body {
    height: 100vh;/*100% of window's height*/
    display: flex;
    flex-direction: column;
    background-color: #32932a;
    
}

#top{
    display: flex;
    justify-content: center;
}

#middle {
    display: flex;
    justify-content: center;
    align-items: center;
    flex: 1;
}

.square {
    width: 20px;
    height: 20px;
    background-color: white;
    border: 1px solid black;
}

#container {
    display: flex;
    max-width: 352px ;
    max-height: 352px;
    flex-wrap: wrap;
}

.my_button {
    padding: 10px 20px;
    font-size: 16px;
    text-align: center;
    text-decoration: none;
    cursor: pointer;
    font-weight: 600;
    color: #fff;
    background-color: #3498db;
    border-radius: 5px;
    border: none;
}