<!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>Atmosphere-Biosphere Carbon Flux</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: #1e293b;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      min-height: 100%;
      padding: 12px 10px;
    }

    .toolbar {
      display: flex;
      flex-wrap: wrap;
      gap: 6px;
      justify-content: center;
      margin-bottom: 8px;
      z-index: 10;
    }

    .filter-btn {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 20px;
      padding: 5px 12px;
      font-size: 12px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      box-shadow: 0 1px 2px rgba(0,0,0,0.04);
      transition: all 0.2s ease;
    }

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

    .filter-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.3);
    }

    .svg-container {
      width: 100%;
      max-width: 620px;
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
    }

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

    /* Flux highlighting transitions */
    .flux-group {
      transition: opacity 0.3s ease;
    }

    .dimmed {
      opacity: 0.15;
    }

    /* Dynamic balance readout */
    .balance-tag {
      font-size: 13px;
      font-weight: 700;
      color: #0f766e;
      background: #ccfbf1;
      padding: 4px 14px;
      border-radius: 9999px;
      border: 1px solid #5eead4;
      display: inline-flex;
      align-items: center;
      gap: 5px;
      margin-top: 4px;
    }
  </style>
</head>
<body>

  
  <div class="toolbar">
    <button class="filter-btn active" id="btn-all" onclick="setMode('all')">Both Fluxes (Balanced)</button>
    <button class="filter-btn" id="btn-photo" onclick="setMode('photo')">Photosynthesis Only</button>
    <button class="filter-btn" id="btn-resp" onclick="setMode('resp')">Respiration Only</button>
  </div>

  
  <div class="svg-container">
    <svg viewBox="0 0 600 370" xmlns="http://www.w3.org/2000/svg">
      <defs>
        
        <linearGradient id="skyGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#e0f2fe"/>
          <stop offset="100%" stop-color="#bae6fd"/>
        </linearGradient>

        <linearGradient id="bioGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#dcfce7"/>
          <stop offset="100%" stop-color="#bbf7d0"/>
        </linearGradient>

        
        <marker id="arrowPhoto" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
          <polygon points="0 1, 8 4, 0 7" fill="#16a34a"/>
        </marker>
        <marker id="arrowResp" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
          <polygon points="0 1, 8 4, 0 7" fill="#0284c7"/>
        </marker>

        
        <path id="pathPhoto" d="M 175 125 C 230 45, 370 45, 425 125" fill="none"/>
        <path id="pathResp" d="M 425 245 C 370 325, 230 325, 175 245" fill="none"/>
      </defs>

      
      <g id="flux-photo" class="flux-group">
        
        <path d="M 175 125 C 230 45, 370 45, 425 125" fill="none" stroke="#16a34a" stroke-width="4" stroke-linecap="round" marker-end="url(#arrowPhoto)"/>

        
        <circle r="5" fill="#15803d">
          <animateMotion dur="3s" repeatCount="indefinite">
            <mpath href="#pathPhoto"/>
          </animateMotion>
        </circle>
        <circle r="4" fill="#22c55e">
          <animateMotion dur="3s" begin="1s" repeatCount="indefinite">
            <mpath href="#pathPhoto"/>
          </animateMotion>
        </circle>
        <circle r="5" fill="#15803d">
          <animateMotion dur="3s" begin="2s" repeatCount="indefinite">
            <mpath href="#pathPhoto"/>
          </animateMotion>
        </circle>

        
        <rect x="200" y="16" width="200" height="58" rx="8" fill="#ffffff" stroke="#86efac" stroke-width="1.5" filter="drop-shadow(0 2px 4px rgba(0,0,0,0.04))"/>
        <text x="300" y="34" text-anchor="middle" font-size="13" font-weight="700" fill="#15803d">Photosynthesis (↓ ~120 GtC/yr)</text>
        <text x="300" y="52" text-anchor="middle" font-size="10.5" font-weight="500" fill="#334155">6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂</text>
        <text x="300" y="66" text-anchor="middle" font-size="9" font-weight="600" fill="#16a34a">Carbon Taken In</text>
      </g>

      
      <g id="flux-resp" class="flux-group">
        
        <path d="M 425 245 C 370 325, 230 325, 175 245" fill="none" stroke="#0284c7" stroke-width="4" stroke-linecap="round" marker-end="url(#arrowResp)"/>

        
        <circle r="5" fill="#0369a1">
          <animateMotion dur="3s" repeatCount="indefinite">
            <mpath href="#pathResp"/>
          </animateMotion>
        </circle>
        <circle r="4" fill="#38bdf8">
          <animateMotion dur="3s" begin="1s" repeatCount="indefinite">
            <mpath href="#pathResp"/>
          </animateMotion>
        </circle>
        <circle r="5" fill="#0369a1">
          <animateMotion dur="3s" begin="2s" repeatCount="indefinite">
            <mpath href="#pathResp"/>
          </animateMotion>
        </circle>

        
        <rect x="180" y="296" width="240" height="58" rx="8" fill="#ffffff" stroke="#7dd3fc" stroke-width="1.5" filter="drop-shadow(0 2px 4px rgba(0,0,0,0.04))"/>
        <text x="300" y="314" text-anchor="middle" font-size="12" font-weight="700" fill="#0369a1">Respiration &amp; Decay (↑ ~120 GtC/yr)</text>
        <text x="300" y="332" text-anchor="middle" font-size="10.5" font-weight="500" fill="#334155">C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O</text>
        <text x="300" y="346" text-anchor="middle" font-size="9" font-weight="600" fill="#0284c7">Carbon Released</text>
      </g>

      
      <g transform="translate(40, 110)">
        <rect x="0" y="0" width="135" height="150" rx="14" fill="url(#skyGrad)" stroke="#7dd3fc" stroke-width="2"/>
        <text x="67" y="30" text-anchor="middle" font-size="28">☁️</text>
        <text x="67" y="58" text-anchor="middle" font-size="14" font-weight="800" fill="#0369a1">Atmosphere</text>
        
        
        <rect x="22" y="70" width="91" height="24" rx="6" fill="#ffffff" stroke="#bae6fd"/>
        <text x="67" y="86" text-anchor="middle" font-size="12" font-weight="700" fill="#0284c7">CO₂ Gas</text>

        <text x="67" y="116" text-anchor="middle" font-size="11" font-weight="600" fill="#475569">~800 GtC Pool</text>
        <text x="67" y="132" text-anchor="middle" font-size="9.5" fill="#64748b">Inorganic C</text>
      </g>

      
      <g transform="translate(425, 110)">
        <rect x="0" y="0" width="135" height="150" rx="14" fill="url(#bioGrad)" stroke="#86efac" stroke-width="2"/>
        <text x="67" y="30" text-anchor="middle" font-size="28">🌿</text>
        <text x="67" y="58" text-anchor="middle" font-size="14" font-weight="800" fill="#15803d">Biosphere</text>
        
        
        <rect x="18" y="70" width="99" height="24" rx="6" fill="#ffffff" stroke="#bbf7d0"/>
        <text x="67" y="86" text-anchor="middle" font-size="11.5" font-weight="700" fill="#16a34a">Organic C (Cells)</text>

        <text x="67" y="116" text-anchor="middle" font-size="11" font-weight="600" fill="#475569">~550 GtC Pool</text>
        <text x="67" y="132" text-anchor="middle" font-size="9.5" fill="#64748b">Living Biomass</text>
      </g>

      
      <g id="center-badge" transform="translate(300, 185)">
        <circle r="22" fill="#ffffff" stroke="#cbd5e1" stroke-width="2" filter="drop-shadow(0 2px 4px rgba(0,0,0,0.06))"/>
        <text x="0" y="6" text-anchor="middle" font-size="16" font-weight="800" fill="#0f766e">⇄</text>
      </g>
    </svg>
  </div>

  
  <div class="balance-tag" id="balanceText">
    <span>✓</span> Balanced Dynamic Flux: Net Change = 0 GtC/yr
  </div>

  <script>
    function setMode(mode) {
      // Buttons state
      document.getElementById('btn-all').classList.remove('active');
      document.getElementById('btn-photo').classList.remove('active');
      document.getElementById('btn-resp').classList.remove('active');

      const photoGroup = document.getElementById('flux-photo');
      const respGroup = document.getElementById('flux-resp');
      const balanceText = document.getElementById('balanceText');

      if (mode === 'all') {
        document.getElementById('btn-all').classList.add('active');
        photoGroup.classList.remove('dimmed');
        respGroup.classList.remove('dimmed');
        balanceText.innerHTML = '<span>✓</span> Balanced Dynamic Flux: In (120) = Out (120) GtC/yr';
        balanceText.style.color = '#0f766e';
        balanceText.style.background = '#ccfbf1';
        balanceText.style.borderColor = '#5eead4';
      } else if (mode === 'photo') {
        document.getElementById('btn-photo').classList.add('active');
        photoGroup.classList.remove('dimmed');
        respGroup.classList.add('dimmed');
        balanceText.innerHTML = '<span>↓</span> Photosynthesis: 120 GtC/yr absorbed into plants &amp; biomass';
        balanceText.style.color = '#15803d';
        balanceText.style.background = '#dcfce7';
        balanceText.style.borderColor = '#86efac';
      } else if (mode === 'resp') {
        document.getElementById('btn-resp').classList.add('active');
        photoGroup.classList.add('dimmed');
        respGroup.classList.remove('dimmed');
        balanceText.innerHTML = '<span>↑</span> Respiration &amp; Decay: 120 GtC/yr returned to atmosphere';
        balanceText.style.color = '#0369a1';
        balanceText.style.background = '#e0f2fe';
        balanceText.style.borderColor = '#7dd3fc';
      }
    }
  </script>
</body>
</html>

Reservoirs and Processes in the Carbon Cycle

<!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;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      user-select: none;
      -webkit-user-select: none;
    }

    body {
      width: 100%;
      min-height: 100vh;
      background: #f8fafc;
      color: #0f172a;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      padding: 10px 12px;
    }

    /* Sub/Sup vertical alignment normalize */
    sub, sup {
      font-size: 72%;
      line-height: 0;
      position: relative;
      vertical-align: baseline;
      font-weight: 700;
    }
    sup {
      top: -0.45em;
    }
    sub {
      bottom: -0.2em;
    }

    .main-diagram {
      width: 100%;
      max-width: 600px;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    /* Section zones */
    .zone {
      border-radius: 10px;
      padding: 8px 10px;
      position: relative;
    }

    .zone-atmo {
      background: linear-gradient(180deg, #f0f9ff 0%, #e0f2fe 100%);
      border: 1.5px dashed #38bdf8;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
    }

    .zone-ocean {
      background: linear-gradient(180deg, #e0f2fe 0%, #bae6fd 35%, #e0f7fa 100%);
      border: 1.5px solid #0284c7;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .zone-tag {
      font-size: 11px;
      font-weight: 800;
      letter-spacing: 0.06em;
      text-transform: uppercase;
    }

    .gas-tag { color: #0284c7; }
    .ocean-tag { color: #0369a1; }

    /* Molecules & Badges */
    .species-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      flex-wrap: wrap;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 5px 9px;
      border-radius: 7px;
      font-size: 14px;
      font-weight: 700;
      box-shadow: 0 1px 3px rgba(0,0,0,0.06);
      transition: all 0.25s ease;
      cursor: pointer;
      white-space: nowrap;
    }

    .badge.active {
      box-shadow: 0 0 0 2.5px #0284c7, 0 4px 12px rgba(2, 132, 199, 0.3);
      background-color: #ffffff;
    }

    .badge-gas {
      background: #ffffff;
      color: #0284c7;
      border: 1.5px solid #38bdf8;
    }

    .badge-aq {
      background: #ffffff;
      color: #0369a1;
      border: 1.5px solid #0284c7;
    }

    .badge-solid {
      background: #fef3c7;
      color: #92400e;
      border: 1.5px solid #d97706;
    }

    .badge-solid.active {
      box-shadow: 0 0 0 2.5px #d97706, 0 4px 12px rgba(217, 119, 6, 0.3);
    }

    .state-sub {
      font-size: 11px;
      font-weight: 600;
      opacity: 0.85;
      margin-left: 2px;
    }

    .op {
      margin: 0 3px;
      font-weight: 700;
      color: #475569;
    }

    .arrow-eq {
      font-size: 16px;
      font-weight: 800;
      color: #0284c7;
      padding: 0 2px;
    }

    .arrow-react {
      font-size: 16px;
      font-weight: 800;
      color: #b45309;
      padding: 0 2px;
    }

    /* Diffusion connector */
    .diffusion-wrap {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      margin: -2px 0;
      z-index: 2;
    }

    .diff-label {
      font-size: 11px;
      font-weight: 700;
      color: #0284c7;
      letter-spacing: 0.02em;
    }

    .diff-arrow {
      color: #0284c7;
      font-size: 14px;
      font-weight: bold;
      animation: pulseDown 1.8s infinite ease-in-out;
    }

    @keyframes pulseDown {
      0%, 100% { transform: translateY(0); opacity: 0.7; }
      50% { transform: translateY(2px); opacity: 1; }
    }

    /* Ocean reactions container */
    .cascade-flow {
      display: grid;
      grid-template-columns: 1fr;
      gap: 6px;
    }

    .flow-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      flex-wrap: wrap;
      background: rgba(255, 255, 255, 0.7);
      border-radius: 8px;
      padding: 6px 8px;
    }

    .calc-row {
      background: rgba(254, 243, 199, 0.5);
      border: 1px dashed #f59e0b;
    }

    /* Step info label */
    .step-info {
      font-size: 11.5px;
      color: #334155;
      text-align: center;
      min-height: 18px;
      font-weight: 500;
      padding: 0 4px;
    }

    /* Legend */
    .legend {
      display: flex;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
      margin-top: 4px;
    }

    .leg-item {
      display: flex;
      align-items: center;
      gap: 5px;
      font-size: 11.5px;
      font-weight: 600;
      color: #475569;
    }

    .leg-dot {
      width: 10px;
      height: 10px;
      border-radius: 3px;
    }

    /* Stepper Controls */
    .ctrl-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 600px;
      margin-top: 6px;
      padding: 0 2px;
    }

    .step-dots {
      display: flex;
      gap: 5px;
    }

    .dot {
      width: 22px;
      height: 22px;
      border-radius: 50%;
      background: #e2e8f0;
      color: #64748b;
      font-size: 11px;
      font-weight: bold;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: all 0.2s;
    }

    .dot.active {
      background: #0284c7;
      color: #ffffff;
    }

    .btn-step {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      color: #334155;
      padding: 4px 10px;
      border-radius: 6px;
      font-size: 11.5px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 4px;
    }

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

    @media (max-width: 440px) {
      body { padding: 6px; }
      .badge { font-size: 12px; padding: 4px 6px; }
      .flow-row { padding: 5px 4px; gap: 4px; }
      .arrow-eq, .arrow-react { font-size: 13px; }
      .legend { gap: 10px; }
      .leg-item { font-size: 10.5px; }
      .zone-tag, .diff-label { font-size: 10px; }
    }
  </style>
</head>
<body>

  <div class="main-diagram">
    
    <div class="zone zone-atmo" id="zone-atmo">
      <span class="zone-tag gas-tag">Atmosphere</span>
      <div class="species-row">
        <div class="badge badge-gas" id="sp-1" onclick="goToStep(0)">
          CO<sub>2</sub><span class="state-sub">(g)</span>
        </div>
      </div>
    </div>

    
    <div class="diffusion-wrap">
      <span class="diff-label">Gas Dissolution</span>
      <span class="diff-arrow">↓</span>
    </div>

    
    <div class="zone zone-ocean" id="zone-ocean">
      <span class="zone-tag ocean-tag">Surface Ocean</span>

      <div class="cascade-flow">
        
        <div class="flow-row">
          <div class="badge badge-aq" id="sp-2" onclick="goToStep(1)">
            CO<sub>2</sub><span class="state-sub">(aq)</span><span class="op">+</span>H<sub>2</sub>O
          </div>
          <span class="arrow-eq">⇌</span>
          <div class="badge badge-aq" id="sp-3" onclick="goToStep(2)">
            H<sub>2</sub>CO<sub>3</sub>
          </div>
        </div>

        
        <div class="flow-row">
          <div class="badge badge-aq" id="sp-4" onclick="goToStep(3)">
            H<sup>+</sup><span class="op">+</span>HCO<sub>3</sub><sup>−</sup>
          </div>
          <span class="arrow-eq">⇌</span>
          <div class="badge badge-aq" id="sp-5" onclick="goToStep(4)">
            2H<sup>+</sup><span class="op">+</span>CO<sub>3</sub><sup>2−</sup>
          </div>
        </div>

        
        <div class="flow-row calc-row">
          <div class="badge badge-aq" id="sp-ca" onclick="goToStep(5)">
            Ca<sup>2+</sup><span class="op">+</span>CO<sub>3</sub><sup>2−</sup>
          </div>
          <span class="arrow-react">→</span>
          <div class="badge badge-solid" id="sp-6" onclick="goToStep(5)">
            🐚 CaCO<sub>3</sub><span class="state-sub">(s)</span>
          </div>
        </div>
      </div>
    </div>

    
    <div class="step-info" id="step-info">
      Step 1: Atmospheric CO₂ dissolves into seawater
    </div>

    
    <div class="legend">
      <div class="leg-item">
        <span class="leg-dot" style="background:#ffffff; border:1.5px solid #38bdf8;"></span>
        Gas (sky blue)
      </div>
      <div class="leg-item">
        <span class="leg-dot" style="background:#ffffff; border:1.5px solid #0284c7;"></span>
        Aqueous ions (marine blue)
      </div>
      <div class="leg-item">
        <span class="leg-dot" style="background:#fef3c7; border:1.5px solid #d97706;"></span>
        Solid mineral (sand color)
      </div>
    </div>
  </div>

  
  <div class="ctrl-bar">
    <button class="btn-step" id="playBtn" onclick="togglePlay()">⏸ Pause</button>
    <div class="step-dots">
      <div class="dot active" onclick="goToStep(0)">1</div>
      <div class="dot" onclick="goToStep(1)">2</div>
      <div class="dot" onclick="goToStep(2)">3</div>
      <div class="dot" onclick="goToStep(3)">4</div>
      <div class="dot" onclick="goToStep(4)">5</div>
      <div class="dot" onclick="goToStep(5)">6</div>
    </div>
  </div>

  <script>
    const steps = [
      { ids: ['sp-1'], desc: "1. Atmospheric carbon dioxide: CO₂(g)" },
      { ids: ['sp-2'], desc: "2. Dissolution in seawater: CO₂(aq) + H₂O" },
      { ids: ['sp-3'], desc: "3. Carbonic acid formation: H₂CO₃" },
      { ids: ['sp-4'], desc: "4. First dissociation: Bicarbonate & Hydrogen ions (H⁺ + HCO₃⁻)" },
      { ids: ['sp-5'], desc: "5. Second dissociation: Carbonate ion release (2H⁺ + CO₃²⁻)" },
      { ids: ['sp-ca', 'sp-6'], desc: "6. Calcification: Ca²⁺ + CO₃²⁻ → CaCO₃(s) shell formation" }
    ];

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

    function renderStep() {
      // Clear all active states
      document.querySelectorAll('.badge').forEach(b => b.classList.remove('active'));
      document.querySelectorAll('.dot').forEach(d => d.classList.remove('active'));

      // Highlight active elements
      steps[currentStep].ids.forEach(id => {
        const el = document.getElementById(id);
        if (el) el.classList.add('active');
      });

      const dots = document.querySelectorAll('.dot');
      if (dots[currentStep]) dots[currentStep].classList.add('active');

      const infoEl = document.getElementById('step-info');
      if (infoEl) infoEl.textContent = steps[currentStep].desc;
    }

    function goToStep(idx) {
      currentStep = idx;
      renderStep();
    }

    function nextStep() {
      currentStep = (currentStep + 1) % steps.length;
      renderStep();
    }

    function startCycle() {
      if (timer) clearInterval(timer);
      timer = setInterval(nextStep, 3000);
    }

    function togglePlay() {
      isPlaying = !isPlaying;
      const btn = document.getElementById('playBtn');
      if (isPlaying) {
        btn.textContent = '⏸ Pause';
        startCycle();
      } else {
        btn.textContent = '▶ Play';
        clearInterval(timer);
      }
    }

    renderStep();
    startCycle();
  </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, sans-serif;
      background: #f8fafc;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      height: 100%;
      padding: 8px;
      overflow: hidden;
      user-select: none;
    }

    .nav-bar {
      display: flex;
      gap: 6px;
      width: 100%;
      max-width: 600px;
      justify-content: center;
      flex-wrap: wrap;
      z-index: 10;
    }

    .btn {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 20px;
      padding: 4px 10px;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      box-shadow: 0 1px 2px rgba(0,0,0,0.04);
      transition: background 0.2s, border-color 0.2s, color 0.2s, box-shadow 0.2s;
    }

    .btn.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #2563eb;
      box-shadow: 0 2px 6px rgba(37,99,235,0.25);
    }

    .svg-container {
      width: 100%;
      max-width: 600px;
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
    }

    svg {
      width: 100%;
      height: 100%;
      max-height: 400px;
    }

    /* Flux pathway animation styling */
    .flow-line {
      stroke-dasharray: 6, 6;
      animation: dash 1.6s linear infinite;
    }

    @keyframes dash {
      to { stroke-dashoffset: -24; }
    }

    .flux-group {
      transition: opacity 0.35s ease;
    }

    .dimmed {
      opacity: 0.15;
    }

    .sphere-tag {
      font-size: 11px;
      font-weight: 800;
      letter-spacing: 0.5px;
      text-transform: uppercase;
      fill: #ffffff;
      paint-order: stroke;
      stroke: rgba(0,0,0,0.4);
      stroke-width: 2px;
    }

    .lbl {
      font-size: 11px;
      font-weight: 700;
      text-anchor: middle;
      pointer-events: none;
    }

    .lbl-bg {
      fill: rgba(255, 255, 255, 0.92);
      rx: 4px;
    }
  </style>
</head>
<body>

  
  <div class="nav-bar">
    <button class="btn active" id="btn-all" onclick="setFlux('all')">✦ All Fluxes</button>
    <button class="btn" id="btn-1" onclick="setFlux('bio')">🌿 Bio-Flux</button>
    <button class="btn" id="btn-2" onclick="setFlux('ocean')">🌊 Hydro-Flux</button>
    <button class="btn" id="btn-3" onclick="setFlux('geo')">🌋 Geo-Flux</button>
  </div>

  
  <div class="svg-container">
    <svg viewBox="0 0 600 380">
      <defs>
        
        <linearGradient id="skyGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#bae6fd" />
          <stop offset="100%" stop-color="#e0f2fe" />
        </linearGradient>

        
        <linearGradient id="oceanGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#38bdf8" />
          <stop offset="40%" stop-color="#0284c7" />
          <stop offset="100%" stop-color="#0369a1" />
        </linearGradient>

        
        <linearGradient id="crustGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#78716c" />
          <stop offset="100%" stop-color="#44403c" />
        </linearGradient>

        <linearGradient id="mantleGrad" x1="0" y1="0" x2="1" y2="0">
          <stop offset="0%" stop-color="#ea580c" />
          <stop offset="50%" stop-color="#c2410c" />
          <stop offset="100%" stop-color="#9a3412" />
        </linearGradient>

        
        <marker id="arr-green" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1 L 8 5 L 0 9 z" fill="#16a34a" />
        </marker>
        <marker id="arr-blue" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1 L 8 5 L 0 9 z" fill="#0284c7" />
        </marker>
        <marker id="arr-orange" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1 L 8 5 L 0 9 z" fill="#ea580c" />
        </marker>
        <marker id="arr-white" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1 L 8 5 L 0 9 z" fill="#ffffff" />
        </marker>
      </defs>

      
      
      <rect x="0" y="0" width="600" height="170" fill="url(#skyGrad)" />

      
      <rect x="0" y="270" width="600" height="110" fill="url(#mantleGrad)" />

      
      <polygon points="340,240 600,240 600,280 440,360 300,360 340,240" fill="#334155" />
      
      <polygon points="340,240 600,240 600,248 450,335 430,335 340,240" fill="#cbd5e1" />

      
      <polygon points="0,170 120,170 160,110 200,170 350,170 340,280 0,280" fill="url(#crustGrad)" />
      
      <path d="M 0,170 Q 60,165 120,170 L 160,110 L 200,170 L 350,170 L 350,178 L 0,178 Z" fill="#4ade80" />

      
      <rect x="350" y="150" width="250" height="90" fill="url(#oceanGrad)" />

      
      <circle cx="48" cy="42" r="24" fill="#fde047" />
      <circle cx="48" cy="42" r="28" fill="#fde047" opacity="0.3" />

      
      
      <path d="M 152,125 Q 160,140 160,280" stroke="#f97316" stroke-width="8" fill="none" stroke-linecap="round" />
      <circle cx="160" cy="290" r="32" fill="#ea580c" />
      <circle cx="160" cy="290" r="20" fill="#f97316" />

      
      <text x="60" y="165" font-size="28">🌲</text>
      <text x="85" y="166" font-size="24">🌳</text>
      <text x="240" y="165" font-size="26">🌲</text>
      <text x="270" y="166" font-size="24">🌳</text>

      
      <text x="400" y="195" font-size="18">🐟</text>
      <text x="490" y="190" font-size="20">🐋</text>
      <text x="540" y="210" font-size="16">🐚</text>

      
      <text x="28" y="90" class="sphere-tag">ATMOSPHERE</text>
      <text x="235" y="148" class="sphere-tag" fill="#86efac">BIOSPHERE</text>
      <text x="500" y="168" class="sphere-tag" fill="#7dd3fc">HYDROSPHERE</text>
      <text x="40" y="265" class="sphere-tag" fill="#fed7aa">GEOSPHERE</text>

      

      
      <g id="flux-bio" class="flux-group">
        
        <path d="M 95,80 L 95,130" stroke="#16a34a" stroke-width="3.5" fill="none" class="flow-line" marker-end="url(#arr-green)" />
        <rect x="52" y="96" width="86" height="17" class="lbl-bg" />
        <text x="95" y="109" class="lbl" fill="#15803d">Photosynthesis ↓</text>

        
        <path d="M 275,130 L 275,80" stroke="#16a34a" stroke-width="3.5" fill="none" class="flow-line" marker-end="url(#arr-green)" />
        <rect x="234" y="96" width="82" height="17" class="lbl-bg" />
        <text x="275" y="109" class="lbl" fill="#15803d">Respiration ↑</text>
      </g>

      
      <g id="flux-ocean" class="flux-group">
        
        <path d="M 430,90 L 430,140" stroke="#0284c7" stroke-width="3.5" fill="none" class="flow-line" marker-end="url(#arr-blue)" />
        <rect x="385" y="105" width="90" height="17" class="lbl-bg" />
        <text x="430" y="118" class="lbl" fill="#0369a1">CO₂ Absorption ↓</text>

        
        <path d="M 480,185 L 480,230" stroke="#ffffff" stroke-width="2.5" fill="none" class="flow-line" marker-end="url(#arr-white)" />
        <rect x="420" y="212" width="120" height="16" class="lbl-bg" />
        <text x="480" y="224" class="lbl" fill="#0f172a">CaCO₃ Shell Rain ↓</text>
      </g>

      
      <g id="flux-geo" class="flux-group">
        
        <path d="M 420,290 L 220,310" stroke="#ea580c" stroke-width="3.5" fill="none" class="flow-line" marker-end="url(#arr-orange)" />
        <rect x="250" y="322" width="130" height="17" class="lbl-bg" />
        <text x="315" y="335" class="lbl" fill="#c2410c">Subduction &amp; Melting ↙</text>

        
        <path d="M 160,110 Q 160,50 190,40" stroke="#ea580c" stroke-width="3.5" fill="none" class="flow-line" marker-end="url(#arr-orange)" />
        
        <circle cx="160" cy="100" r="14" fill="#94a3b8" opacity="0.7" />
        <circle cx="172" cy="85" r="18" fill="#94a3b8" opacity="0.8" />
        <circle cx="190" cy="70" r="22" fill="#64748b" opacity="0.9" />
        <rect x="130" y="32" width="105" height="17" class="lbl-bg" />
        <text x="182.5" y="45" class="lbl" fill="#c2410c">Volcanic Release ↗</text>
      </g>

      
      <rect x="300" y="22" width="90" height="18" rx="4" fill="rgba(255,255,255,0.7)" />
      <text x="345" y="35" class="lbl" fill="#334155">Atmospheric CO₂</text>
    </svg>
  </div>

  <script>
    function setFlux(mode) {
      const groups = {
        bio: document.getElementById('flux-bio'),
        ocean: document.getElementById('flux-ocean'),
        geo: document.getElementById('flux-geo')
      };

      const buttons = {
        all: document.getElementById('btn-all'),
        bio: document.getElementById('btn-1'),
        ocean: document.getElementById('btn-2'),
        geo: document.getElementById('btn-3')
      };

      // Reset buttons
      Object.values(buttons).forEach(b => b.classList.remove('active'));
      buttons[mode].classList.add('active');

      // Update visibility/dimming
      if (mode === 'all') {
        Object.values(groups).forEach(g => g.classList.remove('dimmed'));
      } else {
        Object.keys(groups).forEach(k => {
          if (k === mode) {
            groups[k].classList.remove('dimmed');
          } else {
            groups[k].classList.add('dimmed');
          }
        });
      }
    }
  </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: #f8fafc;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
    }

    /* Step Selector Buttons */
    .controls {
      display: flex;
      gap: 6px;
      width: 100%;
      max-width: 460px;
    }
    .step-btn {
      flex: 1;
      padding: 8px 4px;
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 8px;
      font-size: 13px;
      font-weight: 700;
      color: #64748b;
      cursor: pointer;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 2px;
      transition: all 0.25s ease;
    }
    .step-btn.active {
      border-color: #22b7ff;
      background: #f0f9ff;
      color: #0284c7;
      box-shadow: 0 2px 6px rgba(34, 183, 255, 0.2);
    }
    .step-btn .sub {
      font-size: 10px;
      font-weight: 500;
      opacity: 0.85;
    }

    /* Diagram Arena */
    .arena {
      position: relative;
      width: 100%;
      max-width: 460px;
      height: 280px;
      margin: 10px 0;
      display: grid;
      grid-template-columns: 1fr 1fr;
      grid-template-rows: 1fr 1fr;
      gap: 12px;
    }

    /* Sphere Cards */
    .sphere-card {
      background: #ffffff;
      border-radius: 12px;
      border: 2px solid #e2e8f0;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      position: relative;
      transition: all 0.3s ease;
    }
    .sphere-card .icon {
      font-size: 28px;
      line-height: 1;
      margin-bottom: 4px;
    }
    .sphere-card .name {
      font-size: 13px;
      font-weight: 700;
      color: #334155;
    }
    .sphere-card.active-source {
      border-color: #94a3b8;
      background: #f1f5f9;
    }
    .sphere-card.active-target {
      border-color: #22b7ff;
      background: #e0f2fe;
      box-shadow: 0 4px 12px rgba(34, 183, 255, 0.25);
    }

    /* Center Carbon Molecule Hub */
    .center-hud {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      background: #0f172a;
      color: #ffffff;
      padding: 8px 16px;
      border-radius: 20px;
      display: flex;
      flex-direction: column;
      align-items: center;
      box-shadow: 0 4px 14px rgba(15, 23, 42, 0.25);
      z-index: 10;
      min-width: 110px;
      transition: all 0.3s ease;
    }
    .center-hud .tag {
      font-size: 9px;
      letter-spacing: 0.5px;
      color: #38bdf8;
      font-weight: 700;
      text-transform: uppercase;
    }
    .center-hud .formula {
      font-size: 18px;
      font-weight: 800;
      letter-spacing: 0.5px;
    }
    .center-hud sub {
      font-size: 12px;
    }
    .center-hud sup {
      font-size: 10px;
    }

    /* Flow Indicator Arrow */
    .flow-svg {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
      z-index: 5;
    }
    .flow-path {
      fill: none;
      stroke: #cbd5e1;
      stroke-width: 3;
      stroke-dasharray: 6 6;
    }
    .active-flow {
      fill: none;
      stroke: #22b7ff;
      stroke-width: 4;
      stroke-linecap: round;
      stroke-dasharray: 8 6;
      animation: dash 1s linear infinite;
    }
    @keyframes dash {
      to { stroke-dashoffset: -28; }
    }

    /* Step Playback Footer */
    .playback-bar {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
    }
    .play-btn {
      background: #ffffff;
      border: 1.5px solid #cbd5e1;
      border-radius: 50%;
      width: 28px;
      height: 28px;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      color: #334155;
      font-size: 11px;
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="step-btn active" onclick="setStep(0)">
      <span>1</span>
      <span class="sub">🌋 → ☁️</span>
    </button>
    <button class="step-btn" onclick="setStep(1)">
      <span>2</span>
      <span class="sub">☁️ → 🍃</span>
    </button>
    <button class="step-btn" onclick="setStep(2)">
      <span>3</span>
      <span class="sub">🍃 → 🌊</span>
    </button>
    <button class="step-btn" onclick="setStep(3)">
      <span>4</span>
      <span class="sub">🌊 → 🪨</span>
    </button>
  </div>

  
  <div class="arena">
    
    <div id="sphere-geo" class="sphere-card active-source">
      <div class="icon">🌋</div>
      <div class="name">Geosphere</div>
    </div>

    <div id="sphere-atm" class="sphere-card active-target">
      <div class="icon">☁️</div>
      <div class="name">Atmosphere</div>
    </div>

    <div id="sphere-geo-sed" class="sphere-card">
      <div class="icon">🪨</div>
      <div class="name">Limestone</div>
    </div>

    <div id="sphere-bio-hydro" class="sphere-card">
      <div class="icon" id="bio-hydro-icon">🍃</div>
      <div class="name" id="bio-hydro-name">Biosphere</div>
    </div>

    
    <div class="center-hud">
      <span class="tag">Carbon Form</span>
      <span class="formula" id="formula">CO<sub>2</sub></span>
    </div>

    
    <svg class="flow-svg" viewBox="0 0 460 280">
      
      <path id="path0" d="M 130 70 L 330 70" class="active-flow" />
      
      <path id="path1" d="M 345 90 L 345 190" class="flow-path" />
      
      <path id="path2" d="M 330 210 L 130 210" class="flow-path" />
      
      <path id="path3" d="M 115 190 L 115 90" class="flow-path" />
    </svg>
  </div>

  
  <div class="playback-bar">
    <button id="playBtn" class="play-btn" onclick="togglePlay()">⏸</button>
    <span id="stepLabel">Step 1: Volcanic Release</span>
  </div>

  <script>
    const steps = [
      {
        label: "Step 1: Volcanic Eruption",
        formula: 'CO<sub>2</sub>',
        sourceId: 'sphere-geo',
        targetId: 'sphere-atm',
        bioIcon: '🍃',
        bioName: 'Biosphere',
        pathIdx: 0
      },
      {
        label: "Step 2: Photosynthesis",
        formula: 'C<sub>6</sub>H<sub>12</sub>O<sub>6</sub>',
        sourceId: 'sphere-atm',
        targetId: 'sphere-bio-hydro',
        bioIcon: '🍃',
        bioName: 'Biosphere',
        pathIdx: 1
      },
      {
        label: "Step 3: Dissolved Ocean Ion",
        formula: 'HCO<sub>3</sub><sup>-</sup>',
        sourceId: 'sphere-bio-hydro',
        targetId: 'sphere-bio-hydro',
        bioIcon: '🌊',
        bioName: 'Hydrosphere',
        pathIdx: 2
      },
      {
        label: "Step 4: Shell Sedimentation",
        formula: 'CaCO<sub>3</sub>',
        sourceId: 'sphere-bio-hydro',
        targetId: 'sphere-geo-sed',
        bioIcon: '🐚',
        bioName: 'Hydrosphere',
        pathIdx: 3
      }
    ];

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

    function renderStep() {
      const s = steps[currentStep];

      // Update buttons
      document.querySelectorAll('.step-btn').forEach((btn, idx) => {
        btn.classList.toggle('active', idx === currentStep);
      });

      // Update HUD & labels
      document.getElementById('formula').innerHTML = s.formula;
      document.getElementById('stepLabel').textContent = s.label;
      document.getElementById('bio-hydro-icon').textContent = s.bioIcon;
      document.getElementById('bio-hydro-name').textContent = s.bioName;

      // Update Spheres
      const cards = ['sphere-geo', 'sphere-atm', 'sphere-geo-sed', 'sphere-bio-hydro'];
      cards.forEach(id => {
        const el = document.getElementById(id);
        el.classList.remove('active-source', 'active-target');
      });

      if (s.sourceId === s.targetId) {
        document.getElementById(s.targetId).classList.add('active-target');
      } else {
        document.getElementById(s.sourceId).classList.add('active-source');
        document.getElementById(s.targetId).classList.add('active-target');
      }

      // Update Flow Path
      [0, 1, 2, 3].forEach(idx => {
        const p = document.getElementById('path' + idx);
        p.className.baseVal = (idx === s.pathIdx) ? 'active-flow' : 'flow-path';
      });
    }

    function setStep(idx) {
      currentStep = idx;
      renderStep();
      if (isPlaying) {
        resetAutoTimer();
      }
    }

    function nextStep() {
      currentStep = (currentStep + 1) % steps.length;
      renderStep();
    }

    function startTimer() {
      timer = setInterval(nextStep, 3500);
    }

    function resetAutoTimer() {
      clearInterval(timer);
      startTimer();
    }

    function togglePlay() {
      isPlaying = !isPlaying;
      document.getElementById('playBtn').textContent = isPlaying ? '⏸' : '▶';
      if (isPlaying) {
        startTimer();
      } else {
        clearInterval(timer);
      }
    }

    // Initialize
    renderStep();
    startTimer();
  </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>Earth's Carbon Reservoirs</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: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      width: 100%;
    }

    /* Top control bar */
    .top-bar {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      align-items: center;
      gap: 6px;
    }
    .pill {
      font-size: 11px;
      font-weight: 600;
      color: #475569;
      background: #f1f5f9;
      padding: 4px 8px;
      border-radius: 999px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .toggle-group {
      display: flex;
      background: #f1f5f9;
      padding: 2px;
      border-radius: 8px;
      gap: 2px;
    }
    .toggle-btn {
      border: none;
      background: transparent;
      padding: 4px 10px;
      font-size: 11px;
      font-weight: 600;
      color: #64748b;
      border-radius: 6px;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .toggle-btn.active {
      background: #ffffff;
      color: #0f172a;
      box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    }

    /* Reservoirs list */
    .reservoirs-container {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .reservoir-card {
      border-radius: 10px;
      border: 1.5px solid transparent;
      padding: 8px 10px;
      cursor: pointer;
      transition: background-color 0.2s ease, box-shadow 0.2s ease;
      display: flex;
      flex-direction: column;
      gap: 4px;
      user-select: none;
    }
    .reservoir-card:hover {
      filter: brightness(0.98);
    }
    .reservoir-card.selected {
      box-shadow: 0 0 0 2px #0f172a inset;
    }

    /* Theme colors */
    .res-atmo { background: #f0f9ff; border-color: #bae6fd; color: #0369a1; }
    .res-bio  { background: #f0fdf4; border-color: #bbf7d0; color: #15803d; }
    .res-hydro{ background: #eff6ff; border-color: #bfdbfe; color: #1d4ed8; }
    .res-geo  { background: #f8fafc; border-color: #cbd5e1; color: #334155; }

    .card-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 13px;
      font-weight: 700;
    }
    .card-title {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 13px;
    }
    .gtc-badge {
      font-size: 12px;
      font-weight: 800;
      padding: 2px 6px;
      border-radius: 6px;
      background: rgba(255,255,255,0.85);
      border: 1px solid rgba(0,0,0,0.06);
    }

    /* Scale view visual bar */
    .bar-track {
      width: 100%;
      height: 10px;
      background: rgba(0, 0, 0, 0.05);
      border-radius: 5px;
      overflow: hidden;
      margin: 2px 0;
      position: relative;
    }
    .bar-fill {
      height: 100%;
      border-radius: 5px;
      transition: width 0.4s ease;
    }
    .res-atmo .bar-fill { background: #0284c7; }
    .res-bio .bar-fill  { background: #16a34a; }
    .res-hydro .bar-fill{ background: #2563eb; }
    .res-geo .bar-fill  { background: #475569; }

    /* Compact stats / formulas */
    .chem-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 4px;
      font-size: 11px;
      font-weight: 600;
    }
    .tag {
      background: rgba(255,255,255,0.9);
      padding: 1px 6px;
      border-radius: 4px;
      border: 1px solid rgba(0,0,0,0.08);
      color: #1e2945;
    }

    /* Detail / Inspect panel */
    .inspect-panel {
      margin-top: 2px;
      padding: 8px 10px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      font-size: 11px;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 6px;
    }
    .inspect-stat {
      display: flex;
      flex-direction: column;
      gap: 1px;
    }
    .stat-label {
      font-size: 10px;
      text-transform: uppercase;
      font-weight: 700;
      color: #64748b;
    }
    .stat-val {
      font-weight: 700;
      color: #0f172a;
    }

    .scale-legend {
      display: flex;
      justify-content: space-between;
      font-size: 10px;
      color: #64748b;
      font-weight: 600;
      padding: 0 2px;
    }
  </style>
</head>
<body>

  
  <div class="top-bar">
    <div class="pill">⚖️ 1 GtC = 1 Billion Metric Tons</div>
    <div class="toggle-group">
      <button class="toggle-btn active" id="btnInspect" onclick="setMode('inspect')">Details</button>
      <button class="toggle-btn" id="btnScale" onclick="setMode('scale')">Compare Scale</button>
    </div>
  </div>

  
  <div class="reservoirs-container">

    
    <div class="reservoir-card res-atmo selected" id="card-atmo" onclick="selectCard('atmo')">
      <div class="card-header">
        <div class="card-title">☁️ Atmosphere</div>
        <div class="gtc-badge">~850 GtC</div>
      </div>
      <div class="bar-track">
        <div class="bar-fill" id="bar-atmo" style="width: 15%;"></div>
      </div>
      <div class="chem-tags">
        <span class="tag">CO₂</span>
        <span class="tag">CH₄</span>
        <span class="tag">Fast exchange</span>
      </div>
    </div>

    
    <div class="reservoir-card res-bio" id="card-bio" onclick="selectCard('bio')">
      <div class="card-header">
        <div class="card-title">🌿 Biosphere</div>
        <div class="gtc-badge">~2,500 GtC</div>
      </div>
      <div class="bar-track">
        <div class="bar-fill" id="bar-bio" style="width: 25%;"></div>
      </div>
      <div class="chem-tags">
        <span class="tag">Cellulose (C₆H₁₀O₅)ₙ</span>
        <span class="tag">Sugars</span>
        <span class="tag">Soil Humus</span>
      </div>
    </div>

    
    <div class="reservoir-card res-hydro" id="card-hydro" onclick="selectCard('hydro')">
      <div class="card-header">
        <div class="card-title">🌊 Hydrosphere</div>
        <div class="gtc-badge">~38,000 GtC</div>
      </div>
      <div class="bar-track">
        <div class="bar-fill" id="bar-hydro" style="width: 55%;"></div>
      </div>
      <div class="chem-tags">
        <span class="tag">HCO₃⁻ (Bicarbonate)</span>
        <span class="tag">CO₃²⁻ (Carbonate)</span>
        <span class="tag">Deep Ocean</span>
      </div>
    </div>

    
    <div class="reservoir-card res-geo" id="card-geo" onclick="selectCard('geo')">
      <div class="card-header">
        <div class="card-title">🪨 Geosphere (Lithosphere)</div>
        <div class="gtc-badge">&gt;60,000,000 GtC</div>
      </div>
      <div class="bar-track">
        <div class="bar-fill" id="bar-geo" style="width: 100%;"></div>
      </div>
      <div class="chem-tags">
        <span class="tag">CaCO₃ (Limestone)</span>
        <span class="tag">Kerogen</span>
        <span class="tag">Fossil Fuels</span>
      </div>
    </div>

  </div>

  
  <div class="inspect-panel" id="inspectPanel">
    <div class="inspect-stat">
      <span class="stat-label">Main Form</span>
      <span class="stat-val" id="statForm">CO₂ &amp; CH₄</span>
    </div>
    <div class="inspect-stat">
      <span class="stat-label">Residence Time</span>
      <span class="stat-val" id="statRes">~3 - 5 Years</span>
    </div>
    <div class="inspect-stat">
      <span class="stat-label">Key Flux</span>
      <span class="stat-val" id="statFlux">Photosynthesis / Respiration</span>
    </div>
  </div>

  <div class="scale-legend" id="scaleLegend" style="display: none;">
    <span>Log Scale: 10² GtC</span>
    <span>10⁴ GtC</span>
    <span>10⁶ GtC</span>
    <span>10⁸ GtC</span>
  </div>

  <script>
    const data = {
      atmo: {
        form: 'CO₂ & CH₄',
        res: '~3 - 5 Years',
        flux: 'Photosynthesis ⇄ Respiration',
        logW: '18%',
        linearW: '1%'
      },
      bio: {
        form: 'Cellulose & Sugars',
        res: '~10 - 100 Years',
        flux: 'Decomposition ⇄ Growth',
        logW: '28%',
        linearW: '2%'
      },
      hydro: {
        form: 'HCO₃⁻ & CO₃²⁻',
        res: '~300 - 1,000 Years',
        flux: 'Ocean Dissolution ⇄ Upwelling',
        logW: '60%',
        linearW: '5%'
      },
      geo: {
        form: 'CaCO₃ (Sedimentary Rocks)',
        res: '&gt;100 Million Years',
        flux: 'Volcanism ⇄ Subduction / Weathering',
        logW: '100%',
        linearW: '100%'
      }
    };

    let activeKey = 'atmo';
    let currentMode = 'inspect';

    function updateDetails(key) {
      const d = data[key];
      document.getElementById('statForm').innerHTML = d.form;
      document.getElementById('statRes').innerHTML = d.res;
      document.getElementById('statFlux').innerHTML = d.flux;
    }

    function selectCard(key) {
      activeKey = key;
      ['atmo', 'bio', 'hydro', 'geo'].forEach(k => {
        const el = document.getElementById('card-' + k);
        if (k === key) {
          el.classList.add('selected');
        } else {
          el.classList.remove('selected');
        }
      });
      updateDetails(key);
    }

    function setMode(mode) {
      currentMode = mode;
      document.getElementById('btnInspect').classList.toggle('active', mode === 'inspect');
      document.getElementById('btnScale').classList.toggle('active', mode === 'scale');

      const legend = document.getElementById('scaleLegend');
      const inspect = document.getElementById('inspectPanel');

      if (mode === 'scale') {
        legend.style.display = 'flex';
        inspect.style.display = 'grid';
        ['atmo', 'bio', 'hydro', 'geo'].forEach(k => {
          document.getElementById('bar-' + k).style.width = data[k].logW;
        });
      } else {
        legend.style.display = 'none';
        inspect.style.display = 'grid';
        document.getElementById('bar-atmo').style.width = '15%';
        document.getElementById('bar-bio').style.width = '25%';
        document.getElementById('bar-hydro').style.width = '55%';
        document.getElementById('bar-geo').style.width = '100%';
      }
    }

    // Init
    selectCard('atmo');
  </script>
</body>
</html>

112.43(b)(13)(C)

Aligned learning resources

Related diagrams