index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>counter</title>
    <link rel="stylesheet" href="style.css">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.4/css/all.min.css">
</head>
<body>
    <div class="container">
        <div class="counter">
            <h1 id="num">0</h1>
            <div class="plusbtn"><i class="far fa-plus-square" onclick="plus()"></i></div>
            <div class="clearbtn"><i class="far fa-check-square" onclick="clearAll()"></i></div>
            <div class="minusbtn"><i class="far fa-minus-square" onclick="minus()"></i></div>
        </div>
    </div>


    <script src="./script.js"></script>
</body>
</html>