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✨ Chaowat Intarapanit
<html> <head> <title>Let's Start </title> <style> :root { --h: 0; --l: 50; } body { background: hsl(var(--h), 100%, calc(1% * var(--l))); } </style> </head> <body> <script type="text/javascript"> var h = 0; var l = 50; document.body.onkeyup = function(e){ console.log(e); switch (e.key) { case "ArrowLeft": console.log("I am left"); document.documentElement.style.setProperty("--h", (h += 10)); break; case "ArrowRight": console.log("I am right"); document.documentElement.style.setProperty("--h", (h -= 10)); break; case "ArrowUp": console.log("I am up"); document.documentElement.style.setProperty("--l", (l += 10)); break; case "ArrowDown": console.log("I am down"); document.documentElement.style.setProperty("--l", (l -= 10)); break; } } </script> </body> </html>