index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Color game</title>
    <link rel="stylesheet" href="style.css">
    
</head>
<body>
    <h1>
        The great <br> 
        <span id="colorDisplay">RGB</span> <br>
        color game
    </h1>
    <div id="stripe">
        <button id="reset">New colors</button>
        <span id="message"></span>
        <button class="mode">Easy</button>
        <button class="mode selected">Hard</button>
    </div>
    <div id="container">
        <div class="square"></div>
        <div class="square"></div>
        <div class="square"></div>
        <div class="square"></div>
        <div class="square"></div>
        <div class="square"></div>
    </div>
<script src="main.js"></script>
</body>
</html>