snake.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>Snake! Snake!</title>
    <style>
        html {
            text-align: center;
            font-family: Helvetica, Arial, sans-serif;
        }

        #board {
            width: calc(26 * 24px);
            margin: auto;
        }

        #board div {
            background-color: black;
            border: 1px solid grey;
            box-sizing: border-box;
            float: left;
            width: 24px;
            height: 24px;
        }

        #board .snake {
            background-color: green;
        }

        #board .apple {
            background-color: red;
        }
    </style>

    <script src="js/snake.js"></script>
</head>

<body onload="initGame()" onkeydown="enterKey(event)">

    <h1>Snake</h1>
    <div id="board"></div>
    
</body>
</html>