<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="1:1">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: transparent;
      color: #1e293b;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 8px;
    }

    .ocean-frame {
      position: relative;
      width: 100%;
      max-width: 350px;
      height: 380px;
      border-radius: 18px;
      overflow: hidden;
      display: flex;
      flex-direction: column;
      box-shadow: 0 4px 16px rgba(15, 23, 42, 0.08);
      border: 1px solid #cbd5e1;
    }

    /* Sky area */
    .sky {
      height: 65px;
      background: linear-gradient(180deg, #bae6fd 0%, #e0f2fe 100%);
      position: relative;
      overflow: hidden;
    }

    .sun {
      position: absolute;
      top: 10px;
      right: 18px;
      font-size: 20px;
      opacity: 0.9;
    }

    .cloud {
      position: absolute;
      top: 14px;
      left: 16px;
      font-size: 16px;
      opacity: 0.75;
    }

    /* Boat on surface */
    .boat {
      position: absolute;
      bottom: 2px;
      left: 45px;
      font-size: 26px;
      z-index: 10;
      animation: bob 3.5s ease-in-out infinite alternate;
      transform-origin: bottom center;
    }

    @keyframes bob {
      0% { transform: translateY(0) rotate(-2deg); }
      50% { transform: translateY(-3px) rotate(1deg); }
      100% { transform: translateY(-1px) rotate(3deg); }
    }

    /* Waves transition */
    .wave-line {
      position: absolute;
      bottom: 0;
      left: 0;
      width: 200%;
      height: 12px;
      fill: #38bdf8;
      animation: waveMove 6s linear infinite;
    }

    @keyframes waveMove {
      from { transform: translateX(0); }
      to { transform: translateX(-50%); }
    }

    /* Deep Ocean water column */
    .water {
      flex: 1;
      position: relative;
      background: linear-gradient(180deg, #38bdf8 0%, #0284c7 35%, #0369a1 70%, #0c2340 100%);
      overflow: hidden;
    }

    /* Swimming creatures */
    .creature-fish {
      position: absolute;
      top: 25%;
      left: 20px;
      font-size: 24px;
      animation: swimFish 8s ease-in-out infinite alternate;
    }

    .creature-whale {
      position: absolute;
      bottom: 28%;
      left: 55px;
      font-size: 42px;
      animation: glideWhale 10s ease-in-out infinite alternate;
      filter: drop-shadow(0 4px 6px rgba(0,0,0,0.3));
    }

    @keyframes swimFish {
      0% { transform: translateX(0) translateY(0); }
      100% { transform: translateX(50px) translateY(8px); }
    }

    @keyframes glideWhale {
      0% { transform: translateX(0) translateY(0) scaleX(-1); }
      100% { transform: translateX(40px) translateY(-10px) scaleX(-1); }
    }

    /* Ocean floor */
    .sea-floor {
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 20px;
      background: #78716c;
      border-top: 3px solid #a8a29e;
      border-radius: 50% 50% 0 0 / 10px 10px 0 0;
    }

    /* Magnifier Callout */
    .salt-callout {
      position: absolute;
      top: 22px;
      right: 18px;
      display: flex;
      flex-direction: column;
      align-items: center;
      z-index: 15;
    }

    .lens {
      width: 72px;
      height: 72px;
      border-radius: 50%;
      background: rgba(255, 255, 255, 0.95);
      border: 3.5px solid #ffffff;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25), inset 0 0 8px rgba(56, 189, 248, 0.3);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      position: relative;
    }

    .lens::after {
      content: '';
      position: absolute;
      bottom: -18px;
      left: 8px;
      width: 2px;
      height: 18px;
      border-left: 2px dashed rgba(255, 255, 255, 0.85);
    }

    .salt-icon {
      font-size: 26px;
      line-height: 1;
    }

    .salt-label {
      font-size: 11px;
      font-weight: 700;
      color: #0369a1;
      margin-top: 2px;
      letter-spacing: 0.2px;
    }

    /* Bottom caption footer */
    .footer-badge {
      background: #ffffff;
      padding: 10px 12px;
      text-align: center;
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
      border-top: 1px solid #e2e8f0;
      letter-spacing: -0.2px;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    .footer-badge span {
      color: #0284c7;
    }
  </style>
</head>
<body>

  <div class="ocean-frame">
    
    <div class="sky">
      <span class="cloud">☁️</span>
      <span class="sun">☀️</span>
      <div class="boat">⛵</div>

      
      <svg class="wave-line" viewBox="0 0 1200 24" preserveAspectRatio="none">
        <path d="M0,12 C150,24 350,0 500,12 C650,24 850,0 1000,12 C1150,24 1350,0 1500,12 L1500,24 L0,24 Z"></path>
      </svg>
    </div>

    
    <div class="water">
      
      <div class="salt-callout">
        <div class="lens">
          <span class="salt-icon">🧂</span>
          <span class="salt-label">Saltwater</span>
        </div>
      </div>

      
      <div class="creature-fish">🐟</div>
      <div class="creature-whale">🐋</div>

      
      <div class="sea-floor"></div>
    </div>

    
    <div class="footer-badge">
      <span>🌊</span> Oceans: Huge, Deep, and Salty
    </div>
  </div>

</body>
</html>

Earth's Water: Oceans, Lakes, and Rivers

<!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">
  <link rel="stylesheet" href="{{VENDOR_CDN}}/leaflet.css" />
  <script src="{{VENDOR_CDN}}/leaflet.min.js"></script>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    html, body {
      width: 100%;
      height: 100%;
      overflow: hidden;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #f0f7ff;
      color: #1e2945;
    }

    #app {
      position: relative;
      width: 100%;
      height: 100%;
      display: flex;
      flex-direction: column;
    }

    #map {
      flex: 1;
      width: 100%;
      background: #cbe6ff;
    }

    /* Clean ocean markers */
    .ocean-label {
      background: rgba(255, 255, 255, 0.94);
      border: 2px solid #0284c7;
      border-radius: 8px;
      padding: 4px 8px;
      text-align: center;
      box-shadow: 0 3px 8px rgba(0, 50, 100, 0.18);
      white-space: nowrap;
      cursor: pointer;
      transition: transform 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
      user-select: none;
    }

    .ocean-label.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0369a1;
      transform: scale(1.08);
      z-index: 1000 !important;
    }

    .ocean-title {
      font-size: 13px;
      font-weight: 800;
      letter-spacing: -0.2px;
    }

    .ocean-badge {
      font-size: 10px;
      font-weight: 700;
      margin-top: 1px;
      color: #0369a1;
      opacity: 0.9;
    }

    .ocean-label.active .ocean-badge {
      color: #e0f2fe;
    }

    /* Tab bar / controls */
    .controls {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 5px;
      padding: 6px 8px;
      background: #ffffff;
      border-top: 1px solid #e2e8f0;
      z-index: 500;
    }

    .tab-btn {
      appearance: none;
      border: 1px solid #cbd5e1;
      background: #f8fafc;
      color: #334155;
      padding: 5px 9px;
      border-radius: 6px;
      font-size: 11px;
      font-weight: 700;
      cursor: pointer;
      transition: background 0.15s, color 0.15s, border-color 0.15s;
    }

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

    /* Custom Leaflet overrides */
    .leaflet-control-attribution {
      font-size: 8px !important;
      background: rgba(255, 255, 255, 0.7) !important;
    }
  </style>
</head>
<body>
  <div id="app">
    <div id="map"></div>
    <div class="controls" id="btnBar">
      <button class="tab-btn active" data-idx="0">Pacific</button>
      <button class="tab-btn" data-idx="1">Atlantic</button>
      <button class="tab-btn" data-idx="2">Indian</button>
      <button class="tab-btn" data-idx="3">Southern</button>
      <button class="tab-btn" data-idx="4">Arctic</button>
    </div>
  </div>

  <script>
    const oceans = [
      {
        name: "Pacific Ocean",
        tag: "Largest & Deepest",
        lat: 0,
        lng: -160,
        zoom: 2
      },
      {
        name: "Atlantic Ocean",
        tag: "",
        lat: 8,
        lng: -32,
        zoom: 2
      },
      {
        name: "Indian Ocean",
        tag: "",
        lat: -18,
        lng: 78,
        zoom: 2
      },
      {
        name: "Southern Ocean",
        tag: "",
        lat: -62,
        lng: 15,
        zoom: 2
      },
      {
        name: "Arctic Ocean",
        tag: "Smallest & Shallowest",
        lat: 76,
        lng: 0,
        zoom: 2
      }
    ];

    // Initialize Map with clean light tiles
    const map = L.map('map', {
      center: [15, 0],
      zoom: 1,
      minZoom: 1,
      maxZoom: 4,
      scrollWheelZoom: false,
      zoomControl: false,
      worldCopyJump: false,
      maxBounds: [[-85, -200], [85, 200]],
      maxBoundsViscosity: 0.8
    });

    L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
      attribution: '&copy; CARTO'
    }).addTo(map);

    const markers = [];
    const buttons = document.querySelectorAll('.tab-btn');

    // Add ocean labels as custom DivIcons
    oceans.forEach((ocean, i) => {
      const tagHtml = ocean.tag ? `<div class="ocean-badge">${ocean.tag}</div>` : '';
      const html = `<div class="ocean-label ${i === 0 ? 'active' : ''}" id="marker-${i}">
        <div class="ocean-title">${ocean.name}</div>
        ${tagHtml}
      </div>`;

      const icon = L.divIcon({
        className: 'custom-ocean-marker',
        html: html,
        iconSize: [120, 36],
        iconAnchor: [60, 18]
      });

      const marker = L.marker([ocean.lat, ocean.lng], { icon }).addTo(map);
      marker.on('click', () => selectOcean(i));
      markers.push(marker);
    });

    function selectOcean(idx) {
      oceans.forEach((_, i) => {
        const el = document.getElementById(`marker-${i}`);
        if (el) el.classList.toggle('active', i === idx);
        buttons[i].classList.toggle('active', i === idx);
      });

      const target = oceans[idx];
      map.flyTo([target.lat, target.lng], target.zoom, {
        duration: 0.8,
        easeLinearity: 0.25
      });
    }

    buttons.forEach((btn) => {
      btn.addEventListener('click', (e) => {
        const idx = parseInt(e.target.dataset.idx, 10);
        selectOcean(idx);
      });
    });

    new ResizeObserver(() => {
      map.invalidateSize();
    }).observe(document.getElementById('map'));
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="1:1">
  <title>What is a Lake?</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      width: 100%;
      height: 100%;
      background: #f8fafc;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      user-select: none;
      color: #1e2945;
    }

    .diagram-wrapper {
      position: relative;
      width: 100%;
      max-width: 400px;
      aspect-ratio: 1 / 1;
    }

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

    /* Floating / bobbing animation */
    @keyframes gentleBob {
      0%, 100% { transform: translateY(0px) rotate(0deg); }
      50% { transform: translateY(-4px) rotate(2deg); }
    }

    @keyframes waterPulse {
      0%, 100% { opacity: 0.35; transform: scale(1); }
      50% { opacity: 0.6; transform: scale(1.02); }
    }

    .duck {
      animation: gentleBob 3.5s ease-in-out infinite;
      transform-origin: 175px 195px;
    }

    .lily {
      animation: gentleBob 4.2s ease-in-out infinite reverse;
      transform-origin: 235px 215px;
    }

    .ripple {
      transform-origin: 200px 205px;
      animation: waterPulse 4s ease-in-out infinite;
    }

    /* Text labels styling */
    .label-badge {
      font-size: 13px;
      font-weight: 700;
      fill: #1e2945;
    }

    .badge-bg {
      fill: #ffffff;
      stroke: #cbd5e1;
      stroke-width: 1.5;
      filter: drop-shadow(0 2px 4px rgba(0,0,0,0.06));
      rx: 8;
    }

    .water-badge-bg {
      fill: #e0f2fe;
      stroke: #38bdf8;
    }

    .land-badge-bg {
      fill: #f0fdf4;
      stroke: #4ade80;
    }
  </style>
</head>
<body>
  <div class="diagram-wrapper">
    <svg viewBox="0 0 400 400" aria-label="Top-down diagram of a lake surrounded by land">
      <defs>
        
        <linearGradient id="landGrad" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#86efac" />
          <stop offset="100%" stop-color="#4ade80" />
        </linearGradient>

        <linearGradient id="bankGrad" x1="0%" y1="0%" x2="0%" y2="100%">
          <stop offset="0%" stop-color="#ca8a04" />
          <stop offset="100%" stop-color="#a16207" />
        </linearGradient>

        <linearGradient id="waterGrad" x1="0%" y1="0%" x2="0%" y2="100%">
          <stop offset="0%" stop-color="#38bdf8" />
          <stop offset="100%" stop-color="#0284c7" />
        </linearGradient>

        
        <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="#15803d" />
        </marker>
        <marker id="waterArrow" 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="#0284c7" />
        </marker>
      </defs>

      
      <rect width="400" height="400" fill="url(#landGrad)" />

      
      
      <text x="50" y="55" font-size="28">🌲</text>
      <text x="120" y="45" font-size="26">🌲</text>
      <text x="190" y="40" font-size="30">🌲</text>
      <text x="260" y="45" font-size="26">🌲</text>
      <text x="325" y="55" font-size="28">🌲</text>

      
      <text x="25" y="130" font-size="28">🌲</text>
      <text x="345" y="130" font-size="28">🌲</text>
      <text x="20" y="210" font-size="30">🌲</text>
      <text x="350" y="210" font-size="30">🌲</text>
      <text x="30" y="290" font-size="28">🌲</text>
      <text x="340" y="290" font-size="28">🌲</text>

      
      <text x="55" y="365" font-size="28">🌲</text>
      <text x="125" y="375" font-size="26">🌲</text>
      <text x="200" y="380" font-size="30">🌲</text>
      <text x="270" y="375" font-size="26">🌲</text>
      <text x="325" y="365" font-size="28">🌲</text>

      
      <ellipse cx="200" cy="205" rx="142" ry="92" fill="url(#bankGrad)" opacity="0.45" />

      
      <ellipse cx="200" cy="205" rx="135" ry="85" fill="url(#waterGrad)" />

      
      <ellipse class="ripple" cx="200" cy="205" rx="115" ry="68" fill="none" stroke="#ffffff" stroke-width="2.5" stroke-dasharray="14 18" />

      
      <g class="duck">
        <text x="160" y="200" font-size="32" text-anchor="middle">🦆</text>
      </g>

      
      <g class="lily">
        <text x="240" y="215" font-size="26" text-anchor="middle">🪷</text>
      </g>

      
      
      <line x1="68" y1="205" x2="88" y2="205" stroke="#15803d" stroke-width="3" marker-end="url(#arrow)" />
      
      <line x1="332" y1="205" x2="312" y2="205" stroke="#15803d" stroke-width="3" marker-end="url(#arrow)" />
      
      <line x1="295" y1="105" x2="278" y2="125" stroke="#15803d" stroke-width="3" marker-end="url(#arrow)" />
      
      <line x1="105" y1="305" x2="122" y2="285" stroke="#15803d" stroke-width="3" marker-end="url(#arrow)" />

      
      <g transform="translate(110, 75)">
        <rect class="badge-bg land-badge-bg" x="0" y="0" width="180" height="30" />
        <text class="label-badge" x="90" y="20" text-anchor="middle" fill="#15803d">Surrounded by Land</text>
      </g>

      
      <line x1="200" y1="298" x2="200" y2="258" stroke="#0284c7" stroke-width="3" marker-end="url(#waterArrow)" />

      <g transform="translate(135, 298)">
        <rect class="badge-bg water-badge-bg" x="0" y="0" width="130" height="30" />
        <text class="label-badge" x="65" y="20" text-anchor="middle" fill="#0369a1">💧 Freshwater</text>
      </g>
    </svg>
  </div>
</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>Freshwater vs Salty Lakes</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;
      background: transparent;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .grid-container {
      display: flex;
      flex-direction: row;
      gap: 12px;
      width: 100%;
      max-width: 600px;
    }

    .lake-card {
      flex: 1;
      border-radius: 16px;
      padding: 16px 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 12px;
      transition: box-shadow 0.2s ease;
    }

    /* Freshwater theme */
    .fresh-card {
      background: #f0f9ff;
      border: 2px solid #bae6fd;
    }

    /* Salty theme */
    .salty-card {
      background: #fffbeb;
      border: 2px solid #fde68a;
    }

    .card-header {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 16px;
      font-weight: 700;
    }

    .fresh-header {
      color: #0369a1;
    }

    .salty-header {
      color: #b45309;
    }

    .header-icon {
      font-size: 26px;
      line-height: 1;
    }

    .lake-list {
      width: 100%;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .lake-item {
      width: 100%;
      background: #ffffff;
      padding: 10px 12px;
      border-radius: 12px;
      font-size: 14px;
      font-weight: 600;
      text-align: center;
      cursor: pointer;
      user-select: none;
      transition: background-color 0.2s ease, box-shadow 0.2s ease;
    }

    .fresh-item {
      color: #0284c7;
      border: 1.5px solid #e0f2fe;
      box-shadow: 0 2px 4px rgba(2, 132, 199, 0.06);
    }

    .fresh-item:active, .fresh-item.active {
      background: #e0f2fe;
      border-color: #38bdf8;
      box-shadow: 0 0 0 2px #38bdf8;
    }

    .salty-item {
      color: #d97706;
      border: 1.5px solid #fef3c7;
      box-shadow: 0 2px 4px rgba(217, 119, 6, 0.06);
    }

    .salty-item:active, .salty-item.active {
      background: #fef3c7;
      border-color: #f59e0b;
      box-shadow: 0 0 0 2px #f59e0b;
    }

    @media (max-width: 360px) {
      .grid-container {
        flex-direction: column;
        gap: 10px;
      }
      .lake-card {
        padding: 12px 10px;
        gap: 8px;
      }
      .card-header {
        font-size: 15px;
      }
      .lake-item {
        padding: 8px 10px;
        font-size: 13.5px;
      }
    }
  </style>
</head>
<body>

  <div class="grid-container">
    
    <div class="lake-card fresh-card">
      <div class="card-header fresh-header">
        <span class="header-icon">💧</span>
        <span>Freshwater Lakes</span>
      </div>
      <div class="lake-list">
        <div class="lake-item fresh-item" onclick="selectLake(this, 520)">
          Lake Superior
        </div>
        <div class="lake-item fresh-item" onclick="selectLake(this, 580)">
          Lake Baikal
        </div>
      </div>
    </div>

    
    <div class="lake-card salty-card">
      <div class="card-header salty-header">
        <span class="header-icon">🧂</span>
        <span>Salty Lakes</span>
      </div>
      <div class="lake-list">
        <div class="lake-item salty-item" onclick="selectLake(this, 320)">
          Great Salt Lake
        </div>
        <div class="lake-item salty-item" onclick="selectLake(this, 360)">
          Dead Sea
        </div>
        <div class="lake-item salty-item" onclick="selectLake(this, 400)">
          Caspian Sea
        </div>
      </div>
    </div>
  </div>

  <script>
    let audioCtx = null;

    function playTone(freq) {
      try {
        if (!audioCtx) {
          audioCtx = new (window.AudioContext || window.webkitAudioContext)();
        }
        if (audioCtx.state === 'suspended') {
          audioCtx.resume();
        }
        const osc = audioCtx.createOscillator();
        const gain = audioCtx.createGain();
        osc.type = 'sine';
        osc.frequency.setValueAtTime(freq, audioCtx.currentTime);
        gain.gain.setValueAtTime(0.15, audioCtx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.001, audioCtx.currentTime + 0.25);
        osc.connect(gain);
        gain.connect(audioCtx.destination);
        osc.start();
        osc.stop(audioCtx.currentTime + 0.25);
      } catch (e) {
        // Audio optional fallback
      }
    }

    function selectLake(el, freq) {
      document.querySelectorAll('.lake-item').forEach(item => {
        item.classList.remove('active');
      });
      el.classList.add('active');
      playTone(freq);
    }
  </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 {
      width: 100%;
      height: 100%;
      background: #f8fafc;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }

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

    svg {
      width: 100%;
      height: 100%;
      max-height: 460px;
      display: block;
    }

    /* Flow line animations */
    .flow-dash {
      stroke-dasharray: 8, 12;
      animation: flowMotion 1.8s linear infinite;
    }

    .flow-dash-fast {
      stroke-dasharray: 6, 10;
      animation: flowMotion 1.2s linear infinite;
    }

    @keyframes flowMotion {
      from {
        stroke-dashoffset: 40;
      }
      to {
        stroke-dashoffset: 0;
      }
    }

    /* Ocean ripples */
    .ocean-wave {
      animation: waveSway 3s ease-in-out infinite alternate;
    }
    .ocean-wave-2 {
      animation: waveSway 2.4s ease-in-out infinite alternate-reverse;
    }

    @keyframes waveSway {
      0% {
        transform: translateY(0px) translateX(0px);
      }
      100% {
        transform: translateY(3px) translateX(4px);
      }
    }

    /* Label cards */
    .map-badge {
      font-size: 13px;
      font-weight: 700;
      fill: #0f172a;
      filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
    }

    .badge-bg {
      fill: #ffffff;
      stroke: #cbd5e1;
      stroke-width: 1.5;
      rx: 8;
    }

    .badge-source .badge-bg {
      stroke: #38bdf8;
    }

    .badge-mouth .badge-bg {
      stroke: #2563eb;
    }
  </style>
</head>
<body>
  <div class="scene-container">
    <svg viewBox="0 0 600 420" preserveAspectRatio="xMidYMid meet">
      <defs>
        
        <linearGradient id="skyGrad" x1="0%" y1="0%" x2="0%" y2="100%">
          <stop offset="0%" stop-color="#bae6fd" />
          <stop offset="100%" stop-color="#f0f9ff" />
        </linearGradient>

        <linearGradient id="landGrad" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#bbf7d0" />
          <stop offset="50%" stop-color="#86efac" />
          <stop offset="100%" stop-color="#4ade80" />
        </linearGradient>

        <linearGradient id="riverGrad" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#38bdf8" />
          <stop offset="60%" stop-color="#0284c7" />
          <stop offset="100%" stop-color="#1d4ed8" />
        </linearGradient>

        <linearGradient id="oceanGrad" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#0284c7" />
          <stop offset="50%" stop-color="#1d4ed8" />
          <stop offset="100%" stop-color="#1e3a8a" />
        </linearGradient>

        
        <linearGradient id="hillGrad" x1="0%" y1="0%" x2="0%" y2="100%">
          <stop offset="0%" stop-color="#6ee7b7" />
          <stop offset="100%" stop-color="#22c55e" />
        </linearGradient>

        
        <path id="riverCenterline" d="M 125,128 C 160,170 190,195 165,245 C 140,295 240,305 315,315 C 390,325 435,340 540,370" fill="none" />
      </defs>

      
      <rect width="600" height="420" fill="url(#skyGrad)" />

      
      <path d="M 0,260 Q 180,180 340,240 T 600,220 L 600,420 L 0,420 Z" fill="url(#hillGrad)" opacity="0.6" />

      
      <path d="M 0,200 Q 120,220 220,250 T 600,260 L 600,420 L 0,420 Z" fill="url(#landGrad)" />

      
      <path d="M 370,420 C 400,340 450,290 600,260 L 600,420 Z" fill="url(#oceanGrad)" />

      
      <g fill="none" stroke="#93c5fd" stroke-width="2.5" stroke-linecap="round" opacity="0.7" class="ocean-wave">
        <path d="M 480,315 Q 495,310 510,315" />
        <path d="M 540,295 Q 555,290 570,295" />
        <path d="M 450,370 Q 465,365 480,370" />
      </g>
      <g fill="none" stroke="#bae6fd" stroke-width="2" stroke-linecap="round" opacity="0.6" class="ocean-wave-2">
        <path d="M 525,350 Q 540,345 555,350" />
        <path d="M 470,400 Q 485,395 500,400" />
        <path d="M 550,390 Q 565,385 580,390" />
      </g>

      
      
      <polygon points="10,210 75,70 145,210" fill="#94a3b8" />
      <polygon points="75,70 52,120 75,110 98,120" fill="#ffffff" />

      <polygon points="130,220 210,85 280,220" fill="#94a3b8" />
      <polygon points="210,85 185,130 210,122 235,130" fill="#ffffff" />

      
      <polygon points="60,230 130,45 215,230" fill="#64748b" />
      <polygon points="130,45 100,105 118,95 130,108 145,95 162,105" fill="#ffffff" />

      
      <ellipse cx="127" cy="115" rx="8" ry="4" fill="#7dd3fc" />

      
      <path d="M 125,120 
               C 160,170 195,190 172,245 
               C 145,300 240,320 315,328 
               C 390,335 440,350 560,405 
               L 520,340 
               C 425,310 380,300 310,290 
               C 235,280 150,270 158,235 
               C 165,200 145,170 122,120 Z" 
            fill="url(#riverGrad)" />

      
      <path d="M 125,128 C 160,170 190,195 165,245 C 140,295 240,305 315,315 C 390,325 435,340 540,370" 
            fill="none" 
            stroke="#ffffff" 
            stroke-width="3" 
            stroke-linecap="round"
            opacity="0.8" 
            class="flow-dash" />

      <path d="M 128,135 C 158,175 182,205 162,245 C 146,285 245,296 320,305 C 395,315 445,330 530,355" 
            fill="none" 
            stroke="#bae6fd" 
            stroke-width="2" 
            stroke-linecap="round"
            opacity="0.9" 
            class="flow-dash-fast" />

      
      <circle r="4.5" fill="#ffffff" filter="drop-shadow(0 1px 2px rgba(0,0,0,0.2))">
        <animateMotion dur="3.6s" repeatCount="indefinite" begin="0s">
          <mpath href="#riverCenterline" />
        </animateMotion>
      </circle>

      <circle r="4" fill="#e0f2fe">
        <animateMotion dur="3.6s" repeatCount="indefinite" begin="1.2s">
          <mpath href="#riverCenterline" />
        </animateMotion>
      </circle>

      <circle r="4" fill="#ffffff">
        <animateMotion dur="3.6s" repeatCount="indefinite" begin="2.4s">
          <mpath href="#riverCenterline" />
        </animateMotion>
      </circle>

      
      
      <text x="70" y="240" font-size="16">🌲</text>
      <text x="90" y="255" font-size="14">🌲</text>
      <text x="215" y="240" font-size="16">🌲</text>
      <text x="235" y="260" font-size="14">🌲</text>

      
      <text x="110" y="340" font-size="18">🌳</text>
      <text x="190" y="375" font-size="16">🌳</text>
      <text x="270" y="240" font-size="16">🌳</text>
      <text x="370" y="275" font-size="18">🌳</text>
      <text x="440" y="270" font-size="15">🌴</text>

      
      
      
      <g class="badge-source" transform="translate(24, 25)">
        <rect class="badge-bg" width="180" height="38" x="0" y="0" />
        <circle cx="20" cy="19" r="6" fill="#0284c7" />
        <text x="34" y="24" class="map-badge">Source (High Ground)</text>
      </g>
      
      <path d="M 114,63 L 126,85" fill="none" stroke="#0284c7" stroke-width="2" stroke-dasharray="3,3" />

      
      <g transform="translate(240, 348)">
        <rect class="badge-bg" width="112" height="30" x="0" y="0" rx="6" />
        <text x="12" y="20" class="map-badge" font-size="12" fill="#0369a1">River Flow ➔</text>
      </g>

      
      <g class="badge-mouth" transform="translate(390, 195)">
        <rect class="badge-bg" width="185" height="38" x="0" y="0" />
        <circle cx="20" cy="19" r="6" fill="#1d4ed8" />
        <text x="34" y="24" class="map-badge">River Mouth (Ocean)</text>
      </g>
      
      <path d="M 482,233 L 482,285" fill="none" stroke="#1d4ed8" stroke-width="2" stroke-dasharray="3,3" />
    </svg>
  </div>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>Earth's Water Types</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      user-select: none;
      -webkit-user-select: none;
    }

    body {
      font-family: system-ui, -apple-system, sans-serif;
      background: #f8fafc;
      color: #1e2945;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
      width: 100%;
      max-width: 480px;
    }

    .water-card {
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px 4px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      transition: box-shadow 0.25s ease, border-color 0.25s ease;
      outline: none;
    }

    .water-card:hover {
      border-color: #cbd5e1;
    }

    .water-card.active {
      border-color: #0284c7;
      box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.18);
    }

    .icon-box {
      font-size: 32px;
      line-height: 1;
      margin-bottom: 8px;
      display: inline-block;
      transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    }

    .water-card.active .icon-box {
      transform: translateY(-4px) scale(1.1);
    }

    .title {
      font-size: 15px;
      font-weight: 700;
      color: #0f172a;
      margin-bottom: 8px;
    }

    .tags {
      display: flex;
      flex-direction: column;
      gap: 5px;
      width: 100%;
      padding: 0 4px;
    }

    .tag {
      font-size: 12px;
      font-weight: 600;
      padding: 3px 6px;
      border-radius: 6px;
      background: #f1f5f9;
      color: #64748b;
      transition: background 0.25s ease, color 0.25s ease;
      white-space: nowrap;
    }

    .water-card.active .tag {
      background: #e0f2fe;
      color: #0369a1;
    }

    .water-card.active .tag.highlight {
      background: #0284c7;
      color: #ffffff;
    }

    .hint {
      margin-top: 10px;
      font-size: 12px;
      font-weight: 500;
      color: #94a3b8;
    }
  </style>
</head>
<body>

  <div class="grid">
    
    <div class="water-card active" onclick="selectCard(0)" id="card-0">
      <div class="icon-box">🌊</div>
      <div class="title">Ocean</div>
      <div class="tags">
        <span class="tag highlight">Salty</span>
        <span class="tag">Enormous</span>
        <span class="tag">Open</span>
      </div>
    </div>

    
    <div class="water-card" onclick="selectCard(1)" id="card-1">
      <div class="icon-box">🦆</div>
      <div class="title">Lake</div>
      <div class="tags">
        <span class="tag highlight">Fresh</span>
        <span class="tag">Still</span>
        <span class="tag">Surrounded</span>
      </div>
    </div>

    
    <div class="water-card" onclick="selectCard(2)" id="card-2">
      <div class="icon-box">🏞️</div>
      <div class="title">River</div>
      <div class="tags">
        <span class="tag highlight">Fresh</span>
        <span class="tag">Flowing</span>
        <span class="tag">Downhill</span>
      </div>
    </div>
  </div>

  <div class="hint">Tap to compare</div>

  <script>
    function playTone(freq) {
      try {
        const AudioCtx = window.AudioContext || window.webkitAudioContext;
        if (!AudioCtx) return;
        const ctx = new AudioCtx();
        const osc = ctx.createOscillator();
        const gain = ctx.createGain();
        osc.frequency.setValueAtTime(freq, ctx.currentTime);
        osc.connect(gain);
        gain.connect(ctx.destination);
        gain.gain.setValueAtTime(0.08, ctx.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.001, ctx.currentTime + 0.25);
        osc.start();
        osc.stop(ctx.currentTime + 0.25);
      } catch(e) {}
    }

    const tones = [392.00, 440.00, 523.25]; // G4, A4, C5

    function selectCard(idx) {
      playTone(tones[idx]);
      for (let i = 0; i < 3; i++) {
        const card = document.getElementById('card-' + i);
        if (card) {
          if (i === idx) {
            card.classList.add('active');
          } else {
            card.classList.remove('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 {
      width: 100%;
      min-height: 100%;
      background: #f8f9fa;
      font-family: system-ui, -apple-system, sans-serif;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 16px;
    }
    .diagram-content {
      width: 100%;
      max-width: 580px;
      display: flex;
      flex-direction: row;
      align-items: center;
      justify-content: space-around;
      gap: 20px;
      flex-wrap: wrap;
    }
    .panel {
      flex: 1 1 200px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
    }
    .globe-wrapper {
      position: relative;
      width: 160px;
      height: 160px;
      border-radius: 50%;
      background: #0284c7;
      box-shadow: inset -10px -10px 24px rgba(0, 30, 80, 0.35), 0 8px 20px rgba(34, 183, 255, 0.2);
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .globe-svg {
      width: 100%;
      height: 100%;
      transition: opacity 0.3s ease;
    }
    .ten-frame-panel {
      display: flex;
      flex-direction: column;
      gap: 14px;
      align-items: center;
    }
    .ten-frame {
      display: grid;
      grid-template-columns: repeat(5, 1fr);
      grid-template-rows: repeat(2, 1fr);
      gap: 6px;
      background: #ffffff;
      padding: 8px;
      border-radius: 12px;
      border: 1px solid #e2e8f0;
    }
    .square {
      width: 38px;
      height: 38px;
      border-radius: 6px;
      transition: transform 0.2s ease, opacity 0.2s ease;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 16px;
    }
    .square.water {
      background: #22b7ff;
      border: 1px solid #0284c7;
    }
    .square.land {
      background: #4ade80;
      border: 1px solid #16a34a;
    }
    .square.dim {
      opacity: 0.3;
      filter: grayscale(0.5);
    }
    .legend {
      display: flex;
      gap: 16px;
      align-items: center;
      justify-content: center;
    }
    .legend-item {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 14px;
      font-weight: 700;
      cursor: pointer;
      padding: 6px 10px;
      border-radius: 8px;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      user-select: none;
      transition: background-color 0.2s ease;
    }
    .legend-item:hover {
      background: #f1f5f9;
    }
    .legend-color {
      width: 14px;
      height: 14px;
      border-radius: 4px;
    }
    .legend-water {
      background: #22b7ff;
      border: 1px solid #0284c7;
    }
    .legend-land {
      background: #4ade80;
      border: 1px solid #16a34a;
    }
    .land-shape {
      fill: #4ade80;
      stroke: #16a34a;
      stroke-width: 1.5;
      stroke-linejoin: round;
      transition: opacity 0.3s ease;
    }
    .water-bg {
      fill: #22b7ff;
      transition: opacity 0.3s ease;
    }
    .dim-svg {
      opacity: 0.25;
    }
    @media (max-width: 440px) {
      .globe-wrapper {
        width: 130px;
        height: 130px;
      }
      .square {
        width: 30px;
        height: 30px;
        font-size: 13px;
      }
      .legend-item {
        font-size: 13px;
        padding: 4px 8px;
      }
    }
  </style>
</head>
<body>

  <div class="diagram-content">
    
    <div class="panel">
      <div class="globe-wrapper">
        <svg class="globe-svg" viewBox="0 0 100 100">
          <circle id="globeOcean" class="water-bg" cx="50" cy="50" r="50" />
          
          <g id="globeLand">
            
            <path class="land-shape" d="M18,22 Q28,14 36,25 Q32,40 22,46 Q16,36 18,22 Z" />
            <path class="land-shape" d="M26,50 Q36,52 32,74 Q24,80 20,68 Q24,58 26,50 Z" />
            
            <path class="land-shape" d="M55,18 Q82,14 88,32 Q78,44 65,36 Q54,32 55,18 Z" />
            <path class="land-shape" d="M58,42 Q74,40 76,62 Q66,75 56,66 Q54,52 58,42 Z" />
            
            <path class="land-shape" d="M78,68 Q90,66 88,78 Q76,82 78,68 Z" />
          </g>
        </svg>
      </div>
    </div>

    
    <div class="panel ten-frame-panel">
      <div class="ten-frame" id="tenFrame">
        <div class="square water" data-type="water">💧</div>
        <div class="square water" data-type="water">💧</div>
        <div class="square water" data-type="water">💧</div>
        <div class="square water" data-type="water">💧</div>
        <div class="square water" data-type="water">💧</div>
        <div class="square water" data-type="water">💧</div>
        <div class="square water" data-type="water">💧</div>
        <div class="square land" data-type="land">🌱</div>
        <div class="square land" data-type="land">🌱</div>
        <div class="square land" data-type="land">🌱</div>
      </div>

      <div class="legend">
        <div class="legend-item" id="waterBtn">
          <span class="legend-color legend-water"></span>
          <span>Water (71%)</span>
        </div>
        <div class="legend-item" id="landBtn">
          <span class="legend-color legend-land"></span>
          <span>Land (29%)</span>
        </div>
      </div>
    </div>
  </div>

  <script>
    let activeFilter = 'all';

    const squares = document.querySelectorAll('.square');
    const globeLand = document.getElementById('globeLand');
    const globeOcean = document.getElementById('globeOcean');
    const waterBtn = document.getElementById('waterBtn');
    const landBtn = document.getElementById('landBtn');

    function setFilter(type) {
      if (activeFilter === type) {
        activeFilter = 'all';
      } else {
        activeFilter = type;
      }

      // Update squares
      squares.forEach(sq => {
        if (activeFilter === 'all' || sq.dataset.type === activeFilter) {
          sq.classList.remove('dim');
        } else {
          sq.classList.add('dim');
        }
      });

      // Update globe
      if (activeFilter === 'water') {
        globeOcean.classList.remove('dim-svg');
        globeLand.classList.add('dim-svg');
      } else if (activeFilter === 'land') {
        globeOcean.classList.add('dim-svg');
        globeLand.classList.remove('dim-svg');
      } else {
        globeOcean.classList.remove('dim-svg');
        globeLand.classList.remove('dim-svg');
      }
    }

    waterBtn.addEventListener('click', () => setFilter('water'));
    landBtn.addEventListener('click', () => setFilter('land'));

    squares.forEach(sq => {
      sq.addEventListener('click', () => setFilter(sq.dataset.type));
    });
  </script>
</body>
</html>

OGS.2.ESS.2

Aligned learning resources

Related diagrams