" title="Step 1"></button>
      <button class="dot" title="Step 2"></button>
      <button class="dot" title="Step 3"></button>
      <button class="dot" title="Step 4"></button>
    </div>
  </div>

  <script src="{{VENDOR_CDN}}/classace-diagram.js"></script>
  <script>
    const rows = $$('.step-row');
    const dots = $$('.dot');
    const particle = $('#particle');
    const playBtn = $('#playBtn');
    const nextBtn = $('#nextBtn');

    function updateParticlePosition(index) {
      const activeRow = rows[index];
      if (activeRow) {
        const topPos = activeRow.offsetTop + (activeRow.offsetHeight / 2) - 8;
        particle.style.top = topPos + 'px';
      }
    }

    const player = new StepPlayer('.step-row', {
      interval: 4000,
      onChange: (index) => {
        dots.forEach((d, i) => d.classList.toggle('active', i === index));
        updateParticlePosition(index);
      }
    });

    // Wire up row taps
    rows.forEach((row, i) => {
      onTap(row, () => {
        player.goTo(i);
        if (!player.playing) {
          player.start();
          playBtn.textContent = '⏸ Pause';
        }
      });
    });

    // Wire up pagination dots
    dots.forEach((dot, i) => {
      onTap(dot, () => {
        player.goTo(i);
      });
    });

    // Next step button
    onTap(nextBtn, () => {
      player.next();
    });

    // Play/Pause button
    onTap(playBtn, () => {
      player.toggle();
      playBtn.textContent = player.playing ? '⏸ Pause' : '▶ Play';
    });

    // Initialize layout positions on load
    window.addEventListener('load', () => {
      updateParticlePosition(0);
      player.start();
    });

    window.addEventListener('resize', () => {
      updateParticlePosition(player.current);
    });
  </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">
  <title>Levels of Biological Organization</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #f8fafc;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

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

    .controls {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0 4px;
    }

    .stepper-nav {
      display: flex;
      gap: 6px;
    }

    .nav-btn {
      background: #fff;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      padding: 4px 10px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      user-select: none;
    }
    .nav-btn:active { background: #e2e8f0; }

    .scale-indicator {
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 0.5px;
      color: #64748b;
      text-transform: uppercase;
    }

    /* Ladder Container */
    .ladder {
      display: flex;
      flex-direction: column;
      gap: 4px;
      width: 100%;
    }

    .level-row {
      display: flex;
      flex-direction: column;
      gap: 4px;
    }

    .ladder-step {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 8px 12px;
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 10px;
      cursor: pointer;
      user-select: none;
      transition: background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .ladder-step:hover {
      background: #f1f5f9;
    }

    .ladder-step.active {
      border-color: #22b7ff;
      background: #f0f9ff;
      box-shadow: 0 0 0 3px rgba(34, 183, 255, 0.2);
    }

    .step-left {
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .step-num {
      width: 24px;
      height: 24px;
      border-radius: 50%;
      background: #e2e8f0;
      color: #475569;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      font-weight: 700;
      flex-shrink: 0;
    }

    .ladder-step.active .step-num {
      background: #22b7ff;
      color: #ffffff;
    }

    .step-icon {
      font-size: 20px;
      line-height: 1;
      width: 28px;
      text-align: center;
    }

    .step-info {
      display: flex;
      flex-direction: column;
    }

    .step-name {
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
    }

    .step-example {
      font-size: 12px;
      color: #64748b;
    }

    .step-badge {
      font-size: 11px;
      font-weight: 600;
      padding: 3px 8px;
      border-radius: 12px;
      background: #f1f5f9;
      color: #475569;
    }

    .ladder-step.active .step-badge {
      background: #e0f2fe;
      color: #0284c7;
    }

    /* Transition Arrow */
    .transition-connector {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      font-size: 11px;
      font-weight: 600;
      color: #0ea5e9;
      padding: 1px 0;
    }

    .arrow-icon {
      font-size: 11px;
      font-weight: 800;
      color: #0ea5e9;
    }

    /* Detail View Card */
    .detail-card {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 10px;
      padding: 10px 14px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
      min-height: 54px;
    }

    .detail-text {
      font-size: 13px;
      font-weight: 600;
      color: #1e2945;
    }

    .detail-scale {
      font-size: 11px;
      font-weight: 700;
      color: #64748b;
      background: #f1f5f9;
      padding: 4px 8px;
      border-radius: 6px;
      white-space: nowrap;
    }
  </style>
</head>
<body>
  <div class="main-layout">
    <div class="controls">
      <div class="stepper-nav">
        <button id="prevBtn" class="nav-btn" aria-label="Previous level">▲ Larger</button>
        <button id="nextBtn" class="nav-btn" aria-label="Next level">▼ Smaller</button>
        <button id="playBtn" class="nav-btn" aria-label="Toggle auto-play">⏸ Pause</button>
      </div>
      <div class="scale-indicator" id="scaleLabel">Smallest → Largest</div>
    </div>

    
    <div class="ladder" id="ladder">
      
      <div class="ladder-step" data-index="4">
        <div class="step-left">
          <div class="step-num">5</div>
          <div class="step-icon">🏃</div>
          <div class="step-info">
            <div class="step-name">Organism</div>
            <div class="step-example">Human body</div>
          </div>
        </div>
        <div class="step-badge">Complete living being</div>
      </div>

      <div class="transition-connector">
        <span class="arrow-icon">▲</span> Systems unite
      </div>

      
      <div class="ladder-step" data-index="3">
        <div class="step-left">
          <div class="step-num">4</div>
          <div class="step-icon">🫀</div>
          <div class="step-info">
            <div class="step-name">Organ System</div>
            <div class="step-example">Circulatory system</div>
          </div>
        </div>
        <div class="step-badge">Organs work together</div>
      </div>

      <div class="transition-connector">
        <span class="arrow-icon">▲</span> Organs work together
      </div>

      
      <div class="ladder-step" data-index="2">
        <div class="step-left">
          <div class="step-num">3</div>
          <div class="step-icon">❤️</div>
          <div class="step-info">
            <div class="step-name">Organ</div>
            <div class="step-example">Heart</div>
          </div>
        </div>
        <div class="step-badge">Tissues combine</div>
      </div>

      <div class="transition-connector">
        <span class="arrow-icon">▲</span> Tissues combine
      </div>

      
      <div class="ladder-step" data-index="1">
        <div class="step-left">
          <div class="step-num">2</div>
          <div class="step-icon">🥩</div>
          <div class="step-info">
            <div class="step-name">Tissue</div>
            <div class="step-example">Cardiac muscle</div>
          </div>
        </div>
        <div class="step-badge">Group of cells</div>
      </div>

      <div class="transition-connector">
        <span class="arrow-icon">▲</span> Group of cells
      </div>

      
      <div class="ladder-step active" data-index="0">
        <div class="step-left">
          <div class="step-num">1</div>
          <div class="step-icon">🔬</div>
          <div class="step-info">
            <div class="step-name">Cell</div>
            <div class="step-example">Muscle cell</div>
          </div>
        </div>
        <div class="step-badge">Basic unit of life</div>
      </div>
    </div>

    
    <div class="detail-card" id="detailCard">
      <div class="detail-text" id="detailText">Level 1: Cell — The basic unit of life</div>
      <div class="detail-scale" id="detailScale">Microscopic (10 µm)</div>
    </div>
  </div>

  <script>
    const levels = [
      { num: 1, name: "Cell", example: "Muscle cell", scale: "Microscopic (~20 µm)", desc: "Basic living building block" },
      { num: 2, name: "Tissue", example: "Cardiac muscle", scale: "Microscopic layers", desc: "Coordinated group of cells" },
      { num: 3, name: "Organ", example: "Heart", scale: "Macroscopic (~12 cm)", desc: "Tissues performing one role" },
      { num: 4, name: "Organ System", example: "Circulatory system", scale: "Body-wide network", desc: "Organs working together" },
      { num: 5, name: "Organism", example: "Human runner", scale: "Whole organism (~1.7 m)", desc: "Complete living individual" }
    ];

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

    const stepElements = Array.from(document.querySelectorAll('.ladder-step')).reverse();
    const detailText = document.getElementById('detailText');
    const detailScale = document.getElementById('detailScale');
    const playBtn = document.getElementById('playBtn');
    const prevBtn = document.getElementById('prevBtn');
    const nextBtn = document.getElementById('nextBtn');

    function updateView(index) {
      currentIndex = (index + levels.length) % levels.length;
      stepElements.forEach((el, idx) => {
        el.classList.toggle('active', idx === currentIndex);
      });
      const data = levels[currentIndex];
      detailText.textContent = `Level ${data.num}: ${data.name} — ${data.desc}`;
      detailScale.textContent = data.scale;
    }

    function nextStep() {
      updateView(currentIndex + 1);
    }

    function prevStep() {
      updateView(currentIndex - 1);
    }

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

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

    function toggleAutoPlay() {
      if (isPlaying) stopAutoPlay();
      else startAutoPlay();
    }

    stepElements.forEach((el, idx) => {
      el.addEventListener('click', () => {
        stopAutoPlay();
        updateView(idx);
      });
    });

    nextBtn.addEventListener('click', () => {
      stopAutoPlay();
      prevStep();
    });

    prevBtn.addEventListener('click', () => {
      stopAutoPlay();
      nextStep();
    });

    playBtn.addEventListener('click', toggleAutoPlay);

    // Initial render & autoplay
    updateView(0);
    startAutoPlay();
  </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-color: #f8f9fa;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      padding: 12px;
      min-height: 100%;
      user-select: none;
      -webkit-user-select: none;
    }

    .grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 12px;
      width: 100%;
      max-width: 640px;
    }

    .cell-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      transition: box-shadow 0.25s ease, border-color 0.25s ease;
      position: relative;
    }

    .cell-card:hover,
    .cell-card.active {
      border-color: #22b7ff;
      box-shadow: 0 0 0 2px #22b7ff, 0 6px 18px rgba(34, 183, 255, 0.25);
    }

    .svg-container {
      width: 100%;
      height: 140px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    svg {
      width: 100%;
      height: 100%;
      overflow: visible;
    }

    .cell-title {
      font-size: 15px;
      font-weight: 700;
      color: #1e2945;
      margin-top: 8px;
      line-height: 1.2;
    }

    .cell-role {
      font-size: 13px;
      color: #64748b;
      margin-top: 4px;
      line-height: 1.25;
    }

    /* Signal animation on neuron */
    @keyframes pulseSignal {
      0% { stroke-dashoffset: 60; opacity: 0; }
      30% { opacity: 1; }
      80% { opacity: 1; }
      100% { stroke-dashoffset: 0; opacity: 0; }
    }

    .signal-pulse {
      stroke-dasharray: 8, 20;
      animation: pulseSignal 2.5s cubic-bezier(0.4, 0, 0.2, 1) infinite;
    }

    @media (max-width: 460px) {
      .grid {
        gap: 8px;
      }
      .cell-card {
        padding: 10px 4px;
      }
      .svg-container {
        height: 110px;
      }
      .cell-title {
        font-size: 13px;
      }
      .cell-role {
        font-size: 11px;
      }
    }
  </style>
</head>
<body>

  <div class="grid">
    
    <div class="cell-card" tabindex="0">
      <div class="svg-container">
        <svg viewBox="0 0 160 140" fill="none" xmlns="http://www.w3.org/2000/svg">
          <defs>
            <linearGradient id="muscleGrad" x1="20" y1="20" x2="140" y2="120" gradientUnits="userSpaceOnUse">
              <stop offset="0%" stop-color="#fb7185"/>
              <stop offset="50%" stop-color="#f43f5e"/>
              <stop offset="100%" stop-color="#e11d48"/>
            </linearGradient>
            <linearGradient id="nucleusGrad" x1="0" y1="0" x2="0" y2="1">
              <stop offset="0%" stop-color="#881337"/>
              <stop offset="100%" stop-color="#4c0519"/>
            </linearGradient>
          </defs>
          
          <path d="M 18 122 C 38 102, 60 70, 80 50 C 105 25, 128 16, 142 18 C 140 32, 131 55, 106 80 C 86 100, 54 122, 18 122 Z" 
                fill="url(#muscleGrad)" stroke="#be123c" stroke-width="2"/>
          
          <path d="M 46 108 L 36 96 M 58 97 L 47 84 M 70 86 L 58 72 M 82 75 L 69 60 M 94 64 L 80 48 M 106 53 L 91 36 M 118 42 L 102 24 M 130 31 L 115 14" 
                stroke="#ffffff" stroke-opacity="0.65" stroke-width="3" stroke-linecap="round"/>
          
          <ellipse cx="78" cy="68" rx="14" ry="6" transform="rotate(-42 78 68)" fill="url(#nucleusGrad)"/>
        </svg>
      </div>
      <div class="cell-title">Muscle Cell</div>
      <div class="cell-role">Contracts for<br>movement</div>
    </div>

    
    <div class="cell-card" tabindex="0">
      <div class="svg-container">
        <svg viewBox="0 0 160 140" fill="none" xmlns="http://www.w3.org/2000/svg">
          <defs>
            <linearGradient id="neuronGrad" x1="20" y1="20" x2="140" y2="120">
              <stop offset="0%" stop-color="#38bdf8"/>
              <stop offset="100%" stop-color="#0284c7"/>
            </linearGradient>
          </defs>
          
          <path d="M 40 38 L 22 20 M 22 20 L 12 18 M 22 20 L 20 10 M 34 50 L 14 46 M 14 46 L 6 52 M 42 62 L 20 74 M 20 74 L 16 86 M 20 74 L 8 72 M 52 34 L 46 14 M 46 14 L 38 6 M 46 14 L 56 6" 
                stroke="#0284c7" stroke-width="2.5" stroke-linecap="round"/>
          
          <path d="M 64 64 L 122 108" stroke="#0284c7" stroke-width="3" stroke-linecap="round"/>
          
          <path class="signal-pulse" d="M 64 64 L 122 108" stroke="#ffffff" stroke-width="3.5" stroke-linecap="round"/>
          
          <rect x="68" y="65" width="13" height="7" rx="3.5" transform="rotate(37 68 65)" fill="#7dd3fc" stroke="#0284c7" stroke-width="1.5"/>
          <rect x="85" y="78" width="13" height="7" rx="3.5" transform="rotate(37 85 78)" fill="#7dd3fc" stroke="#0284c7" stroke-width="1.5"/>
          <rect x="102" y="91" width="13" height="7" rx="3.5" transform="rotate(37 102 91)" fill="#7dd3fc" stroke="#0284c7" stroke-width="1.5"/>
          
          <path d="M 122 108 L 138 116 M 138 116 L 148 114 M 138 116 L 144 126 M 122 108 L 130 126 M 130 126 L 136 134 M 122 108 L 136 100" 
                stroke="#0284c7" stroke-width="2" stroke-linecap="round"/>
          <circle cx="148" cy="114" r="2" fill="#0284c7"/>
          <circle cx="144" cy="126" r="2" fill="#0284c7"/>
          <circle cx="136" cy="134" r="2" fill="#0284c7"/>
          <circle cx="136" cy="100" r="2" fill="#0284c7"/>
          
          <path d="M 40 42 C 48 32, 60 38, 62 48 C 65 55, 62 64, 56 68 C 48 72, 38 66, 38 54 Z" 
                fill="url(#neuronGrad)" stroke="#0369a1" stroke-width="2"/>
          
          <circle cx="49" cy="51" r="5" fill="#0c4a6e"/>
        </svg>
      </div>
      <div class="cell-title">Nerve Cell</div>
      <div class="cell-role">Sends electrical<br>signals</div>
    </div>

    
    <div class="cell-card" tabindex="0">
      <div class="svg-container">
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Teoria celular e níveis de organização da vida

Estrutura básica das células: membrana, citoplasma e núcleo

A célula como unidade funcional dos seres vivos

A célula como unidade estrutural: do microscópio ao organismo

Dos tecidos aos sistemas: níveis de organização

Organismos como arranjo complexo de sistemas

science

Células e organização dos seres vivos

Nervous System: Brain, Spinal Cord, and Nerves

Sensory Receptors and Stimulus-Response

Musculoskeletal System: Bones, Joints, and Muscles

Circulatory System: Heart, Blood Vessels, and Blood

Respiratory System: Breathing and Gas Exchange

Digestive System: Organs, Enzymes, and Absorption

Excretory System: Kidneys and Waste Removal

System Coordination During Exercise and Rest

Hierarchical Organization and Human Body Systems

Sistema nervoso: estrutura e funções básicas

Coordenação das ações motoras e sensoriais

Neurônios: os mensageiros do sistema nervoso

A visão: como o olho capta imagens

Interpretação de imagens pelo cérebro

Defeitos da visão: miopia e hipermetropia

Lentes corretivas: como escolher a lente certa

Sistemas muscular e ósseo: a sustentação do corpo

Movimentação dos animais: integração dos sistemas nervoso, muscular e ósseo

OGS.7.LS.2

Aligned learning resources

Related diagrams