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<!DOCTYPE html>

<html lang=en>

<head>

  <meta charset=UTF-8>

  <meta name=viewport content="width=device-width,initial-scale=1">

  <title>onwheel — font size</title>

  <style>body{font-family:system-ui,sans-serif;margin:0;padding:1.5rem;background:#f8fafc;color:#334155;line-height:1.7}h1{margin:0 0 .75rem;font-size:1.25rem;color:#0f172a}#scrollText{font-size:16px;padding:.75rem 1rem;background:#eef2ff;border:2px solid #6366f1;border-radius:8px;max-width:420px;color:#3730a3;font-weight:600}#status{margin-top:.75rem;padding:.75rem 1rem;border-radius:8px;font-size:.875rem;font-weight:600;max-width:420px;background:#eff6ff;border:1px solid #bfdbfe;color:#1e40af}.hint{font-size:.875rem;color:#64748b}</style>

</head>

<body>

  <h1>onwheel font-size demo</h1>

  <p class=hint>Scroll the wheel over the blue text — up increases size, down decreases.</p>

  <p id=scrollText onwheel=changeFontSize(event)>Scroll to change font size!</p>

  <p id=status aria-live=polite>Font size: 16px</p>



  <script>function changeFontSize(t){var e=document.getElementById("scrollText"),o=parseFloat(getComputedStyle(e).fontSize);t.deltaY<0?o+=2:t.deltaY>0&&(o-=2),o=Math.max(12,Math.min(32,o)),e.style.fontSize=o+"px";var n=document.getElementById("status");n.textContent="Font size: "+o+"px",n.style.background="#f0fdf4",n.style.borderColor="#bbf7d0",n.style.color="#166534"}</script>

</body>

</html>

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HTML onwheel Attribute — font size on paragraph