<!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>Tundra Biome Cross-Section</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      -webkit-tap-highlight-color: transparent;
    }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: #ffffff;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 10px;
      user-select: none;
    }
    .diagram-wrap {
      width: 100%;
      max-width: 580px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .btn-group {
      display: flex;
      gap: 6px;
      width: 100%;
      justify-content: center;
    }
    .nav-btn {
      flex: 1;
      padding: 8px 6px;
      font-size: 13px;
      font-weight: 700;
      border: 1.5px solid #cbd5e1;
      border-radius: 8px;
      background: #f8fafc;
      color: #64748b;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      transition: all 0.25s ease;
    }
    .nav-btn.active {
      border-color: #0284c7;
      background: #e0f2fe;
      color: #0369a1;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.15);
    }
    .svg-container {
      width: 100%;
      position: relative;
      border-radius: 12px;
      overflow: hidden;
      box-shadow: 0 1px 3px rgba(0,0,0,0.08);
      border: 1px solid #e2e8f0;
      background: #f0f9ff;
    }
    svg {
      display: block;
      width: 100%;
      height: auto;
    }
    .info-banner {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 8px 12px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 13px;
      font-weight: 600;
      color: #1e2945;
      min-height: 40px;
    }
    .highlight-badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      background: #0284c7;
      color: #ffffff;
      padding: 2px 8px;
      border-radius: 12px;
      font-size: 12px;
    }
    /* Transitions & Focus Indicators */
    .focus-ring {
      transition: opacity 0.3s ease, stroke 0.3s ease;
      pointer-events: none;
    }
    .clickable-zone {
      cursor: pointer;
    }
  </style>
</head>
<body>

<div class="diagram-wrap">
  
  <div class="btn-group">
    <button class="nav-btn active" id="btn-0" onclick="setFocus(0)">
      <span>🐇</span> 1. Adaptations
    </button>
    <button class="nav-btn" id="btn-1" onclick="setFocus(1)">
      <span>🌱</span> 2. Active Layer
    </button>
    <button class="nav-btn" id="btn-2" onclick="setFocus(2)">
      <span>🧊</span> 3. Permafrost
    </button>
  </div>

  
  <div class="svg-container">
    <svg viewBox="0 0 540 380" xmlns="http://www.w3.org/2000/svg">
      <defs>
        
        <linearGradient id="skyGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#bae6fd" />
          <stop offset="60%" stop-color="#e0f2fe" />
          <stop offset="100%" stop-color="#f8fafc" />
        </linearGradient>

        
        <linearGradient id="activeSoil" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#78350f" />
          <stop offset="100%" stop-color="#92400e" />
        </linearGradient>

        
        <linearGradient id="permafrostGrad" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stop-color="#0284c7" />
          <stop offset="40%" stop-color="#0369a1" />
          <stop offset="100%" stop-color="#075985" />
        </linearGradient>

        
        <pattern id="icePattern" width="40" height="40" patternUnits="userSpaceOnUse">
          <path d="M0 20 L20 0 L40 20 L20 40 Z" fill="none" stroke="#38bdf8" stroke-width="1.2" opacity="0.35" />
          <path d="M10 10 L30 30 M30 10 L10 30" stroke="#7dd3fc" stroke-width="1" opacity="0.4" />
          <circle cx="20" cy="20" r="1.5" fill="#ffffff" opacity="0.6" />
        </pattern>
      </defs>

      
      <rect x="0" y="0" width="540" height="150" fill="url(#skyGrad)" />
      
      
      <path d="M 20 28 Q 70 20 120 28" fill="none" stroke="#38bdf8" stroke-width="2" stroke-dasharray="6 4" opacity="0.6" />
      <path d="M 400 22 Q 450 30 500 22" fill="none" stroke="#38bdf8" stroke-width="2" stroke-dasharray="6 4" opacity="0.6" />
      <text x="70" y="18" fill="#0284c7" font-size="11" font-weight="700" text-anchor="middle">EXTREME COLD &amp; DRY</text>

      
      <polygon points="0,150 70,120 150,140 260,115 380,145 470,125 540,150" fill="#cbd5e1" opacity="0.5" />
      <polygon points="50,150 140,130 220,150 340,132 430,150" fill="#94a3b8" opacity="0.4" />

      
      
      <path d="M 0 150 Q 135 147 270 150 T 540 150 L 540 155 L 0 155 Z" fill="#65a30d" />
      <ellipse cx="140" cy="149" rx="35" ry="3" fill="#84cc16" />
      <ellipse cx="380" cy="149" rx="45" ry="3" fill="#a3e635" />

      
      <g id="surface-group" class="clickable-zone" onclick="setFocus(0)">
        
        <g transform="translate(85, 96)">
          <ellipse cx="25" cy="38" rx="18" ry="14" fill="#ffffff" stroke="#94a3b8" stroke-width="1.5" />
          <ellipse cx="14" cy="24" rx="10" ry="10" fill="#ffffff" stroke="#94a3b8" stroke-width="1.5" />
          
          <ellipse cx="25" cy="38" rx="14" ry="10" fill="#e2e8f0" opacity="0.5" />
          <ellipse cx="8" cy="10" rx="3" ry="9" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2" transform="rotate(-15 8 10)" />
          <ellipse cx="15" cy="9" rx="3" ry="9" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2" transform="rotate(10 15 9)" />
          <circle cx="11" cy="23" r="1.5" fill="#1e2945" />
          <ellipse cx="38" cy="42" rx="4" ry="4" fill="#ffffff" stroke="#94a3b8" stroke-width="1" />
        </g>
        <text x="110" y="85" fill="#1e2945" font-size="12" font-weight="700" text-anchor="middle">Arctic Hare</text>
        <text x="110" y="97" fill="#64748b" font-size="10" text-anchor="middle">Thick Fur &amp; Blubber</text>

        
        <g transform="translate(340, 105)">
          
          <path d="M 40 45 Q 35 30 20 25 M 40 45 Q 45 25 55 18 M 40 45 Q 55 35 65 30" fill="none" stroke="#451a03" stroke-width="3" stroke-linecap="round" />
          
          <circle cx="18" cy="23" r="5" fill="#4d7c0f" />
          <circle cx="56" cy="16" r="5.5" fill="#65a30d" />
          <circle cx="67" cy="28" r="5" fill="#4d7c0f" />
          <circle cx="34" cy="22" r="4.5" fill="#3f6212" />
        </g>

        
        <g transform="translate(235, 140)">
          <path d="M 0 10 Q 5 0 12 6 Q 20 -2 26 8 Q 32 2 36 10 Z" fill="#d97706" opacity="0.9" />
        </g>
        <text x="252" y="134" fill="#1e2945" font-size="11" font-weight="700" text-anchor="middle">Lichens</text>
        <text x="390" y="98" fill="#1e2945" font-size="12" font-weight="700" text-anchor="middle">Dwarf Shrubs</text>
        <text x="390" y="110" fill="#64748b" font-size="10" text-anchor="middle">Low to avoid winds</text>
      </g>

      
      <g id="active-group" class="clickable-zone" onclick="setFocus(1)">
        <rect x="0" y="152" width="540" height="68" fill="url(#activeSoil)" />
        
        
        <circle cx="45" cy="180" r="1.5" fill="#b45309" opacity="0.6" />
        <circle cx="180" cy="195" r="2" fill="#78350f" opacity="0.8" />
        <circle cx="310" cy="170" r="1.5" fill="#b45309" opacity="0.6" />
        <circle cx="480" cy="190" r="2" fill="#78350f" opacity="0.8" />

        
        <g stroke="#fde68a" stroke-linecap="round" opacity="0.95">
          
          <path d="M 245 152 Q 242 162 235 168 M 255 152 Q 260 164 270 170" stroke-width="1.5" fill="none" />
          
          <path d="M 380 152 Q 380 175 360 195 Q 330 205 290 208" stroke-width="2.5" fill="none" />
          <path d="M 380 152 Q 395 180 430 200 Q 470 208 510 210" stroke-width="2.5" fill="none" />
          <path d="M 380 175 Q 405 190 415 210" stroke-width="1.8" fill="none" />
          <path d="M 360 195 Q 345 208 320 212" stroke-width="1.5" fill="none" />
          
          <line x1="285" y1="214" x2="515" y2="214" stroke="#ef4444" stroke-width="1.5" stroke-dasharray="3 3" />
        </g>

        
        <rect x="14" y="162" width="168" height="48" rx="6" fill="#1e2945" opacity="0.85" />
        <text x="98" y="180" fill="#38bdf8" font-size="12" font-weight="700" text-anchor="middle">ACTIVE LAYER</text>
        <text x="98" y="194" fill="#ffffff" font-size="10" text-anchor="middle">Thaws in Summer (~30 cm)</text>
        <text x="98" y="204" fill="#fde68a" font-size="9" font-weight="700" text-anchor="middle">Shallow Roots Only</text>

        
        <path d="M 525 152 L 532 152 L 532 186 L 536 186 L 532 186 L 532 220 L 525 220" fill="none" stroke="#ffffff" stroke-width="2" />
        <text x="508" y="190" fill="#ffffff" font-size="10" font-weight="700" text-anchor="middle">30cm</text>
      </g>

      
      <g id="permafrost-group" class="clickable-zone" onclick="setFocus(2)">
        <rect x="0" y="220" width="540" height="160" fill="url(#permafrostGrad)" />
        <rect x="0" y="220" width="540" height="160" fill="url(#icePattern)" />

        
        <polygon points="120,220 140,290 160,220" fill="#bae6fd" opacity="0.75" />
        <polygon points="132,220 140,270 148,220" fill="#ffffff" opacity="0.9" />

        <polygon points="420,220 445,310 470,220" fill="#bae6fd" opacity="0.75" />
        <polygon points="438,220 445,285 452,220" fill="#ffffff" opacity="0.9" />

        
        <line x1="0" y1="220" x2="540" y2="220" stroke="#38bdf8" stroke-width="3" />

        
        <rect x="140" y="270" width="260" height="58" rx="8" fill="#0f172a" opacity="0.9" stroke="#38bdf8" stroke-width="1.5" />
        <text x="270" y="292" fill="#38bdf8" font-size="14" font-weight="800" text-anchor="middle">PERMAFROST</text>
        <text x="270" y="307" fill="#f8fafc" font-size="11" text-anchor="middle">Permanently Frozen Soil &amp; Ice</text>
        <text x="270" y="320" fill="#94a3b8" font-size="10" text-anchor="middle">Prevents Deep Root Growth</text>
      </g>

      
      <rect id="ring-0" class="focus-ring" x="6" y="70" width="528" height="78" rx="8" fill="none" stroke="#0284c7" stroke-width="3" opacity="1" />
      <rect id="ring-1" class="focus-ring" x="4" y="150" width="532" height="68" rx="4" fill="none" stroke="#0284c7" stroke-width="3" opacity="0" />
      <rect id="ring-2" class="focus-ring" x="4" y="220" width="532" height="156" rx="4" fill="none" stroke="#0284c7" stroke-width="3" opacity="0" />
    </svg>
  </div>

  
  <div class="info-banner" id="info-text">
    <span><strong>1. Adaptations:</strong> Thick fur & blubber insulate against extreme cold and dry winds.</span>
    <span class="highlight-badge">Step 1/3</span>
  </div>
</div>

<script>
  const infoData = [
    {
      title: "1. Adaptations",
      desc: "Thick fur & blubber insulate; low shrubs resist fierce winds.",
      badge: "Surface"
    },
    {
      title: "2. Active Layer",
      desc: "Thin topsoil (~30 cm) thaws in summer, hosting shallow root networks.",
      badge: "Thaw Zone"
    },
    {
      title: "3. Permafrost",
      desc: "Impenetrable frozen ground blocks deep roots and water drainage.",
      badge: "Frozen Block"
    }
  ];

  let currentStep = 0;

  function setFocus(index) {
    currentStep = index;
    for (let i = 0; i < 3; i++) {
      const btn = document.getElementById(`btn-${i}`);
      const ring = document.getElementById(`ring-${i}`);
      if (i === index) {
        btn.classList.add('active');
        ring.style.opacity = '1';
      } else {
        btn.classList.remove('active');
        ring.style.opacity = '0';
      }
    }

    const item = infoData[index];
    document.getElementById('info-text').innerHTML = `
      <span><strong>${item.title}:</strong> ${item.desc}</span>
      <span class="highlight-badge">${item.badge}</span>
    `;
  }
</script>

</body>
</html>

Major Terrestrial and Aquatic Biomes

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Rainforest Layers</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    html, body {
      width: 100%;
      height: 100%;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: transparent;
      color: #0f172a;
      user-select: none;
      -webkit-user-select: none;
      overflow: hidden;
    }

    .diagram {
      display: flex;
      flex-direction: column;
      width: 100%;
      max-width: 100%;
      height: 100%;
      max-height: 560px;
      gap: 6px;
      padding: 4px;
      box-sizing: border-box;
      overflow: hidden;
    }

    .main-view {
      display: flex;
      flex: 1;
      gap: 6px;
      min-height: 0;
      min-width: 0;
      width: 100%;
    }

    /* Sunlight Meter Indicator */
    .sunlight-meter {
      width: 48px;
      flex-shrink: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 5px 2px;
      box-sizing: border-box;
    }

    .light-header {
      font-size: 9px;
      font-weight: 800;
      text-transform: uppercase;
      letter-spacing: 0.2px;
      color: #334155;
      text-align: center;
      line-height: 1.1;
      margin-bottom: 4px;
    }

    .light-scale-wrap {
      flex: 1;
      width: 100%;
      display: flex;
      align-items: stretch;
      justify-content: center;
      gap: 4px;
      padding: 2px 0;
      min-height: 0;
    }

    .light-track {
      width: 7px;
      border-radius: 4px;
      background: linear-gradient(to bottom, 
        #facc15 0%, 
        #eab308 25%, 
        #15803d 50%, 
        #093818 75%, 
        #09090b 100%
      );
      box-shadow: inset 0 0 2px rgba(0,0,0,0.25);
    }

    .light-labels {
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      align-items: flex-start;
      padding: 1px 0;
    }

    .light-val {
      font-size: 9px;
      font-weight: 800;
      color: #1e293b;
      line-height: 1;
    }

    /* Rainforest Layers Stack */
    .layers-container {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 5px;
      min-height: 0;
      min-width: 0;
    }

    .layer {
      flex: 1;
      border-radius: 8px;
      position: relative;
      display: flex;
      flex-direction: column;
      justify-content: center;
      padding: 6px 10px;
      cursor: pointer;
      border: 2px solid transparent;
      box-shadow: 0 1px 3px rgba(0,0,0,0.08);
      transition: flex 0.25s ease, opacity 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
      overflow: hidden;
      min-width: 0;
      box-sizing: border-box;
    }

    .layer:hover {
      box-shadow: 0 3px 8px rgba(0,0,0,0.18);
    }

    .layer.dimmed {
      opacity: 0.35;
    }

    .layer.active {
      flex: 2;
      opacity: 1;
      border-color: #38bdf8;
      box-shadow: 0 4px 12px rgba(0,0,0,0.22);
    }

    /* Layer Themes & High-Contrast Colors */
    .layer-emergent {
      background: linear-gradient(135deg, #bae6fd 0%, #7dd3fc 45%, #38bdf8 100%);
      color: #082f49;
    }
    .layer-emergent .badge {
      background: rgba(8, 47, 73, 0.12);
      color: #082f49;
    }

    .layer-canopy {
      background: linear-gradient(135deg, #16a34a 0%, #15803d 70%, #166534 100%);
      color: #ffffff;
    }
    .layer-canopy .badge {
      background: rgba(255, 255, 255, 0.2);
      color: #ffffff;
    }

    .layer-understory {
      background: linear-gradient(135deg, #166534 0%, #14532d 65%, #064e3b 100%);
      color: #ecfdf5;
    }
    .layer-understory .badge {
      background: rgba(255, 255, 255, 0.16);
      color: #ecfdf5;
    }

    .layer-floor {
      background: linear-gradient(135deg, #3f3f46 0%, #27272a 65%, #18181b 100%);
      color: #fafaf9;
    }
    .layer-floor .badge {
      background: rgba(255, 255, 255, 0.16);
      color: #fafaf9;
    }

    /* Layer Content Structure */
    .layer-header-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 4px;
      min-width: 0;
    }

    .layer-title-group {
      display: flex;
      align-items: center;
      gap: 4px;
      flex-wrap: wrap;
      min-width: 0;
    }

    .layer-name {
      font-size: 12px;
      font-weight: 800;
      letter-spacing: -0.2px;
      white-space: nowrap;
    }

    .badge {
      font-size: 9px;
      font-weight: 700;
      padding: 1px 5px;
      border-radius: 10px;
      white-space: nowrap;
    }

    .layer-icons {
      font-size: 14px;
      display: flex;
      gap: 2px;
      align-items: center;
      flex-shrink: 0;
      line-height: 1;
    }

    .layer-summary {
      font-size: 10.5px;
      font-weight: 500;
      opacity: 0.95;
      margin-top: 2px;
      white-space: nowrap;
      overflow: hidden;
      text-overflow: ellipsis;
      min-width: 0;
    }

    .layer-details {
      display: none;
      font-size: 10px;
      line-height: 1.3;
      margin-top: 3px;
      padding-top: 3px;
      border-top: 1px solid rgba(255,255,255,0.2);
      overflow-y: auto;
    }

    .layer-emergent .layer-details {
      border-top-color: rgba(8, 47, 73, 0.2);
    }

    .layer.active .layer-details {
      display: block;
    }

    .layer.active .layer-summary {
      white-space: normal;
    }

    /* Controls Bar */
    .nav-bar {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 4px;
      flex-shrink: 0;
      width: 100%;
    }

    .tab-btn {
      flex: 1 1 calc(20% - 4px);
      min-width: 50px;
      padding: 5px 2px;
      font-size: 10.5px;
      font-weight: 700;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      background: #f8fafc;
      color: #334155;
      cursor: pointer;
      transition: background 0.15s, color 0.15s, border-color 0.15s;
      white-space: nowrap;
      text-align: center;
      box-sizing: border-box;
    }

    .tab-btn:hover {
      background: #f1f5f9;
    }

    .tab-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
    }

    /* Responsive Adjustments for Mobile (< 480px / 350px) */
    @media (max-width: 480px) {
      .diagram {
        gap: 4px;
        padding: 2px;
      }
      .sunlight-meter {
        width: 42px;
        padding: 4px 1px;
      }
      .light-header {
        font-size: 8px;
      }
      .light-val {
        font-size: 8px;
      }
      .light-track {
        width: 6px;
      }
      .layer {
        padding: 4px 6px;
      }
      .layer-name {
        font-size: 11px;
      }
      .badge {
        font-size: 8.5px;
        padding: 1px 3px;
      }
      .layer-icons {
        font-size: 12px;
        gap: 1px;
      }
      .layer-summary {
        font-size: 9.5px;
        line-height: 1.2;
      }
      .layer-details {
        font-size: 9px;
        line-height: 1.25;
      }
      .tab-btn {
        font-size: 9px;
        padding: 4px 1px;
        min-width: 45px;
      }
    }
  </style>
</head>
<body>
  <div class="diagram">
    <div class="main-view">
      
      <div class="sunlight-meter" aria-label="Sunlight levels indicator">
        <div class="light-header">☀️ Light</div>
        <div class="light-scale-wrap">
          <div class="light-track"></div>
          <div class="light-labels">
            <span class="light-val">100%</span>
            <span class="light-val">20%</span>
            <span class="light-val">5%</span>
            <span class="light-val">2%</span>
          </div>
        </div>
      </div>

      
      <div class="layers-container" id="layers">
        
        <div class="layer layer-emergent" data-index="0" role="button" tabindex="0">
          <div class="layer-header-row">
            <div class="layer-title-group">
              <span class="layer-name">1. Emergent</span>
              <span class="badge">40m+</span>
              <span class="badge">100% Sun</span>
            </div>
            <div class="layer-icons" title="Giant Trees, Eagles, Bats">🦅 🦇 ☀️</div>
          </div>
          <div class="layer-summary">Giant trees punching into full sun &amp; strong winds.</div>
          <div class="layer-details">
            <strong>Ecology:</strong> Trees reach up to 70m. Home to harpy eagles, fruit bats, and winged seed dispersers.
          </div>
        </div>

        
        <div class="layer layer-canopy" data-index="1" role="button" tabindex="0">
          <div class="layer-header-row">
            <div class="layer-title-group">
              <span class="layer-name">2. Canopy</span>
              <span class="badge">~30m</span>
              <span class="badge">90% Light Blocked</span>
            </div>
            <div class="layer-icons" title="Monkeys, Toucans, Tree Frogs">🐒 🦜 🐸</div>
          </div>
          <div class="layer-summary">Dense leafy roof housing ~50% of all rainforest species.</div>
          <div class="layer-details">
            <strong>Ecology:</strong> Overlapping branches form a green roof packed with flowers, fruits, toucans, and monkeys.
          </div>
        </div>

        
        <div class="layer layer-understory" data-index="2" role="button" tabindex="0">
          <div class="layer-header-row">
            <div class="layer-title-group">
              <span class="layer-name">3. Understory</span>
              <span class="badge">~15m</span>
              <span class="badge">5% Light</span>
            </div>
            <div class="layer-icons" title="Jaguars, Broad Leaves, Chameleons">🐆 🌿 🦎</div>
          </div>
          <div class="layer-summary">Dark, humid shade with wide leaves capturing dim light.</div>
          <div class="layer-details">
            <strong>Ecology:</strong> Warm and stagnant. Giant broad leaves capture filtered light; shelter for jaguars &amp; tree frogs.
          </div>
        </div>

        
        <div class="layer layer-floor" data-index="3" role="button" tabindex="0">
          <div class="layer-header-row">
            <div class="layer-title-group">
              <span class="layer-name">4. Forest Floor</span>
              <span class="badge">0m</span>
              <span class="badge">&lt; 2% Light</span>
            </div>
            <div class="layer-icons" title="Anteaters, Fungi, Decomposers">🐜 🍄 🍃</div>
          </div>
          <div class="layer-summary">Pitch-black zone of rapid organic decomposition.</div>
          <div class="layer-details">
            <strong>Ecology:</strong> Fungi, ants, and anteaters rapidly recycle fallen leaves and wood back into rich soil nutrients.
          </div>
        </div>
      </div>
    </div>

    
    <div class="nav-bar">
      <button class="tab-btn" data-index="0">Emergent</button>
      <button class="tab-btn" data-index="1">Canopy</button>
      <button class="tab-btn" data-index="2">Understory</button>
      <button class="tab-btn" data-index="3">Floor</button>
      <button class="tab-btn active" data-index="-1">All Layers</button>
    </div>
  </div>

  <script>
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    const tabs = document.querySelectorAll('.tab-btn');
    let activeIdx = -1;

    function selectLayer(idx) {
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      layers.forEach((layer, i) => {
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          layer.classList.remove('active', 'dimmed');
        } else if (i === idx) {
          layer.classList.add('active');
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        } else {
          layer.classList.remove('active');
          layer.classList.add('dimmed');
        }
      });
    }

    layers.forEach((layer, i) => {
      layer.addEventListener('click', () => {
        selectLayer(activeIdx === i ? -1 : i);
      });
      layer.addEventListener('keydown', (e) => {
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          selectLayer(activeIdx === i ? -1 : i);
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      tab.addEventListener('click', () => {
        selectLayer(parseInt(tab.dataset.index));
      });
    });
  </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: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 10px;
      gap: 8px;
      user-select: none;
    }
    
    .nav-tabs {
      display: flex;
      gap: 6px;
      background: #f1f5f9;
      padding: 4px;
      border-radius: 20px;
      flex-wrap: wrap;
      justify-content: center;
      max-width: 100%;
    }
    .tab-btn {
      border: none;
      background: transparent;
      padding: 6px 12px;
      border-radius: 16px;
      font-size: 13px;
      font-weight: 600;
      color: #64748b;
      cursor: pointer;
      transition: all 0.25s ease;
    }
    .tab-btn.active {
      background: #22b7ff;
      color: #ffffff;
      box-shadow: 0 2px 6px rgba(34, 183, 255, 0.35);
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    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
      width: 100%;
      max-width: 600px;
      height: 340px;
    }

    .biome-panel {
      border-radius: 12px;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      position: relative;
      border: 1px solid #e2e8f0;
    }

    .panel-header {
      padding: 6px;
      text-align: center;
      font-size: 13px;
      font-weight: 700;
      z-index: 5;
      background: #ffffff;
      border-bottom: 1px solid #e2e8f0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 6px 10px;
    }
    .badge {
      font-size: 11px;
      font-weight: 600;
      padding: 2px 6px;
      border-radius: 10px;
    }
    .fresh-badge { background: #e0f2fe; color: #0369a1; }
    .marine-badge { background: #dbeafe; color: #1d4ed8; }

    .water-column {
      flex: 1;
      position: relative;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      transition: background 0.4s ease;
    }

    .fresh-water {
      background: linear-gradient(180deg, #bae6fd 0%, #7dd3fc 45%, #38bdf8 80%, #0284c7 100%);
    }

    .marine-water {
      background: linear-gradient(180deg, #93c5fd 0%, #3b82f6 40%, #1e3a8a 85%, #0f172a 100%);
    }

    /* Overlays */
    .zone-overlay {
      position: absolute;
      inset: 0;
      display: flex;
      flex-direction: column;
      pointer-events: none;
      opacity: 0;
      transition: opacity 0.3s ease;
      z-index: 2;
    }
    .zone-photic {
      flex: 1;
      border-bottom: 2px dashed rgba(255, 255, 255, 0.7);
      padding: 6px;
      display: flex;
      align-items: flex-start;
      color: #fff;
      font-size: 11px;
      font-weight: 700;
      text-shadow: 0 1px 3px rgba(0,0,0,0.5);
    }
    .zone-aphotic {
      flex: 1;
      padding: 6px;
      display: flex;
      align-items: flex-end;
      color: rgba(255, 255, 255, 0.75);
      font-size: 11px;
      font-weight: 700;
      background: rgba(0, 0, 0, 0.35);
    }

    .salt-layer {
      position: absolute;
      inset: 0;
      display: flex;
      flex-wrap: wrap;
      align-content: space-around;
      justify-content: space-around;
      padding: 10px;
      pointer-events: none;
      opacity: 0;
      transition: opacity 0.3s ease;
      z-index: 2;
    }
    .salt-ion {
      background: #ffffff;
      color: #0f172a;
      font-size: 9px;
      font-weight: 800;
      padding: 2px 4px;
      border-radius: 4px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.2);
    }

    /* Biome elements */
    .layer-content {
      position: absolute;
      inset: 0;
      z-index: 1;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: 8px;
    }

    .item-group {
      position: relative;
      width: 100%;
      height: 100%;
    }

    .bio-item {
      position: absolute;
      transition: all 0.3s ease;
      display: flex;
      align-items: center;
      gap: 3px;
      font-size: 18px;
      filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
    }
    .bio-item .lbl {
      font-size: 11px;
      font-weight: 700;
      color: #ffffff;
      background: rgba(15, 23, 42, 0.6);
      padding: 1px 5px;
      border-radius: 4px;
      backdrop-filter: blur(2px);
    }

    /* Mode specifics */
    body[data-mode="salinity"] .salt-layer { opacity: 1; }
    body[data-mode="salinity"] .bio-item { opacity: 0.25; }

    body[data-mode="depth"] .zone-overlay { opacity: 1; }
    body[data-mode="depth"] .bio-item { opacity: 0.85; }

    body[data-mode="producers"] .consumer { opacity: 0.15; }
    body[data-mode="producers"] .producer { transform: scale(1.15); }

    body[data-mode="animals"] .producer { opacity: 0.2; }
    body[data-mode="animals"] .consumer { transform: scale(1.15); }
  </style>
</head>
<body data-mode="all">

  <div class="nav-tabs">
    <button class="tab-btn active" onclick="setMode('all', this)">Overview</button>
    <button class="tab-btn" onclick="setMode('salinity', this)">Salinity</button>
    <button class="tab-btn" onclick="setMode('depth', this)">Light Zones</button>
    <button class="tab-btn" onclick="setMode('producers', this)">Producers</button>
    <button class="tab-btn" onclick="setMode('animals', this)">Animals</button>
  </div>

  <div class="comparison-grid">
    
    
    <div class="biome-panel">
      <div class="panel-header">
        <span>Freshwater</span>
        <span class="badge fresh-badge">&lt; 1% Salt</span>
      </div>
      <div class="water-column fresh-water">
        
        <div class="zone-overlay">
          <div class="zone-photic">☀️ Photic (Sunlit)</div>
          <div class="zone-aphotic">🌑 Shallow floor</div>
        </div>

        <div class="salt-layer">
          <span class="salt-ion">Na⁺</span>
          <span class="salt-ion">Cl⁻</span>
        </div>

        <div class="layer-content">
          <div class="item-group">
            
            <div class="bio-item consumer" style="top: 2%; left: 4%;">
              <span>🪰</span><span class="lbl">Dragonfly</span>
            </div>
            
            <div class="bio-item producer" style="top: 18%; right: 4%;">
              <span>🪷</span><span class="lbl">Lily Pad</span>
            </div>
            
            <div class="bio-item consumer" style="top: 48%; left: 18%;">
              <span>🐟</span><span class="lbl">Trout</span>
            </div>
            
            <div class="bio-item producer" style="bottom: 4%; right: 8%;">
              <span>🌾</span><span class="lbl">Reeds</span>
            </div>
          </div>
        </div>

      </div>
    </div>

    
    <div class="biome-panel">
      <div class="panel-header">
        <span>Marine</span>
        <span class="badge marine-badge">~3.5% Salt</span>
      </div>
      <div class="water-column marine-water">
        
        <div class="zone-overlay">
          <div class="zone-photic">☀️ Photic (Sunlit)</div>
          <div class="zone-aphotic">🌑 Aphotic (Dark)</div>
        </div>

        <div class="salt-layer">
          <span class="salt-ion">Na⁺</span><span class="salt-ion">Cl⁻</span><span class="salt-ion">Na⁺</span>
          <span class="salt-ion">Cl⁻</span><span class="salt-ion">Na⁺</span><span class="salt-ion">Cl⁻</span>
          <span class="salt-ion">Na⁺</span><span class="salt-ion">Cl⁻</span><span class="salt-ion">Na⁺</span>
          <span class="salt-ion">Cl⁻</span><span class="salt-ion">Na⁺</span><span class="salt-ion">Cl⁻</span>
        </div>

        <div class="layer-content">
          <div class="item-group">
            
            <div class="bio-item producer" style="top: 4%; left: 6%;">
              <span>✨</span><span class="lbl">Plankton</span>
            </div>
            
            <div class="bio-item consumer" style="top: 24%; right: 6%;">
              <span>🐢</span><span class="lbl">Turtle</span>
            </div>
            
            <div class="bio-item consumer" style="top: 52%; left: 10%;">
              <span>🐠</span><span class="lbl">Clownfish</span>
            </div>
            
            <div class="bio-item producer" style="bottom: 4%; right: 12%;">
              <span>🌿</span><span class="lbl">Kelp</span>
            </div>
          </div>
        </div>

      </div>
    </div>

  </div>

  <script>
    function setMode(mode, btn) {
      document.body.setAttribute('data-mode', mode);
      document.querySelectorAll('.tab-btn').forEach(b => b.classList.remove('active'));
      btn.classList.add('active');
    }
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: transparent;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 8px 12px 12px;
      user-select: none;
      -webkit-user-select: none;
    }
    .chart-container {
      width: 100%;
      max-width: 580px;
      position: relative;
    }
    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
    }
    .biome-zone {
      cursor: pointer;
      transition: opacity 0.25s ease, filter 0.25s ease;
      opacity: 0.88;
    }
    .biome-zone:hover, .biome-zone.active {
      opacity: 1;
      filter: brightness(1.08) drop-shadow(0 2px 6px rgba(0,0,0,0.15));
      stroke: #1e2945;
      stroke-width: 2.5px;
    }
    .zone-label {
      font-size: 11px;
      font-weight: 700;
      fill: #1e2945;
      pointer-events: none;
      text-anchor: middle;
      letter-spacing: 0.3px;
    }
    .axis-label {
      font-size: 11px;
      font-weight: 600;
      fill: #64748b;
      text-anchor: middle;
    }
    .axis-arrow {
      stroke: #94a3b8;
      stroke-width: 1.5;
      fill: none;
      stroke-linecap: round;
      stroke-linejoin: round;
    }
    .axis-tick {
      font-size: 9.5px;
      fill: #94a3b8;
      text-anchor: middle;
    }
    /* Info Card */
    .card-wrap {
      width: 100%;
      max-width: 580px;
      margin-top: 6px;
      height: 68px;
    }
    .info-card {
      height: 100%;
      background: #f8fafc;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 8px 14px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 10px;
      transition: border-color 0.2s ease, background 0.2s ease;
    }
    .card-title {
      font-size: 14px;
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .card-badge {
      display: inline-block;
      width: 10px;
      height: 10px;
      border-radius: 50%;
    }
    .card-metrics {
      display: flex;
      gap: 12px;
      font-size: 12px;
      color: #475569;
    }
    .metric-val {
      font-weight: 600;
      color: #1e2945;
    }
    .hint-text {
      font-size: 13px;
      color: #64748b;
      font-weight: 500;
      text-align: center;
      width: 100%;
    }
    @media (max-width: 440px) {
      .card-wrap { height: 76px; }
      .info-card { flex-direction: column; align-items: flex-start; justify-content: center; gap: 4px; padding: 6px 10px; }
      .card-metrics { font-size: 11px; gap: 8px; }
      .zone-label { font-size: 9.5px; }
    }
  </style>
</head>
<body>

  <div class="chart-container">
    <svg viewBox="0 0 520 310">
      <defs>
        <marker id="arrow" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
          <path d="M 0 1.5 L 8 5 L 0 8.5 z" fill="#94a3b8" />
        </marker>
      </defs>

      
      <line x1="65" y1="50" x2="495" y2="50" stroke="#f1f5f9" stroke-width="1.5" />
      <line x1="65" y1="120" x2="495" y2="120" stroke="#f1f5f9" stroke-width="1.5" />
      <line x1="65" y1="190" x2="495" y2="190" stroke="#f1f5f9" stroke-width="1.5" />
      <line x1="170" y1="20" x2="170" y2="260" stroke="#f1f5f9" stroke-width="1.5" />
      <line x1="280" y1="20" x2="280" y2="260" stroke="#f1f5f9" stroke-width="1.5" />
      <line x1="390" y1="20" x2="390" y2="260" stroke="#f1f5f9" stroke-width="1.5" />

      
      
      
      <path id="zone-tundra" class="biome-zone"
            d="M 65 30 Q 110 30 150 40 L 130 90 Q 95 90 65 85 Z"
            fill="#a5f3fc" stroke="#38bdf8" stroke-width="1.5" />
      <text x="100" y="62" class="zone-label">Tundra</text>

      
      <path id="zone-forest" class="biome-zone"
            d="M 150 40 Q 230 45 290 80 L 370 175 Q 260 170 190 140 L 130 90 Z"
            fill="#86efac" stroke="#22c55e" stroke-width="1.5" />
      <text x="235" y="115" class="zone-label">Temperate Forest</text>

      
      <path id="zone-grassland" class="biome-zone"
            d="M 65 85 Q 110 90 130 90 L 190 140 Q 180 200 135 220 L 65 170 Z"
            fill="#fde047" stroke="#eab308" stroke-width="1.5" />
      <text x="122" y="150" class="zone-label">Grassland</text>

      
      <path id="zone-desert" class="biome-zone"
            d="M 65 170 L 135 220 L 175 260 L 65 260 Z"
            fill="#fed7aa" stroke="#f97316" stroke-width="1.5" />
      <text x="108" y="235" class="zone-label">Desert</text>

      
      <path id="zone-rainforest" class="biome-zone"
            d="M 190 140 Q 260 170 370 175 L 490 260 L 175 260 Q 180 200 190 140 Z"
            fill="#6ee7b7" stroke="#059669" stroke-width="1.5" />
      <text x="330" y="225" class="zone-label">Tropical Rainforest</text>

      
      
      <line x1="65" y1="20" x2="65" y2="265" class="axis-arrow" marker-end="url(#arrow)" />
      
      
      <line x1="60" y1="260" x2="498" y2="260" class="axis-arrow" marker-end="url(#arrow)" />

      
      <text x="54" y="34" class="axis-tick">-15°C</text>
      <text x="54" y="145" class="axis-tick">10°C</text>
      <text x="54" y="258" class="axis-tick">30°C</text>
      
      <text x="24" y="145" class="axis-label" transform="rotate(-90 24 145)">
        Temperature (Cold → Hot)
      </text>

      
      <text x="65" y="276" class="axis-tick">0</text>
      <text x="170" y="276" class="axis-tick">100</text>
      <text x="280" y="276" class="axis-tick">200</text>
      <text x="390" y="276" class="axis-tick">300</text>
      <text x="490" y="276" class="axis-tick">400 cm</text>
      
      <text x="280" y="298" class="axis-label">
        Annual Precipitation (Dry → Wet)
      </text>
    </svg>
  </div>

  
  <div class="card-wrap">
    <div id="infoCard" class="info-card">
      <span class="hint-text">👆 Tap or hover any climate zone to explore</span>
    </div>
  </div>

  <script>
    const biomes = {
      tundra: {
        name: 'Tundra',
        color: '#06b6d4',
        temp: '-15°C to 0°C',
        rain: '10–25 cm/yr',
        species: 'Polar bear, Lichen 🐻‍❄️'
      },
      forest: {
        name: 'Temperate Forest',
        color: '#16a34a',
        temp: '5°C to 20°C',
        rain: '75–150 cm/yr',
        species: 'Oak tree, Red deer 🦌'
      },
      grassland: {
        name: 'Grassland',
        color: '#d97706',
        temp: '0°C to 25°C',
        rain: '25–75 cm/yr',
        species: 'Bison, Wild grasses 🦬'
      },
      desert: {
        name: 'Desert',
        color: '#ea580c',
        temp: '20°C to 35°C',
        rain: '< 25 cm/yr',
        species: 'Cactus, Fennec fox 🌵'
      },
      rainforest: {
        name: 'Tropical Rainforest',
        color: '#059669',
        temp: '22°C to 30°C',
        rain: '200–400 cm/yr',
        species: 'Toucan, Jaguar 🦜'
      }
    };

    const card = document.getElementById('infoCard');
    const zones = document.querySelectorAll('.biome-zone');

    function showBiome(key) {
      const data = biomes[key];
      if (!data) return;

      zones.forEach(z => z.classList.remove('active'));
      const activeEl = document.getElementById('zone-' + key);
      if (activeEl) activeEl.classList.add('active');

      card.style.borderColor = data.color;
      card.innerHTML = `
        <div class="card-title">
          <span class="card-badge" style="background: ${data.color}"></span>
          <span>${data.name}</span>
        </div>
        <div class="card-metrics">
          <div>🌡️ <span class="metric-val">${data.temp}</span></div>
          <div>💧 <span class="metric-val">${data.rain}</span></div>
          <div>🐾 <span class="metric-val">${data.species}</span></div>
        </div>
      `;
    }

    zones.forEach(zone => {
      const key = zone.id.replace('zone-', '');
      zone.addEventListener('mouseenter', () => showBiome(key));
      zone.addEventListener('click', () => showBiome(key));
      zone.addEventListener('touchstart', (e) => {
        e.preventDefault();
        showBiome(key);
      }, { passive: false });
    });
  </script>
</body>
</html>

OGS.7.LS.7

Aligned learning resources

Related diagrams