index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Test</title>
    <style>
        .chessBoard {
            width: 400px;
            height: 416px;
            border: 1px solid black;
            display: flex;
            flex-wrap: wrap;
        }

        .whiteBkgr {
            width: 50px;
            height: 50px;
            background-color: white;
            flex: 1 0 12.5%; 
        }

        .blackBkgr {
            width: 50px;
            height: 50px;
            background-color: black;
            flex: 1 0 12.5%; 
        }
    </style>
</head>
<body>
    <div class="chessBoard"></div>
    <script>
        const chessBoard = document.querySelector('.chessBoard');

        function createChessBoard() {
            for (let i = 0; i < 8; i++) {
                for (let j = 0; j < 8; j++) {
                    const square = document.createElement('div');
                    if ((i + j) % 2 === 0) {
                        square.classList.add('whiteBkgr');
                    } else {
                        square.classList.add('blackBkgr');
                    }
                    chessBoard.appendChild(square);
                }
            }
        }

        createChessBoard();
    </script>
</body>
</html>