body {
    background-color: #F52727;
    display: flex;
    flex-direction: column;
    align-items: center;
}

#mainHeading {
    font-family: sans-serif;
    color: yellow;
    font-weight: bold;
    margin-top: 20px;
    text-shadow: 2px 2px 2px black;
}

#gridSizeButton {
    background-color: yellow;
    font-size: 20px;
    margin-bottom: 20px;
}

.container {
    display: flex;
    width: 960px;
    height: 960px;
    margin: auto;
    border: 5px solid black;
}

.squareRow {
    display: flex;
    flex-direction: column;
    justify-content: space-evenly;
    align-items: center;
    flex: 1 1 auto;
}

.square {
    background-color: grey;
    flex: 1 1 auto;
    width: 100%;
}