.grid {
    width: 606px;
    height: 606px;
    display: flex;
    flex-wrap: wrap;
    background-color: saddlebrown;
}

.square {
    height: 200px;
    width: 200px;
    border: solid black 1px;
}

.mole {
    background-image: url('mole.png');
    background-size: cover;
}

#start-button {
    background-color: saddlebrown;
    color: white;
    margin-bottom: 5px;
    padding: 10px 20px;
    font-size: 16px;
    border-radius: 5px;
    cursor: pointer;
    margin-bottom: 10px;
}

body {
    background-color: forestgreen;
}