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✨ SANTHITA KRAJANGWONGPAISAN
<html> <head> <title>E10 </title> <style> :root{ --h: 0; } body{ background:hsl(var(--h), 50%, 50%); height:3600vh; } h1{ position:fixed; color:white; } </style> </head> <body> <h1> window.scrollY = <span id="val"> </span> </h1> <script type="text/javascript"> window.onscroll = function(){ let scrollY = window.scrollY; val.innerText = scrollY; document.documentElement.style.setProperty("--h", scrollY/50) } </script> </body> </html>