<!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: #ffffff;
      color: #1e2945;
      padding: 16px 12px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      min-height: 100%;
    }

    .header-tag {
      text-align: center;
      font-size: 13px;
      font-weight: 700;
      color: #64748b;
      letter-spacing: 0.5px;
      text-transform: uppercase;
      margin-bottom: 8px;
    }

    /* Comparison Grid */
    .grid {
      display: grid;
      grid-template-columns: 1fr 1fr 1.15fr;
      gap: 8px;
      margin-bottom: 12px;
    }

    .col-card {
      background: #f8fafc;
      border-radius: 12px;
      padding: 10px 6px;
      text-align: center;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      border: 1px solid #e2e8f0;
      cursor: pointer;
      transition: box-shadow 0.2s ease, border-color 0.2s ease;
    }

    .col-card.active {
      border-color: #0284c7;
      box-shadow: 0 4px 12px rgba(2, 132, 199, 0.15);
      background: #f0f9ff;
    }

    .icon {
      font-size: 24px;
      margin-bottom: 4px;
      line-height: 1;
    }

    .title {
      font-size: 13px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 4px;
    }

    .ppm-badge {
      font-size: 12px;
      font-weight: 800;
      padding: 3px 6px;
      border-radius: 6px;
      margin-bottom: 8px;
      white-space: nowrap;
    }

    .fresh .ppm-badge { background: #e0f2fe; color: #0369a1; }
    .brackish .ppm-badge { background: #fef3c7; color: #b45309; }
    .sea .ppm-badge { background: #dbeafe; color: #1e40af; }

    /* Ion Density Visualization Tank */
    .tank {
      width: 100%;
      height: 90px;
      border-radius: 8px;
      position: relative;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .fresh .tank { background: linear-gradient(180deg, #f0f9ff 0%, #bae6fd 100%); border: 1px solid #7dd3fc; }
    .brackish .tank { background: linear-gradient(180deg, #fffbeb 0%, #fde68a 100%); border: 1px solid #fcd34d; }
    .sea .tank { background: linear-gradient(180deg, #eff6ff 0%, #60a5fa 100%); border: 1px solid #3b82f6; }

    .ion-canvas {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
    }

    /* Reduction Flow Banner */
    .reduction-bar {
      background: #eff6ff;
      border: 1px dashed #3b82f6;
      border-radius: 10px;
      padding: 10px 12px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
    }

    .arrow-flow {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      font-weight: 800;
      font-size: 15px;
      color: #1d4ed8;
      width: 100%;
    }

    .reduction-pill {
      background: #2563eb;
      color: #ffffff;
      padding: 4px 10px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 800;
      box-shadow: 0 2px 6px rgba(37, 99, 235, 0.3);
    }
  </style>
</head>
<body>

  <div class="header-tag">Dissolved Salt Concentration</div>

  <div class="grid">
    
    <div class="col-card fresh active" id="cardFresh">
      <div class="icon">💧</div>
      <div class="title">Fresh Potable</div>
      <div class="ppm-badge">&lt; 500 ppm</div>
      <div class="tank">
        <canvas id="canvasFresh" class="ion-canvas"></canvas>
      </div>
    </div>

    
    <div class="col-card brackish" id="cardBrackish">
      <div class="icon">🌾</div>
      <div class="title">Brackish</div>
      <div class="ppm-badge">1k – 10k ppm</div>
      <div class="tank">
        <canvas id="canvasBrackish" class="ion-canvas"></canvas>
      </div>
    </div>

    
    <div class="col-card sea" id="cardSea">
      <div class="icon">🌊</div>
      <div class="title">Seawater</div>
      <div class="ppm-badge">~35,000 ppm</div>
      <div class="tank">
        <canvas id="canvasSea" class="ion-canvas"></canvas>
      </div>
    </div>
  </div>

  
  <div class="reduction-bar">
    <div class="arrow-flow">
      <span>🌊 Seawater</span>
      <span>➔</span>
      <span class="reduction-pill">70× Salt Reduction</span>
      <span>➔</span>
      <span>💧 Drinkable</span>
    </div>
  </div>

  <script>
    // Draw salt ions (proportional representation: 1 : 10 : 70)
    function drawIons(canvasId, count, dotColor) {
      const canvas = document.getElementById(canvasId);
      const ctx = canvas.getContext('2d');
      const dpr = window.devicePixelRatio || 1;
      
      const rect = canvas.getBoundingClientRect();
      canvas.width = rect.width * dpr;
      canvas.height = rect.height * dpr;
      ctx.scale(dpr, dpr);

      const w = rect.width;
      const h = rect.height;

      ctx.clearRect(0, 0, w, h);
      ctx.fillStyle = dotColor;

      // Seeded-like spread for consistent, neat look
      for (let i = 0; i < count; i++) {
        const x = 6 + ((i * 37 + 13) % (w - 12));
        const y = 6 + ((i * 53 + 7) % (h - 12));
        ctx.beginPath();
        ctx.arc(x, y, count > 30 ? 2 : 2.5, 0, Math.PI * 2);
        ctx.fill();
      }
    }

    function renderAll() {
      drawIons('canvasFresh', 2, '#0369a1');       // <500 ppm representation
      drawIons('canvasBrackish', 14, '#b45309');   // ~5,000 ppm
      drawIons('canvasSea', 100, '#1e3a8a');       // ~35,000 ppm (~70x)
    }

    window.addEventListener('resize', renderAll);
    window.addEventListener('load', renderAll);

    // Subtle interactive focus
    const cards = document.querySelectorAll('.col-card');
    cards.forEach(card => {
      card.addEventListener('click', () => {
        cards.forEach(c => c.classList.remove('active'));
        card.classList.add('active');
      });
    });

    renderAll();
  </script>
</body>
</html>

Desalination: When Fresh Water Supplies Are Limited

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      width: 100%;
      height: 100%;
      background: #ffffff;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      overflow: hidden;
      color: #1e2945;
    }
    .diagram-svg {
      width: 100%;
      max-width: 680px;
      height: auto;
      max-height: 480px;
      display: block;
    }
    .flow-line {
      stroke-dasharray: 8 6;
      animation: flow 1.6s linear infinite;
    }
    @keyframes flow {
      to {
        stroke-dashoffset: -28;
      }
    }
    .card {
      transition: filter 0.2s ease, stroke 0.2s ease;
      cursor: pointer;
    }
    .card:hover {
      filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.08));
    }
    .badge {
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .title {
      font-size: 15px;
      font-weight: 700;
    }
    .val-main {
      font-size: 20px;
      font-weight: 800;
    }
    .val-sub {
      font-size: 13px;
      font-weight: 600;
    }
  </style>
</head>
<body>

  <svg class="diagram-svg" viewBox="0 0 680 440" fill="none" xmlns="http://www.w3.org/2000/svg">
    <defs>
      
      <linearGradient id="seaGrad" x1="0" y1="0" x2="1" y2="1">
        <stop offset="0%" stop-color="#f0f9ff" />
        <stop offset="100%" stop-color="#e0f2fe" />
      </linearGradient>
      <linearGradient id="plantGrad" x1="0" y1="0" x2="1" y2="1">
        <stop offset="0%" stop-color="#f8fafc" />
        <stop offset="100%" stop-color="#f1f5f9" />
      </linearGradient>
      <linearGradient id="freshGrad" x1="0" y1="0" x2="1" y2="1">
        <stop offset="0%" stop-color="#ecfeff" />
        <stop offset="100%" stop-color="#cffafe" />
      </linearGradient>
      <linearGradient id="brineGrad" x1="0" y1="0" x2="1" y2="1">
        <stop offset="0%" stop-color="#fff7ed" />
        <stop offset="100%" stop-color="#ffedd5" />
      </linearGradient>
      <linearGradient id="energyGrad" x1="0" y1="0" x2="1" y2="1">
        <stop offset="0%" stop-color="#fefce8" />
        <stop offset="100%" stop-color="#fef08a" />
      </linearGradient>

      
      <marker id="arr-sea" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
        <path d="M1 1 L7 4 L1 7 Z" fill="#0284c7" />
      </marker>
      <marker id="arr-fresh" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
        <path d="M1 1 L7 4 L1 7 Z" fill="#0891b2" />
      </marker>
      <marker id="arr-brine" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
        <path d="M1 1 L7 4 L1 7 Z" fill="#ea580c" />
      </marker>
      <marker id="arr-energy" markerWidth="8" markerHeight="8" refX="6" refY="4" orient="auto">
        <path d="M1 1 L7 4 L1 7 Z" fill="#eab308" />
      </marker>
    </defs>

    
    
    <path d="M 210 240 L 275 240" stroke="#bae6fd" stroke-width="8" stroke-linecap="round" />
    <path d="M 210 240 L 275 240" stroke="#0284c7" stroke-width="3" fill="none" class="flow-line" marker-end="url(#arr-sea)" />

    
    <path d="M 340 100 L 340 155" stroke="#fef08a" stroke-width="8" stroke-linecap="round" />
    <path d="M 340 100 L 340 155" stroke="#eab308" stroke-width="3" fill="none" class="flow-line" marker-end="url(#arr-energy)" />

    
    <path d="M 405 215 C 435 215, 440 135, 475 135" stroke="#a5f3fc" stroke-width="8" stroke-linecap="round" fill="none" />
    <path d="M 405 215 C 435 215, 440 135, 475 135" stroke="#0891b2" stroke-width="3" fill="none" class="flow-line" marker-end="url(#arr-fresh)" />

    
    <path d="M 405 265 C 435 265, 440 345, 475 345" stroke="#fed7aa" stroke-width="8" stroke-linecap="round" fill="none" />
    <path d="M 405 265 C 435 265, 440 345, 475 345" stroke="#ea580c" stroke-width="3" fill="none" class="flow-line" marker-end="url(#arr-brine)" />

    
    <g class="card">
      <rect x="235" y="40" width="210" height="60" rx="12" fill="url(#energyGrad)" stroke="#facc15" stroke-width="1.5" />
      <text x="252" y="76" font-size="24">⚡</text>
      <text x="282" y="66" class="title" fill="#854d0e">High Energy Demand</text>
      <text x="282" y="83" class="badge" fill="#a16207">Thermal or Electricity</text>
    </g>

    
    <g class="card">
      <rect x="25" y="170" width="185" height="140" rx="14" fill="url(#seaGrad)" stroke="#38bdf8" stroke-width="1.5" />
      <rect x="37" y="182" width="70" height="20" rx="6" fill="#e0f2fe" />
      <text x="44" y="196" class="badge" fill="#0369a1">INTAKE</text>
      
      <text x="37" y="224" class="title" fill="#0c4a6e">Seawater</text>
      
      <text x="37" y="260" class="val-main" fill="#0284c7">100 L</text>
      <text x="37" y="288" class="val-sub" fill="#0369a1">35 g/L salt</text>
    </g>

    
    <g class="card">
      <rect x="275" y="165" width="130" height="150" rx="16" fill="url(#plantGrad)" stroke="#cbd5e1" stroke-width="2" />
      
      
      <circle cx="340" cy="210" r="24" fill="#e2e8f0" />
      <text x="328" y="218" font-size="22">⚙️</text>
      
      
      <text x="340" y="260" class="title" fill="#1e2945" text-anchor="middle">Desalination</text>
      <text x="340" y="280" class="val-sub" fill="#64748b" text-anchor="middle">Separation</text>

      
      <line x1="300" y1="298" x2="380" y2="298" stroke="#94a3b8" stroke-width="2" stroke-dasharray="4 3" />
    </g>

    
    <g class="card">
      <rect x="475" y="65" width="180" height="140" rx="14" fill="url(#freshGrad)" stroke="#22d3ee" stroke-width="1.5" />
      <rect x="487" y="77" width="82" height="20" rx="6" fill="#cffafe" />
      <text x="494" y="91" class="badge" fill="#0e7490">POTABLE 🚰</text>
      
      <text x="487" y="119" class="title" fill="#164e63">Fresh Water</text>
      
      <text x="487" y="155" class="val-main" fill="#0891b2">~45 L</text>
      <text x="487" y="183" class="val-sub" fill="#0e7490">&lt; 0.5 g/L salt</text>
    </g>

    
    <g class="card">
      <rect x="475" y="275" width="180" height="140" rx="14" fill="url(#brineGrad)" stroke="#fb923c" stroke-width="1.5" />
      <rect x="487" y="287" width="70" height="20" rx="6" fill="#fed7aa" />
      <text x="494" y="301" class="badge" fill="#c2410c">WASTE 🌊</text>
      
      <text x="487" y="329" class="title" fill="#7c2d12">Brine</text>
      
      <text x="487" y="365" class="val-main" fill="#ea580c">~55 L</text>
      <text x="487" y="393" class="val-sub" fill="#c2410c">~65 g/L salt</text>
    </g>
  </svg>

</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>Global Water Distribution</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;
      gap: 10px;
    }
    
    .header {
      text-align: center;
    }
    .header h1 {
      font-size: 15px;
      font-weight: 700;
      color: #0f172a;
      letter-spacing: -0.2px;
    }
    .header p {
      font-size: 12px;
      color: #64748b;
    }

    .main-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      align-items: stretch;
    }

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

    .panel-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .panel-title {
      font-size: 12px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #475569;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    /* 10x10 Waffle Grid */
    .waffle-grid {
      display: grid;
      grid-template-columns: repeat(10, 1fr);
      gap: 2.5px;
      aspect-ratio: 1 / 1;
      width: 100%;
      max-width: 180px;
      margin: 0 auto;
    }

    .tile {
      border-radius: 2px;
      transition: opacity 0.25s ease, transform 0.2s ease, box-shadow 0.2s ease;
    }

    .tile.ocean { background-color: #1d4ed8; }
    .tile.glacier { background-color: #7dd3fc; }
    .tile.fresh {
      background-color: #06b6d4;
      animation: pulse-fresh 2s infinite ease-in-out;
      position: relative;
      z-index: 2;
    }

    @keyframes pulse-fresh {
      0%, 100% { box-shadow: 0 0 0 0 rgba(6, 182, 212, 0.7); }
      50% { box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.3); }
    }

    .tile.dimmed {
      opacity: 0.15;
    }

    /* Filter Buttons */
    .filters {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 4px;
    }

    .filter-btn {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 6px;
      padding: 4px 6px;
      font-size: 11px;
      font-weight: 600;
      color: #334155;
      display: flex;
      align-items: center;
      gap: 5px;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .filter-btn:hover {
      background: #f1f5f9;
      border-color: #cbd5e1;
    }

    .filter-btn.active {
      background: #0f172a;
      color: #ffffff;
      border-color: #0f172a;
    }

    .color-swatch {
      width: 8px;
      height: 8px;
      border-radius: 1.5px;
      flex-shrink: 0;
    }
    .swatch-all { background: linear-gradient(135deg, #1d4ed8 70%, #06b6d4 100%); }
    .swatch-ocean { background: #1d4ed8; }
    .swatch-glacier { background: #7dd3fc; }
    .swatch-fresh { background: #06b6d4; }

    /* Zoom Breakdown Panel */
    .zoom-container {
      display: flex;
      flex-direction: column;
      gap: 10px;
      height: 100%;
      justify-content: space-between;
    }

    .breakdown-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

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

    .bar-label {
      display: flex;
      justify-content: space-between;
      font-size: 11px;
      font-weight: 600;
      color: #334155;
    }

    .bar-track {
      height: 12px;
      background: #f1f5f9;
      border-radius: 3px;
      overflow: hidden;
      display: flex;
    }

    .bar-fill {
      height: 100%;
      transition: width 0.4s ease;
    }

    .callout {
      background: #f0fdf4;
      border: 1px solid #bbf7d0;
      border-radius: 6px;
      padding: 6px 8px;
      font-size: 11px;
      color: #166534;
      line-height: 1.35;
    }

    .desal-badge {
      background: #eff6ff;
      border: 1px solid #bfdbfe;
      border-radius: 6px;
      padding: 6px 8px;
      font-size: 11px;
      color: #1e40af;
      line-height: 1.35;
    }

    .desal-badge strong {
      display: block;
      color: #1d4ed8;
      margin-bottom: 2px;
    }
  </style>
</head>
<body>

  <div class="header">
    <h1>Global Water Distribution</h1>
    <p>100 tiles = 100% of Earth's total water</p>
  </div>

  <div class="main-grid">
    
    <div class="panel-card">
      <div class="panel-title">
        <span>Total Global Water</span>
        <span style="font-weight: 500; font-size: 11px;" id="status-label">All (100%)</span>
      </div>

      <div class="waffle-grid" id="grid" aria-label="100 blocks of total water"></div>

      <div class="filters">
        <button class="filter-btn active" data-filter="all">
          <span class="color-swatch swatch-all"></span> All (100%)
        </button>
        <button class="filter-btn" data-filter="ocean">
          <span class="color-swatch swatch-ocean"></span> Ocean (97%)
        </button>
        <button class="filter-btn" data-filter="glacier">
          <span class="color-swatch swatch-glacier"></span> Glaciers (2%)
        </button>
        <button class="filter-btn" data-filter="fresh">
          <span class="color-swatch swatch-fresh"></span> Fresh (&lt;1%)
        </button>
      </div>
    </div>

    
    <div class="panel-card">
      <div class="panel-title">
        <span>Inside that &lt;1% Fresh Water</span>
      </div>

      <div class="zoom-container">
        <div class="breakdown-group">
          <div class="bar-item">
            <div class="bar-label">
              <span>💧 Groundwater &amp; Aquifers</span>
              <span>~99%</span>
            </div>
            <div class="bar-track">
              <div class="bar-fill" style="width: 99%; background: #06b6d4;"></div>
            </div>
          </div>

          <div class="bar-item">
            <div class="bar-label">
              <span>🏞️ Surface Lakes</span>
              <span>~0.8%</span>
            </div>
            <div class="bar-track">
              <div class="bar-fill" style="width: 15%; background: #38bdf8;"></div>
            </div>
          </div>

          <div class="bar-item">
            <div class="bar-label">
              <span>🌊 Rivers &amp; Atmosphere</span>
              <span>~0.2%</span>
            </div>
            <div class="bar-track">
              <div class="bar-fill" style="width: 6%; background: #818cf8;"></div>
            </div>
          </div>
        </div>

        <div class="desal-badge">
          <strong>Why Desalination?</strong>
          97% of Earth's water is saline seawater. Arid coastal nations remove dissolved salts to manufacture potable fresh water.
        </div>
      </div>
    </div>
  </div>

  <script>
    const grid = document.getElementById('grid');
    const statusLabel = document.getElementById('status-label');
    const buttons = document.querySelectorAll('.filter-btn');

    // Build 100 tiles: 97 oceans, 2 glaciers, 1 accessible freshwater
    for (let i = 0; i < 100; i++) {
      const tile = document.createElement('div');
      tile.classList.add('tile');
      if (i < 97) {
        tile.classList.add('ocean');
      } else if (i < 99) {
        tile.classList.add('glacier');
      } else {
        tile.classList.add('fresh');
      }
      grid.appendChild(tile);
    }

    const tiles = document.querySelectorAll('.tile');

    buttons.forEach(btn => {
      btn.addEventListener('click', () => {
        buttons.forEach(b => b.classList.remove('active'));
        btn.classList.add('active');

        const filter = btn.dataset.filter;

        if (filter === 'all') {
          tiles.forEach(t => t.classList.remove('dimmed'));
          statusLabel.textContent = 'All (100%)';
        } else if (filter === 'ocean') {
          tiles.forEach(t => {
            if (t.classList.contains('ocean')) t.classList.remove('dimmed');
            else t.classList.add('dimmed');
          });
          statusLabel.textContent = 'Saline Ocean (97%)';
        } else if (filter === 'glacier') {
          tiles.forEach(t => {
            if (t.classList.contains('glacier')) t.classList.remove('dimmed');
            else t.classList.add('dimmed');
          });
          statusLabel.textContent = 'Frozen Glaciers (2%)';
        } else if (filter === 'fresh') {
          tiles.forEach(t => {
            if (t.classList.contains('fresh')) t.classList.remove('dimmed');
            else t.classList.add('dimmed');
          });
          statusLabel.textContent = 'Accessible Fresh (<1%)';
        }
      });
    });
  </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>Aquifer Depletion & Saltwater Intrusion</title>
  <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;
      padding: 8px;
      user-select: none;
    }

    .stepper {
      display: flex;
      gap: 8px;
      margin-bottom: 8px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .step-btn {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      color: #1e2945;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: background-color 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
    }

    .step-btn:hover {
      background: #e2e8f0;
    }

    .step-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0369a1;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.35);
    }

    .diagram-box {
      width: 100%;
      max-width: 600px;
      aspect-ratio: 4 / 3;
      position: relative;
    }

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

    /* Calmed and smoothed animations */
    .heat-wave {
      animation: rise 3s infinite ease-in-out;
    }
    .heat-wave-2 {
      animation: rise 3s infinite ease-in-out 1s;
    }
    @keyframes rise {
      0% { transform: translateY(0); opacity: 0.15; }
      50% { transform: translateY(-7px); opacity: 0.75; }
      100% { transform: translateY(-14px); opacity: 0; }
    }

    .pump-arrow {
      animation: flowUp 2.2s infinite linear;
    }
    @keyframes flowUp {
      0% { stroke-dashoffset: 24; }
      100% { stroke-dashoffset: 0; }
    }

    .water-transition {
      transition: all 0.75s cubic-bezier(0.4, 0, 0.2, 1);
    }

    .label-text {
      font-size: 12px;
      font-weight: 700;
      fill: #1e2945;
    }
    
    .label-sub {
      font-size: 10px;
      font-weight: 600;
      fill: #475569;
    }
  </style>
</head>
<body>

  
  <div class="stepper">
    <button class="step-btn active" id="btn1" onclick="setStage(1)">1. Natural Balance</button>
    <button class="step-btn" id="btn2" onclick="setStage(2)">2. Over-Pumping</button>
    <button class="step-btn" id="btn3" onclick="setStage(3)">3. Saltwater Intrusion</button>
  </div>

  <div class="diagram-box">
    <svg viewBox="0 0 600 450">
      <defs>
        
        <linearGradient id="skyGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#fed7aa" stop-opacity="0.6"/>
          <stop offset="100%" stop-color="#fffbeb" stop-opacity="0.2"/>
        </linearGradient>

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

        <linearGradient id="freshGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#38bdf8"/>
          <stop offset="100%" stop-color="#bae6fd"/>
        </linearGradient>

        <linearGradient id="saltWedgeGrad" x1="1" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#0369a1"/>
          <stop offset="100%" stop-color="#0284c7" stop-opacity="0.85"/>
        </linearGradient>

        
        <pattern id="soilPattern" width="20" height="20" patternUnits="userSpaceOnUse">
          <rect width="20" height="20" fill="#d7c4b7"/>
          <circle cx="4" cy="5" r="1.2" fill="#bfa090"/>
          <circle cx="15" cy="14" r="1.5" fill="#bfa090"/>
          <circle cx="12" cy="4" r="1" fill="#bfa090"/>
          <circle cx="5" cy="16" r="1" fill="#bfa090"/>
        </pattern>
      </defs>

      
      <rect x="0" y="0" width="600" height="180" fill="url(#skyGrad)"/>

      
      <g transform="translate(70, 45)">
        <circle cx="0" cy="0" r="22" fill="#f59e0b"/>
        <circle cx="0" cy="0" r="28" fill="#fcd34d" opacity="0.4"/>
        
        <path class="heat-wave" d="M 50,-10 Q 55,-20 50,-30 T 50,-45" fill="none" stroke="#f59e0b" stroke-width="2.5" stroke-linecap="round"/>
        <path class="heat-wave-2" d="M 70,-8 Q 75,-18 70,-28 T 70,-43" fill="none" stroke="#f59e0b" stroke-width="2.5" stroke-linecap="round"/>
        <path class="heat-wave" d="M 90,-10 Q 95,-20 90,-30 T 90,-45" fill="none" stroke="#f59e0b" stroke-width="2.5" stroke-linecap="round"/>
      </g>
      <text x="145" y="30" class="label-text">Evaporation ♨️</text>

      
      <g transform="translate(260, 40)" opacity="0.85">
        <path d="M 10,20 A 15,15 0 0,1 35,10 A 20,20 0 0,1 70,12 A 14,14 0 0,1 85,25 A 12,12 0 0,1 75,35 L 15,35 A 12,12 0 0,1 10,20 Z" fill="#cbd5e1"/>
        <text x="47" y="52" class="label-sub" text-anchor="middle">Zero Rain</text>
      </g>

      
      <rect x="0" y="390" width="600" height="60" fill="#94a3b8"/>
      <text x="240" y="425" fill="#ffffff" font-size="12" font-weight="700">Impermeable Rock</text>

      
      <rect x="0" y="160" width="480" height="230" fill="url(#soilPattern)"/>

      
      <path id="freshwater" class="water-transition" d="M 0,230 L 470,230 L 470,390 L 0,390 Z" fill="url(#freshGrad)"/>

      
      <path id="saltWedge" class="water-transition" d="M 470,330 Q 440,390 400,390 L 480,390 L 480,330 Z" fill="url(#saltWedgeGrad)"/>

      
      <path id="waterTableLine" class="water-transition" d="M 0,230 L 470,230" fill="none" stroke="#0284c7" stroke-width="3" stroke-dasharray="6,4"/>

      
      <path d="M 0,165 L 80,165 Q 110,185 140,165 L 430,165 Q 460,165 480,210 L 600,240 L 600,450 L 0,450 Z" fill="none" stroke="#78350f" stroke-width="3"/>

      
      <path d="M 85,166 Q 110,182 135,166" fill="#b45309" opacity="0.3"/>
      <text x="110" y="152" class="label-text" text-anchor="middle">Dry Riverbed</text>

      
      
      <rect x="220" y="145" width="22" height="18" fill="#e2e8f0" stroke="#475569" stroke-width="1.5"/>
      <polygon points="218,145 231,133 244,145" fill="#ea580c"/>
      
      <rect x="248" y="140" width="26" height="23" fill="#f8fafc" stroke="#475569" stroke-width="1.5"/>
      <polygon points="245,140 261,128 277,140" fill="#dc2626"/>

      
      <rect x="290" y="135" width="20" height="28" fill="#64748b" rx="2"/>
      <rect x="295" y="123" width="10" height="12" fill="#0284c7"/>
      <text x="300" y="115" class="label-text" text-anchor="middle">Well Pump</text>

      
      <rect x="297" y="163" width="6" height="170" fill="#334155"/>
      
      <line id="pumpFlow" x1="300" y1="330" x2="300" y2="165" stroke="#38bdf8" stroke-width="3" stroke-dasharray="6,6" class="pump-arrow"/>

      
      <path d="M 465,190 Q 480,210 500,218 L 600,240 L 600,390 L 480,390 L 465,190 Z" fill="url(#seaGrad)"/>
      
      <path d="M 470,195 Q 490,190 510,195 T 550,195 T 590,195" fill="none" stroke="#bae6fd" stroke-width="2"/>
      
      <text x="545" y="275" fill="#ffffff" font-size="14" font-weight="700" text-anchor="middle" letter-spacing="1">OCEAN</text>

      
      
      <g id="wtGroup" class="water-transition" transform="translate(20, 222)">
        <rect x="0" y="-14" width="100" height="20" fill="rgba(255,255,255,0.85)" rx="4"/>
        <text x="5" y="0" class="label-text" fill="#0284c7">Water Table</text>
      </g>

      
      <text id="freshLabel" x="70" y="320" class="label-text" fill="#0369a1">Freshwater Aquifer</text>

      
      <g id="intrusionAlert" class="water-transition" transform="translate(350, 340)" opacity="0">
        <rect x="0" y="-16" width="138" height="24" fill="#ef4444" rx="4"/>
        <text x="69" y="0" fill="#ffffff" font-size="11" font-weight="700" text-anchor="middle">Saltwater Intrusion ⚠️</text>
      </g>
      
      
      <circle id="wellIntakeStatus" cx="300" cy="333" r="7" fill="#22c55e" stroke="#ffffff" stroke-width="2" class="water-transition"/>
    </svg>
  </div>

  <script>
    let currentStage = 1;
    let autoTimer = null;

    function setStage(stage) {
      currentStage = stage;
      
      // Update buttons
      document.querySelectorAll('.step-btn').forEach((btn, idx) => {
        btn.classList.toggle('active', idx + 1 === stage);
      });

      const freshwater = document.getElementById('freshwater');
      const saltWedge = document.getElementById('saltWedge');
      const waterTableLine = document.getElementById('waterTableLine');
      const wtGroup = document.getElementById('wtGroup');
      const intrusionAlert = document.getElementById('intrusionAlert');
      const wellIntakeStatus = document.getElementById('wellIntakeStatus');
      const pumpFlow = document.getElementById('pumpFlow');

      if (stage === 1) {
        // High water table, natural state
        freshwater.setAttribute('d', 'M 0,225 L 470,225 L 470,390 L 0,390 Z');
        waterTableLine.setAttribute('d', 'M 0,225 L 470,225');
        wtGroup.setAttribute('transform', 'translate(20, 218)');
        saltWedge.setAttribute('d', 'M 470,350 Q 450,390 430,390 L 480,390 L 480,350 Z');
        intrusionAlert.style.opacity = '0';
        wellIntakeStatus.setAttribute('fill', '#22c55e'); // clean fresh
        pumpFlow.setAttribute('stroke', '#38bdf8');
      } else if (stage === 2) {
        // Lowering water table, cone of depression forming
        freshwater.setAttribute('d', 'M 0,265 Q 200,270 290,295 Q 380,270 470,260 L 470,390 L 0,390 Z');
        waterTableLine.setAttribute('d', 'M 0,265 Q 200,270 290,295 Q 380,270 470,260');
        wtGroup.setAttribute('transform', 'translate(20, 258)');
        saltWedge.setAttribute('d', 'M 470,290 Q 400,370 350,390 L 480,390 L 480,290 Z');
        intrusionAlert.style.opacity = '0.9';
        wellIntakeStatus.setAttribute('fill', '#eab308'); // warning
        pumpFlow.setAttribute('stroke', '#38bdf8');
      } else if (stage === 3) {
        // Severe depletion, saltwater reaches well intake
        freshwater.setAttribute('d', 'M 0,315 Q 180,320 290,345 Q 390,320 470,300 L 470,390 L 0,390 Z');
        waterTableLine.setAttribute('d', 'M 0,315 Q 180,320 290,345 Q 390,320 470,300');
        wtGroup.setAttribute('transform', 'translate(20, 308)');
        saltWedge.setAttribute('d', 'M 470,270 Q 360,320 285,350 L 480,390 L 480,270 Z');
        intrusionAlert.style.opacity = '1';
        wellIntakeStatus.setAttribute('fill', '#ef4444'); // contaminated with salt
        pumpFlow.setAttribute('stroke', '#0284c7'); // saline pumped up
      }
    }

    // Auto-advance loop with calm pacing
    function startLoop() {
      autoTimer = setInterval(() => {
        let next = currentStage >= 3 ? 1 : currentStage + 1;
        setStage(next);
      }, 4500);
    }

    // Pause auto loop on manual click, resume after delay
    document.querySelectorAll('.step-btn').forEach(btn => {
      btn.addEventListener('click', () => {
        clearInterval(autoTimer);
        startLoop();
      });
    });

    startLoop();
  </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: #1e293b;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      min-height: 100%;
    }

    /* Top Mode Selector */
    .controls {
      display: flex;
      justify-content: center;
      gap: 6px;
      background: #e2e8f0;
      padding: 4px;
      border-radius: 8px;
    }
    .tab-btn {
      flex: 1;
      max-width: 170px;
      padding: 8px 6px;
      border: none;
      background: transparent;
      font-size: 13px;
      font-weight: 600;
      color: #475569;
      border-radius: 6px;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 5px;
      transition: all 0.2s ease;
      white-space: nowrap;
    }
    .tab-btn.active {
      background: #ffffff;
      color: #0284c7;
      box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    }

    /* Grid Layout */
    .dashboard-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
      flex: 1;
    }
    @media (max-width: 580px) {
      .dashboard-grid {
        grid-template-columns: 1fr;
      }
    }

    /* Cards */
    .lab-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      position: relative;
      transition: border-color 0.2s, box-shadow 0.2s;
    }
    .lab-card.active {
      border-color: #0284c7;
      box-shadow: 0 0 0 2px rgba(2, 132, 199, 0.15);
    }

    .card-header {
      text-align: center;
    }
    .card-title {
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
    }
    .card-subtitle {
      font-size: 11px;
      color: #64748b;
      margin-bottom: 4px;
    }
    .badge {
      display: inline-block;
      font-size: 10px;
      font-weight: 700;
      padding: 2px 6px;
      border-radius: 4px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }
    .badge-danger { background: #fee2e2; color: #b91c1c; }
    .badge-safe { background: #dcfce7; color: #15803d; }
    .badge-pure { background: #e0f2fe; color: #0369a1; }

    /* Visual Zone */
    .visual-stage {
      height: 120px;
      background: #f1f5f9;
      border-radius: 8px;
      position: relative;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    /* Beaker View (Overview) */
    .beaker-view {
      position: relative;
      width: 70px;
      height: 90px;
      border: 3px solid #94a3b8;
      border-top: none;
      border-radius: 0 0 8px 8px;
      background: rgba(255, 255, 255, 0.5);
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
      padding: 4px;
    }
    .beaker-view::before {
      content: '';
      position: absolute;
      top: -3px;
      left: -8px;
      width: 8px;
      height: 3px;
      background: #94a3b8;
      border-radius: 2px 0 0 0;
    }
    .water-fill {
      width: 100%;
      height: 70%;
      border-radius: 0 0 5px 5px;
      position: relative;
      transition: all 0.3s ease;
    }
    .fresh-water { background: linear-gradient(180deg, rgba(56, 189, 248, 0.4) 0%, rgba(163, 230, 53, 0.3) 100%); }
    .potable-water { background: rgba(56, 189, 248, 0.5); }
    .pure-water { background: rgba(14, 165, 233, 0.6); }

    .sediment {
      position: absolute;
      bottom: 2px;
      left: 6px;
      right: 6px;
      height: 4px;
      background: #a16207;
      border-radius: 2px;
    }

    /* Particle View */
    .particle-chamber {
      width: 100px;
      height: 100px;
      border-radius: 50%;
      background: #ffffff;
      border: 3px solid #38bdf8;
      position: relative;
      overflow: hidden;
      box-shadow: inset 0 0 8px rgba(0,0,0,0.06);
    }
    .particle-item {
      position: absolute;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      font-weight: 700;
      font-size: 9px;
      transition: transform 0.5s ease;
    }
    .p-h2o {
      width: 16px;
      height: 16px;
      background: #bae6fd;
      border: 1.5px solid #0284c7;
      color: #0369a1;
      font-size: 8px;
    }
    .p-ion {
      width: 14px;
      height: 14px;
      background: #fef08a;
      border: 1.5px solid #ca8a04;
      color: #854d0e;
      font-size: 8px;
    }
    .p-microbe {
      width: 16px;
      height: 16px;
      background: #fbcfe8;
      border: 1.5px solid #db2777;
      color: #9d174d;
      border-radius: 3px;
      transform: rotate(45deg);
      font-size: 7px;
    }

    /* Evaporation View */
    .evap-view {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 6px;
      width: 100%;
    }
    .dish {
      width: 80px;
      height: 24px;
      border: 2.5px solid #64748b;
      border-top: none;
      border-radius: 0 0 50px 50px;
      background: #ffffff;
      position: relative;
      overflow: hidden;
    }
    .dish-residue {
      position: absolute;
      bottom: 2px;
      left: 15%;
      width: 70%;
      height: 6px;
      border-radius: 3px;
    }
    .res-brown { background: #b45309; }
    .res-white { background: #cbd5e1; border: 1px solid #94a3b8; }
    .dish-temp {
      font-size: 11px;
      font-weight: 700;
      color: #475569;
      background: #e2e8f0;
      padding: 2px 8px;
      border-radius: 12px;
    }

    /* Properties Table */
    .props-list {
      display: flex;
      flex-direction: column;
      gap: 4px;
      font-size: 11px;
    }
    .prop-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 3px 6px;
      background: #f8fafc;
      border-radius: 4px;
      border: 1px solid #f1f5f9;
    }
    .prop-name {
      color: #64748b;
      font-weight: 500;
    }
    .prop-val {
      font-weight: 700;
      color: #1e293b;
    }

    /* Legend */
    .legend {
      display: flex;
      justify-content: center;
      gap: 12px;
      flex-wrap: wrap;
      padding-top: 4px;
      border-top: 1px solid #e2e8f0;
    }
    .legend-item {
      display: flex;
      align-items: center;
      gap: 5px;
      font-size: 11px;
      font-weight: 600;
      color: #475569;
    }
    .legend-swatch {
      width: 12px;
      height: 12px;
      border-radius: 50%;
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="tab-btn active" id="tab-overview">👁️ Overview</button>
    <button class="tab-btn" id="tab-micro">🔬 Microscopic</button>
    <button class="tab-btn" id="tab-evap">🔥 Evaporation</button>
  </div>

  
  <div class="dashboard-grid">
    
    
    <div class="lab-card active" id="card-fresh">
      <div class="card-header">
        <div class="card-title">Fresh Water</div>
        <div class="card-subtitle">Lakes & Rivers</div>
        <span class="badge badge-danger">Untreated / Unsafe</span>
      </div>

      <div class="visual-stage" id="stage-fresh">
        
      </div>

      <div class="props-list">
        <div class="prop-row">
          <span class="prop-name">Classification</span>
          <span class="prop-val">Mixture</span>
        </div>
        <div class="prop-row">
          <span class="prop-name">Dissolved Ions</span>
          <span class="prop-val">High (Variable)</span>
        </div>
        <div class="prop-row">
          <span class="prop-name">Microbes</span>
          <span class="prop-val" style="color: #b91c1c;">Present ✗</span>
        </div>
      </div>
    </div>

    
    <div class="lab-card" id="card-potable">
      <div class="card-header">
        <div class="card-title">Potable Water</div>
        <div class="card-subtitle">Drinking / Tap Water</div>
        <span class="badge badge-safe">Safe Mixture</span>
      </div>

      <div class="visual-stage" id="stage-potable">
        
      </div>

      <div class="props-list">
        <div class="prop-row">
          <span class="prop-name">Classification</span>
          <span class="prop-val">Mixture</span>
        </div>
        <div class="prop-row">
          <span class="prop-name">Dissolved Ions</span>
          <span class="prop-val">Safe / Low</span>
        </div>
        <div class="prop-row">
          <span class="prop-name">Microbes</span>
          <span class="prop-val" style="color: #15803d;">None / Safe ✓</span>
        </div>
      </div>
    </div>

    
    <div class="lab-card" id="card-pure">
      <div class="card-header">
        <div class="card-title">Pure Water</div>
        <div class="card-subtitle">Distilled / Deionised</div>
        <span class="badge badge-pure">Single Compound</span>
      </div>

      <div class="visual-stage" id="stage-pure">
        
      </div>

      <div class="props-list">
        <div class="prop-row">
          <span class="prop-name">Classification</span>
          <span class="prop-val">Pure Substance</span>
        </div>
        <div class="prop-row">
          <span class="prop-name">Dissolved Ions</span>
          <span class="prop-val">Zero (0%)</span>
        </div>
        <div class="prop-row">
          <span class="prop-name">Microbes</span>
          <span class="prop-val" style="color: #0284c7;">Zero (0%)</span>
        </div>
      </div>
    </div>

  </div>

  
  <div class="legend">
    <div class="legend-item">
      <div class="legend-swatch" style="background: #bae6fd; border: 1.5px solid #0284c7;"></div>
      <span>H₂O</span>
    </div>
    <div class="legend-item">
      <div class="legend-swatch" style="background: #fef08a; border: 1.5px solid #ca8a04;"></div>
      <span>Ions (Na⁺/Ca²⁺)</span>
    </div>
    <div class="legend-item">
      <div class="legend-swatch" style="background: #fbcfe8; border: 1.5px solid #db2777; border-radius: 2px;"></div>
      <span>Microbes</span>
    </div>
  </div>

  <script>
    const state = {
      mode: 'overview' // 'overview' | 'micro' | 'evap'
    };

    const stages = {
      fresh: document.getElementById('stage-fresh'),
      potable: document.getElementById('stage-potable'),
      pure: document.getElementById('stage-pure')
    };

    function renderStage() {
      if (state.mode === 'overview') {
        stages.fresh.innerHTML = `
          <div class="beaker-view">
            <div class="water-fill fresh-water"></div>
            <div class="sediment"></div>
          </div>
        `;
        stages.potable.innerHTML = `
          <div class="beaker-view">
            <div class="water-fill potable-water"></div>
          </div>
        `;
        stages.pure.innerHTML = `
          <div class="beaker-view">
            <div class="water-fill pure-water"></div>
          </div>
        `;
      } else if (state.mode === 'micro') {
        stages.fresh.innerHTML = `
          <div class="particle-chamber">
            <div class="particle-item p-h2o" style="top:20%; left:25%;">H₂O</div>
            <div class="particle-item p-h2o" style="top:55%; left:65%;">H₂O</div>
            <div class="particle-item p-ion" style="top:60%; left:20%;">Na⁺</div>
            <div class="particle-item p-ion" style="top:25%; left:65%;">Ca²⁺</div>
            <div class="particle-item p-microbe" style="top:42%; left:42%;">🦠</div>
          </div>
        `;
        stages.potable.innerHTML = `
          <div class="particle-chamber">
            <div class="particle-item p-h2o" style="top:20%; left:30%;">H₂O</div>
            <div class="particle-item p-h2o" style="top:60%; left:30%;">H₂O</div>
            <div class="particle-item p-h2o" style="top:40%; left:65%;">H₂O</div>
            <div class="particle-item p-ion" style="top:25%; left:65%;">Na⁺</div>
          </div>
        `;
        stages.pure.innerHTML = `
          <div class="particle-chamber">
            <div class="particle-item p-h2o" style="top:20%; left:25%;">H₂O</div>
            <div class="particle-item p-h2o" style="top:55%; left:25%;">H₂O</div>
            <div class="particle-item p-h2o" style="top:25%; left:60%;">H₂O</div>
            <div class="particle-item p-h2o" style="top:60%; left:65%;">H₂O</div>
          </div>
        `;
      } else if (state.mode === 'evap') {
        stages.fresh.innerHTML = `
          <div class="evap-view">
            <div class="dish">
              <div class="dish-residue res-brown"></div>
            </div>
            <span class="dish-temp">Residue Left</span>
          </div>
        `;
        stages.potable.innerHTML = `
          <div class="evap-view">
            <div class="dish">
              <div class="dish-residue res-white"></div>
            </div>
            <span class="dish-temp">White Salt Ring</span>
          </div>
        `;
        stages.pure.innerHTML = `
          <div class="evap-view">
            <div class="dish"></div>
            <span class="dish-temp">0 Residue (100°C)</span>
          </div>
        `;
      }
    }

    // Tab buttons
    const tabs = {
      overview: document.getElementById('tab-overview'),
      micro: document.getElementById('tab-micro'),
      evap: document.getElementById('tab-evap')
    };

    function setMode(mode) {
      state.mode = mode;
      Object.keys(tabs).forEach(k => {
        tabs[k].classList.toggle('active', k === mode);
      });
      renderStage();
    }

    tabs.overview.addEventListener('click', () => setMode('overview'));
    tabs.micro.addEventListener('click', () => setMode('micro'));
    tabs.evap.addEventListener('click', () => setMode('evap'));

    // Card selection
    const cards = document.querySelectorAll('.lab-card');
    cards.forEach(card => {
      card.addEventListener('click', () => {
        cards.forEach(c => c.classList.remove('active'));
        card.classList.add('active');
      });
    });

    // Initial render
    renderStage();
  </script>
</body>
</html>

Defining Potable Water vs Chemically Pure Water

<!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: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px;
      user-select: none;
    }

    /* Controls */
    .controls {
      display: flex;
      gap: 8px;
      margin-bottom: 8px;
      z-index: 10;
    }
    .btn {
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
      border-radius: 20px;
      border: 1px solid #cbd5e1;
      background: #f8fafc;
      color: #475569;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .btn.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #2563eb;
      box-shadow: 0 2px 6px rgba(37,99,235,0.25);
    }

    /* Graphic Area */
    .diagram-svg {
      width: 100%;
      max-width: 600px;
      height: auto;
      display: block;
    }

    /* Animated states */
    .steam-line {
      stroke-dasharray: 6 6;
      animation: steamRise 2s linear infinite;
    }
    @keyframes steamRise {
      from { stroke-dashoffset: 24; }
      to { stroke-dashoffset: 0; }
    }

    .flame-core {
      animation: flamePulse 1.2s ease-in-out infinite alternate;
      transform-origin: center bottom;
    }
    @keyframes flamePulse {
      0% { transform: scale(0.95, 0.92); }
      100% { transform: scale(1.05, 1.08); }
    }

    /* Interactive state toggles */
    .state-heating, .state-dry {
      transition: opacity 0.4s ease, transform 0.4s ease;
    }
    body[data-state="heating"] .state-dry {
      opacity: 0;
      pointer-events: none;
    }
    body[data-state="dry"] .state-heating {
      opacity: 0;
      pointer-events: none;
    }
    body[data-state="dry"] .flame-group {
      opacity: 0.2;
    }
  </style>
</head>
<body data-state="heating">

  
  <div class="controls">
    <button class="btn active" id="btnHeating" onclick="setState('heating')">1. During Heating</button>
    <button class="btn" id="btnDry" onclick="setState('dry')">2. After Evaporation</button>
  </div>

  
  <svg class="diagram-svg" viewBox="0 0 600 400" fill="none" xmlns="http://www.w3.org/2000/svg">
    
    
    <line x1="300" y1="20" x2="300" y2="380" stroke="#f1f5f9" stroke-width="2" stroke-dasharray="6 6"/>

    
    <g transform="translate(0, 0)">
      
      <rect x="25" y="10" width="250" height="32" rx="16" fill="#f8fafc" stroke="#e2e8f0"/>
      <text x="150" y="31" font-size="14" font-weight="700" fill="#0f172a" text-anchor="middle">Tap Water (Potable)</text>

      
      <g transform="translate(60, 52)">
        <rect width="180" height="30" rx="6" fill="#fffbeb" stroke="#fef3c7"/>
        <circle cx="16" cy="15" r="5" fill="#d97706"/>
        <text x="30" y="20" font-size="13" font-weight="700" fill="#92400e">>100°C (Boiling range)</text>
      </g>

      
      <g stroke="#94a3b8" stroke-width="3" stroke-linecap="round">
        <line x1="150" y1="90" x2="150" y2="185"/>
        <circle cx="150" cy="188" r="6" fill="#ef4444" stroke="#ef4444"/>
        <line x1="150" y1="130" x2="150" y2="185" stroke="#ef4444" stroke-width="2"/>
      </g>

      
      <g class="state-heating" stroke="#93c5fd" stroke-width="2" stroke-linecap="round" fill="none">
        <path d="M 120,150 Q 115,135 125,120 T 120,95" class="steam-line"/>
        <path d="M 150,145 Q 145,130 155,115 T 150,90" class="steam-line" style="animation-delay: -0.6s"/>
        <path d="M 180,150 Q 175,135 185,120 T 180,95" class="steam-line" style="animation-delay: -1.2s"/>
      </g>

      
      <path d="M 90 170 C 90 220, 210 220, 210 170 Z" fill="#ffffff" stroke="#64748b" stroke-width="3"/>

      
      <path class="state-heating" d="M 98 180 C 105 212, 195 212, 202 180 Z" fill="#38bdf8" fill-opacity="0.45"/>

      
      
      <g class="state-heating" fill="#b45309">
        <circle cx="130" cy="195" r="2.5"/>
        <circle cx="145" cy="202" r="2"/>
        <circle cx="160" cy="192" r="3"/>
        <circle cx="172" cy="200" r="2.5"/>
        <circle cx="138" cy="188" r="2"/>
      </g>

      
      <g class="state-dry">
        
        <path d="M 115 208 C 130 216, 170 216, 185 208 C 175 212, 125 212, 115 208 Z" fill="#d97706" stroke="#b45309" stroke-width="1"/>
        <circle cx="132" cy="209" r="3" fill="#f59e0b"/>
        <circle cx="145" cy="211" r="3.5" fill="#f59e0b"/>
        <circle cx="158" cy="210" r="3" fill="#f59e0b"/>
        <circle cx="168" cy="208" r="2.5" fill="#f59e0b"/>
        <circle cx="124" cy="207" r="2" fill="#fbbf24"/>
        
        
        <rect x="45" y="115" width="210" height="28" rx="6" fill="#fef2f2" stroke="#fecaca"/>
        <text x="150" y="134" font-size="12" font-weight="700" fill="#b91c1c" text-anchor="middle">Solid mineral residue (salts)</text>
      </g>

      
      <line x1="85" y1="210" x2="215" y2="210" stroke="#475569" stroke-width="4" stroke-linecap="round"/>
      <line x1="85" y1="210" x2="60" y2="340" stroke="#64748b" stroke-width="3" stroke-linecap="round"/>
      <line x1="215" y1="210" x2="240" y2="340" stroke="#64748b" stroke-width="3" stroke-linecap="round"/>
      <line x1="150" y1="210" x2="150" y2="335" stroke="#94a3b8" stroke-width="2" stroke-linecap="round"/>

      
      <g class="flame-group" transform="translate(150, 210)">
        
        <path class="flame-core" d="M -16 0 C -16 -40, 0 -60, 0 -60 C 0 -60, 16 -40, 16 0 Z" fill="#60a5fa" fill-opacity="0.75"/>
        
        <path class="flame-core" d="M -9 0 C -9 -25, 0 -42, 0 -42 C 0 -42, 9 -25, 9 0 Z" fill="#38bdf8"/>
        
        <rect x="-8" y="0" width="16" height="85" fill="#64748b"/>
        <rect x="-10" y="20" width="20" height="12" fill="#94a3b8"/>
        
        <rect x="-35" y="85" width="70" height="12" rx="3" fill="#334155"/>
      </g>
    </g>

    
    <g transform="translate(300, 0)">
      
      <rect x="25" y="10" width="250" height="32" rx="16" fill="#f8fafc" stroke="#e2e8f0"/>
      <text x="150" y="31" font-size="14" font-weight="700" fill="#0f172a" text-anchor="middle">Pure Water (Distilled)</text>

      
      <g transform="translate(60, 52)">
        <rect width="180" height="30" rx="6" fill="#ecfdf5" stroke="#d1fae5"/>
        <circle cx="16" cy="15" r="5" fill="#059669"/>
        <text x="30" y="20" font-size="13" font-weight="700" fill="#065f46">100.0°C (Sharp / Exact)</text>
      </g>

      
      <g stroke="#94a3b8" stroke-width="3" stroke-linecap="round">
        <line x1="150" y1="90" x2="150" y2="185"/>
        <circle cx="150" cy="188" r="6" fill="#ef4444" stroke="#ef4444"/>
        <line x1="150" y1="130" x2="150" y2="185" stroke="#ef4444" stroke-width="2"/>
      </g>

      
      <g class="state-heating" stroke="#93c5fd" stroke-width="2" stroke-linecap="round" fill="none">
        <path d="M 120,150 Q 115,135 125,120 T 120,95" class="steam-line"/>
        <path d="M 150,145 Q 145,130 155,115 T 150,90" class="steam-line" style="animation-delay: -0.6s"/>
        <path d="M 180,150 Q 175,135 185,120 T 180,95" class="steam-line" style="animation-delay: -1.2s"/>
      </g>

      
      <path d="M 90 170 C 90 220, 210 220, 210 170 Z" fill="#ffffff" stroke="#64748b" stroke-width="3"/>

      
      <path class="state-heating" d="M 98 180 C 105 212, 195 212, 202 180 Z" fill="#38bdf8" fill-opacity="0.45"/>

      
      <g class="state-dry">
        
        <path d="M 150 195 Q 150 205 160 205 Q 150 205 150 215 Q 150 205 140 205 Q 150 205 150 195 Z" fill="#0284c7"/>
        <path d="M 130 188 Q 130 193 135 193 Q 130 193 130 198 Q 130 193 125 193 Q 130 193 130 188 Z" fill="#38bdf8"/>
        
        
        <rect x="50" y="115" width="200" height="28" rx="6" fill="#f0fdf4" stroke="#bbf7d0"/>
        <text x="150" y="134" font-size="12" font-weight="700" fill="#15803d" text-anchor="middle">Zero residue (Clean basin)</text>
      </g>

      
      <line x1="85" y1="210" x2="215" y2="210" stroke="#475569" stroke-width="4" stroke-linecap="round"/>
      <line x1="85" y1="210" x2="60" y2="340" stroke="#64748b" stroke-width="3" stroke-linecap="round"/>
      <line x1="215" y1="210" x2="240" y2="340" stroke="#64748b" stroke-width="3" stroke-linecap="round"/>
      <line x1="150" y1="210" x2="150" y2="335" stroke="#94a3b8" stroke-width="2" stroke-linecap="round"/>

      
      <g class="flame-group" transform="translate(150, 210)">
        
        <path class="flame-core" d="M -16 0 C -16 -40, 0 -60, 0 -60 C 0 -60, 16 -40, 16 0 Z" fill="#60a5fa" fill-opacity="0.75"/>
        
        <path class="flame-core" d="M -9 0 C -9 -25, 0 -42, 0 -42 C 0 -42, 9 -25, 9 0 Z" fill="#38bdf8"/>
        
        <rect x="-8" y="0" width="16" height="85" fill="#64748b"/>
        <rect x="-10" y="20" width="20" height="12" fill="#94a3b8"/>
        
        <rect x="-35" y="85" width="70" height="12" rx="3" fill="#334155"/>
      </g>
    </g>

    
    <line x1="20" y1="340" x2="580" y2="340" stroke="#334155" stroke-width="3" stroke-linecap="round"/>
    <rect x="20" y="342" width="560" height="12" fill="#f1f5f9"/>
  </svg>

  <script>
    function setState(state) {
      document.body.setAttribute('data-state', state);
      document.getElementById('btnHeating').classList.toggle('active', state === 'heating');
      document.getElementById('btnDry').classList.toggle('active', state === 'dry');
    }

    // Auto-cycle gently every 4.5 seconds for passive learners
    let autoCycle = setInterval(() => {
      const current = document.body.getAttribute('data-state');
      setState(current === 'heating' ? 'dry' : 'heating');
    }, 4500);

    // Stop auto-cycling once user interacts
    document.querySelectorAll('.btn').forEach(btn => {
      btn.addEventListener('click', () => clearInterval(autoCycle), { once: true });
    });
  </script>
</body>
</html>

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

    body {
      background: #f8fafc;
      color: #1e293b;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
      width: 100%;
    }

    @media (max-width: 480px) {
      .comparison-grid {
        grid-template-columns: 1fr;
      }
    }

    .panel {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .panel-header {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
      border-bottom: 1px solid #f1f5f9;
      padding-bottom: 6px;
    }

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

    .panel-badge {
      font-size: 11px;
      font-weight: 600;
      padding: 2px 6px;
      border-radius: 4px;
      background: #f1f5f9;
      color: #475569;
    }

    .pure-badge {
      background: #eff6ff;
      color: #2563eb;
    }

    .potable-badge {
      background: #ecfdf5;
      color: #059669;
    }

    .svg-container {
      width: 100%;
      height: 180px;
      background: #f8fafc;
      border-radius: 8px;
      border: 1px solid #f1f5f9;
      overflow: hidden;
    }

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

    .stats-list {
      display: grid;
      grid-template-columns: 1fr;
      gap: 4px;
      font-size: 12px;
    }

    .stat-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 3px 6px;
      background: #f8fafc;
      border-radius: 5px;
    }

    .stat-label {
      color: #64748b;
    }

    .stat-value {
      font-weight: 700;
      color: #1e293b;
    }

    .ion-legend {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 6px;
      padding: 6px 8px;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
    }

    .legend-item {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      font-size: 11px;
      font-weight: 600;
      color: #334155;
      padding: 2px 6px;
      border-radius: 4px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      cursor: pointer;
      user-select: none;
      transition: opacity 0.2s, background-color 0.2s;
    }

    .legend-item:hover {
      background: #f1f5f9;
    }

    .legend-item.active {
      background: #e2e8f0;
      border-color: #cbd5e1;
    }

    .dot-key {
      width: 8px;
      height: 8px;
      border-radius: 50%;
      display: inline-block;
    }

    .h2o-mol {
      transition: opacity 0.3s ease;
    }

    .ion-mol {
      transition: transform 0.3s ease, opacity 0.3s ease;
    }
  </style>
</head>
<body>

  <div class="comparison-grid">
    
    <div class="panel">
      <div class="panel-header">
        <span class="panel-title">Pure Water</span>
        <span class="panel-badge pure-badge">Single Substance</span>
      </div>

      <div class="svg-container">
        <svg viewBox="0 0 200 160" id="pureSvg">
          
          <g class="h2o-mol" transform="translate(35, 30)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>
          <g class="h2o-mol" transform="translate(100, 30)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>
          <g class="h2o-mol" transform="translate(165, 30)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>

          <g class="h2o-mol" transform="translate(68, 80)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>
          <g class="h2o-mol" transform="translate(133, 80)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>

          <g class="h2o-mol" transform="translate(35, 130)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>
          <g class="h2o-mol" transform="translate(100, 130)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>
          <g class="h2o-mol" transform="translate(165, 130)">
            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
          </g>
        </svg>
      </div>

      <div class="stats-list">
        <div class="stat-row">
          <span class="stat-label">Composition</span>
          <span class="stat-value">100% H₂O</span>
        </div>
        <div class="stat-row">
          <span class="stat-label">Boiling Point</span>
          <span class="stat-value">100.0°C</span>
        </div>
        <div class="stat-row">
          <span class="stat-label">Dissolved Solids</span>
          <span class="stat-value">0 mg/L</span>
        </div>
      </div>
    </div>

    
    <div class="panel">
      <div class="panel-header">
        <span class="panel-title">Potable Water</span>
        <span class="panel-badge potable-badge">Safe Mixture</span>
      </div>

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            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
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            <circle cx="-5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
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            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
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            <circle cx="5" cy="-5" r="4.5" fill="#93c5fd" stroke="#1d4ed8" stroke-width="1"/>
            <circle cx="0" cy="2" r="8" fill="#2563eb"/>
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      </div>

      <div class="stats-list">
        <div class="stat-row">
          <span class="stat-label">Composition</span>
          <span class="stat-value">H₂O + Minerals</span>
        </div>
        <div class="stat-row">
          <span class="stat-label">Boiling Point</span>
          <span class="stat-value">~100.2°C</span>
        </div>
        <div class="stat-row">
          <span class="stat-label">Dissolved Solids</span>
          <span class="stat-value">&lt; 500 mg/L</span>
        </div>
      </div>
    </div>
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    <div class="legend-item" data-filter="ca"><span class="dot-key" style="background:#ea580c"></span>Ca²⁺</div>
    <div class="legend-item" data-filter="mg"><span class="dot-key" style="background:#9333ea"></span>Mg²⁺</div>
    <div class="legend-item" data-filter="o2"><span class="dot-key" style="background:#06b6d4"></span>O₂</div>
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UK-GCSE-SCIENCE-CHEM-EA-04

Child standards (1)

Aligned learning resources

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