HTML/CSS - Toggle dark/light mode 🔥💯 Online Editor and JavaScript Compiler

html
<!DOCTYPE html>
<html lang="pt">
<head>
    <meta charset="UTF-8">
    <title>Título da página</title>
    <script src="https://kit.fontawesome.com/cbcc2cb107.js" crossorigin="anonymous"></script>
    <style>
        :root {
            --s: #424248;
            --o: -15px;
            --c: #222222;
            --f: #131313;
            --n: 0px;
            --t: 10px;
            --d: #eaeaff2a;
        } body {
            background: var(--f);
            display: flex;
            justify-content: center;
        } .container {
            margin-top: 60%;
            background: var(--c);
            width: 110px; 
            height: 50px;
            border-radius: 30px;
            padding: 5px;
            border: 2px solid #1c1f303a;
        } .circle {
css
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