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

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #ffffff;
      color: #1e293b;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 12px;
      min-height: 100vh;
      user-select: none;
      -webkit-user-select: none;
    }

    .main-layout {
      width: 100%;
      max-width: 500px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 12px;
    }

    .header-info {
      text-align: center;
    }

    .header-title {
      font-size: 17px;
      font-weight: 700;
      color: #0f172a;
      letter-spacing: -0.2px;
    }

    .header-sub {
      font-size: 12px;
      color: #64748b;
      margin-top: 2px;
    }

    /* Pie chart SVG container */
    .chart-container {
      position: relative;
      width: 150px;
      height: 150px;
      margin: 0 auto;
      flex-shrink: 0;
    }

    .chart-svg {
      width: 100%;
      height: 100%;
      display: block;
      overflow: visible;
    }

    .bg-circle {
      fill: #f1f5f9;
      stroke: #cbd5e1;
      stroke-width: 2;
    }

    .sector-path {
      fill: #2563eb;
      transition: d 0.3s ease-out;
    }

    .arc-stroke-path {
      fill: none;
      stroke: #1d4ed8;
      stroke-width: 3.5;
      stroke-linecap: round;
      transition: d 0.3s ease-out;
    }

    .start-ray {
      stroke: #1d4ed8;
      stroke-width: 2;
      stroke-dasharray: 3 3;
    }

    .center-donut {
      fill: #ffffff;
      stroke: #e2e8f0;
      stroke-width: 1.5;
      filter: drop-shadow(0 2px 4px rgba(0,0,0,0.06));
    }

    .chart-overlay {
      position: absolute;
      inset: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      pointer-events: none;
      text-align: center;
      border-radius: 50%;
    }

    .chart-label-val {
      font-size: 18px;
      font-weight: 800;
      color: #0f172a;
      line-height: 1.1;
      transition: color 0.3s ease;
    }

    .chart-gas-name {
      font-size: 10px;
      font-weight: 800;
      color: #2563eb;
      letter-spacing: 0.6px;
      margin-top: 2px;
      transition: all 0.3s ease;
    }

    /* Preset buttons */
    .presets-row {
      display: flex;
      gap: 6px;
      justify-content: center;
      width: 100%;
      flex-wrap: wrap;
    }

    .preset-btn {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      color: #334155;
      font-size: 11px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: 14px;
      cursor: pointer;
      transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
    }

    .preset-btn:hover {
      background: #eff6ff;
      border-color: #93c5fd;
      color: #1d4ed8;
    }

    .preset-btn.active {
      background: #2563eb;
      border-color: #2563eb;
      color: #ffffff;
    }

    /* Slider control */
    .slider-section {
      width: 100%;
      display: flex;
      flex-direction: column;
      gap: 4px;
      padding: 0 2px;
    }

    .slider-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 12px;
      font-weight: 600;
      color: #475569;
    }

    .slider-wrap {
      width: 100%;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .slider-limit {
      font-size: 11px;
      font-weight: 600;
      color: #64748b;
      min-width: 28px;
    }

    .slider-limit.right {
      text-align: right;
    }

    input[type="range"] {
      flex: 1;
      height: 8px;
      -webkit-appearance: none;
      appearance: none;
      background: #e2e8f0;
      border-radius: 4px;
      outline: none;
      cursor: pointer;
      transition: background 0.3s ease;
    }

    input[type="range"]::-webkit-slider-thumb {
      -webkit-appearance: none;
      appearance: none;
      width: 22px;
      height: 22px;
      border-radius: 50%;
      background: #2563eb;
      border: 2.5px solid #ffffff;
      box-shadow: 0 2px 6px rgba(37,99,235,0.4);
      cursor: pointer;
      transition: background-color 0.3s ease;
    }

    input[type="range"]::-moz-range-thumb {
      width: 22px;
      height: 22px;
      border-radius: 50%;
      background: #2563eb;
      border: 2.5px solid #ffffff;
      box-shadow: 0 2px 6px rgba(37,99,235,0.4);
      cursor: pointer;
      transition: background-color 0.3s ease;
    }

    /* Step calculation cards */
    .steps-container {
      width: 100%;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
    }

    .step-card {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 10px 8px;
      text-align: center;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 5px;
      min-width: 0;
      transition: background-color 0.3s ease, border-color 0.3s ease;
    }

    .step-badge {
      font-size: 10px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      background: #eff6ff;
      color: #2563eb;
      padding: 2px 6px;
      border-radius: 4px;
      display: inline-block;
    }

    .step-title {
      font-size: 11px;
      font-weight: 600;
      color: #475569;
    }

    .step-math {
      font-size: 13px;
      font-weight: 700;
      color: #0f172a;
      line-height: 1.3;
      word-break: break-word;
      transition: color 0.3s ease;
    }

    .highlight-blue {
      color: #2563eb;
    }

    .highlight-green {
      color: #059669;
    }

    /* Responsive stacking for compact widths */
    @media (max-width: 440px) {
      body {
        padding: 8px;
      }

      .steps-container {
        grid-template-columns: 1fr;
        gap: 6px;
      }

      .step-card {
        flex-direction: row;
        justify-content: space-between;
        padding: 8px 12px;
        text-align: left;
      }

      .step-info {
        display: flex;
        flex-direction: column;
        gap: 2px;
      }

      .step-math {
        text-align: right;
        font-size: 12.5px;
      }

      .chart-container {
        width: 130px;
        height: 130px;
      }
    }
  </style>
</head>
<body>

  <div class="main-layout">
    <div class="header-info">
      <div class="header-title">Angle to Percentage Calculation</div>
      <div class="header-sub">Drag the slider or pick a preset to calculate percentage from degrees</div>
    </div>

    
    <div class="chart-container">
      <svg class="chart-svg" viewBox="0 0 200 200">
        
        <circle class="bg-circle" cx="100" cy="100" r="86" />

        
        <path id="pieSector" class="sector-path" d="" />

        
        <path id="arcStroke" class="arc-stroke-path" d="" />

        
        <line class="start-ray" x1="100" y1="100" x2="100" y2="14" />

        
        <circle class="center-donut" cx="100" cy="100" r="54" />
      </svg>
      <div class="chart-overlay">
        <div id="centerAngle" class="chart-label-val">280.8°</div>
        <div id="centerGas" class="chart-gas-name">NITROGEN (78%)</div>
      </div>
    </div>

    
    <div class="presets-row">
      <button type="button" class="preset-btn active" onclick="setAngle(280.8)">Nitrogen 280.8° (78%)</button>
      <button type="button" class="preset-btn" onclick="setAngle(75.6)">Oxygen 75.6° (21%)</button>
      <button type="button" class="preset-btn" onclick="setAngle(90)">Quarter 90° (25%)</button>
      <button type="button" class="preset-btn" onclick="setAngle(180)">Half 180° (50%)</button>
    </div>

    
    <div class="slider-section">
      <div class="slider-header">
        <span>Angle Slider (θ)</span>
        <span id="sliderAngleLabel" class="highlight-blue" style="font-weight:700;">280.8°</span>
      </div>
      <div class="slider-wrap">
        <span class="slider-limit">0°</span>
        <input type="range" id="angleSlider" min="0" max="360" step="0.1" value="280.8" aria-label="Angle in degrees">
        <span class="slider-limit right">360°</span>
      </div>
    </div>

    
    <div class="steps-container">
      
      <div class="step-card">
        <div class="step-info">
          <span class="step-badge">Step 1</span>
          <div class="step-title">Identify Angle</div>
        </div>
        <div class="step-math highlight-blue" id="step1Val">θ = 280.8°</div>
      </div>

      
      <div class="step-card">
        <div class="step-info">
          <span class="step-badge">Step 2</span>
          <div class="step-title">Set up Ratio</div>
        </div>
        <div class="step-math" id="step2Val">280.8° / 360° = 0.78</div>
      </div>

      
      <div class="step-card">
        <div class="step-info">
          <span class="step-badge">Step 3</span>
          <div class="step-title">Multiply by 100%</div>
        </div>
        <div class="step-math highlight-green" id="step3Val">0.78 × 100% = 78%</div>
      </div>
    </div>
  </div>

  <script>
    const slider = document.getElementById('angleSlider');
    const pieSector = document.getElementById('pieSector');
    const arcStroke = document.getElementById('arcStroke');
    const centerAngle = document.getElementById('centerAngle');
    const centerGas = document.getElementById('centerGas');
    const sliderAngleLabel = document.getElementById('sliderAngleLabel');
    const step1Val = document.getElementById('step1Val');
    const step2Val = document.getElementById('step2Val');
    const step3Val = document.getElementById('step3Val');
    const presetBtns = document.querySelectorAll('.preset-btn');

    function update(deg) {
      const angle = Math.max(0, Math.min(360, parseFloat(deg)));
      const cx = 100;
      const cy = 100;
      const r = 86;

      // Calculate end coordinates starting from top (0 deg = 12 o'clock)
      const rad = ((angle - 90) * Math.PI) / 180;
      const x = cx + r * Math.cos(rad);
      const y = cy + r * Math.sin(rad);
      const largeArc = angle > 180 ? 1 : 0;

      let sectorD = '';
      let arcD = '';

      if (angle >= 359.9) {
        sectorD = `M ${cx} ${cy - r} A ${r} ${r} 0 1 1 ${cx - 0.01} ${cy - r} Z`;
        arcD = `M ${cx} ${cy - r} A ${r} ${r} 0 1 1 ${cx - 0.01} ${cy - r}`;
      } else if (angle <= 0.1) {
        sectorD = '';
        arcD = '';
      } else {
        sectorD = `M ${cx} ${cy} L ${cx} ${cy - r} A ${r} ${r} 0 ${largeArc} 1 ${x.toFixed(2)} ${y.toFixed(2)} Z`;
        arcD = `M ${cx} ${cy - r} A ${r} ${r} 0 ${largeArc} 1 ${x.toFixed(2)} ${y.toFixed(2)}`;
      }

      pieSector.setAttribute('d', sectorD);
      arcStroke.setAttribute('d', arcD);

      // Calculations
      const ratio = angle / 360;
      const percent = ratio * 100;
      const angleFormatted = angle % 1 === 0 ? angle.toFixed(0) : angle.toFixed(1);
      const ratioFormatted = ratio.toFixed(2);
      const percentFormatted = percent % 1 === 0 ? percent.toFixed(0) : percent.toFixed(1);

      // Gas label
      if (Math.abs(angle - 280.8) < 0.6) {
        centerGas.textContent = 'NITROGEN (78%)';
        centerGas.style.color = '#2563eb';
      } else if (Math.abs(angle - 75.6) < 0.6) {
        centerGas.textContent = 'OXYGEN (21%)';
        centerGas.style.color = '#059669';
      } else {
        centerGas.textContent = `${percentFormatted}% OF CIRCLE`;
        centerGas.style.color = '#64748b';
      }

      // Update text displays
      centerAngle.textContent = `${angleFormatted}°`;
      sliderAngleLabel.textContent = `${angleFormatted}°`;
      step1Val.textContent = `θ = ${angleFormatted}°`;
      step2Val.innerHTML = `<span class="highlight-blue">${angleFormatted}°</span> / 360° = <b>${ratioFormatted}</b>`;
      
      let step3Suffix = '';
      if (Math.abs(angle - 280.8) < 0.6) {
        step3Suffix = ' Nitrogen';
      } else if (Math.abs(angle - 75.6) < 0.6) {
        step3Suffix = ' Oxygen';
      }
      step3Val.innerHTML = `${ratioFormatted} × 100% = <span class="highlight-green"><b>${percentFormatted}%${step3Suffix}</b></span>`;

      // Update preset buttons state
      presetBtns.forEach(btn => {
        const match = btn.getAttribute('onclick').match(/setAngle$([\d.]+)$/);
        if (match && Math.abs(parseFloat(match[1]) - angle) < 0.6) {
          btn.classList.add('active');
        } else {
          btn.classList.remove('active');
        }
      });
    }

    function setAngle(deg) {
      slider.value = deg;
      update(deg);
    }

    slider.addEventListener('input', (e) => update(e.target.value));

    // Initialize Nitrogen preset
    update(280.8);
  </script>
</body>
</html>

Extracting Data from Atmospheric Pie Charts and Tables

<!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: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    }
    body {
      background: #ffffff;
      color: #1e2945;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .header-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0 4px 4px 4px;
      border-bottom: 2px solid #f1f5f9;
    }
    .legend {
      display: flex;
      gap: 12px;
      font-size: 13px;
      font-weight: 600;
    }
    .legend-item {
      display: flex;
      align-items: center;
      gap: 5px;
    }
    .swatch {
      width: 10px;
      height: 10px;
      border-radius: 3px;
    }
    .swatch.early { background: #ea580c; }
    .swatch.modern { background: #0284c7; }

    .tabs {
      display: flex;
      gap: 4px;
      background: #f1f5f9;
      padding: 3px;
      border-radius: 8px;
    }
    .tab-btn {
      border: none;
      background: transparent;
      padding: 4px 10px;
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      border-radius: 6px;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .tab-btn.active {
      background: #ffffff;
      color: #1e2945;
      box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    }

    .cards-container {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .gas-card {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 8px 12px;
      display: flex;
      flex-direction: column;
      gap: 6px;
      transition: opacity 0.25s ease, transform 0.25s ease;
    }
    .gas-card.dimmed {
      opacity: 0.3;
      transform: scale(0.98);
    }
    .gas-header {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
    }
    .gas-title {
      font-weight: 700;
      font-size: 14px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .gas-badge {
      font-size: 11px;
      font-weight: 700;
      padding: 2px 7px;
      border-radius: 20px;
    }
    .badge-decrease {
      background: #fee2e2;
      color: #b91c1c;
    }
    .badge-increase {
      background: #dcfce7;
      color: #15803d;
    }

    .bar-row {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 12px;
      font-weight: 600;
    }
    .bar-label {
      width: 48px;
      color: #64748b;
      font-size: 11px;
    }
    .bar-track {
      flex: 1;
      height: 14px;
      background: #e2e8f0;
      border-radius: 7px;
      overflow: hidden;
      position: relative;
    }
    .bar-fill {
      height: 100%;
      border-radius: 7px;
      transition: width 0.4s ease;
    }
    .bar-fill.early { background: #ea580c; }
    .bar-fill.modern { background: #0284c7; }
    .bar-val {
      min-width: 44px;
      text-align: right;
      font-variant-numeric: tabular-nums;
    }
  </style>
</head>
<body>

  <div class="header-row">
    <div class="legend">
      <span class="legend-item"><span class="swatch early"></span> Early</span>
      <span class="legend-item"><span class="swatch modern"></span> Modern</span>
    </div>
    <div class="tabs">
      <button class="tab-btn active" onclick="filterGas('all', this)">All</button>
      <button class="tab-btn" onclick="filterGas('co2', this)">CO₂</button>
      <button class="tab-btn" onclick="filterGas('o2', this)">O₂</button>
      <button class="tab-btn" onclick="filterGas('n2', this)">N₂</button>
    </div>
  </div>

  <div class="cards-container">
    
    <div class="gas-card" id="card-co2">
      <div class="gas-header">
        <div class="gas-title">Carbon Dioxide (CO₂)</div>
        <div class="gas-badge badge-decrease">÷ 2,375×</div>
      </div>
      <div class="bar-row">
        <span class="bar-label">Early</span>
        <div class="bar-track">
          <div class="bar-fill early" style="width: 95%;"></div>
        </div>
        <span class="bar-val">95%</span>
      </div>
      <div class="bar-row">
        <span class="bar-label">Modern</span>
        <div class="bar-track">
          <div class="bar-fill modern" style="width: 2%;"></div>
        </div>
        <span class="bar-val">0.04%</span>
      </div>
    </div>

    
    <div class="gas-card" id="card-o2">
      <div class="gas-header">
        <div class="gas-title">Oxygen (O₂)</div>
        <div class="gas-badge badge-increase">+21% pts</div>
      </div>
      <div class="bar-row">
        <span class="bar-label">Early</span>
        <div class="bar-track">
          <div class="bar-fill early" style="width: 0.5%;"></div>
        </div>
        <span class="bar-val">~0%</span>
      </div>
      <div class="bar-row">
        <span class="bar-label">Modern</span>
        <div class="bar-track">
          <div class="bar-fill modern" style="width: 21%;"></div>
        </div>
        <span class="bar-val">21%</span>
      </div>
    </div>

    
    <div class="gas-card" id="card-n2">
      <div class="gas-header">
        <div class="gas-title">Nitrogen (N₂)</div>
        <div class="gas-badge badge-increase">+74% pts</div>
      </div>
      <div class="bar-row">
        <span class="bar-label">Early</span>
        <div class="bar-track">
          <div class="bar-fill early" style="width: 4%;"></div>
        </div>
        <span class="bar-val">~4%</span>
      </div>
      <div class="bar-row">
        <span class="bar-label">Modern</span>
        <div class="bar-track">
          <div class="bar-fill modern" style="width: 78%;"></div>
        </div>
        <span class="bar-val">78%</span>
      </div>
    </div>
  </div>

  <script>
    function filterGas(type, btn) {
      document.querySelectorAll('.tab-btn').forEach(b => b.classList.remove('active'));
      btn.classList.add('active');

      const cards = {
        co2: document.getElementById('card-co2'),
        o2: document.getElementById('card-o2'),
        n2: document.getElementById('card-n2')
      };

      Object.keys(cards).forEach(key => {
        if (type === 'all' || type === key) {
          cards[key].classList.remove('dimmed');
        } else {
          cards[key].classList.add('dimmed');
        }
      });
    }
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>Atmospheric Composition Comparison</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 12px;
      user-select: none;
      -webkit-user-select: none;
    }

    .grid-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
      max-width: 680px;
      margin: 0 auto;
    }

    @media (max-width: 520px) {
      .grid-container {
        grid-template-columns: 1fr;
        gap: 14px;
      }
    }

    .atm-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px 14px;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    .card-title {
      font-size: 15px;
      font-weight: 700;
      color: #0f172a;
      text-align: center;
      margin-bottom: 2px;
    }

    .card-subtitle {
      font-size: 12px;
      font-weight: 500;
      color: #64748b;
      margin-bottom: 10px;
      text-align: center;
    }

    .chart-wrapper {
      position: relative;
      width: 140px;
      height: 140px;
      margin: 4px 0 10px;
    }

    svg.pie-chart {
      width: 100%;
      height: 100%;
      transform: rotate(-90deg);
      border-radius: 50%;
      overflow: visible;
    }

    .slice {
      cursor: pointer;
      transition: opacity 0.2s ease, filter 0.2s ease;
    }

    .slice:hover, .slice.active {
      filter: brightness(1.08) drop-shadow(0 0 4px rgba(0,0,0,0.25));
      opacity: 1 !important;
    }

    .dimmed {
      opacity: 0.35;
    }

    .info-display {
      width: 100%;
      min-height: 28px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 13px;
      font-weight: 600;
      color: #334155;
      margin-bottom: 8px;
      padding: 2px 8px;
      text-align: center;
      transition: background-color 0.2s ease;
    }

    .info-display .gas-name {
      margin-right: 6px;
    }

    .info-display .angle-tag {
      color: #2563eb;
      font-weight: 700;
    }

    .legend-list {
      display: flex;
      flex-direction: column;
      gap: 5px;
      width: 100%;
    }

    .legend-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 4px 8px;
      border-radius: 6px;
      background: #f8fafc;
      font-size: 12px;
      cursor: pointer;
      border: 1px solid transparent;
      transition: background 0.15s ease, border-color 0.15s ease;
    }

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

    .legend-left {
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .color-swatch {
      width: 10px;
      height: 10px;
      border-radius: 3px;
      flex-shrink: 0;
    }

    .gas-label {
      font-weight: 600;
      color: #1e2945;
    }

    .pct-badge {
      font-weight: 700;
      font-size: 11px;
      padding: 1px 6px;
      border-radius: 4px;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      color: #0f172a;
    }
  </style>
</head>
<body>
  <div class="grid-container">
    
    <div class="atm-card" id="card-early">
      <div class="card-title">Early Atmosphere</div>
      <div class="card-subtitle">~4.4 Billion Years Ago</div>

      <div class="chart-wrapper">
        <svg class="pie-chart" viewBox="0 0 100 100" id="svg-early">
          
          <circle class="slice" data-gas="Carbon Dioxide (CO₂)" data-pct="95%" data-deg="342.0°" r="25" cx="50" cy="50" fill="transparent" stroke="#ea580c" stroke-width="50" stroke-dasharray="149.23 157.08" stroke-dashoffset="0" />
          
          <circle class="slice" data-gas="Water Vapor (H₂O)" data-pct="4%" data-deg="14.4°" r="25" cx="50" cy="50" fill="transparent" stroke="#38bdf8" stroke-width="50" stroke-dasharray="6.28 157.08" stroke-dashoffset="-149.23" />
          
          <circle class="slice" data-gas="Other Gases" data-pct="1%" data-deg="3.6°" r="25" cx="50" cy="50" fill="transparent" stroke="#94a3b8" stroke-width="50" stroke-dasharray="1.57 157.08" stroke-dashoffset="-155.51" />
        </svg>
      </div>

      <div class="info-display" id="info-early">Tap or hover slice for angle</div>

      <div class="legend-list">
        <div class="legend-item" data-gas="Carbon Dioxide (CO₂)" data-pct="95%" data-deg="342.0°" data-target="0">
          <div class="legend-left">
            <span class="color-swatch" style="background:#ea580c;"></span>
            <span class="gas-label">Carbon Dioxide</span>
          </div>
          <span class="pct-badge">95%</span>
        </div>
        <div class="legend-item" data-gas="Water Vapor (H₂O)" data-pct="4%" data-deg="14.4°" data-target="1">
          <div class="legend-left">
            <span class="color-swatch" style="background:#38bdf8;"></span>
            <span class="gas-label">Water Vapor</span>
          </div>
          <span class="pct-badge">4%</span>
        </div>
        <div class="legend-item" data-gas="Other Gases" data-pct="1%" data-deg="3.6°" data-target="2">
          <div class="legend-left">
            <span class="color-swatch" style="background:#94a3b8;"></span>
            <span class="gas-label">Other Gases</span>
          </div>
          <span class="pct-badge">1%</span>
        </div>
      </div>
    </div>

    
    <div class="atm-card" id="card-modern">
      <div class="card-title">Modern Atmosphere</div>
      <div class="card-subtitle">Present Day</div>

      <div class="chart-wrapper">
        <svg class="pie-chart" viewBox="0 0 100 100" id="svg-modern">
          
          <circle class="slice" data-gas="Nitrogen (N₂)" data-pct="78%" data-deg="280.8°" r="25" cx="50" cy="50" fill="transparent" stroke="#2563eb" stroke-width="50" stroke-dasharray="122.52 157.08" stroke-dashoffset="0" />
          
          <circle class="slice" data-gas="Oxygen (O₂)" data-pct="21%" data-deg="75.6°" r="25" cx="50" cy="50" fill="transparent" stroke="#06b6d4" stroke-width="50" stroke-dasharray="32.99 157.08" stroke-dashoffset="-122.52" />
          
          <circle class="slice" data-gas="Argon (Ar)" data-pct="0.9%" data-deg="3.24°" r="25" cx="50" cy="50" fill="transparent" stroke="#f59e0b" stroke-width="50" stroke-dasharray="1.41 157.08" stroke-dashoffset="-155.51" />
          
          <circle class="slice" data-gas="CO₂ & Trace" data-pct="0.1%" data-deg="0.36°" r="25" cx="50" cy="50" fill="transparent" stroke="#dc2626" stroke-width="50" stroke-dasharray="0.8 157.08" stroke-dashoffset="-156.92" />
        </svg>
      </div>

      <div class="info-display" id="info-modern">Tap or hover slice for angle</div>

      <div class="legend-list">
        <div class="legend-item" data-gas="Nitrogen (N₂)" data-pct="78%" data-deg="280.8°" data-target="0">
          <div class="legend-left">
            <span class="color-swatch" style="background:#2563eb;"></span>
            <span class="gas-label">Nitrogen</span>
          </div>
          <span class="pct-badge">78%</span>
        </div>
        <div class="legend-item" data-gas="Oxygen (O₂)" data-pct="21%" data-deg="75.6°" data-target="1">
          <div class="legend-left">
            <span class="color-swatch" style="background:#06b6d4;"></span>
            <span class="gas-label">Oxygen</span>
          </div>
          <span class="pct-badge">21%</span>
        </div>
        <div class="legend-item" data-gas="Argon (Ar)" data-pct="0.9%" data-deg="3.24°" data-target="2">
          <div class="legend-left">
            <span class="color-swatch" style="background:#f59e0b;"></span>
            <span class="gas-label">Argon</span>
          </div>
          <span class="pct-badge">0.9%</span>
        </div>
        <div class="legend-item" data-gas="Carbon Dioxide (CO₂)" data-pct="0.04%" data-deg="0.14°" data-target="3">
          <div class="legend-left">
            <span class="color-swatch" style="background:#dc2626;"></span>
            <span class="gas-label">CO₂ (Trace)</span>
          </div>
          <span class="pct-badge">0.04%</span>
        </div>
      </div>
    </div>
  </div>

  <script>
    function setupCard(cardId, infoId) {
      const card = document.getElementById(cardId);
      const info = document.getElementById(infoId);
      const slices = card.querySelectorAll('.slice');
      const items = card.querySelectorAll('.legend-item');
      const defaultText = 'Tap or hover slice for angle';

      function highlight(gas, pct, deg, index) {
        info.innerHTML = `<span class="gas-name">${gas}</span> <span>${pct}</span> = <span class="angle-tag">${deg}</span>`;
        slices.forEach((s, idx) => {
          if (idx === index) {
            s.classList.add('active');
            s.classList.remove('dimmed');
          } else {
            s.classList.add('dimmed');
            s.classList.remove('active');
          }
        });
        items.forEach((item, idx) => {
          if (idx === index) {
            item.classList.add('active');
          } else {
            item.classList.remove('active');
          }
        });
      }

      function reset() {
        info.textContent = defaultText;
        slices.forEach(s => {
          s.classList.remove('active');
          s.classList.remove('dimmed');
        });
        items.forEach(item => item.classList.remove('active'));
      }

      slices.forEach((slice, idx) => {
        const gas = slice.dataset.gas;
        const pct = slice.dataset.pct;
        const deg = slice.dataset.deg;

        slice.addEventListener('mouseenter', () => highlight(gas, pct, deg, idx));
        slice.addEventListener('mouseleave', reset);
        slice.addEventListener('click', (e) => {
          e.stopPropagation();
          highlight(gas, pct, deg, idx);
        });
      });

      items.forEach((item, idx) => {
        const gas = item.dataset.gas;
        const pct = item.dataset.pct;
        const deg = item.dataset.deg;

        item.addEventListener('mouseenter', () => highlight(gas, pct, deg, idx));
        item.addEventListener('mouseleave', reset);
        item.addEventListener('click', (e) => {
          e.stopPropagation();
          highlight(gas, pct, deg, idx);
        });
      });

      card.addEventListener('click', (e) => {
        if (!e.target.closest('.slice') && !e.target.closest('.legend-item')) {
          reset();
        }
      });
    }

    setupCard('card-early', 'info-early');
    setupCard('card-modern', 'info-modern');
  </script>
</body>
</html>

UK-GCSE-SCIENCE-CHEM-EA-05-01

Aligned learning resources

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