first.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="icon" type="image" href="img/200w (1).gif">
    <link rel="stylesheet" href="style.css">
    <title>Simon Says</title>
</head>
<body>
    <div class="score">
        <h1 style="color: rgb(163, 27, 163);">SimonSays Game</h1><span id="highest-score">Highest Score:0</span>
    </div>
    <h3 style="color: whitesmoke">Press Start And Play the Game!!</h3>
    <div class="container">
        <div class="upper">
            <div class="btn red" type="button" id="red"></div>
            <div class="btn yellow" type="button" id="yellow"></div>
        </div>
        <div class="lower">
            <div class="btn green" type="button" id="green"></div>
            <div class="btn blue" type="button" id="blue"></div>
        </div>
    </div>
    <button class="start">START</button>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<button class="restart">RESET</button>
    <script src="app.js"></script>
</body>
</html>